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Buchanan RA, Wang Y, May JM, Harrison FE. Ascorbate insufficiency disrupts glutamatergic signaling and alters electroencephalogram phenotypes in a mouse model of Alzheimer's disease. Neurobiol Dis 2024; 199:106602. [PMID: 39004234 DOI: 10.1016/j.nbd.2024.106602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 07/08/2024] [Accepted: 07/09/2024] [Indexed: 07/16/2024] Open
Abstract
Clinical studies have reported that increased epileptiform and subclinical epileptiform activity can be detected in many patients with an Alzheimer's disease (AD) diagnosis using electroencephalogram (EEG) and this may correlate with poorer cognition. Ascorbate may have a specific role as a neuromodulator in AD as it is released concomitantly with glutamate reuptake following excitatory neurotransmission. Insufficiency may therefore result in an exacerbated excitatory/inhibitory imbalance in neuronal signaling. Using a mouse model of AD that requires dietary ascorbate (Gulo-/-APPswe/PSEN1dE9), EEG was recorded at baseline and during 4 weeks of ascorbate depletion in young (5-month-old) and aged (20-month-old) animals. Data were scored for changes in quantity of spike trains, individual spikes, sleep-wake rhythms, sleep fragmentation, and brainwave power bands during light periods each week. We found an early increase in neuronal spike discharges with age and following ascorbate depletion in AD model mice and not controls, which did not correlate with brain amyloid load. Our data also show more sleep fragmentation with age and with ascorbate depletion. Additionally, changes in brain wave activity were observed within different vigilance states in both young and aged mice, where Gulo-/-APPswe/PSEN1dE9 mice had shifts towards higher frequency bands (alpha, beta, and gamma) and ascorbate depletion resulted in shifts towards lower frequency bands (delta and theta). Microarray data supported ascorbate insufficiency altering glutamatergic transmission through the decreased expression of glutamate related genes, however no changes in protein expression of glutamate reuptake transporters were observed. These data suggest that maintaining optimal brain ascorbate levels may support normal brain electrical activity and sleep patterns, particularly in AD patient populations where disruptions are observed.
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Affiliation(s)
- Rebecca A Buchanan
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, United States
| | - Yuhan Wang
- Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - James M May
- Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Fiona E Harrison
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, United States; Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States.
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2
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Zhuang D, Yu N, Han S, Zhang X, Ju C. The Kv7 channel opener Retigabine reduces neuropathology and alleviates behavioral deficits in APP/PS1 transgenic mice. Behav Brain Res 2024; 471:115137. [PMID: 38971432 DOI: 10.1016/j.bbr.2024.115137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 06/19/2024] [Accepted: 07/01/2024] [Indexed: 07/08/2024]
Abstract
Hyperexcitability of neuronal networks is central to the pathogenesis of Alzheimer's disease (AD). Pharmacological activation of Kv7 channels is an effective way to reduce neuronal firing. Our results showed that that pharmacologically activating the Kv7 channel with Retigabine (RTG) can alleviate cognitive impairment in mice without affecting spontaneous activity. RTG could also ameliorate damage to the Nissl bodies in cortex and hippocampal CA and DG regions in 9-month-old APP/PS1 mice. Additionally, RTG could reduce the Aβ plaque number in the hippocampus and cortex of both 6-month-old and 9-month-old mice. By recordings of electroencephalogram, we showed that a decrease in the number of abnormal discharges in the brains of the AD model mice when the Kv7 channel was opened. Moreover, Western blot analysis revealed a reduction in the expression of the p-Tau protein in both the hippocampus and cortex upon Kv7 channel opening. These findings suggest that Kv7 channel opener RTG may ameliorate cognitive impairment in AD, most likely by reducing brain excitability.
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Affiliation(s)
- Dongpei Zhuang
- Department of Pharmacology, School of Pharmacy, Qingdao University Qingdao Medical College, China.
| | - Nan Yu
- Department of Pharmacy, Qingdao Eighth People's Hospital, China.
| | - Shuo Han
- Department of Pharmacology, School of Pharmacy, Qingdao University Qingdao Medical College, China.
| | - Xinyao Zhang
- Department of Pharmacology, School of Pharmacy, Qingdao University Qingdao Medical College, China.
| | - Chuanxia Ju
- Department of Pharmacology, School of Pharmacy, Qingdao University Qingdao Medical College, China.
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Zhou X, Liu Y, Wu Z, Zhang X, Tao H. Alzheimer's disease and epilepsy: Research hotspots for comorbidity in the era of global aging. Epilepsy Behav 2024; 157:109849. [PMID: 38820684 DOI: 10.1016/j.yebeh.2024.109849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 05/18/2024] [Accepted: 05/19/2024] [Indexed: 06/02/2024]
Abstract
Neurological conditions such as Alzheimer's disease (AD) and epilepsy share a significant clinical overlap, particularly in the elderly, with each disorder potentiating the risk of the other. This interplay is significant amidst an aging global demographic. The review explores the classical pathologies of AD, including amyloid-beta plaques and hyperphosphorylated tau, and their potential role in the genesis of epilepsy. It also delves into the imbalance of glutamate and gamma-amino butyric acid activities, a key mechanism in epilepsy that may be influenced by AD pathology. The impact of age of onset on comorbidity is examined, with early-onset AD and Down syndrome presenting higher risks of epilepsy. The review suggests that epilepsy might precede cognitive symptoms in AD, indicating a complex interaction. Sleep modulation is highlighted as a factor, with sleep disturbances potentially contributing to AD progression. The necessity for cautious medication management is emphasized due to the cognitive effects of certain antiepileptic drugs. Animal models are recognized for their importance in understanding the relationship between AD and epilepsy, though creating fully representative models presents a challenge. The review concludes by noting the efficacy of medications such as lamotrigine, levetiracetam, and memantine in managing both conditions and suggests the ketogenic diet and cannabidiol as emerging treatment options, warranting further investigation for comprehensive patient care strategies.
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Affiliation(s)
- Xu Zhou
- Clinical Research and Experimental Center, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong 524001, China
| | - Yang Liu
- Department of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong 524001, China
| | - Zhengjuan Wu
- Department of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong 524001, China
| | - Xiaolu Zhang
- Department of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong 524001, China
| | - Hua Tao
- Department of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong 524001, China; Guangdong Key Laboratory of Age-related Cardiac and Cerebral Diseases, Guangdong Medical University, Zhanjiang, Guangdong 524001, China.
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Lee R, Kim G, Kim S. Co-activation of selective nicotinic acetylcholine receptor subtypes is required to reverse hippocampal network dysfunction and prevent fear memory loss in Alzheimer's disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.08.602576. [PMID: 39026693 PMCID: PMC11257460 DOI: 10.1101/2024.07.08.602576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Alzheimer's disease (AD) is the most common form of dementia with no known cause and cure. Research suggests that a reduction of GABAergic inhibitory interneurons' activity in the hippocampus by beta-amyloid peptide (Aβ) is a crucial trigger for cognitive impairment in AD via hyperexcitability. Therefore, enhancing hippocampal inhibition is thought to be protective against AD. However, hippocampal inhibitory cells are highly diverse, and these distinct interneuron subtypes differentially regulate hippocampal inhibitory circuits and cognitive processes. Moreover, Aβ unlikely affects all subtypes of inhibitory interneurons in the hippocampus equally. Hence, identifying the affected interneuron subtypes in AD to enhance hippocampal inhibition optimally is conceptually and practically challenging. We have previously found that Aβ selectively binds to two of the three major hippocampal nicotinic acetylcholine receptor (nAChR) subtypes, α7- and α4β2-nAChRs, but not α3β4-nAChRs, and inhibits these two receptors in cultured hippocampal inhibitory interneurons to decrease their activity, leading to hyperexcitation and synaptic dysfunction in excitatory neurons. We have also revealed that co-activation of α7- and α4β2-nAChRs is required to reverse the Aβ-induced adverse effects in hippocampal excitatory neurons. Here, we discover that α7- and α4β2-nAChRs predominantly control the nicotinic cholinergic signaling and neuronal activity in hippocampal parvalbumin-positive (PV+) and somatostatin-positive (SST+) inhibitory interneurons, respectively. Furthermore, we reveal that co-activation of these receptors is necessary to reverse hippocampal network dysfunction and fear memory loss in the amyloid pathology model mice. We thus suggest that co-activation of PV+ and SST+ cells is a novel strategy to reverse hippocampal dysfunction and cognitive decline in AD.
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Goettemoeller AM, Banks E, Kumar P, Olah VJ, McCann KE, South K, Ramelow CC, Eaton A, Duong DM, Seyfried NT, Weinshenker D, Rangaraju S, Rowan MJ. Entorhinal cortex vulnerability to human APP expression promotes hyperexcitability and tau pathology. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.06.565629. [PMID: 39005389 PMCID: PMC11244896 DOI: 10.1101/2023.11.06.565629] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Preventative treatment for Alzheimer's Disease is of dire importance, and yet, cellular mechanisms underlying early regional vulnerability in Alzheimer's Disease remain unknown. In human patients with Alzheimer's Disease, one of the earliest observed pathophysiological correlates to cognitive decline is hyperexcitability. In mouse models, early hyperexcitability has been shown in the entorhinal cortex, the first cortical region impacted by Alzheimer's Disease. The origin of hyperexcitability in early-stage disease and why it preferentially emerges in specific regions is unclear. Using cortical-region and cell-type-specific proteomics coupled with ex vivo and in vivo electrophysiology, we uncovered differential susceptibility to human-specific amyloid precursor protein (hAPP) in a model of sporadic Alzheimer's. Unexpectedly, our findings reveal that early entorhinal hyperexcitability may result from intrinsic vulnerability of parvalbumin (PV) interneurons, rather than the suspected layer II excitatory neurons. This vulnerability of entorhinal PV interneurons is specific to hAPP, as it could not be recapitulated with increased murine APP expression. However, partial replication of the findings could be seen after introduction of a murine APP chimera containing a humanized amyloid-beta sequence. Surprisingly, neurons in the Somatosensory Cortex showed no such vulnerability to adult-onset hAPP expression. hAPP-induced hyperexcitability in entorhinal cortex could be ameliorated by enhancing PV interneuron excitability in vivo. Co-expression of human Tau with hAPP decreased circuit hyperexcitability, but at the expense of increased pathological tau species. This study suggests early disease interventions targeting non-excitatory cell types may protect regions with early vulnerability to pathological symptoms of Alzheimer's Disease and downstream cognitive decline.
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Tabuena DR, Jang SS, Grone B, Yip O, Aery Jones EA, Blumenfeld J, Liang Z, Koutsodendris N, Rao A, Ding L, Zhang AR, Hao Y, Xu Q, Yoon SY, Leon SD, Huang Y, Zilberter M. Neuronal APOE4-induced Early Hippocampal Network Hyperexcitability in Alzheimer's Disease Pathogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.28.555153. [PMID: 37693533 PMCID: PMC10491126 DOI: 10.1101/2023.08.28.555153] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
The full impact of apolipoprotein E4 (APOE4), the strongest genetic risk factor for Alzheimer's disease (AD), on neuronal and network function remains unclear. We found hippocampal region-specific network hyperexcitability in young APOE4 knock-in (E4-KI) mice which predicted cognitive deficits at old age. Network hyperexcitability in young E4-KI mice was mediated by hippocampal region-specific subpopulations of smaller and hyperexcitable neurons that were eliminated by selective removal of neuronal APOE4. Aged E4-KI mice exhibited hyperexcitable granule cells, a progressive inhibitory deficit, and E/I imbalance in the dentate gyrus, exacerbating hippocampal hyperexcitability. Single-nucleus RNA-sequencing revealed neuronal cell type-specific and age-dependent transcriptomic changes, including Nell2 overexpression in E4-KI mice. Reducing Nell2 expression in specific neuronal types of E4-KI mice with CRISPRi rescued their abnormal excitability phenotypes, implicating Nell2 overexpression as a cause of APOE4-induced hyperexcitability. These findings highlight the early transcriptomic and electrophysiological alterations underlying APOE4-induced hippocampal network dysfunction and its contribution to AD pathogenesis with aging.
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Park KI. Understanding epileptogenesis from molecules to network alteration. ENCEPHALITIS 2024; 4:47-54. [PMID: 38886161 PMCID: PMC11237188 DOI: 10.47936/encephalitis.2024.00038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Accepted: 05/14/2024] [Indexed: 06/20/2024] Open
Abstract
Epilepsy is characterized by recurrent seizures. Following an initial insult, a latent period precedes the onset of spontaneous seizures, a process referred to as epileptogenesis. This period plays a critical role in halting the progression toward epilepsy before the onset of abnormal molecular and network alterations. In this study, the fundamental concepts of epileptogenesis as well as the associated molecular and cellular targets are reviewed.
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Affiliation(s)
- Kyung-Il Park
- Department of Neurology, Seoul National University Hospital Healthcare System Gangnam Center, Seoul National University College of Medicine, Seoul, Korea
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Kalyvas AC, Dimitriou M, Ioannidis P, Grigoriadis N, Afrantou T. Alzheimer's Disease and Epilepsy: Exploring Shared Pathways and Promising Biomarkers for Future Treatments. J Clin Med 2024; 13:3879. [PMID: 38999445 PMCID: PMC11242231 DOI: 10.3390/jcm13133879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Revised: 06/25/2024] [Accepted: 06/29/2024] [Indexed: 07/14/2024] Open
Abstract
Background: Alzheimer's disease (AD) and epilepsy represent two complex neurological disorders with distinct clinical manifestations, yet recent research has highlighted their intricate interplay. This review examines the association between AD and epilepsy, with particular emphasis on late-onset epilepsy of unknown etiology, increasingly acknowledged as a prodrome of AD. It delves into epidemiology, pathogenic mechanisms, clinical features, diagnostic characteristics, treatment strategies, and emerging biomarkers to provide a comprehensive understanding of this relationship. Methods: A comprehensive literature search was conducted, identifying 128 relevant articles published between 2018 and 2024. Results: Findings underscore a bidirectional relationship between AD and epilepsy, indicating shared pathogenic pathways that extend beyond traditional amyloid-beta and Tau protein pathology. These pathways encompass neuroinflammation, synaptic dysfunction, structural and network alterations, as well as molecular mechanisms. Notably, epileptic activity in AD patients may exacerbate cognitive decline, necessitating prompt detection and treatment. Novel biomarkers, such as subclinical epileptiform activity detected via advanced electroencephalographic techniques, offer promise for early diagnosis and targeted interventions. Furthermore, emerging therapeutic approaches targeting shared pathogenic mechanisms hold potential for disease modification in both AD and epilepsy. Conclusions: This review highlights the importance of understanding the relationship between AD and epilepsy, providing insights into future research directions. Clinical data and diagnostic methods are also reviewed, enabling clinicians to implement more effective treatment strategies.
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Affiliation(s)
- Athanasios-Christos Kalyvas
- 2nd Department of Neurology, AHEPA University Hospital, Aristotle University of Thessaloniki, GR54636 Thessaloniki, Greece
| | - Maria Dimitriou
- 2nd Department of Neurology, AHEPA University Hospital, Aristotle University of Thessaloniki, GR54636 Thessaloniki, Greece
| | - Panagiotis Ioannidis
- 2nd Department of Neurology, AHEPA University Hospital, Aristotle University of Thessaloniki, GR54636 Thessaloniki, Greece
| | - Nikolaos Grigoriadis
- 2nd Department of Neurology, AHEPA University Hospital, Aristotle University of Thessaloniki, GR54636 Thessaloniki, Greece
| | - Theodora Afrantou
- 2nd Department of Neurology, AHEPA University Hospital, Aristotle University of Thessaloniki, GR54636 Thessaloniki, Greece
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Chartampila E, Elayouby KS, Leary P, LaFrancois JJ, Alcantara-Gonzalez D, Jain S, Gerencer K, Botterill JJ, Ginsberg SD, Scharfman HE. Choline supplementation in early life improves and low levels of choline can impair outcomes in a mouse model of Alzheimer's disease. eLife 2024; 12:RP89889. [PMID: 38904658 PMCID: PMC11192536 DOI: 10.7554/elife.89889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/22/2024] Open
Abstract
Maternal choline supplementation (MCS) improves cognition in Alzheimer's disease (AD) models. However, the effects of MCS on neuronal hyperexcitability in AD are unknown. We investigated the effects of MCS in a well-established mouse model of AD with hyperexcitability, the Tg2576 mouse. The most common type of hyperexcitability in Tg2576 mice are generalized EEG spikes (interictal spikes [IIS]). IIS also are common in other mouse models and occur in AD patients. In mouse models, hyperexcitability is also reflected by elevated expression of the transcription factor ∆FosB in the granule cells (GCs) of the dentate gyrus (DG), which are the principal cell type. Therefore, we studied ΔFosB expression in GCs. We also studied the neuronal marker NeuN within hilar neurons of the DG because reduced NeuN protein expression is a sign of oxidative stress or other pathology. This is potentially important because hilar neurons regulate GC excitability. Tg2576 breeding pairs received a diet with a relatively low, intermediate, or high concentration of choline. After weaning, all mice received the intermediate diet. In offspring of mice fed the high choline diet, IIS frequency declined, GC ∆FosB expression was reduced, and hilar NeuN expression was restored. Using the novel object location task, spatial memory improved. In contrast, offspring exposed to the relatively low choline diet had several adverse effects, such as increased mortality. They had the weakest hilar NeuN immunoreactivity and greatest GC ΔFosB protein expression. However, their IIS frequency was low, which was surprising. The results provide new evidence that a diet high in choline in early life can improve outcomes in a mouse model of AD, and relatively low choline can have mixed effects. This is the first study showing that dietary choline can regulate hyperexcitability, hilar neurons, ΔFosB, and spatial memory in an animal model of AD.
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Affiliation(s)
- Elissavet Chartampila
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric ResearchOrangeburgUnited States
| | - Karim S Elayouby
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric ResearchOrangeburgUnited States
| | - Paige Leary
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric ResearchOrangeburgUnited States
- Department of Neuroscience and Physiology, New York University Grossman School of MedicineNew YorkUnited States
| | - John J LaFrancois
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric ResearchOrangeburgUnited States
- Departments of Child and Adolescent Psychiatry, New York University Grossman School of MedicineNew YorkUnited States
| | - David Alcantara-Gonzalez
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric ResearchOrangeburgUnited States
- Departments of Child and Adolescent Psychiatry, New York University Grossman School of MedicineNew YorkUnited States
| | - Swati Jain
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric ResearchOrangeburgUnited States
| | - Kasey Gerencer
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric ResearchOrangeburgUnited States
| | - Justin J Botterill
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric ResearchOrangeburgUnited States
| | - Stephen D Ginsberg
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric ResearchOrangeburgUnited States
- Department of Neuroscience and Physiology, New York University Grossman School of MedicineNew YorkUnited States
- Department of Psychiatry, New York University Grossman School of MedicineNew YorkUnited States
- NYU Neuroscience Institute, New York University Grossman School of MedicineNew YorkUnited States
| | - Helen E Scharfman
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric ResearchOrangeburgUnited States
- Department of Neuroscience and Physiology, New York University Grossman School of MedicineNew YorkUnited States
- Departments of Child and Adolescent Psychiatry, New York University Grossman School of MedicineNew YorkUnited States
- Department of Psychiatry, New York University Grossman School of MedicineNew YorkUnited States
- NYU Neuroscience Institute, New York University Grossman School of MedicineNew YorkUnited States
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Al-Musawi I, Dennis BH, Clowry GJ, LeBeau FEN. Evidence for prodromal changes in neuronal excitability and neuroinflammation in the hippocampus in young alpha-synuclein (A30P) transgenic mice. FRONTIERS IN DEMENTIA 2024; 3:1404841. [PMID: 39081599 PMCID: PMC11285622 DOI: 10.3389/frdem.2024.1404841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Accepted: 05/20/2024] [Indexed: 08/02/2024]
Abstract
Introduction Neuronal hyperexcitability and neuroinflammation are thought to occur at early stages in a range of neurodegenerative diseases. Neuroinflammation, notably activation of microglia, has been identified as a potential prodromal marker of dementia with Lewy bodies (DLB). Using a transgenic mouse model of DLB that over-expresses human mutant (A30P) alpha-synuclein (hα-syn) we have investigated whether early neuroinflammation is evident in the hippocampus in young pre-symptomatic animals. Methods Previous studies have shown early hyperexcitability in the hippocampal CA3 region in male A30P mice at 2-4 months of age, therefore, in the current study we have immunostained this region for markers of neuronal activity (c-Fos), reactive astrocytes (glial fibrillary acidic protein, GFAP), microglia (ionizing calcium binding adapter protein 1, Iba-1) and reactive microglia (inducible nitric oxide synthase, iNOS). Results We found an interesting biphasic change in the expression of c-Fos in A30P mice with high expression at 1 month, consistent with early onset of hyperexcitability, but lower expression from 2-4 months in male A30P mice compared to wild-type (WT) controls, possibly indicating chronic hyperexcitability. Neuroinflammation was indicated by significant increases in the % area of GFAP and the number of Iba-1+ cells that expressed iNOS immunoreactivity in the CA3 region in 2-4 months A30P male mice compared to WT controls. A similar increase in % area of GFAP was observed in female A30P mice, however, the Iba-1 count was not different between female WT and A30P mice. In WT mice aged 2-4 months only 4.6% of Iba-1+ cells co-expressed iNOS. In contrast, in age matched A30P mice 87% of cells co-expressed Iba-1 and iNOS. Although there was no difference in GFAP immunoreactivity at 1 month, Iba-1/iNOS co-expression was also increased in a cohort of 1 month old A30P mice. Discussion Abnormal hα-syn expression in A30P mice caused early changes in network excitability, as indicated by c-Fos expression, and neuroinflammation which might contribute to disease progression.
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Affiliation(s)
| | | | | | - Fiona E. N. LeBeau
- Biosciences Institute and Centre for Transformative Neuroscience, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
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Barbour AJ, Gourmaud S, Lancaster E, Li X, Stewart DA, Hoag KF, Irwin DJ, Talos DM, Jensen FE. Seizures exacerbate excitatory: inhibitory imbalance in Alzheimer's disease and 5XFAD mice. Brain 2024; 147:2169-2184. [PMID: 38662500 PMCID: PMC11146435 DOI: 10.1093/brain/awae126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 03/02/2024] [Accepted: 03/24/2024] [Indexed: 05/14/2024] Open
Abstract
Approximately 22% of Alzheimer's disease (AD) patients suffer from seizures, and the co-occurrence of seizures and epileptiform activity exacerbates AD pathology and related cognitive deficits, suggesting that seizures may be a targetable component of AD progression. Given that alterations in neuronal excitatory:inhibitory (E:I) balance occur in epilepsy, we hypothesized that decreased markers of inhibition relative to those of excitation would be present in AD patients. We similarly hypothesized that in 5XFAD mice, the E:I imbalance would progress from an early stage (prodromal) to later symptomatic stages and be further exacerbated by pentylenetetrazol (PTZ) kindling. Post-mortem AD temporal cortical tissues from patients with or without seizure history were examined for changes in several markers of E:I balance, including levels of the inhibitory GABAA receptor, the sodium potassium chloride cotransporter 1 (NKCC1) and potassium chloride cotransporter 2 (KCC2) and the excitatory NMDA and AMPA type glutamate receptors. We performed patch-clamp electrophysiological recordings from CA1 neurons in hippocampal slices and examined the same markers of E:I balance in prodromal 5XFAD mice. We next examined 5XFAD mice at chronic stages, after PTZ or control protocols, and in response to chronic mTORC1 inhibitor rapamycin, administered following kindled seizures, for markers of E:I balance. We found that AD patients with comorbid seizures had worsened cognitive and functional scores and decreased GABAA receptor subunit expression, as well as increased NKCC1/KCC2 ratios, indicative of depolarizing GABA responses. Patch clamp recordings of prodromal 5XFAD CA1 neurons showed increased intrinsic excitability, along with decreased GABAergic inhibitory transmission and altered glutamatergic neurotransmission, indicating that E:I imbalance may occur in early disease stages. Furthermore, seizure induction in prodromal 5XFAD mice led to later dysregulation of NKCC1/KCC2 and a reduction in GluA2 AMPA glutamate receptor subunit expression, indicative of depolarizing GABA receptors and calcium permeable AMPA receptors. Finally, we found that chronic treatment with the mTORC1 inhibitor, rapamycin, at doses we have previously shown to attenuate seizure-induced amyloid-β pathology and cognitive deficits, could also reverse elevations of the NKCC1/KCC2 ratio in these mice. Our data demonstrate novel mechanisms of interaction between AD and epilepsy and indicate that targeting E:I balance, potentially with US Food and Drug Administration-approved mTOR inhibitors, hold therapeutic promise for AD patients with a seizure history.
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Affiliation(s)
- Aaron J Barbour
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sarah Gourmaud
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Eunjoo Lancaster
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Xiaofan Li
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David A Stewart
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Duke University School of Medicine, Durham, NC 27708, USA
| | - Keegan F Hoag
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David J Irwin
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Penn Frontotemporal Degeneration Center, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Delia M Talos
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Frances E Jensen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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Moguilner SG, Berezuk C, Bender AC, Pellerin KR, Gomperts SN, Cash SS, Sarkis RA, Lam AD. Sleep functional connectivity, hyperexcitability, and cognition in Alzheimer's disease. Alzheimers Dement 2024; 20:4234-4249. [PMID: 38764252 PMCID: PMC11180941 DOI: 10.1002/alz.13861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 03/29/2024] [Accepted: 04/01/2024] [Indexed: 05/21/2024]
Abstract
INTRODUCTION Sleep disturbances are common in Alzheimer's disease (AD) and may reflect pathologic changes in brain networks. To date, no studies have examined changes in sleep functional connectivity (FC) in AD or their relationship with network hyperexcitability and cognition. METHODS We assessed electroencephalogram (EEG) sleep FC in 33 healthy controls, 36 individuals with AD without epilepsy, and 14 individuals with AD and epilepsy. RESULTS AD participants showed increased gamma connectivity in stage 2 sleep (N2), which was associated with longitudinal cognitive decline. Network hyperexcitability in AD was associated with a distinct sleep connectivity signature, characterized by decreased N2 delta connectivity and reversal of several connectivity changes associated with AD. Machine learning algorithms using sleep connectivity features accurately distinguished diagnostic groups and identified "fast cognitive decliners" among study participants who had AD. DISCUSSION Our findings reveal changes in sleep functional networks associated with cognitive decline in AD and may have implications for disease monitoring and therapeutic development. HIGHLIGHTS Brain functional connectivity (FC) in Alzheimer's disease is altered during sleep. Sleep FC measures correlate with cognitive decline in AD. Network hyperexcitability in AD has a distinct sleep connectivity signature.
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Affiliation(s)
- Sebastian G. Moguilner
- Department of NeurologyHarvard Medical SchoolBostonMassachusettsUSA
- Department of NeurologyMassachusetts General HospitalBostonMassachusettsUSA
| | - Courtney Berezuk
- Department of NeurologyHarvard Medical SchoolBostonMassachusettsUSA
- Department of NeurologyMassachusetts General HospitalBostonMassachusettsUSA
| | - Alex C. Bender
- Department of NeurologyHarvard Medical SchoolBostonMassachusettsUSA
- Department of NeurologyMassachusetts General HospitalBostonMassachusettsUSA
| | - Kyle R. Pellerin
- Department of NeurologyMassachusetts General HospitalBostonMassachusettsUSA
| | - Stephen N. Gomperts
- Department of NeurologyHarvard Medical SchoolBostonMassachusettsUSA
- Department of NeurologyMassachusetts General HospitalBostonMassachusettsUSA
| | - Sydney S. Cash
- Department of NeurologyHarvard Medical SchoolBostonMassachusettsUSA
- Department of NeurologyMassachusetts General HospitalBostonMassachusettsUSA
| | - Rani A. Sarkis
- Department of NeurologyHarvard Medical SchoolBostonMassachusettsUSA
- Department of NeurologyBrigham and Women's HospitalBostonMassachusettsUSA
| | - Alice D. Lam
- Department of NeurologyHarvard Medical SchoolBostonMassachusettsUSA
- Department of NeurologyMassachusetts General HospitalBostonMassachusettsUSA
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13
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Stephens GS, Park J, Eagle A, You J, Silva-Pérez M, Fu CH, Choi S, Romain CPS, Sugimoto C, Buffington SA, Zheng Y, Costa-Mattioli M, Liu Y, Robison AJ, Chin J. Persistent ∆FosB expression limits recurrent seizure activity and provides neuroprotection in the dentate gyrus of APP mice. Prog Neurobiol 2024; 237:102612. [PMID: 38642602 DOI: 10.1016/j.pneurobio.2024.102612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 03/14/2024] [Accepted: 04/12/2024] [Indexed: 04/22/2024]
Abstract
Recurrent seizures lead to accumulation of the activity-dependent transcription factor ∆FosB in hippocampal dentate granule cells in both mouse models of epilepsy and mouse models of Alzheimer's disease (AD), which is also associated with increased incidence of seizures. In patients with AD and related mouse models, the degree of ∆FosB accumulation corresponds with increasing severity of cognitive deficits. We previously found that ∆FosB impairs spatial memory in mice by epigenetically regulating expression of target genes such as calbindin that are involved in synaptic plasticity. However, the suppression of calbindin in conditions of neuronal hyperexcitability has been demonstrated to provide neuroprotection to dentate granule cells, indicating that ∆FosB may act over long timescales to coordinate neuroprotective pathways. To test this hypothesis, we used viral-mediated expression of ∆JunD to interfere with ∆FosB signaling over the course of several months in transgenic mice expressing mutant human amyloid precursor protein (APP), which exhibit spontaneous seizures and develop AD-related neuropathology and cognitive deficits. Our results demonstrate that persistent ∆FosB activity acts through discrete modes of hippocampal target gene regulation to modulate neuronal excitability, limit recurrent seizure activity, and provide neuroprotection to hippocampal dentate granule cells in APP mice.
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Affiliation(s)
| | - Jin Park
- Department of Neuroscience, Baylor College of Medicine, USA
| | - Andrew Eagle
- Department of Physiology, Michigan State University, USA
| | - Jason You
- Department of Neuroscience, Baylor College of Medicine, USA
| | | | - Chia-Hsuan Fu
- Department of Neuroscience, Baylor College of Medicine, USA
| | - Sumin Choi
- Department of Neuroscience, Baylor College of Medicine, USA
| | | | - Chiho Sugimoto
- Department of Physiology, Michigan State University, USA
| | - Shelly A Buffington
- Center for Precision Environmental Health, Department of Neuroscience, Baylor College of Medicine, USA
| | - Yi Zheng
- Department of Neuroscience, Baylor College of Medicine, USA
| | | | - Yin Liu
- Department of Neurobiology and Anatomy, McGovern Medical School at UT Health, USA
| | - A J Robison
- Department of Physiology, Michigan State University, USA
| | - Jeannie Chin
- Department of Neuroscience, Baylor College of Medicine, USA.
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14
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Leitch B. Parvalbumin Interneuron Dysfunction in Neurological Disorders: Focus on Epilepsy and Alzheimer's Disease. Int J Mol Sci 2024; 25:5549. [PMID: 38791587 PMCID: PMC11122153 DOI: 10.3390/ijms25105549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 05/11/2024] [Accepted: 05/16/2024] [Indexed: 05/26/2024] Open
Abstract
Parvalbumin expressing (PV+) GABAergic interneurons are fast spiking neurons that provide powerful but relatively short-lived inhibition to principal excitatory cells in the brain. They play a vital role in feedforward and feedback synaptic inhibition, preventing run away excitation in neural networks. Hence, their dysfunction can lead to hyperexcitability and increased susceptibility to seizures. PV+ interneurons are also key players in generating gamma oscillations, which are synchronized neural oscillations associated with various cognitive functions. PV+ interneuron are particularly vulnerable to aging and their degeneration has been associated with cognitive decline and memory impairment in dementia and Alzheimer's disease (AD). Overall, dysfunction of PV+ interneurons disrupts the normal excitatory/inhibitory balance within specific neurocircuits in the brain and thus has been linked to a wide range of neurodevelopmental and neuropsychiatric disorders. This review focuses on the role of dysfunctional PV+ inhibitory interneurons in the generation of epileptic seizures and cognitive impairment and their potential as targets in the design of future therapeutic strategies to treat these disorders. Recent research using cutting-edge optogenetic and chemogenetic technologies has demonstrated that they can be selectively manipulated to control seizures and restore the balance of neural activity in the brains of animal models. This suggests that PV+ interneurons could be important targets in developing future treatments for patients with epilepsy and comorbid disorders, such as AD, where seizures and cognitive decline are directly linked to specific PV+ interneuron deficits.
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Affiliation(s)
- Beulah Leitch
- Department of Anatomy, School of Biomedical Sciences, Brain Health Research Centre, University of Otago, Dunedin 9016, New Zealand
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15
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Voskobiynyk Y, Li Z, Cochran JN, Davis MN, Carullo NVN, Creed RB, Buckingham SC, Hall AM, Wilson SM, Roberson ED. Excitoprotective effects of conditional tau reduction in excitatory neurons and in adulthood. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.14.594246. [PMID: 38798487 PMCID: PMC11118377 DOI: 10.1101/2024.05.14.594246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Tau reduction is a promising therapeutic strategy for Alzheimer's disease. In numerous models, tau reduction via genetic knockout is beneficial, at least in part due to protection against hyperexcitability and seizures, but the underlying mechanisms are unclear. Here we describe the generation and initial study of a new conditional Tau flox model to address these mechanisms. Given the protective effects of tau reduction against hyperexcitability, we compared the effects of selective tau reduction in excitatory or inhibitory neurons. Tau reduction in excitatory neurons mimicked the protective effects of global tau reduction, while tau reduction in inhibitory neurons had the opposite effect and increased seizure susceptibility. Since most prior studies used knockout mice lacking tau throughout development, we crossed Tau flox mice with inducible Cre mice and found beneficial effects of tau reduction in adulthood. Our findings support the effectiveness of tau reduction in adulthood and indicate that excitatory neurons may be a key site for its excitoprotective effects. SUMMARY A new conditional tau knockout model was generated to study the protective effects of tau reduction against hyperexcitability. Conditional tau reduction in excitatory, but not inhibitory, neurons was excitoprotective, and induced tau reduction in adulthood was excitoprotective without adverse effects.
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16
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Olkhova EA, Smith LA, Dennis BH, Ng YS, LeBeau FEN, Gorman GS. Delineating mechanisms underlying parvalbumin neuron impairment in different neurological and neurodegenerative disorders: the emerging role of mitochondrial dysfunction. Biochem Soc Trans 2024; 52:553-565. [PMID: 38563502 PMCID: PMC11088917 DOI: 10.1042/bst20230191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 03/11/2024] [Accepted: 03/12/2024] [Indexed: 04/04/2024]
Abstract
Given the current paucity of effective treatments in many neurological disorders, delineating pathophysiological mechanisms among the major psychiatric and neurodegenerative diseases may fuel the development of novel, potent treatments that target shared pathways. Recent evidence suggests that various pathological processes, including bioenergetic failure in mitochondria, can perturb the function of fast-spiking, parvalbumin-positive neurons (PV+). These inhibitory neurons critically influence local circuit regulation, the generation of neuronal network oscillations and complex brain functioning. Here, we survey PV+ cell vulnerability in the major neuropsychiatric, and neurodegenerative diseases and review associated cellular and molecular pathophysiological alterations purported to underlie disease aetiology.
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Affiliation(s)
- Elizaveta A. Olkhova
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, U.K
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, U.K
| | - Laura A. Smith
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, U.K
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, U.K
| | - Bethany H. Dennis
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, U.K
| | - Yi Shiau Ng
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, U.K
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, U.K
- NIHR Newcastle Biomedical Research Centre, Biomedical Research Building, Campus for Ageing and Vitality, Newcastle upon Tyne NE4 5PL, U.K
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE2 4HH, U.K
| | - Fiona E. N. LeBeau
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, U.K
| | - Gráinne S. Gorman
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, U.K
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, U.K
- NIHR Newcastle Biomedical Research Centre, Biomedical Research Building, Campus for Ageing and Vitality, Newcastle upon Tyne NE4 5PL, U.K
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne NE2 4HH, U.K
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17
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Musaeus CS, Kjaer TW, Lindberg U, Vestergaard MB, Bo H, Larsson W, Press DZ, Andersen BB, Høgh P, Kidmose P, Hemmsen MC, Rank ML, Hasselbalch SG, Waldemar G, Frederiksen KS. Subclinical epileptiform discharges in Alzheimer's disease are associated with increased hippocampal blood flow. Alzheimers Res Ther 2024; 16:80. [PMID: 38610005 PMCID: PMC11010418 DOI: 10.1186/s13195-024-01432-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 03/19/2024] [Indexed: 04/14/2024]
Abstract
BACKGROUND In epilepsy, the ictal phase leads to cerebral hyperperfusion while hypoperfusion is present in the interictal phases. Patients with Alzheimer's disease (AD) have an increased prevalence of epileptiform discharges and a study using intracranial electrodes have shown that these are very frequent in the hippocampus. However, it is not known whether there is an association between hippocampal hyperexcitability and regional cerebral blood flow (rCBF). The objective of the study was to investigate the association between rCBF in hippocampus and epileptiform discharges as measured with ear-EEG in patients with Alzheimer's disease. Our hypothesis was that increased spike frequency may be associated with increased rCBF in hippocampus. METHODS A total of 24 patients with AD, and 15 HC were included in the analysis. Using linear regression, we investigated the association between rCBF as measured with arterial spin-labelling MRI (ASL-MRI) in the hippocampus and the number of spikes/sharp waves per 24 h as assessed by ear-EEG. RESULTS No significant difference in hippocampal rCBF was found between AD and HC (p-value = 0.367). A significant linear association between spike frequency and normalized rCBF in the hippocampus was found for patients with AD (estimate: 0.109, t-value = 4.03, p-value < 0.001). Changes in areas that typically show group differences (temporal-parietal cortex) were found in patients with AD, compared to HC. CONCLUSIONS Increased spike frequency was accompanied by a hemodynamic response of increased blood flow in the hippocampus in patients with AD. This phenomenon has also been shown in patients with epilepsy and supports the hypothesis of hyperexcitability in patients with AD. The lack of a significant difference in hippocampal rCBF may be due to an increased frequency of epileptiform discharges in patients with AD. TRIAL REGISTRATION The study is registered at clinicaltrials.gov (NCT04436341).
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Affiliation(s)
- Christian Sandøe Musaeus
- Danish Dementia Research Centre (DDRC), Department of Neurology, Copenhagen University Hospital - Rigshospitalet, Inge Lehmanns vej 8, Copenhagen, 2100, Denmark.
| | - Troels Wesenberg Kjaer
- Danish Dementia Research Centre (DDRC), Department of Neurology, Copenhagen University Hospital - Rigshospitalet, Inge Lehmanns vej 8, Copenhagen, 2100, Denmark
| | - Ulrich Lindberg
- Functional Imaging Unit, Department of Clinical Physiology and Nuclear Medicine, University of Copenhagen, Valdemar Hansens Vej 13, Glostrup, 2600, Denmark
| | - Mark B Vestergaard
- Functional Imaging Unit, Department of Clinical Physiology and Nuclear Medicine, University of Copenhagen, Valdemar Hansens Vej 13, Glostrup, 2600, Denmark
| | - Henrik Bo
- Danish Dementia Research Centre (DDRC), Department of Neurology, Copenhagen University Hospital - Rigshospitalet, Inge Lehmanns vej 8, Copenhagen, 2100, Denmark
| | - Wiberg Larsson
- Functional Imaging Unit, Department of Clinical Physiology and Nuclear Medicine, University of Copenhagen, Valdemar Hansens Vej 13, Glostrup, 2600, Denmark
| | - Daniel Zvi Press
- Berenson-Allen Center for Non-invasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Ave, Boston, MA, 02215, USA
| | - Birgitte Bo Andersen
- Danish Dementia Research Centre (DDRC), Department of Neurology, Copenhagen University Hospital - Rigshospitalet, Inge Lehmanns vej 8, Copenhagen, 2100, Denmark
| | - Peter Høgh
- Regional Dementia Research Centre, Department of Neurology, Zealand University Hospital, Vestermarksvej 11, Roskilde, 4000, Denmark
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, Copenhagen, 2200, Denmark
| | - Preben Kidmose
- Department of Electrical and Computer Engineering, Aarhus University, Finlandsgade 22, Aarhus N, 8200, Denmark
| | | | | | - Steen Gregers Hasselbalch
- Danish Dementia Research Centre (DDRC), Department of Neurology, Copenhagen University Hospital - Rigshospitalet, Inge Lehmanns vej 8, Copenhagen, 2100, Denmark
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, Copenhagen, 2200, Denmark
| | - Gunhild Waldemar
- Danish Dementia Research Centre (DDRC), Department of Neurology, Copenhagen University Hospital - Rigshospitalet, Inge Lehmanns vej 8, Copenhagen, 2100, Denmark
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, Copenhagen, 2200, Denmark
| | - Kristian Steen Frederiksen
- Danish Dementia Research Centre (DDRC), Department of Neurology, Copenhagen University Hospital - Rigshospitalet, Inge Lehmanns vej 8, Copenhagen, 2100, Denmark
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, Copenhagen, 2200, Denmark
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18
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Blanpain LT, Cole ER, Chen E, Park JK, Walelign MY, Gross RE, Cabaniss BT, Willie JT, Singer AC. Multisensory flicker modulates widespread brain networks and reduces interictal epileptiform discharges. Nat Commun 2024; 15:3156. [PMID: 38605017 PMCID: PMC11009358 DOI: 10.1038/s41467-024-47263-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 03/26/2024] [Indexed: 04/13/2024] Open
Abstract
Modulating brain oscillations has strong therapeutic potential. Interventions that both non-invasively modulate deep brain structures and are practical for chronic daily home use are desirable for a variety of therapeutic applications. Repetitive audio-visual stimulation, or sensory flicker, is an accessible approach that modulates hippocampus in mice, but its effects in humans are poorly defined. We therefore quantified the neurophysiological effects of flicker with high spatiotemporal resolution in patients with focal epilepsy who underwent intracranial seizure monitoring. In this interventional trial (NCT04188834) with a cross-over design, subjects underwent different frequencies of flicker stimulation in the same recording session with the effect of sensory flicker exposure on local field potential (LFP) power and interictal epileptiform discharges (IEDs) as primary and secondary outcomes, respectively. Flicker focally modulated local field potentials in expected canonical sensory cortices but also in the medial temporal lobe and prefrontal cortex, likely via resonance of stimulated long-range circuits. Moreover, flicker decreased interictal epileptiform discharges, a pathological biomarker of epilepsy and degenerative diseases, most strongly in regions where potentials were flicker-modulated, especially the visual cortex and medial temporal lobe. This trial met the scientific goal and is now closed. Our findings reveal how multi-sensory stimulation may modulate cortical structures to mitigate pathological activity in humans.
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Affiliation(s)
- Lou T Blanpain
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA
- Neuroscience Graduate Program, Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, GA, USA
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, USA
| | - Eric R Cole
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, USA
| | - Emily Chen
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA
| | - James K Park
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA
| | - Michael Y Walelign
- Department of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Robert E Gross
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA
- Departments of Neurosurgery and Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, New Brunswick and New Jersey Medical School, Newark, NJ, USA
| | - Brian T Cabaniss
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA
| | - Jon T Willie
- Departments of Neurological Surgery, Neurology, Psychiatry, and Biomedical Engineering, Washington University, St. Louis, MO, USA.
| | - Annabelle C Singer
- Neuroscience Graduate Program, Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, GA, USA.
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, USA.
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19
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Prabhu P, Morise H, Kudo K, Beagle A, Mizuiri D, Syed F, Kotegar KA, Findlay A, Miller BL, Kramer JH, Rankin KP, Garcia PA, Kirsch HE, Vossel K, Nagarajan SS, Ranasinghe KG. Abnormal gamma phase-amplitude coupling in the parahippocampal cortex is associated with network hyperexcitability in Alzheimer's disease. Brain Commun 2024; 6:fcae121. [PMID: 38665964 PMCID: PMC11043655 DOI: 10.1093/braincomms/fcae121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 03/08/2024] [Accepted: 04/07/2024] [Indexed: 04/28/2024] Open
Abstract
While animal models of Alzheimer's disease (AD) have shown altered gamma oscillations (∼40 Hz) in local neural circuits, the low signal-to-noise ratio of gamma in the resting human brain precludes its quantification via conventional spectral estimates. Phase-amplitude coupling (PAC) indicating the dynamic integration between the gamma amplitude and the phase of low-frequency (4-12 Hz) oscillations is a useful alternative to capture local gamma activity. In addition, PAC is also an index of neuronal excitability as the phase of low-frequency oscillations that modulate gamma amplitude, effectively regulates the excitability of local neuronal firing. In this study, we sought to examine the local neuronal activity and excitability using gamma PAC, within brain regions vulnerable to early AD pathophysiology-entorhinal cortex and parahippocampus, in a clinical population of patients with AD and age-matched controls. Our clinical cohorts consisted of a well-characterized cohort of AD patients (n = 50; age, 60 ± 8 years) with positive AD biomarkers, and age-matched, cognitively unimpaired controls (n = 35; age, 63 ± 5.8 years). We identified the presence or the absence of epileptiform activity in AD patients (AD patients with epileptiform activity, AD-EPI+, n = 20; AD patients without epileptiform activity, AD-EPI-, n = 30) using long-term electroencephalography (LTM-EEG) and 1-hour long magnetoencephalography (MEG) with simultaneous EEG. Using the source reconstructed MEG data, we computed gamma PAC as the coupling between amplitude of the gamma frequency (30-40 Hz) with phase of the theta (4-8 Hz) and alpha (8-12 Hz) frequency oscillations, within entorhinal and parahippocampal cortices. We found that patients with AD have reduced gamma PAC in the left parahippocampal cortex, compared to age-matched controls. Furthermore, AD-EPI+ patients showed greater reductions in gamma PAC than AD-EPI- in bilateral parahippocampal cortices. In contrast, entorhinal cortices did not show gamma PAC abnormalities in patients with AD. Our findings demonstrate the spatial patterns of altered gamma oscillations indicating possible region-specific manifestations of network hyperexcitability within medial temporal lobe regions vulnerable to AD pathophysiology. Greater deficits in AD-EPI+ suggests that reduced gamma PAC is a sensitive index of network hyperexcitability in AD patients. Collectively, the current results emphasize the importance of investigating the role of neural circuit hyperexcitability in early AD pathophysiology and explore its potential as a modifiable contributor to AD pathobiology.
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Affiliation(s)
- Pooja Prabhu
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA 94158, USA
- Department of Data science and Computer Applications, Manipal Institute of Technology, Manipal 576104, India
| | - Hirofumi Morise
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA 94158, USA
- Medical Imaging Business Center, Ricoh Company Ltd., Kanazawa 920-0177, Japan
| | - Kiwamu Kudo
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA 94158, USA
- Medical Imaging Business Center, Ricoh Company Ltd., Kanazawa 920-0177, Japan
| | - Alexander Beagle
- Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Danielle Mizuiri
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA 94158, USA
| | - Faatimah Syed
- Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Karunakar A Kotegar
- Department of Data science and Computer Applications, Manipal Institute of Technology, Manipal 576104, India
| | - Anne Findlay
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA 94158, USA
| | - Bruce L Miller
- Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Joel H Kramer
- Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Katherine P Rankin
- Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Paul A Garcia
- Epilepsy Center, Department of Neurology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Heidi E Kirsch
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA 94158, USA
- Epilepsy Center, Department of Neurology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Keith Vossel
- Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA 94158, USA
- Mary S. Easton Center for Alzheimer’s Research and Care, Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Srikantan S Nagarajan
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA 94158, USA
| | - Kamalini G Ranasinghe
- Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA 94158, USA
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Terman SW, Kirkpatrick L, Kerr WT, Akiyama LF, Baajour W, Atilgan D, Dorotan MKC, Choi HW, French JA. Challenges and directions in epilepsy diagnostics and therapeutics: Proceedings of the 17th Epilepsy Therapies and Diagnostics Development conference. Epilepsia 2024; 65:846-860. [PMID: 38135921 PMCID: PMC11018495 DOI: 10.1111/epi.17875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 12/19/2023] [Accepted: 12/20/2023] [Indexed: 12/24/2023]
Abstract
Substantial efforts are underway toward optimizing the diagnosis, monitoring, and treatment of seizures and epilepsy. We describe preclinical programs in place for screening investigational therapeutic candidates in animal models, with particular attention to identifying and eliminating drugs that might paradoxically aggravate seizure burden. After preclinical development, we discuss challenges and solutions in the design and regulatory logistics of clinical trial execution, and efforts to develop disease biomarkers and interventions that may be not only seizure-suppressing, but also disease-modifying. As disease-modifying treatments are designed, there is clear recognition that, although seizures represent one critical therapeutic target, targeting nonseizure outcomes like cognitive development or functional outcomes requires changes to traditional designs. This reflects our increasing understanding that epilepsy is a disease with profound impact on quality of life for the patient and caregivers due to both seizures themselves and other nonseizure factors. This review examines selected key challenges and future directions in epilepsy diagnostics and therapeutics, from drug discovery to translational application.
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Affiliation(s)
- Samuel W Terman
- University of Michigan Department of Neurology, Ann Arbor, MI 48109, USA
| | - Laura Kirkpatrick
- University of Pittsburgh Department of Neurology, Pittsburgh, PA 15213, USA
- University of Pittsburgh Department of Pediatrics, Pittsburgh, PA 15213, USA
| | - Wesley T Kerr
- University of Michigan Department of Neurology, Ann Arbor, MI 48109, USA
- University of Pittsburgh Department of Neurology, Pittsburgh, PA 15213, USA
- University of Pittsburgh Department of Biomedical Informatics, Pittsburgh, PA 15213, USA
| | - Lisa F Akiyama
- University of Washington Department of Neurology, Seattle, WA 98105, USA
| | - Wadih Baajour
- University of Texas Health Science Center at Houston, Department of Neurology, Houston, TX 77030, USA
| | - Deniz Atilgan
- University of Texas Health Science Center at Houston, Department of Neurology, Houston, TX 77030, USA
| | | | - Hyoung Won Choi
- Emory University Department of Pediatrics, Division of Neurology, Atlanta, GA 30322
| | - Jacqueline A French
- NYU Grossman School of Medicine and NYU Langone Health, New York, NY 10016, USA
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van Nifterick AM, Scheijbeler EP, Gouw AA, de Haan W, Stam CJ. Local signal variability and functional connectivity: Sensitive measures of the excitation-inhibition ratio? Cogn Neurodyn 2024; 18:519-537. [PMID: 38699618 PMCID: PMC11061092 DOI: 10.1007/s11571-023-10003-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 06/08/2023] [Accepted: 08/13/2023] [Indexed: 05/05/2024] Open
Abstract
A novel network version of permutation entropy, the inverted joint permutation entropy (JPEinv), holds potential as non-invasive biomarker of abnormal excitation-inhibition (E-I) ratio in Alzheimer's disease (AD). In this computational modelling study, we test the hypotheses that this metric, and related measures of signal variability and functional connectivity, are sensitive to altered E-I ratios. The E-I ratio in each neural mass of a whole-brain computational network model was systematically varied. We evaluated whether JPEinv, local signal variability (by permutation entropy) and functional connectivity (by weighted symbolic mutual information (wsMI)) were related to E-I ratio, on whole-brain and regional level. The hub disruption index can identify regions primarily affected in terms of functional connectivity strength (or: degree) by the altered E-I ratios. Analyses were performed for a range of coupling strengths, filter and time-delay settings. On whole-brain level, higher E-I ratios were associated with higher functional connectivity (by JPEinv and wsMI) and lower local signal variability. These relationships were nonlinear and depended on the coupling strength, filter and time-delay settings. On regional level, hub-like regions showed a selective decrease in functional degree (by JPEinv and wsMI) upon a lower E-I ratio, and non-hub-like regions showed a selective increase in degree upon a higher E-I ratio. These results suggest that abnormal functional connectivity and signal variability, as previously reported in patients across the AD continuum, can inform us about altered E-I ratios. Supplementary Information The online version contains supplementary material available at 10.1007/s11571-023-10003-x.
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Affiliation(s)
- Anne M. van Nifterick
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, The Netherlands
- Clinical Neurophysiology and MEG Center, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, The Netherlands
- Amsterdam Neuroscience, Neurodegeneration, Amsterdam, The Netherlands
| | - Elliz P. Scheijbeler
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, The Netherlands
- Clinical Neurophysiology and MEG Center, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, The Netherlands
- Amsterdam Neuroscience, Neurodegeneration, Amsterdam, The Netherlands
| | - Alida A. Gouw
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, The Netherlands
- Clinical Neurophysiology and MEG Center, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, The Netherlands
- Amsterdam Neuroscience, Neurodegeneration, Amsterdam, The Netherlands
| | - Willem de Haan
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, The Netherlands
- Clinical Neurophysiology and MEG Center, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, The Netherlands
- Amsterdam Neuroscience, Neurodegeneration, Amsterdam, The Netherlands
| | - Cornelis J. Stam
- Clinical Neurophysiology and MEG Center, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, The Netherlands
- Amsterdam Neuroscience, Neurodegeneration, Amsterdam, The Netherlands
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22
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Slutsky I. Linking activity dyshomeostasis and sleep disturbances in Alzheimer disease. Nat Rev Neurosci 2024; 25:272-284. [PMID: 38374463 DOI: 10.1038/s41583-024-00797-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/30/2024] [Indexed: 02/21/2024]
Abstract
The presymptomatic phase of Alzheimer disease (AD) starts with the deposition of amyloid-β in the cortex and begins a decade or more before the emergence of cognitive decline. The trajectory towards dementia and neurodegeneration is shaped by the pathological load and the resilience of neural circuits to the effects of this pathology. In this Perspective, I focus on recent advances that have uncovered the vulnerability of neural circuits at early stages of AD to hyperexcitability, particularly when the brain is in a low-arousal states (such as sleep and anaesthesia). Notably, this hyperexcitability manifests before overt symptoms such as sleep and memory deficits. Using the principles of control theory, I analyse the bidirectional relationship between homeostasis of neuronal activity and sleep and propose that impaired activity homeostasis during sleep leads to hyperexcitability and subsequent sleep disturbances, whereas sleep disturbances mitigate hyperexcitability via negative feedback. Understanding the interplay among activity homeostasis, neuronal excitability and sleep is crucial for elucidating the mechanisms of vulnerability to and resilience against AD pathology and for identifying new therapeutic avenues.
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Affiliation(s)
- Inna Slutsky
- Department of Physiology and Pharmacology, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
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23
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Nagaraja N, Ballur Narayana Reddy V. Prevalence of Concomitant Neurological Disorders and Long-Term Outcome of Patients Hospitalized for Intracerebral Hemorrhage with Versus without Cerebral Amyloid Angiopathy. Neurocrit Care 2024; 40:486-494. [PMID: 37258986 DOI: 10.1007/s12028-023-01753-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 05/10/2023] [Indexed: 06/02/2023]
Abstract
BACKGROUND Patients with intracerebral hemorrhage (ICH) related to cerebral amyloid angiopathy (CAA) are at increased risk of developing epilepsy and cognitive disorders such as Alzheimer's disease (AD), mild cognitive impairment (MCI), and vascular dementia. In a retrospective cohort observation study of patients hospitalized for ICH with CAA versus ICH without CAA, we evaluated the prevalence of neurological comorbidities at admission and the risk of new diagnosis of epilepsy, relevant cognitive disorders, and mortality at 1 year. METHODS In the TriNetX health research network, adult patients aged ≥ 55 years hospitalized with a diagnosis of ICH were stratified based on presence or absence of concomitant CAA diagnosis. Demographics and medical comorbidities were compared by using χ2 test and Student's t-test. After 1:1 propensity score matching, 1-year survival was assessed with Kaplan-Meier curves. The 1-year risk of new diagnosis of epilepsy, AD, MCI, vascular dementia, and dementia unspecified was assessed with Cox proportional hazards estimate. RESULTS The study included a total of 1757 patients with ICH and CAA and 53,364 patients with ICH without CAA. Patients with CAA were older compared with those without CAA (74.1 ± 7.5 vs. 69.8 ± 8.8 years, p ≤ 0.001). Compared with ICH without CAA, patients with ICH and CAA had higher baseline prevalence of cerebral infarction (30% vs. 20%), nontraumatic ICH (36% vs. 7%), nontraumatic subarachnoid hemorrhage (14% vs. 5%), epilepsy (11% vs. 6%), and AD (5% vs. 2%) with significance at p < 0.001. After propensity score matching, a total of 1746 patients were included in both cohorts. In the matched cohorts, compared with patients with ICH without CAA, patients with ICH and CAA had lower 1-year all-cause mortality (479 [27%] vs. 563 [32%]; hazard ratio [HR] 0.80; 95% confidence interval [CI] 0.71-0.90) and higher risk of new diagnosis of epilepsy (280 [18%] vs. 167 [11%]; HR 1.70; 95% CI 1.40-2.06), AD (101 [6%] vs. 38 [2%]; HR 2.62; 95% CI 1.80-3.80), MCI (85 [5%] vs. 35 [2%]; HR 2.39; 95% CI 1.61-3.54), vascular dementia (117 [7%] vs. 60 [4%]; HR 1.92; 95% CI 1.41-2.62), and dementia unspecified (245 [16%] vs. 150 [9%]; HR 1.70; 95% CI 1.39-2.08). CONCLUSIONS Among patients admitted for ICH, patients with CAA have lower mortality but have 2-3 times more risk of diagnosis of epilepsy and dementia at 1 year, compared with those without CAA.
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Affiliation(s)
- Nandakumar Nagaraja
- Department of Neurology, Milton S. Hershey Medical Center, Penn State College of Medicine, 30 Hope Drive EC037, Hershey, PA, 17033, USA.
| | - Varalakshmi Ballur Narayana Reddy
- Department of Neurology, Milton S. Hershey Medical Center, Penn State College of Medicine, 30 Hope Drive EC037, Hershey, PA, 17033, USA
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24
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Brigo F, Lattanzi S. Diagnosing epileptic seizures in patients with Alzheimer's disease and deciding on the appropriate treatment plan. Expert Rev Neurother 2024; 24:361-370. [PMID: 38426448 DOI: 10.1080/14737175.2024.2325038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 02/26/2024] [Indexed: 03/02/2024]
Abstract
INTRODUCTION Alzheimer's disease (AD) is the predominant cause of dementia and a significant contributor to morbidity among the elderly. Patients diagnosed with AD face an increased risk of epileptic seizures. AREAS COVERED Herein, the authors review the challenges in the diagnosis of seizures in patients with AD, the risks of seizures related to medications used in AD and the pharmacological treatment of seizures in AD. The authors also provide the reader with their expert opinion on the subject matter and future perspectives. EXPERT OPINION Healthcare professionals should maintain a vigilant approach to suspecting seizures in AD patients. Acute symptomatic seizures triggered by metabolic disturbances, infections, toxins, or drug-related factors often have a low risk of recurrence. In such cases, addressing the underlying cause may suffice without initiating antiseizure medications (ASMs). However, unprovoked seizures in certain AD patients carry a higher risk of recurrence over time, warranting the use of ASMs. Although data is limited, both lamotrigine and levetiracetam appear to be reasonable choices for controlling seizures in elderly AD patients. Decisions should be informed by the best available evidence, the treating physician's clinical experience, and the patient's preferences.
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Affiliation(s)
- Francesco Brigo
- Innovation, Research and Teaching Service (SABES-ASDAA), Teaching Hospital of the Paracelsus Medical Private University (PMU), Bolzano, Italy
| | - Simona Lattanzi
- Neurological Clinic, Department of Experimental and Clinical Medicine, Marche Polytechnic University, Ancona, Italy
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25
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Almeida VN. Somatostatin and the pathophysiology of Alzheimer's disease. Ageing Res Rev 2024; 96:102270. [PMID: 38484981 DOI: 10.1016/j.arr.2024.102270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 03/09/2024] [Accepted: 03/09/2024] [Indexed: 03/28/2024]
Abstract
Among the central features of Alzheimer's disease (AD) progression are altered levels of the neuropeptide somatostatin (SST), and the colocalisation of SST-positive interneurons (SST-INs) with amyloid-β plaques, leading to cell death. In this theoretical review, I propose a molecular model for the pathogenesis of AD based on SST-IN hypofunction and hyperactivity. Namely, hypofunctional and hyperactive SST-INs struggle to control hyperactivity in medial regions in early stages, leading to axonal Aβ production through excessive presynaptic GABAB inhibition, GABAB1a/APP complex downregulation and internalisation. Concomitantly, excessive SST-14 release accumulates near SST-INs in the form of amyloids, which bind to Aβ to form toxic mixed oligomers. This leads to differential SST-IN death through excitotoxicity, further disinhibition, SST deficits, and increased Aβ release, fibrillation and plaque formation. Aβ plaques, hyperactive networks and SST-IN distributions thereby tightly overlap in the brain. Conversely, chronic stimulation of postsynaptic SST2/4 on gulutamatergic neurons by hyperactive SST-INs promotes intense Mitogen-Activated Protein Kinase (MAPK) p38 activity, leading to somatodendritic p-tau staining and apoptosis/neurodegeneration - in agreement with a near complete overlap between p38 and neurofibrillary tangles. This model is suitable to explain some of the principal risk factors and markers of AD progression, including mitochondrial dysfunction, APOE4 genotype, sex-dependent vulnerability, overactive glial cells, dystrophic neurites, synaptic/spine losses, inter alia. Finally, the model can also shed light on qualitative aspects of AD neuropsychology, especially within the domains of spatial and declarative (episodic, semantic) memory, under an overlying pattern of contextual indiscrimination, ensemble instability, interference and generalisation.
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Affiliation(s)
- Victor N Almeida
- Institute of Psychiatry, Faculty of Medicine, University of São Paulo (USP), Brazil; Faculty of Languages, Federal University of Minas Gerais (UFMG), Brazil.
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26
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Hoffman C, Cheng J, Morales R, Ji D, Dabaghian Y. Altered patterning of neural activity in a tauopathy mouse model. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.23.586417. [PMID: 38585991 PMCID: PMC10996513 DOI: 10.1101/2024.03.23.586417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Alzheimer's disease (AD) is a complex neurodegenerative condition that manifests at multiple levels and involves a spectrum of abnormalities ranging from the cellular to cognitive. Here, we investigate the impact of AD-related tau-pathology on hippocampal circuits in mice engaged in spatial navigation, and study changes of neuronal firing and dynamics of extracellular fields. While most studies are based on analyzing instantaneous or time-averaged characteristics of neuronal activity, we focus on intermediate timescales-spike trains and waveforms of oscillatory potentials, which we consider as single entities. We find that, in healthy mice, spike arrangements and wave patterns (series of crests or troughs) are coupled to the animal's location, speed, and acceleration. In contrast, in tau-mice, neural activity is structurally disarrayed: brainwave cadence is detached from locomotion, spatial selectivity is lost, the spike flow is scrambled. Importantly, these alterations start early and accumulate with age, which exposes progressive disinvolvement the hippocampus circuit in spatial navigation. These features highlight qualitatively different neurodynamics than the ones provided by conventional analyses, and are more salient, thus revealing a new level of the hippocampal circuit disruptions.
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Affiliation(s)
- C Hoffman
- Department of Neurology, The University of Texas McGovern Medical School, 6431 Fannin St, Houston, TX 77030
| | - J Cheng
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030
| | - R Morales
- Department of Neurology, The University of Texas McGovern Medical School, 6431 Fannin St, Houston, TX 77030
| | - D Ji
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030
| | - Y Dabaghian
- Department of Neurology, The University of Texas McGovern Medical School, 6431 Fannin St, Houston, TX 77030
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27
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Liu AA, Barr WB. Overlapping and distinct phenotypic profiles in Alzheimer's disease and late onset epilepsy: a biologically-based approach. Front Neurol 2024; 14:1260523. [PMID: 38545454 PMCID: PMC10965692 DOI: 10.3389/fneur.2023.1260523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 12/18/2023] [Indexed: 04/05/2024] Open
Abstract
Due to shared hippocampal dysfunction, patients with Alzheimer's dementia and late-onset epilepsy (LOE) report memory decline. Multiple studies have described the epidemiological, pathological, neurophysiological, and behavioral overlap between Alzheimer's Disease and LOE, implying a bi-directional relationship. We describe the neurobiological decline occurring at different spatial in AD and LOE patients, which may explain why their phenotypes overlap and differ. We provide suggestions for clinical recognition of dual presentation and novel approaches for behavioral testing that reflect an "inside-out," or biologically-based approach to testing memory. New memory and language assessments could detect-and treat-memory impairment in AD and LOE at an earlier, actionable stage.
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Affiliation(s)
- Anli A. Liu
- Langone Medical Center, New York University, New York, NY, United States
- Department of Neurology, School of Medicine, New York University, New York, NY, United States
- Neuroscience Institute, Langone Medical Center, New York University, New York, NY, United States
| | - William B. Barr
- Department of Neurology, School of Medicine, New York University, New York, NY, United States
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28
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Yook Y, Lee KY, Kim E, Lizarazo S, Yu X, Tsai NP. Hyperfunction of post-synaptic density protein 95 promotes seizure response in early-stage aβ pathology. EMBO Rep 2024; 25:1233-1255. [PMID: 38413732 PMCID: PMC10933348 DOI: 10.1038/s44319-024-00090-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 01/24/2024] [Accepted: 01/30/2024] [Indexed: 02/29/2024] Open
Abstract
Accumulation of amyloid-beta (Aβ) can lead to the formation of aggregates that contribute to neurodegeneration in Alzheimer's disease (AD). Despite globally reduced neural activity during AD onset, recent studies have suggested that Aβ induces hyperexcitability and seizure-like activity during the early stages of the disease that ultimately exacerbate cognitive decline. However, the underlying mechanism is unknown. Here, we reveal an Aβ-induced elevation of postsynaptic density protein 95 (PSD-95) in cultured neurons in vitro and in an in vivo AD model using APP/PS1 mice at 8 weeks of age. Elevation of PSD-95 occurs as a result of reduced ubiquitination caused by Akt-dependent phosphorylation of E3 ubiquitin ligase murine-double-minute 2 (Mdm2). The elevation of PSD-95 is consistent with the facilitation of excitatory synapses and the surface expression of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors induced by Aβ. Inhibition of PSD-95 corrects these Aβ-induced synaptic defects and reduces seizure activity in APP/PS1 mice. Our results demonstrate a mechanism underlying elevated seizure activity during early-stage Aβ pathology and suggest that PSD-95 could be an early biomarker and novel therapeutic target for AD.
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Affiliation(s)
- Yeeun Yook
- Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Kwan Young Lee
- Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Eunyoung Kim
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Simon Lizarazo
- Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Xinzhu Yu
- Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Nien-Pei Tsai
- Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
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29
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Kamondi A, Grigg-Damberger M, Löscher W, Tanila H, Horvath AA. Epilepsy and epileptiform activity in late-onset Alzheimer disease: clinical and pathophysiological advances, gaps and conundrums. Nat Rev Neurol 2024; 20:162-182. [PMID: 38356056 DOI: 10.1038/s41582-024-00932-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/17/2024] [Indexed: 02/16/2024]
Abstract
A growing body of evidence has demonstrated a link between Alzheimer disease (AD) and epilepsy. Late-onset epilepsy and epileptiform activity can precede cognitive deterioration in AD by years, and its presence has been shown to predict a faster disease course. In animal models of AD, amyloid and tau pathology are linked to cortical network hyperexcitability that precedes the first signs of memory decline. Thus, detection of epileptiform activity in AD has substantial clinical importance as a potential novel modifiable risk factor for dementia. In this Review, we summarize the epidemiological evidence for the complex bidirectional relationship between AD and epilepsy, examine the effect of epileptiform activity and seizures on cognition in people with AD, and discuss the precision medicine treatment strategies based on the latest research in human and animal models. Finally, we outline some of the unresolved questions of the field that should be addressed by rigorous research, including whether particular clinicopathological subtypes of AD have a stronger association with epilepsy, and the sequence of events between epileptiform activity and amyloid and tau pathology.
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Affiliation(s)
- Anita Kamondi
- National Institute of Mental Health, Neurology and Neurosurgery, Budapest, Hungary.
- Department of Neurology, Semmelweis University, Budapest, Hungary.
| | | | - Wolfgang Löscher
- Department of Experimental Otology of the ENT Clinics, Hannover Medical School, Hannover, Germany
| | - Heikki Tanila
- A. I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland
| | - Andras Attila Horvath
- National Institute of Mental Health, Neurology and Neurosurgery, Budapest, Hungary
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
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30
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Aschner A, Kowal C, Arski O, Crispo JAG, Farhat N, Donner E. Prevalence of epileptiform electroencephalographic abnormalities in people without a history of seizures: A systematic review and meta-analysis. Epilepsia 2024; 65:583-599. [PMID: 38101821 DOI: 10.1111/epi.17864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 12/12/2023] [Accepted: 12/12/2023] [Indexed: 12/17/2023]
Abstract
Abnormal patterns identified on electroencephalogram (EEG) are one of the primary diagnostic tests for epilepsy. However, epidemiological studies have established that both benign and epileptiform abnormalities (EAs) occur on the EEG of nonepileptic, seizure-free people as well. The reported rates of EAs in nonepileptic, seizure-free populations vary, and the true prevalence is unknown. The primary objective of this systematic review and meta-analysis was to estimate the overall prevalence of EAs in the EEG of people without a history of seizures. Secondary aims were to characterize (1) the cortical localization of focal abnormalities, (2) the proportion of findings that occurred during standard EEG stimulation protocols, and (3) the persistence and implications of abnormalities at follow-up. A comprehensive electronic search of six bibliographic databases was completed: Embase, MEDLINE, PsycInfo, Cumulative Index of Nursing and Allied Health Literature, Cochrane Central Register for Controlled Trials, and Web of Science. No search date restrictions were applied. Overall effect size was calculated using a generalized linear mixed-effects model. Fifty-three studies, totaling 73 990 individuals, met our inclusion criteria. The overall point prevalence of EAs was 1.74% (95% confidence interval [CI] = 1.13-2.67). Due to the risk of bias in the literature, especially from participant selection, we believe this to be an overestimate of the true prevalence. Prevalence of EAs was greater in children (2.45%, 95% CI = 1.41-4.21) and the elderly (5.96%, 95% CI = 1.39-22.13) compared with adults (.93%, 95% CI = .48-1.80). Reports of developing epilepsy after an EA-positive EEG were rare. The likelihood of subsequent positive findings on follow-up EEG may be as high as 50%. Our study has limitations in that males were overrepresented in the study samples, there is substantial heterogeneity among studies, and many studies provided insufficient detail about their exclusion criteria. Nonetheless, our estimates provide benchmark data for future studies examining EAs in clinical populations, particularly behavioral and psychiatric populations.
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Affiliation(s)
- Amir Aschner
- Division of Neurology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Christine Kowal
- Division of Neurology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Olivia Arski
- Division of Neurology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - James A G Crispo
- Collaboration for Outcomes Research and Evaluation, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
- Human Sciences Division, Northern Ontario School of Medicine University, Sudbury, Ontario, Canada
- TruEffect, Sudbury, Ontario, Canada
| | - Nawal Farhat
- TruEffect, Sudbury, Ontario, Canada
- School of Mathematics and Statistics, Carleton University, Ottawa, Ontario, Canada
| | - Elizabeth Donner
- Division of Neurology, Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
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31
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Vicente M, Addo-Osafo K, Vossel K. Latest advances in mechanisms of epileptic activity in Alzheimer's disease and dementia with Lewy Bodies. Front Neurol 2024; 15:1277613. [PMID: 38390593 PMCID: PMC10882721 DOI: 10.3389/fneur.2024.1277613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 01/12/2024] [Indexed: 02/24/2024] Open
Abstract
Alzheimer's disease (AD) and dementia with Lewy bodies (DLB) stand as the prevailing sources of neurodegenerative dementia, impacting over 55 million individuals across the globe. Patients with AD and DLB exhibit a higher prevalence of epileptic activity compared to those with other forms of dementia. Seizures can accompany AD and DLB in early stages, and the associated epileptic activity can contribute to cognitive symptoms and exacerbate cognitive decline. Aberrant neuronal activity in AD and DLB may be caused by several mechanisms that are not yet understood. Hyperexcitability could be a biomarker for early detection of AD or DLB before the onset of dementia. In this review, we compare and contrast mechanisms of network hyperexcitability in AD and DLB. We examine the contributions of genetic risk factors, Ca2+ dysregulation, glutamate, AMPA and NMDA receptors, mTOR, pathological amyloid beta, tau and α-synuclein, altered microglial and astrocytic activity, and impaired inhibitory interneuron function. By gaining a deeper understanding of the molecular mechanisms that cause neuronal hyperexcitability, we might uncover therapeutic approaches to effectively ease symptoms and slow down the advancement of AD and DLB.
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Affiliation(s)
- Mariane Vicente
- Mary S. Easton Center for Alzheimer's Research and Care, Department of Neurology, David Geffen School of Medicine at University of California, Los Angeles, CA, United States
| | - Kwaku Addo-Osafo
- Mary S. Easton Center for Alzheimer's Research and Care, Department of Neurology, David Geffen School of Medicine at University of California, Los Angeles, CA, United States
| | - Keith Vossel
- Mary S. Easton Center for Alzheimer's Research and Care, Department of Neurology, David Geffen School of Medicine at University of California, Los Angeles, CA, United States
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32
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Fu M, Tran T, Eskin E, Lajonchere C, Pasaniuc B, Geschwind DH, Vossel K, Chang TS. Multi-class Modeling Identifies Shared Genetic Risk for Late-onset Epilepsy and Alzheimer's Disease. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.02.05.24302353. [PMID: 38370677 PMCID: PMC10871371 DOI: 10.1101/2024.02.05.24302353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Background Previous studies have established a strong link between late-onset epilepsy (LOE) and Alzheimer's disease (AD). However, their shared genetic risk beyond the APOE gene remains unclear. Our study sought to examine the shared genetic factors of AD and LOE, interpret the biological pathways involved, and evaluate how AD onset may be mediated by LOE and shared genetic risks. Methods We defined phenotypes using phecodes mapped from diagnosis codes, with patients' records aged 60-90. A two-step Least Absolute Shrinkage and Selection Operator (LASSO) workflow was used to identify shared genetic variants based on prior AD GWAS integrated with functional genomic data. We calculated an AD-LOE shared risk score and used it as a proxy in a causal mediation analysis. We used electronic health records from an academic health center (UCLA Health) for discovery analyses and validated our findings in a multi-institutional EHR database (All of Us). Results The two-step LASSO method identified 34 shared genetic loci between AD and LOE, including the APOE region. These loci were mapped to 65 genes, which showed enrichment in molecular functions and pathways such as tau protein binding and lipoprotein metabolism. Individuals with high predicted shared risk scores have a higher risk of developing AD, LOE, or both in their later life compared to those with low-risk scores. LOE partially mediates the effect of AD-LOE shared genetic risk on AD (15% proportion mediated on average). Validation results from All of Us were consistent with findings from the UCLA sample. Conclusions We employed a machine learning approach to identify shared genetic risks of AD and LOE. In addition to providing substantial evidence for the significant contribution of the APOE-TOMM40-APOC1 gene cluster to shared risk, we uncovered novel genes that may contribute. Our study is one of the first to utilize All of Us genetic data to investigate AD, and provides valuable insights into the potential common and disease-specific mechanisms underlying AD and LOE, which could have profound implications for the future of disease prevention and the development of targeted treatment strategies to combat the co-occurrence of these two diseases.
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Affiliation(s)
- Mingzhou Fu
- Mary S. Easton Center for Alzheimer’s Research and Care, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
- Medical Informatics Home Area, Department of Bioinformatics, University of California, Los Angeles, CA 90095, USA
| | - Thai Tran
- Medical Informatics Home Area, Department of Bioinformatics, University of California, Los Angeles, CA 90095, USA
| | - Eleazar Eskin
- Department of Computational Medicine, University of California, Los Angeles, CA 90095, USA
| | - Clara Lajonchere
- Institute of Precision Health, University of California, Los Angeles, CA 90095, USA
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Bogdan Pasaniuc
- Department of Computational Medicine, University of California, Los Angeles, CA 90095, USA
| | - Daniel H. Geschwind
- Institute of Precision Health, University of California, Los Angeles, CA 90095, USA
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Keith Vossel
- Mary S. Easton Center for Alzheimer’s Research and Care, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Timothy S Chang
- Mary S. Easton Center for Alzheimer’s Research and Care, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
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Blumenfeld J, Yip O, Kim MJ, Huang Y. Cell type-specific roles of APOE4 in Alzheimer disease. Nat Rev Neurosci 2024; 25:91-110. [PMID: 38191720 PMCID: PMC11073858 DOI: 10.1038/s41583-023-00776-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/28/2023] [Indexed: 01/10/2024]
Abstract
The ɛ4 allele of the apolipoprotein E gene (APOE), which translates to the APOE4 isoform, is the strongest genetic risk factor for late-onset Alzheimer disease (AD). Within the CNS, APOE is produced by a variety of cell types under different conditions, posing a challenge for studying its roles in AD pathogenesis. However, through powerful advances in research tools and the use of novel cell culture and animal models, researchers have recently begun to study the roles of APOE4 in AD in a cell type-specific manner and at a deeper and more mechanistic level than ever before. In particular, cutting-edge omics studies have enabled APOE4 to be studied at the single-cell level and have allowed the identification of critical APOE4 effects in AD-vulnerable cellular subtypes. Through these studies, it has become evident that APOE4 produced in various types of CNS cell - including astrocytes, neurons, microglia, oligodendrocytes and vascular cells - has diverse roles in AD pathogenesis. Here, we review these scientific advances and propose a cell type-specific APOE4 cascade model of AD. In this model, neuronal APOE4 emerges as a crucial pathological initiator and driver of AD pathogenesis, instigating glial responses and, ultimately, neurodegeneration. In addition, we provide perspectives on future directions for APOE4 research and related therapeutic developments in the context of AD.
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Affiliation(s)
- Jessica Blumenfeld
- Gladstone Institute of Neurological Disease, Gladstone Institutes, San Francisco, CA, USA
- Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Oscar Yip
- Gladstone Institute of Neurological Disease, Gladstone Institutes, San Francisco, CA, USA
- Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Min Joo Kim
- Gladstone Institute of Neurological Disease, Gladstone Institutes, San Francisco, CA, USA
- Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Yadong Huang
- Gladstone Institute of Neurological Disease, Gladstone Institutes, San Francisco, CA, USA.
- Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA, USA.
- Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA, USA.
- Gladstone Center for Translational Advancement, Gladstone Institutes, San Francisco, CA, USA.
- Department of Neurology, University of California, San Francisco, San Francisco, CA, USA.
- Department of Pathology, University of California, San Francisco, San Francisco, CA, USA.
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Leitner D, Pires G, Kavanagh T, Kanshin E, Askenazi M, Ueberheide B, Devinsky O, Wisniewski T, Drummond E. Similar brain proteomic signatures in Alzheimer's disease and epilepsy. Acta Neuropathol 2024; 147:27. [PMID: 38289539 PMCID: PMC10827928 DOI: 10.1007/s00401-024-02683-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 12/15/2023] [Accepted: 01/03/2024] [Indexed: 02/01/2024]
Abstract
The prevalence of epilepsy is increased among Alzheimer's Disease (AD) patients and cognitive impairment is common among people with epilepsy. Epilepsy and AD are linked but the shared pathophysiological changes remain poorly defined. We aim to identify protein differences associated with epilepsy and AD using published proteomics datasets. We observed a highly significant overlap in protein differences in epilepsy and AD: 89% (689/777) of proteins altered in the hippocampus of epilepsy patients were significantly altered in advanced AD. Of the proteins altered in both epilepsy and AD, 340 were altered in the same direction, while 216 proteins were altered in the opposite direction. Synapse and mitochondrial proteins were markedly decreased in epilepsy and AD, suggesting common disease mechanisms. In contrast, ribosome proteins were increased in epilepsy but decreased in AD. Notably, many of the proteins altered in epilepsy interact with tau or are regulated by tau expression. This suggests that tau likely mediates common protein changes in epilepsy and AD. Immunohistochemistry for Aβ and multiple phosphorylated tau species (pTau396/404, pTau217, pTau231) showed a trend for increased intraneuronal pTau217 and pTau231 but no phosphorylated tau aggregates or amyloid plaques in epilepsy hippocampal sections. Our results provide insights into common mechanisms in epilepsy and AD and highlights the potential role of tau in mediating common pathological protein changes in epilepsy and AD.
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Affiliation(s)
- Dominique Leitner
- Center for Cognitive Neurology, Department of Neurology, Grossman School of Medicine, New York University, New York, NY, 10016, USA
- Comprehensive Epilepsy Center, New York University Grossman School of Medicine, New York, 10016, USA
| | - Geoffrey Pires
- Center for Cognitive Neurology, Department of Neurology, Grossman School of Medicine, New York University, New York, NY, 10016, USA
| | - Tomas Kavanagh
- Brain and Mind Centre and School of Medical Sciences, University of Sydney, Camperdown, NSW, 2050, Australia
| | - Evgeny Kanshin
- Proteomics Laboratory, Division of Advanced Research Technologies and Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, 10016, USA
| | | | - Beatrix Ueberheide
- Center for Cognitive Neurology, Department of Neurology, Grossman School of Medicine, New York University, New York, NY, 10016, USA
- Proteomics Laboratory, Division of Advanced Research Technologies and Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, 10016, USA
| | - Orrin Devinsky
- Comprehensive Epilepsy Center, New York University Grossman School of Medicine, New York, 10016, USA
| | - Thomas Wisniewski
- Center for Cognitive Neurology, Department of Neurology, Grossman School of Medicine, New York University, New York, NY, 10016, USA.
| | - Eleanor Drummond
- Center for Cognitive Neurology, Department of Neurology, Grossman School of Medicine, New York University, New York, NY, 10016, USA.
- Brain and Mind Centre and School of Medical Sciences, University of Sydney, Camperdown, NSW, 2050, Australia.
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Burton CP, Chumin EJ, Collins AY, Persohn SA, Onos KD, Pandey RS, Quinney SK, Territo PR. Levetiracetam modulates brain metabolic networks and transcriptomic signatures in the 5XFAD mouse model of Alzheimer's disease. Front Neurosci 2024; 17:1336026. [PMID: 38328556 PMCID: PMC10847229 DOI: 10.3389/fnins.2023.1336026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 12/13/2023] [Indexed: 02/09/2024] Open
Abstract
Introduction Subcritical epileptiform activity is associated with impaired cognitive function and is commonly seen in patients with Alzheimer's disease (AD). The anti-convulsant, levetiracetam (LEV), is currently being evaluated in clinical trials for its ability to reduce epileptiform activity and improve cognitive function in AD. The purpose of the current study was to apply pharmacokinetics (PK), network analysis of medical imaging, gene transcriptomics, and PK/PD modeling to a cohort of amyloidogenic mice to establish how LEV restores or drives alterations in the brain networks of mice in a dose-dependent basis using the rigorous preclinical pipeline of the MODEL-AD Preclinical Testing Core. Methods Chronic LEV was administered to 5XFAD mice of both sexes for 3 months based on allometrically scaled clinical dose levels from PK models. Data collection and analysis consisted of a multi-modal approach utilizing 18F-FDG PET/MRI imaging and analysis, transcriptomic analyses, and PK/PD modeling. Results Pharmacokinetics of LEV showed a sex and dose dependence in Cmax, CL/F, and AUC0-∞, with simulations used to estimate dose regimens. Chronic dosing at 10, 30, and 56 mg/kg, showed 18F-FDG specific regional differences in brain uptake, and in whole brain covariance measures such as clustering coefficient, degree, network density, and connection strength (i.e., positive and negative). In addition, transcriptomic analysis via nanoString showed dose-dependent changes in gene expression in pathways consistent 18F-FDG uptake and network changes, and PK/PD modeling showed a concentration dependence for key genes, but not for network covariance modeling. Discussion This study represents the first report detailing the relationships of metabolic covariance and transcriptomic network changes resulting from LEV administration in 5XFAD mice. Overall, our results highlight non-linear kinetics based on dose and sex, where gene expression analysis demonstrated LEV dose- and concentration-dependent changes, along with cerebral metabolism, and/or cerebral homeostatic mechanisms relevant to human AD, which aligned closely with network covariance analysis of 18F-FDG images. Collectively, this study show cases the value of a multimodal connectomic, transcriptomic, and pharmacokinetic approach to further investigate dose dependent relationships in preclinical studies, with translational value toward informing clinical study design.
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Affiliation(s)
- Charles P. Burton
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Evgeny J. Chumin
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, United States
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Alyssa Y. Collins
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Scott A. Persohn
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, United States
| | | | - Ravi S. Pandey
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, United States
| | - Sara K. Quinney
- Department of Medicine, Division of Clinical Pharmacology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Paul R. Territo
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, United States
- Department of Medicine, Division of Clinical Pharmacology, Indiana University School of Medicine, Indianapolis, IN, United States
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Nous A, Seynaeve L, Feys O, Wens V, De Tiège X, Van Mierlo P, Baroumand AG, Nieboer K, Allemeersch GJ, Mangelschots S, Michiels V, van der Zee J, Van Broeckhoven C, Ribbens A, Houbrechts R, De Witte S, Wittens MMJ, Bjerke M, Vanlersberghe C, Ceyssens S, Nagels G, Smolders I, Engelborghs S. Subclinical epileptiform activity in the Alzheimer continuum: association with disease, cognition and detection method. Alzheimers Res Ther 2024; 16:19. [PMID: 38263073 PMCID: PMC10804650 DOI: 10.1186/s13195-023-01373-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 12/17/2023] [Indexed: 01/25/2024]
Abstract
BACKGROUND Epileptic seizures are an established comorbidity of Alzheimer's disease (AD). Subclinical epileptiform activity (SEA) as detected by 24-h electroencephalography (EEG) or magneto-encephalography (MEG) has been reported in temporal regions of clinically diagnosed AD patients. Although epileptic activity in AD probably arises in the mesial temporal lobe, electrical activity within this region might not propagate to EEG scalp electrodes and could remain undetected by standard EEG. However, SEA might lead to faster cognitive decline in AD. AIMS 1. To estimate the prevalence of SEA and interictal epileptic discharges (IEDs) in a well-defined cohort of participants belonging to the AD continuum, including preclinical AD subjects, as compared with cognitively healthy controls. 2. To evaluate whether long-term-EEG (LTM-EEG), high-density-EEG (hd-EEG) or MEG is superior to detect SEA in AD. 3. To characterise AD patients with SEA based on clinical, neuropsychological and neuroimaging parameters. METHODS Subjects (n = 49) belonging to the AD continuum were diagnosed according to the 2011 NIA-AA research criteria, with a high likelihood of underlying AD pathophysiology. Healthy volunteers (n = 24) scored normal on neuropsychological testing and were amyloid negative. None of the participants experienced a seizure before. Subjects underwent LTM-EEG and/or 50-min MEG and/or 50-min hd-EEG to detect IEDs. RESULTS We found an increased prevalence of SEA in AD subjects (31%) as compared to controls (8%) (p = 0.041; Fisher's exact test), with increasing prevalence over the disease course (50% in dementia, 27% in MCI and 25% in preclinical AD). Although MEG (25%) did not withhold a higher prevalence of SEA in AD as compared to LTM-EEG (19%) and hd-EEG (19%), MEG was significantly superior to detect spikes per 50 min (p = 0.002; Kruskall-Wallis test). AD patients with SEA scored worse on the RBANS visuospatial and attention subset (p = 0.009 and p = 0.05, respectively; Mann-Whitney U test) and had higher left frontal, (left) temporal and (left and right) entorhinal cortex volumes than those without. CONCLUSION We confirmed that SEA is increased in the AD continuum as compared to controls, with increasing prevalence with AD disease stage. In AD patients, SEA is associated with more severe visuospatial and attention deficits and with increased left frontal, (left) temporal and entorhinal cortex volumes. TRIAL REGISTRATION Clinicaltrials.gov, NCT04131491. 12/02/2020.
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Affiliation(s)
- Amber Nous
- Department of Neurology, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
- Neuroprotection and Neuromodulation (NEUR) Research Group, Center for Neurosciences, Vrije Universiteit Brussel, Laarbeeklaan 103, Brussels, Belgium
- Department of Biomedical Sciences, Universiteit Antwerpen, Antwerp, Belgium
- Laboratory of Pharmaceutical Chemistry, Drug Analysis and Drug Information (FASC), Research Group Experimental Pharmacology (EFAR), Center for Neurosciences, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Laura Seynaeve
- Department of Neurology, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
- Neuroprotection and Neuromodulation (NEUR) Research Group, Center for Neurosciences, Vrije Universiteit Brussel, Laarbeeklaan 103, Brussels, Belgium
| | - Odile Feys
- Department of Neurology, Université Libre de Bruxelles (ULB), Hôpital Universitaire de Bruxelles (HUB), Hôpital Erasme, Brussels, Belgium
- Laboratoire de Neuroimagerie Et Neuroanatomie Translationnelles (LN2T), Université Libre de Bruxelles (ULB), ULB Neuroscience Institute (UNI), Brussels, Belgium
| | - Vincent Wens
- Laboratoire de Neuroimagerie Et Neuroanatomie Translationnelles (LN2T), Université Libre de Bruxelles (ULB), ULB Neuroscience Institute (UNI), Brussels, Belgium
- Department of Translational Neuroimaging, Université Libre de Bruxelles (ULB), Hôpital Universitaire de Bruxelles (HUB), Hôpital Erasme, Brussels, Belgium
| | - Xavier De Tiège
- Laboratoire de Neuroimagerie Et Neuroanatomie Translationnelles (LN2T), Université Libre de Bruxelles (ULB), ULB Neuroscience Institute (UNI), Brussels, Belgium
- Department of Translational Neuroimaging, Université Libre de Bruxelles (ULB), Hôpital Universitaire de Bruxelles (HUB), Hôpital Erasme, Brussels, Belgium
| | | | | | - Koenraad Nieboer
- Department of Radiology, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels, Belgium
| | - Gert-Jan Allemeersch
- Department of Radiology, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels, Belgium
| | - Shana Mangelschots
- Neuroprotection and Neuromodulation (NEUR) Research Group, Center for Neurosciences, Vrije Universiteit Brussel, Laarbeeklaan 103, Brussels, Belgium
- Department of Biomedical Sciences, Universiteit Antwerpen, Antwerp, Belgium
| | - Veronique Michiels
- Department of Neurology, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
| | - Julie van der Zee
- Department of Biomedical Sciences, Universiteit Antwerpen, Antwerp, Belgium
- Neurodegenerative Brain Diseases, VIB Center for Molecular Neurology, Antwerp, Belgium
| | - Christine Van Broeckhoven
- Department of Biomedical Sciences, Universiteit Antwerpen, Antwerp, Belgium
- Neurodegenerative Brain Diseases, VIB Center for Molecular Neurology, Antwerp, Belgium
| | | | | | - Sara De Witte
- Department of Neurology, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
- Neuroprotection and Neuromodulation (NEUR) Research Group, Center for Neurosciences, Vrije Universiteit Brussel, Laarbeeklaan 103, Brussels, Belgium
| | - Mandy Melissa Jane Wittens
- Neuroprotection and Neuromodulation (NEUR) Research Group, Center for Neurosciences, Vrije Universiteit Brussel, Laarbeeklaan 103, Brussels, Belgium
- Department of Biomedical Sciences, Universiteit Antwerpen, Antwerp, Belgium
| | - Maria Bjerke
- Neuroprotection and Neuromodulation (NEUR) Research Group, Center for Neurosciences, Vrije Universiteit Brussel, Laarbeeklaan 103, Brussels, Belgium
- Department of Biomedical Sciences, Universiteit Antwerpen, Antwerp, Belgium
- Department of Clinical Biology, Laboratory of Clinical Neurochemistry, Universitair Ziekenhuis Brussel, Brussels, Belgium
| | - Caroline Vanlersberghe
- Department of Anaesthesiology and Perioperative Medicine, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
| | - Sarah Ceyssens
- Department of Nuclear Medicine, Universitair Ziekenhuis Antwerpen, University of Antwerp, Antwerpen, Belgium
| | - Guy Nagels
- Department of Neurology, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
- Artificial Intelligence Supported Modelling in Clinical Sciences (AIMS) Research Group, Center for Neurosciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Ilse Smolders
- Laboratory of Pharmaceutical Chemistry, Drug Analysis and Drug Information (FASC), Research Group Experimental Pharmacology (EFAR), Center for Neurosciences, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Sebastiaan Engelborghs
- Department of Neurology, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium.
- Neuroprotection and Neuromodulation (NEUR) Research Group, Center for Neurosciences, Vrije Universiteit Brussel, Laarbeeklaan 103, Brussels, Belgium.
- Department of Biomedical Sciences, Universiteit Antwerpen, Antwerp, Belgium.
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Locskai LF, Alyenbaawi H, Allison WT. Antiepileptic Drugs as Potential Dementia Prophylactics Following Traumatic Brain Injury. Annu Rev Pharmacol Toxicol 2024; 64:577-598. [PMID: 37788493 DOI: 10.1146/annurev-pharmtox-051921-013930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Seizures and other forms of neurovolatility are emerging as druggable prodromal mechanisms that link traumatic brain injury (TBI) to the progression of later dementias. TBI neurotrauma has both acute and long-term impacts on health, and TBI is a leading risk factor for dementias, including chronic traumatic encephalopathy and Alzheimer's disease. Treatment of TBI already considers acute management of posttraumatic seizures and epilepsy, and impressive efforts have optimized regimens of antiepileptic drugs (AEDs) toward that goal. Here we consider that expanding these management strategies could determine which AED regimens best prevent dementia progression in TBI patients. Challenges with this prophylactic strategy include the potential consequences of prolonged AED treatment and that a large subset of patients are refractory to available AEDs. Addressing these challenges is warranted because the management of seizure activity following TBI offers a rare opportunity to prevent the onset or progression of devastating dementias.
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Affiliation(s)
- Laszlo F Locskai
- Centre for Prions and Protein Folding Diseases and Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada;
| | - Hadeel Alyenbaawi
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, Al Majmaah, Saudi Arabia
| | - W Ted Allison
- Centre for Prions and Protein Folding Diseases and Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada;
- Department of Medical Genetics, University of Alberta, Edmonton, Alberta, Canada
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Swatzyna RJ, Morrow LM, Collins DM, Barr EA, Roark AJ, Turner RP. Evidentiary Significance of Routine EEG in Refractory Cases: A Paradigm Shift in Psychiatry. Clin EEG Neurosci 2024:15500594231221313. [PMID: 38238932 DOI: 10.1177/15500594231221313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
Over the past decade, the Diagnostic and Statistical Manual's method of prescribing medications based on presenting symptoms has been challenged. The shift toward precision medicine began with the National Institute of Mental Health and culminated with the World Psychiatric Association's posit that a paradigm shift is needed. This study supports that shift by providing evidence explaining the high rate of psychiatric medication failure and suggests a possible first step toward precision medicine. A large psychiatric practice began collecting electroencephalograms (EEGs) for this study in 2012. The EEGs were analyzed by the same neurophysiologist (board certified in electroencephalography) on 1,233 patients. This study identified 4 EEG biomarkers accounting for medication failure in refractory patients: focal slowing, spindling excessive beta, encephalopathy, and isolated epileptiform discharges. Each EEG biomarker suggests underlying brain dysregulation, which may explain why prior medication attempts have failed. The EEG biomarkers cannot be identified based on current psychiatric assessment methods, and depending upon the localization, intensity, and duration, can all present as complex behavioral or psychiatric issues. The study highlights that the EEG biomarker identification approach can be a positive step toward personalized medicine in psychiatry, furthering the clinical thinking of "testing the organ we are trying to treat."
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Affiliation(s)
| | | | - Diana M Collins
- Child, Adolescent, and Adult Psychiatry, Sugar Land, TX, USA
| | - Emma A Barr
- Houston Neuroscience Brain Center, Houston, TX, USA
| | | | - Robert P Turner
- Network Neurology, LLC, University of South Carolina School of Medicine, Charleston, SC, USA
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Fu CH, You JC, Mohila C, Rissman RA, Yoshor D, Viaene AN, Chin J. Hippocampal ΔFosB expression is associated with cognitive impairment in a subgroup of patients with childhood epilepsies. Front Neurol 2024; 14:1331194. [PMID: 38274865 PMCID: PMC10808715 DOI: 10.3389/fneur.2023.1331194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 12/27/2023] [Indexed: 01/27/2024] Open
Abstract
Epilepsy is a chronic neurological disorder characterized by recurrent seizures, and is often comorbid with other neurological and neurodegenerative diseases, such as Alzheimer's disease (AD). Patients with recurrent seizures often present with cognitive impairment. However, it is unclear how seizures, even when infrequent, produce long-lasting deficits in cognition. One mechanism may be seizure-induced expression of ΔFosB, a long-lived transcription factor that persistently regulates expression of plasticity-related genes and drives cognitive dysfunction. We previously found that, compared with cognitively-intact subjects, the activity-dependent expression of ΔFosB in the hippocampal dentate gyrus (DG) was increased in individuals with mild cognitive impairment (MCI) and in individuals with AD. In MCI patients, higher ΔFosB expression corresponded to lower Mini-Mental State Examination scores. Surgically resected DG tissue from patients with temporal lobe epilepsy also showed robust ΔFosB expression; however, it is unclear whether ΔFosB expression also corresponds to cognitive dysfunction in non-AD-related epilepsy. To test whether DG ΔFosB expression is indicative of cognitive impairment in epilepsies with different etiologies, we assessed ΔFosB expression in surgically-resected hippocampal tissue from 33 patients with childhood epilepsies who had undergone Wechsler Intelligence Scale for Children (WISC) testing prior to surgery. We found that ΔFosB expression is inversely correlated with Full-Scale Intelligence Quotient (FSIQ) in patients with mild to severe intellectual disability (FSIQ < 85). Our data indicate that ΔFosB expression corresponds to cognitive impairment in epilepsies with different etiologies, supporting the hypothesis that ΔFosB may epigenetically regulate gene expression and impair cognition across a wide range of epilepsy syndromes.
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Affiliation(s)
- Chia-Hsuan Fu
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
| | - Jason C. You
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
| | - Carrie Mohila
- Department of Pathology, Texas Children's Hospital and Baylor College of Medicine, Houston, TX, United States
| | - Robert A. Rissman
- Department of Neurosciences, University of California San Diego School of Medicine, La Jolla, CA, United States
- Veteran's Affairs (VA) San Diego Healthcare System, San Diego, CA, United States
| | - Daniel Yoshor
- Department of Neurosurgery, Baylor College of Medicine, Houston, TX, United States
| | - Angela N. Viaene
- Department of Pathology and Laboratory Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA, United States
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Jeannie Chin
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
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Costa C, Nardi Cesarini E, Eusebi P, Franchini D, Casucci P, De Giorgi MF, Calvello C, Paolini Paoletti F, Romoli M, Parnetti L. Incidence and Risk Factors Epilepsy in Patients with Dementia: A Population-Based Study Using Regional Healthcare Databases in Umbria. J Alzheimers Dis 2024; 98:1533-1542. [PMID: 38607757 DOI: 10.3233/jad-231309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2024]
Abstract
Background Dementia is prevalent among the elderly, also representing a risk for seizures/epilepsy. Estimations of epilepsy risk in dementia patients are not widely available. Objective Our research aims to ascertain the incidence of epilepsy and its associated risk factors in subjects with dementia in the Umbria region, based on data from healthcare databases. Methods In this retrospective study based on the healthcare administrative database of Umbria, we identified all patients diagnosed with dementia from 2013 to 2017, based on ICD-9-CM codes. For epilepsy ascertainment, we used a validated algorithm that required an EEG and the prescription of one or more anti-seizure medications post-dementia diagnosis. A case-control analysis was conducted, matching five non-dementia subjects by gender and age to each dementia patient. Cox proportional hazards models were then utilized in the analysis. Results We identified 7,314 dementia cases, also including 35,280 age- and sex-matched control subjects. Out of patients with dementia, 148 individuals (2.02%) were diagnosed with epilepsy. We observed a progressive increase in the cumulative incidence of seizures over time, registering 1.45% in the first year following the diagnosis, and rising to 1.96% after three years. Analysis using Cox regression revealed a significant association between the development of epilepsy and dementia (HR = 4.58, 95% CI = 3.67-5.72). Additional risk factors were male gender (HR = 1.35, 95% CI = 1.07-1.69) and a younger age at dementia onset (HR = 1.03, 95% CI=1.02-1.04). Conclusions Dementia increases epilepsy risk, especially with early onset and male gender. Clinicians should have a low threshold to suspect seizures in dementia cases.
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Affiliation(s)
- Cinzia Costa
- Department of Medicine and Surgery, Neurology Clinic, University of Perugia, S.M. Misericordia Hospital, Perugia, Italy
| | - Elena Nardi Cesarini
- Department of Medicine and Surgery, Neurology Clinic, University of Perugia, S.M. Misericordia Hospital, Perugia, Italy
- UOC Neurologia, Ospedali Riuniti Marche Nord, Fano-Pesaro, Italy
| | - Paolo Eusebi
- Department of Medicine and Surgery, Neurology Clinic, University of Perugia, S.M. Misericordia Hospital, Perugia, Italy
| | - David Franchini
- Health ICT Service, Regional Health Authority of Umbria, Perugia, Italy
| | - Paola Casucci
- Health ICT Service, Regional Health Authority of Umbria, Perugia, Italy
| | | | - Carmen Calvello
- Department of Medicine and Surgery, Neurology Clinic, University of Perugia, S.M. Misericordia Hospital, Perugia, Italy
- UOC Neurologia, SM Goretti, Latina, Italy
| | - Federico Paolini Paoletti
- Department of Medicine and Surgery, Neurology Clinic, University of Perugia, S.M. Misericordia Hospital, Perugia, Italy
| | - Michele Romoli
- Neurology and Stroke Unit, Bufalini Hospital, Cesena, Italy
| | - Lucilla Parnetti
- Department of Medicine and Surgery, Neurology Clinic, University of Perugia, S.M. Misericordia Hospital, Perugia, Italy
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Stam CJ, de Haan W. Network Hyperexcitability in Early-Stage Alzheimer's Disease: Evaluation of Functional Connectivity Biomarkers in a Computational Disease Model. J Alzheimers Dis 2024; 99:1333-1348. [PMID: 38759000 PMCID: PMC11191539 DOI: 10.3233/jad-230825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/18/2024] [Indexed: 05/19/2024]
Abstract
Background There is increasing evidence from animal and clinical studies that network hyperexcitability (NH) may be an important pathophysiological process and potential target for treatment in early Alzheimer's disease (AD). Measures of functional connectivity (FC) have been proposed as promising biomarkers for NH, but it is unknown which measure has the highest sensitivity for early-stage changes in the excitation/inhibition balance. Objective We aim to test the performance of different FC measures in detecting NH at the earliest stage using a computational approach. Methods We use a whole brain computational model of activity dependent degeneration to simulate progressive AD pathology and NH. We investigate if and at what stage four measures of FC (amplitude envelope correlation corrected [AECc], phase lag index [PLI], joint permutation entropy [JPE] and a new measure: phase lag time [PLT]) can detect early-stage AD pathophysiology. Results The activity dependent degeneration model replicates spectral changes in line with clinical data and demonstrates increasing NH. Compared to relative theta power as a gold standard the AECc and PLI are shown to be less sensitive in detecting early-stage NH and AD-related neurophysiological abnormalities, while the JPE and the PLT show more sensitivity with excellent test characteristics. Conclusions Novel FC measures, which are better in detecting rapid fluctuations in neural activity and connectivity, may be superior to well-known measures such as the AECc and PLI in detecting early phase neurophysiological abnormalities and in particular NH in AD. These markers could improve early diagnosis and treatment target identification.
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Affiliation(s)
- Cornelis Jan Stam
- Department of Neurology, Clinical Neurophysiology and MEG Center, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam University Medical Center (Amsterdam UMC), Amsterdam, The Netherlands
| | - Willem de Haan
- Department of Neurology, Clinical Neurophysiology and MEG Center, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam University Medical Center (Amsterdam UMC), Amsterdam, The Netherlands
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam University Medical Center (Amsterdam UMC), Amsterdam, The Netherlands
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Ohno M. A Strategy for Allowing Earlier Diagnosis and Rigorous Evaluation of BACE1 Inhibitors in Preclinical Alzheimer's Disease. J Alzheimers Dis 2024; 99:431-445. [PMID: 38701146 DOI: 10.3233/jad-231451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2024]
Abstract
Given continued failure of BACE1 inhibitor programs at symptomatic and prodromal stages of Alzheimer's disease (AD), clinical trials need to target the earlier preclinical stage. However, trial design is complex in this population with negative diagnosis of classical hippocampal amnesia on standard memory tests. Besides recent advances in brain imaging, electroencephalogram, and fluid-based biomarkers, new cognitive markers should be established for earlier diagnosis that can optimize recruitment to BACE1 inhibitor trials in presymptomatic AD. Notably, accelerated long-term forgetting (ALF) is emerging as a sensitive cognitive measure that can discriminate between asymptomatic individuals with high risks for developing AD and healthy controls. ALF is a form of declarative memory impairment characterized by increased forgetting rates over longer delays (days to months) despite normal storage within the standard delays of testing (20-60 min). Therefore, ALF may represent a harbinger of preclinical dementia and the impairment of systems memory consolidation, during which memory traces temporarily stored in the hippocampus become gradually integrated into cortical networks. This review provides an overview of the utility of ALF in a rational design of next-generation BACE1 inhibitor trials in preclinical AD. I explore potential mechanisms underlying ALF and relevant early-stage biomarkers useful for BACE1 inhibitor evaluation, including synaptic protein alterations, astrocytic dysregulation and neuron hyperactivity in the hippocampal-cortical network. Furthermore, given the physiological role of the isoform BACE2 as an AD-suppressor gene, I also discuss the possible association between the poor selectivity of BACE1 inhibitors and their side effects (e.g., cognitive worsening) in prior clinical trials.
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Affiliation(s)
- Masuo Ohno
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, USA
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Burton CP, Chumin EJ, Collins AY, Persohn SA, Onos KD, Pandey RS, Quinney SK, Territo PR. Levetiracetam Modulates Brain Metabolic Networks and Transcriptomic Signatures in the 5XFAD Mouse Model of Alzheimer's disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.10.566574. [PMID: 38014102 PMCID: PMC10680636 DOI: 10.1101/2023.11.10.566574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
INTRODUCTION Subcritical epileptiform activity is associated with impaired cognitive function and is commonly seen in patients with Alzheimer's disease (AD). The anti-convulsant, levetiracetam (LEV), is currently being evaluated in clinical trials for its ability to reduce epileptiform activity and improve cognitive function in AD. The purpose of the current study was to apply pharmacokinetics (PK), network analysis of medical imaging, gene transcriptomics, and PK/PD modeling to a cohort of amyloidogenic mice to establish how LEV restores or drives alterations in the brain networks of mice in a dose-dependent basis using the rigorous preclinical pipeline of the MODEL-AD Preclinical Testing Core. METHODS Chronic LEV was administered to 5XFAD mice of both sexes for 3 months based on allometrically scaled clinical dose levels from PK models. Data collection and analysis consisted of a multi-modal approach utilizing 18F-FDG PET/MRI imaging and analysis, transcriptomic analyses, and PK/PD modeling. RESULTS Pharmacokinetics of LEV showed a sex and dose dependence in Cmax, CL/F, and AUC0-∞, with simulations used to estimate dose regimens. Chronic dosing at 10, 30, and 56 mg/kg, showed 18F-FDG specific regional differences in brain uptake, and in whole brain covariance measures such as clustering coefficient, degree, network density, and connection strength (i.e. positive and negative). In addition, transcriptomic analysis via nanoString showed dose-dependent changes in gene expression in pathways consistent 18F-FDG uptake and network changes, and PK/PD modeling showed a concentration dependence for key genes, but not for network covariance modeling. DISCUSSION This study represents the first report detailing the relationships of metabolic covariance and transcriptomic network changes resulting from LEV administration in 5XFAD mice. Overall, our results highlight non-linear kinetics based on dose and sex, where gene expression analysis demonstrated LEV dose- and concentration- dependent changes, along with cerebral metabolism, and/or cerebral homeostatic mechanisms relevant to human AD, which aligned closely with network covariance analysis of 18F-FDG images. Collectively, this study show cases the value of a multimodal connectomic, transcriptomic, and pharmacokinetic approach to further investigate dose dependent relationships in preclinical studies, with translational value towards informing clinical study design.
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Affiliation(s)
- Charles P. Burton
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis IN 46202 USA
| | - Evgeny J. Chumin
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis IN 46202 USA
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis IN 46202
| | - Alyssa Y. Collins
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis IN 46202 USA
| | - Scott A. Persohn
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis IN 46202 USA
| | | | - Ravi S. Pandey
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032
| | - Sara K. Quinney
- Department of Medicine, Division of Clinical Pharmacology, Indiana University School of Medicine, Indianapolis IN 46202 USA
| | - Paul R. Territo
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis IN 46202 USA
- Department of Medicine, Division of Clinical Pharmacology, Indiana University School of Medicine, Indianapolis IN 46202 USA
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Radulescu CI, Doostdar N, Zabouri N, Melgosa-Ecenarro L, Wang X, Sadeh S, Pavlidi P, Airey J, Kopanitsa M, Clopath C, Barnes SJ. Age-related dysregulation of homeostatic control in neuronal microcircuits. Nat Neurosci 2023; 26:2158-2170. [PMID: 37919424 PMCID: PMC10689243 DOI: 10.1038/s41593-023-01451-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 09/06/2023] [Indexed: 11/04/2023]
Abstract
Neuronal homeostasis prevents hyperactivity and hypoactivity. Age-related hyperactivity suggests homeostasis may be dysregulated in later life. However, plasticity mechanisms preventing age-related hyperactivity and their efficacy in later life are unclear. We identify the adult cortical plasticity response to elevated activity driven by sensory overstimulation, then test how plasticity changes with age. We use in vivo two-photon imaging of calcium-mediated cellular/synaptic activity, electrophysiology and c-Fos-activity tagging to show control of neuronal activity is dysregulated in the visual cortex in late adulthood. Specifically, in young adult cortex, mGluR5-dependent population-wide excitatory synaptic weakening and inhibitory synaptogenesis reduce cortical activity following overstimulation. In later life, these mechanisms are downregulated, so that overstimulation results in synaptic strengthening and elevated activity. We also find overstimulation disrupts cognition in older but not younger animals. We propose that specific plasticity mechanisms fail in later life dysregulating neuronal microcircuit homeostasis and that the age-related response to overstimulation can impact cognitive performance.
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Affiliation(s)
- Carola I Radulescu
- UK Dementia Research Institute, Department of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, London, UK
| | - Nazanin Doostdar
- UK Dementia Research Institute, Department of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, London, UK
| | - Nawal Zabouri
- Department of Biomedical Engineering, Imperial College London, South Kensington Campus, London, UK
| | - Leire Melgosa-Ecenarro
- UK Dementia Research Institute, Department of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, London, UK
| | - Xingjian Wang
- UK Dementia Research Institute, Department of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, London, UK
| | - Sadra Sadeh
- Department of Biomedical Engineering, Imperial College London, South Kensington Campus, London, UK
- Department of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, London, UK
| | - Pavlina Pavlidi
- UK Dementia Research Institute, Department of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, London, UK
- Department of Pharmacology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Joe Airey
- UK Dementia Research Institute, Department of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, London, UK
| | | | - Claudia Clopath
- Department of Biomedical Engineering, Imperial College London, South Kensington Campus, London, UK
| | - Samuel J Barnes
- UK Dementia Research Institute, Department of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, London, UK.
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Lee HC, Kim BK, Kang K, Lee WW, Yoo I, Kim YS, Lee JJ. Aphasic Status Epilepticus Associated with Alzheimer's Disease: Clinical and Electrographic Characteristics. J Epilepsy Res 2023; 13:55-58. [PMID: 38223360 PMCID: PMC10783961 DOI: 10.14581/jer.23009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 09/06/2023] [Accepted: 12/12/2023] [Indexed: 01/16/2024] Open
Abstract
In aphasic status epilepticus (ASE), aphasia is the sole manifestation of seizure in patients with this disorder. Alzheimer's disease (AD) is one of neurological disorders causing ASE. Herein, we report two cases of ASE associated with AD, and discuss their clinical characteristics. Patient 1 presented Broca's aphasia, and patient 2 presented global aphasia during the ictal period. Both patients exhibited atypical ictal electroencephalographic (EEG) patterns, which improved after antiepileptic drug administration. ASE was the presenting symptom of AD in patient 1. ASE can develop at any stage of AD. Alterations in clinical symptoms and EEG patterns after treatment with antiepileptic drug are the key to diagnosis. Prompt diagnosis and treatment are critical for preventing further consciousness dysfunction.
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Affiliation(s)
- Hyoung Cheol Lee
- Department of Neurology, Nowon Eulji Medical Center, Eulji University School of Medicine, Seoul, Korea
| | - Byung-Kun Kim
- Department of Neurology, Nowon Eulji Medical Center, Eulji University School of Medicine, Seoul, Korea
| | - Kyusik Kang
- Department of Neurology, Nowon Eulji Medical Center, Eulji University School of Medicine, Seoul, Korea
| | - Woong-Woo Lee
- Department of Neurology, Nowon Eulji Medical Center, Eulji University School of Medicine, Seoul, Korea
| | - Ilhan Yoo
- Department of Neurology, Nowon Eulji Medical Center, Eulji University School of Medicine, Seoul, Korea
| | - Yong Soo Kim
- Department of Neurology, Nowon Eulji Medical Center, Eulji University School of Medicine, Seoul, Korea
| | - Jung-Ju Lee
- Department of Neurology, Nowon Eulji Medical Center, Eulji University School of Medicine, Seoul, Korea
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46
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Kuroda T, Tanaka T, Abe S, Inoue M, Morita Y, Mukaida T, Iwai T, Ihara M. Seizure-associated takotsubo cardiomyopathy with Alzheimer's disease: A case report. Epileptic Disord 2023; 25:895-899. [PMID: 37518895 DOI: 10.1002/epd2.20128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 06/29/2023] [Accepted: 07/11/2023] [Indexed: 08/01/2023]
Affiliation(s)
- Takehito Kuroda
- Department of Neurology, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Tomotaka Tanaka
- Department of Neurology, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Soichiro Abe
- Department of Neurology, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Manabu Inoue
- Department of Cerebrovascular Medicine, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Yoshiaki Morita
- Department of Radiology, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Takuto Mukaida
- Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Takamasa Iwai
- Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Masafumi Ihara
- Department of Neurology, National Cerebral and Cardiovascular Center, Osaka, Japan
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Devulder A, Macea J, Kalkanis A, De Winter F, Vandenbulcke M, Vandenberghe R, Testelmans D, Van Den Bossche MJA, Van Paesschen W. Subclinical epileptiform activity and sleep disturbances in Alzheimer's disease. Brain Behav 2023; 13:e3306. [PMID: 37950422 PMCID: PMC10726840 DOI: 10.1002/brb3.3306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 10/16/2023] [Accepted: 10/22/2023] [Indexed: 11/12/2023] Open
Abstract
INTRODUCTION Subclinical epileptiform activity (SEA) and sleep disturbances are frequent in Alzheimer's disease (AD). Both have an important relation to cognition and potential therapeutic implications. We aimed to study a possible relationship between SEA and sleep disturbances in AD. METHODS In this cross-sectional study, we performed a 24-h ambulatory EEG and polysomnography in 48 AD patients without diagnosis of epilepsy and 34 control subjects. RESULTS SEA, mainly detected in frontotemporal brain regions during N2 with a median of three spikes/night [IQR1-17], was three times more prevalent in AD. AD patients had lower sleep efficacy, longer wake after sleep onset, more awakenings, more N1%, less REM sleep and a higher apnea-hypopnea index (AHI) and oxygen desaturation index (ODI). Sleep was not different between AD subgroup with SEA (AD-Epi+) and without SEA (AD-Epi-); however, compared to controls, REM% was decreased and AHI and ODI were increased in the AD-Epi+ subgroup. DISCUSSION Decreased REM sleep and more severe sleep-disordered breathing might be related to SEA in AD. These results could have diagnostic and therapeutic implications and warrant further study at the intersection between sleep and epileptiform activity in AD.
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Affiliation(s)
- Astrid Devulder
- Laboratory for Epilepsy Research, KU Leuven and Department of NeurologyUniversity Hospitals LeuvenLeuvenBelgium
| | - Jaiver Macea
- Laboratory for Epilepsy Research, KU Leuven and Department of NeurologyUniversity Hospitals LeuvenLeuvenBelgium
| | - Alexandros Kalkanis
- Laboratory of Respiratory Diseases and Thoracic Surgery (BREATHE), KU Leuven and Department of Pulmonary DiseasesUniversity Hospitals LeuvenLeuvenBelgium
| | - François‐Laurent De Winter
- Division of Neuropsychiatry, Department of Neurosciences, Leuven Brain Institute, KU Leuven and Department of Geriatric PsychiatryUniversity Psychiatric Center (UPC) KU LeuvenLeuvenBelgium
| | - Mathieu Vandenbulcke
- Division of Neuropsychiatry, Department of Neurosciences, Leuven Brain Institute, KU Leuven and Department of Geriatric PsychiatryUniversity Psychiatric Center (UPC) KU LeuvenLeuvenBelgium
| | - Rik Vandenberghe
- Laboratory for Cognitive Neurology, KU Leuven and Department of NeurologyUniversity Hospitals LeuvenLeuvenBelgium
| | - Dries Testelmans
- Laboratory of Respiratory Diseases and Thoracic Surgery (BREATHE), KU Leuven and Department of Pulmonary DiseasesUniversity Hospitals LeuvenLeuvenBelgium
| | - Maarten J. A. Van Den Bossche
- Division of Neuropsychiatry, Department of Neurosciences, Leuven Brain Institute, KU Leuven and Department of Geriatric PsychiatryUniversity Psychiatric Center (UPC) KU LeuvenLeuvenBelgium
| | - Wim Van Paesschen
- Laboratory for Epilepsy Research, KU Leuven and Department of NeurologyUniversity Hospitals LeuvenLeuvenBelgium
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Zilberter Y, Tabuena DR, Zilberter M. NOX-induced oxidative stress is a primary trigger of major neurodegenerative disorders. Prog Neurobiol 2023; 231:102539. [PMID: 37838279 DOI: 10.1016/j.pneurobio.2023.102539] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 10/10/2023] [Indexed: 10/16/2023]
Abstract
Neurodegenerative diseases (NDDs) causing cognitive impairment and dementia are difficult to treat due to the lack of understanding of primary initiating factors. Meanwhile, major sporadic NDDs share many risk factors and exhibit similar pathologies in their early stages, indicating the existence of common initiation pathways. Glucose hypometabolism associated with oxidative stress is one such primary, early and shared pathology, and a likely major cause of detrimental disease-associated cascades; targeting this common pathology may therefore be an effective preventative strategy for most sporadic NDDs. However, its exact cause and trigger remain unclear. Recent research suggests that early oxidative stress caused by NADPH oxidase (NOX) activation is a shared initiating mechanism among major sporadic NDDs and could prove to be the long-sought ubiquitous NDD trigger. We focus on two major NDDs - Alzheimer's disease (AD) and Parkinson's disease (PD), as well as on acquired epilepsy which is an increasingly recognized comorbidity in NDDs. We also discuss available data suggesting the relevance of the proposed mechanisms to other NDDs. We delve into the commonalities among these NDDs in neuroinflammation and NOX involvement to identify potential therapeutic targets and gain a deeper understanding of the underlying causes of NDDs.
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Affiliation(s)
- Yuri Zilberter
- Aix-Marseille Université, INSERM UMR1106, Institut de Neurosciences des Systèmes, Marseille, France
| | - Dennis R Tabuena
- Gladstone Institute of Neurological Disease, San Francisco, CA, USA
| | - Misha Zilberter
- Gladstone Institute of Neurological Disease, San Francisco, CA, USA.
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Ciliento R, Gjini K, Dabbs K, Hermann B, Riedner B, Jones S, Fatima S, Johnson S, Bendlin B, Lam AD, Boly M, Struck AF. Prevalence and localization of nocturnal epileptiform discharges in mild cognitive impairment. Brain Commun 2023; 5:fcad302. [PMID: 37965047 PMCID: PMC10642616 DOI: 10.1093/braincomms/fcad302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 09/18/2023] [Accepted: 11/06/2023] [Indexed: 11/16/2023] Open
Abstract
Recent evidence shows that identifying and treating epileptiform abnormalities in patients with Alzheimer's disease could represent a potential avenue to improve clinical outcome. Specifically, animal and human studies have revealed that in the early phase of Alzheimer's disease, there is an increased risk of seizures. It has also been demonstrated that the administration of anti-seizure medications can slow the functional progression of the disease only in patients with EEG signs of cortical hyperexcitability. In addition, although it is not known at what disease stage hyperexcitability emerges, there remains no consensus regarding the imaging and diagnostic methods best able to detect interictal events to further distinguish different phenotypes of Alzheimer's disease. In this exploratory work, we studied 13 subjects with amnestic mild cognitive impairment and 20 healthy controls using overnight high-density EEG with 256 channels. All participants also underwent MRI and neuropsychological assessment. Electronic source reconstruction was also used to better select and localize spikes. We found spikes in six of 13 (46%) amnestic mild cognitive impairment compared with two of 20 (10%) healthy control participants (P = 0.035), representing a spike prevalence similar to that detected in previous studies of patients with early-stage Alzheimer's disease. The interictal events were low-amplitude temporal spikes more prevalent during non-rapid eye movement sleep. No statistically significant differences were found in cognitive performance between amnestic mild cognitive impairment patients with and without spikes, but a trend in immediate and delayed memory was observed. Moreover, no imaging findings of cortical and subcortical atrophy were found between amnestic mild cognitive impairment participants with and without epileptiform spikes. In summary, our exploratory study shows that patients with amnestic mild cognitive impairment reveal EEG signs of hyperexcitability early in the disease course, while no other significant differences in neuropsychological or imaging features were observed among the subgroups. If confirmed with longitudinal data, these exploratory findings could represent one of the first signatures of a preclinical epileptiform phenotype of amnestic mild cognitive impairment and its progression.
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Affiliation(s)
- Rosario Ciliento
- Department of Neurology, University of Wisconsin-Madison, Madison, WI 53726, USA
| | - Klevest Gjini
- Department of Neurology, University of Wisconsin-Madison, Madison, WI 53726, USA
| | - Kevin Dabbs
- Department of Neurology, University of Wisconsin-Madison, Madison, WI 53726, USA
| | - Bruce Hermann
- Department of Neurology, University of Wisconsin-Madison, Madison, WI 53726, USA
| | - Brady Riedner
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA
| | - Stephanie Jones
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA
| | - Safoora Fatima
- Department of Neurology, University of Wisconsin-Madison, Madison, WI 53726, USA
| | - Sterling Johnson
- Department of Medicine, University of Wisconsin, Madison, WI 53705, USA
| | - Barbara Bendlin
- Department of Medicine, University of Wisconsin, Madison, WI 53705, USA
| | - Alice D Lam
- Department of Neurology, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02115, USA
| | - Melanie Boly
- Department of Neurology, University of Wisconsin-Madison, Madison, WI 53726, USA
| | - Aaron F Struck
- Department of Neurology, University of Wisconsin-Madison, Madison, WI 53726, USA
- Department of Neurology, William S. Middleton Veterans Administration Hospital, Madison, WI 53705, USA
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Goettemoeller AM, Banks E, McCann KE, Kumar P, South K, Olah VJ, Ramelow CC, Duong DM, Seyfried NT, Rangaraju S, Weinshenker D, Rowan MJM. Entorhinal cortex vulnerability to human APP expression promotes hyperexcitability and tau pathology. RESEARCH SQUARE 2023:rs.3.rs-3370607. [PMID: 37987015 PMCID: PMC10659529 DOI: 10.21203/rs.3.rs-3370607/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Preventative treatment for Alzheimer's Disease is of dire importance, and yet, cellular mechanisms underlying early regional vulnerability in Alzheimer's Disease remain unknown. In human patients with Alzheimer's Disease, one of the earliest observed pathophysiological correlates to cognitive decline is hyperexcitability1. In mouse models, early hyperexcitability has been shown in the entorhinal cortex, the first cortical region impacted by Alzheimer's Disease2-4. The origin of hyperexcitability in early-stage disease and why it preferentially emerges in specific regions is unclear. Using cortical-region and cell-type- specific proteomics and patch-clamp electrophysiology, we uncovered differential susceptibility to human-specific amyloid precursor protein (hAPP) in a model of sporadic Alzheimer's. Unexpectedly, our findings reveal that early entorhinal hyperexcitability may result from intrinsic vulnerability of parvalbumin interneurons, rather than the suspected layer II excitatory neurons. This vulnerability of entorhinal PV interneurons is specific to hAPP, as it could not be recapitulated with increased murine APP expression. Furthermore, the Somatosensory Cortex showed no such vulnerability to adult-onset hAPP expression, likely resulting from PV-interneuron variability between the two regions based on physiological and proteomic evaluations. Interestingly, entorhinal hAPP-induced hyperexcitability was quelled by co-expression of human Tau at the expense of increased pathological tau species. This study suggests early disease interventions targeting non-excitatory cell types may protect regions with early vulnerability to pathological symptoms of Alzheimer's Disease and downstream cognitive decline.
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Affiliation(s)
- Annie M Goettemoeller
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, 30322
- GDBBS Graduate Program, Laney Graduate School, Emory University
| | - Emmie Banks
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, 30322
- GDBBS Graduate Program, Laney Graduate School, Emory University
| | | | - Prateek Kumar
- Department of Neurology, Emory University School of Medicine
| | - Kelly South
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, 30322
- GDBBS Graduate Program, Laney Graduate School, Emory University
| | - Viktor J Olah
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, 30322
| | - Christina C Ramelow
- Department of Neurology, Emory University School of Medicine
- GDBBS Graduate Program, Laney Graduate School, Emory University
| | - Duc M Duong
- Department of Neurology, Emory University School of Medicine
- Department of Biochemistry, Emory University
| | - Nicholas T Seyfried
- Department of Neurology, Emory University School of Medicine
- Department of Biochemistry, Emory University
- Center for Neurodegenerative Disease, Emory University School of Medicine
| | - Srikant Rangaraju
- Department of Neurology, Emory University School of Medicine
- GDBBS Graduate Program, Laney Graduate School, Emory University
| | | | - Matthew JM Rowan
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, 30322
- Center for Neurodegenerative Disease, Emory University School of Medicine
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