Chronic divalproex sodium use and brain atrophy in Alzheimer disease

Effect of olanzapine exposure on relapse and brain structure in patients with major depressive disorder with psychotic features

Some data suggest that antipsychotics may adversely affect brain structure. We examined the relationship among olanzapine exposure, relapse, and changes in brain structure in patients with major depressive disorder with psychotic features. We analyzed data from the Study of the Pharmacotherapy of Psychotic Depression II trial (STOP-PD II), a randomized, placebo-controlled trial in patients with psychotic depression who attained remission on sertraline and olanzapine and were randomized to continue sertraline plus olanzapine or placebo for 36 weeks. Olanzapine steady state concentration (SSC) were calculated based on sparsely-sampled levels. Rates of relapse and changes in brain structure were assessed as outcomes. There were significant associations between dosage and relapse rates (N = 118; HR = 0.94, 95% CI [0.897, 0.977], p = 0.002) or changes in left cortical thickness (N = 44; B = -2.0 × 10-3, 95% CI [-3.1 × 10-3, -9.6 × 10-4], p < 0.001) and between SSC and changes in left cortical thickness (N = 44; B = -8.7 × 10-4, 95% CI [-1.4 × 10-3, -3.6 × 10-4], p = 0.001). Similar results were found for the right cortex. These associations were no longer significant when the analysis was restricted to participants treated with olanzapine. Our findings suggest that, within its therapeutic range, the effect of olanzapine on relapse or cortical thickness does not depend on its dosage or SSC. Further research is needed on the effect of olanzapine and other antipsychotics on mood symptoms and brain structure.

mRNA and circRNA mislocalization to synapses are key features of Alzheimer's disease

Proper transport of RNAs to synapses is essential for localized translation of proteins in response to synaptic signals and synaptic plasticity. Alzheimer's disease (AD) is a neurodegenerative disease characterized by accumulation of amyloid aggregates and hyperphosphorylated tau neurofibrillary tangles followed by widespread synapse loss. To understand whether RNA synaptic localization is impacted in AD, we performed RNA sequencing on synaptosomes and brain homogenates from AD patients and cognitively healthy controls. This resulted in the discovery of hundreds of mislocalized mRNAs in AD among frontal and temporal brain regions. Similar observations were found in an APPswe/PSEN1dE9 mouse model. Furthermore, major differences were observed among circular RNAs (circRNAs) localized to synapses in AD including two overlapping isoforms of circGSK3β, one upregulated, and one downregulated. Expression of these distinct isoforms affected tau phosphorylation in neuronal cells substantiating the importance of circRNAs in the brain and pointing to a new class of therapeutic targets.

Anti-epileptic drug use and subsequent degenerative dementia occurrence

INTRODUCTION

The use of anti-epileptic drugs (AEDs) in degenerative dementia (DD) remains uncertain. We aimed to evaluate the association of early AED administration with subsequent DD occurrence.

METHODS

Using a large nationwide database, we enrolled patients newly diagnosed with epilepsy from 2014 to 2019 (n = 104,225), and using propensity score matching, we divided them into treatment (those prescribed AEDs in 2014) and control groups. The primary outcome was subsequent DD occurrence in 2019.

RESULTS

Overall, 4489 pairs of patients (2156 women) were matched. The odds ratio (treatment/control) for DD occurrence was 0.533 (95% confidence interval: 0.459-0.617). The DD proportions significantly differed between the treatment (340/4489 = 0.076) and control (577/4489 = 0.129) groups.

DISCUSSION

Among patients newly diagnosed with epilepsy, compared to non-use, early AED use was associated with a lower occurrence of subsequent DD. Further investigations into and optimization of early intervention for epilepsy in DD are warranted.

Highlights

Anti-epileptic drug (AED) use before epilepsy diagnosis was linked with a lower subsequent degenerative dementia (DD) occurrence.Identifying the epileptic phenotype was crucial for justifying early AED use in DD.AED use with an epilepsy diagnosis did not pose an additional risk of DD.The potential contribution of combination drug therapy to the strategy was noted.

Predicting brain age using Tri-UNet and various MRI scale features

In the process of human aging, significant age-related changes occur in brain tissue. To assist individuals in assessing the degree of brain aging, screening for disease risks, and further diagnosing age-related diseases, it is crucial to develop an accurate method for predicting brain age. This paper proposes a multi-scale feature fusion method called Tri-UNet based on the U-Net network structure, as well as a brain region information fusion method based on multi-channel input networks. These methods address the issue of insufficient image feature learning in brain neuroimaging data. They can effectively utilize features at different scales of MRI and fully leverage feature information from different regions of the brain. In the end, experiments were conducted on the Cam-CAN dataset, resulting in a minimum Mean Absolute Error (MAE) of 7.46. The results demonstrate that this method provides a new approach to feature learning at different scales in brain age prediction tasks, contributing to the advancement of the field and holding significance for practical applications in the context of elderly education.

Association of Age-Related Neuropathologic Findings at Autopsy With a Claims-Based Epilepsy Diagnosis in Older Adults

BACKGROUND AND OBJECTIVES

Epilepsy is 1 of the 3 most common neurologic diseases of older adults, but few studies have examined its underlying pathologies in older age. We examined the associations of age-related brain pathologies with epilepsy in older persons.

METHODS

Clinical and pathologic data came from 2 ongoing clinical pathologic cohort studies of community-dwelling older adults. Epilepsy was ascertained using Medicare fee-for-service Parts A and B claims data that were linked to data from the cohort studies. The postmortem pathologic assessment collected indices of 9 pathologies including Alzheimer disease, hippocampal sclerosis, macroinfarcts, and cerebral amyloid angiopathy. The fixed brain hemisphere was imaged using 3T MRI scanners before the pathologic assessments in a subgroup of participants.

RESULTS

The participants (n = 1,369) were on average 89.3 (6.6) years at death, and 67.0% were women. Epilepsy was identified in 58 (4.2%) participants. Cerebral amyloid angiopathy (odds ratio [OR] = 2.21, 95% CI 1.24-3.95, p = 0.007) and cortical macroinfarcts (OR = 2.74, 95% CI 1.42-5.28, p = 0.003) were associated with a higher odds of epilepsy. Of note, hippocampal sclerosis and Alzheimer disease pathology were not associated with epilepsy (both p's > 0.25), although hippocampal sclerosis was not common and thus hard to examine with the modest number of epilepsy cases here. In 673 participants with MRI data, the association of cerebral amyloid angiopathy and cortical macroinfarcts with epilepsy did not change after controlling for cortical gray matter atrophy, which was independently associated with a higher odds of epilepsy (OR = 1.06, 95% CI 1.02-1.10, p = 0.003). By contrast, hippocampal volume was not associated with epilepsy.

DISCUSSION

Cerebrovascular pathologies and cortical atrophy were associated with epilepsy in older persons.

Alzheimer's Disease-Related Epigenetic Changes: Novel Therapeutic Targets

Aging is a significant risk factor for Alzheimer's disease (AD), although the precise mechanism and molecular basis of AD are not yet fully understood. Epigenetic mechanisms, such as DNA methylation and hydroxymethylation, mitochondrial DNA methylation, histone modifications, and non-coding RNAs (ncRNAs), play a role in regulating gene expression related to neuron plasticity and integrity, which are closely associated with learning and memory development. This review describes the impact of dynamic and reversible epigenetic modifications and factors on memory and plasticity throughout life, emphasizing their potential as target for therapeutic intervention in AD. Additionally, we present insight from postmortem and animal studies on abnormal epigenetics regulation in AD, as well as current strategies aiming at targeting these factors in the context of AD therapy.

Targets, trials and tribulations in Alzheimer therapeutics

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by abnormal accumulation of extracellular amyloid beta senile plaques and intracellular neurofibrillary tangles in the parts of the brain responsible for cognition. The therapeutic burden for the management of AD relies solely on cholinesterase inhibitors that provide only symptomatic relief. The urgent need for disease-modifying drugs has resulted in intensive research in this domain, which has led to better understanding of the disease pathology and identification of a plethora of new pathological targets. Currently, there are over a hundred and seventy clinical trials exploring disease modification, cognitive enhancement, and reduction of neuro-psychiatric complications. However, the path to developing safe and efficacious AD therapeutics has not been without challenges. Several clinical trials have been terminated in advanced stages due to lack of therapeutic translation or increased incidence of adverse events. This review presents an in-depth look at the various therapeutic targets of AD and the lessons learnt during their clinical assessment. Comprehensive understanding of the implication of modulating various aspects of Alzheimer brain pathology is crucial for development of drugs with potential to halt disease progression in Alzheimer therapeutics.

Valproate use associated with frontal and cerebellar gray matter volume reductions: A voxel-based morphometry study

Recent morphometric magnetic resonance imaging (MRI) studies suggested the possibility that valproate (VPA) use is associated with parieto-occipital cortical thinning in patients with heterogeneous epilepsy syndromes. In this study, we examined the effect of VPA on the brain volume using a large number of homogenous patients with idiopathic generalized epilepsy. Voxel-based morphometry was used to compare regional gray matter (GM) volume between 112 patients currently taking VPA (VPA+ group), 81 patients not currently taking VPA (VPA- group), and 120 healthy subjects (control group). The VPA+ group showed a significant GM volume reduction in the bilateral cerebellum, hippocampus, insula, caudate nucleus, medial frontal cortex/anterior cingulate cortex, primary motor/premotor cortex, medial occipital cortex, and anteromedial thalamus, as compared to the control group. The VPA- group showed a significant GM volume reduction in the anteromedial thalamus and right hippocampus/temporal cortex, as compared to the control group. Compared to the VPA- group, the VPA+ group had a significant GM volume reduction in the bilateral cerebellum, primary motor/premotor cortex, and medial frontal cortex/anterior cingulate cortex. We have provided evidence that VPA use could result in GM volume reductions in the frontal cortex and cerebellum. Our findings should be acknowledged as a potential confounding factor in morphometric MRI studies that include subjects taking VPA.

Alzheimer's disease phenotype based upon the carrier status of the apolipoprotein E ɛ4 allele

The apolipoprotein E ɛ4 allele (APOE4) is universally acknowledged as the most potent genetic risk factor for Alzheimer's disease (AD). APOE4 promotes the initiation and progression of AD. Although the underlying mechanisms are unclearly understood, differences in lipid-bound affinity among the three APOE isoforms may constitute the basis. The protein APOE4 isoform has a high affinity with triglycerides and cholesterol. A distinction in lipid metabolism extensively impacts neurons, microglia, and astrocytes. APOE4 carriers exhibit phenotypic differences from non-carriers in clinical examinations and respond differently to multiple treatments. Therefore, we hypothesized that phenotypic classification of AD patients according to the status of APOE4 carrier will help specify research and promote its use in diagnosing and treating AD. Recent reviews have mainly evaluated the differences between APOE4 allele carriers and non-carriers from gene to protein structures, clinical features, neuroimaging, pathology, the neural network, and the response to various treatments, and have provided the feasibility of phenotypic group classification based on APOE4 carrier status. This review will facilitate the application of APOE phenomics concept in clinical practice and promote further medical research on AD.

Impact of psychotropic medications on cognition among older adults: a systematic review

OBJECTIVES

The aim of this systematic review is to examine the cognitive impact of psychotropic medications including benzodiazepines, antidepressants, mood stabilizers, antipsychotics, or a combination of these drugs on older adults.

DESIGN

Systematic review.

SETTING

We searched Medline, PsycINFO, and Embase through the Ovid platform, CINAHL through EBSCO, and Web of Science.

PARTICIPANTS AND INTERVENTIONS

Randomized control trials (RCTs) and cohort studies that used a validated scale to measure cognition with a follow-up period of at least six months were included.

MEASUREMENT

The primary outcome of interest was cognitive change associated with psychotropic medication use.

RESULTS

A total of 7551 articles were identified from the primary electronic literature search across the five databases after eliminating duplicates. Based on full-text analysis, 27 articles (two RCTs, 25 cohorts) met the inclusion criteria. Of these, nine each examined the impact of benzodiazepines and antidepressants, five examined psychotropic combinations, three on antipsychotic drugs, and one on the effects of mood stabilizers.

CONCLUSIONS

This is the first systematic review to examine the cognitive impact of multiple psychotropic drug classes in older adults over an extended follow-up period (six months or more) using robust sample sizes, drug-free control groups, and validated cognitive instruments. We found evidence to indicate cognitive decline with the cumulative use of benzodiazepines and the use of antidepressants, especially those with anticholinergic properties among older adults without cognitive impairment at baseline. Further, the use of antipsychotics and psychotropic combinations is also associated with cognitive decline in older adults.

Clinical, imaging, and biomarker evidence of amyloid- and tau-related neurodegeneration in late-onset epilepsy of unknown etiology

Accumulating evidence suggests amyloid and tau-related neurodegeneration may play a role in development of late-onset epilepsy of unknown etiology (LOEU). In this article, we review recent evidence that epilepsy may be an initial manifestation of an amyloidopathy or tauopathy that precedes development of Alzheimer's disease (AD). Patients with LOEU demonstrate an increased risk of cognitive decline, and patients with AD have increased prevalence of preceding epilepsy. Moreover, investigations of LOEU that use CSF biomarkers and imaging techniques have identified preclinical neurodegeneration with evidence of amyloid and tau deposition. Overall, findings to date suggest a relationship between acquired, non-lesional late-onset epilepsy and amyloid and tau-related neurodegeneration, which supports that preclinical or prodromal AD is a distinct etiology of late-onset epilepsy. We propose criteria for assessing elevated risk of developing dementia in patients with late-onset epilepsy utilizing clinical features, available imaging techniques, and biomarker measurements. Further research is needed to validate these criteria and assess optimal treatment strategies for patients with probable epileptic preclinical AD and epileptic prodromal AD.

Antiseizure Medications in Alzheimer's Disease from Preclinical to Clinical Evidence

Alzheimer's disease (AD) and epilepsy are common neurological disorders in the elderly. A bi-directional link between these neurological diseases has been reported, with patients with either condition carrying almost a two-fold risk of contracting the other compared to healthy subjects. AD/epilepsy adversely affects patients' quality of life and represents a severe public health problem. Thus, identifying the relationship between epilepsy and AD represents an ongoing challenge and continuing need. Seizures in AD patients are often unrecognized because they are often nonconvulsive and sometimes mimic some behavioral symptoms of AD. Regarding this, it has been hypothesized that epileptogenesis and neurodegeneration share common underlying mechanisms. Targeted treatment to decrease epileptiform activity could represent a valuable strategy for delaying the neurodegenerative process and related cognitive impairment. Several preclinical studies have shown that some antiseizure medications (ASMs) targeting abnormal network hyperexcitability may change the natural progression of AD. However, to date, no guidelines are available for managing seizures in AD patients because of the paucity of randomized clinical trials sufficient for answering the correlated questions. Future AD clinical studies are mandatory to update clinicians about the symptomatic treatment of seizures in AD patients and recognize whether ASM therapy could change the natural progression of the disease, thereby rescuing cognitive performance.

Loss of normal Alzheimer's disease-associated Presenilin 2 function alters antiseizure medicine potency and tolerability in the 6-Hz focal seizure model

Introduction

Patients with early-onset Alzheimer's disease (EOAD) experience seizures and subclinical epileptiform activity, which may accelerate cognitive and functional decline. Antiseizure medicines (ASMs) may be a tractable disease-modifying strategy; numerous ASMs are marketed with well-established safety. However, little information is available to guide ASM selection as few studies have rigorously quantified ASM potency and tolerability in traditional seizure models in rodents with EOAD-associated risk factors. Presenilin 2 (PSEN2) variants evoke EOAD, and these patients experience seizures. This study thus established the anticonvulsant profile of mechanistically distinct ASMs in the frontline 6-Hz limbic seizure test evoked in PSEN2-knockout (KO) mice to better inform seizure management in EOAD.

Methods

The median effective dose (ED50) of prototype ASMs was quantified in the 6-Hz test in male and female PSEN2-KO and wild-type (WT) C57BL/6J mice (3-4 months old). Minimal motor impairment (MMI) was assessed to estimate a protective index (PI). Immunohistological detection of cFos established the extent to which 6-Hz stimulation activates discrete brain regions in KO vs. WT mice.

Results

There were significant genotype-related differences in the potency and tolerability of several ASMs. Valproic acid and levetiracetam were significantly more potent in male KO than in WT mice. Additionally, high doses of valproic acid significantly worsened MMI in KO mice. Conversely, carbamazepine was significantly less potent in female KO vs. WT mice. In both male and female KO mice vs. WTs, perampanel and lamotrigine were equally potent. However, there were marked genotype-related shifts in PI of both carbamazepine and perampanel, with KO mice exhibiting less MMI at the highest doses tested. Gabapentin was ineffective against 6-Hz seizures in KO mice vs. WTs without MMI changes. Neuronal activation 90 min following 6-Hz stimulation was significantly increased in the posterior parietal association cortex overlying CA1 and in the piriform cortex of WT mice, while stimulation-induced increases in cFos immunoreactivity were absent in KO mice.

Discussion

Acute ASM potency and tolerability in the high-throughput 6-Hz test may be significantly altered with loss of normal PSEN2 function. Seizures in discrete EOAD populations may benefit from precisely selected medicines optimized for primary ASM pharmacological mechanisms.

Diagnosis and treatment of late-onset myoclonic epilepsy in Down syndrome (LOMEDS): A systematic review with individual patients' data analysis

INTRODUCTION

The late onset myoclonic epilepsy in Down Syndrome (LOMEDS) is a peculiar epilepsy type characterized by cortical myoclonus and generalized tonic-clonic seizures (GTCS), in people suffering from cognitive decline in Down syndrome (DS). In this review, we analyzed available data on the diagnostic and therapeutic management of individuals with LOMEDS.

METHODS

We performed a systematic search of the literature to identify the diagnostic and therapeutic management of patients with LOMEDS. The following databases were used: PubMed, Google Scholar, EMBASE, CrossRef. The protocol was registered on PROSPERO (registration code: CRD42023390748).

RESULTS

Data from 46 patients were included. DS was diagnosed according to the patient's clinical and genetic characteristics. Diagnosis of Alzheimer's dementia (AD) preceded the onset of epilepsy in all cases. Both myoclonic seizures (MS) and generalized tonic-clonic seizures (GTCS) were reported, the latter preceding the onset of MS in 28 cases. EEG was performed in 45 patients, showing diffuse theta/delta slowing with superimposed generalized spike-and-wave or polyspike-and-wave. A diffuse cortical atrophy was detected in 34 patients on neuroimaging. Twenty-seven patients were treated with antiseizure medication (ASM) monotherapy, with reduced seizure frequency in 17 patients. Levetiracetam and valproic acid were the most used ASMs. Up to 41% of patients were unresponsive to first-line treatment and needed adjunctive therapy for seizure control.

CONCLUSIONS

AD-related pathological changes in the brain may play a role in LOMEDS onset, although the mechanism underlying this phenomenon is still unknown. EEG remains the most relevant investigation to be performed. A significant percentage of patients developed a first-line ASM refractory epilepsy. ASMs which modulate the glutamatergic system may represent a good therapeutic option.

Mega-analysis of association between obesity and cortical morphology in bipolar disorders: ENIGMA study in 2832 participants

BACKGROUND

Obesity is highly prevalent and disabling, especially in individuals with severe mental illness including bipolar disorders (BD). The brain is a target organ for both obesity and BD. Yet, we do not understand how cortical brain alterations in BD and obesity interact.

METHODS

We obtained body mass index (BMI) and MRI-derived regional cortical thickness, surface area from 1231 BD and 1601 control individuals from 13 countries within the ENIGMA-BD Working Group. We jointly modeled the statistical effects of BD and BMI on brain structure using mixed effects and tested for interaction and mediation. We also investigated the impact of medications on the BMI-related associations.

RESULTS

BMI and BD additively impacted the structure of many of the same brain regions. Both BMI and BD were negatively associated with cortical thickness, but not surface area. In most regions the number of jointly used psychiatric medication classes remained associated with lower cortical thickness when controlling for BMI. In a single region, fusiform gyrus, about a third of the negative association between number of jointly used psychiatric medications and cortical thickness was mediated by association between the number of medications and higher BMI.

CONCLUSIONS

We confirmed consistent associations between higher BMI and lower cortical thickness, but not surface area, across the cerebral mantle, in regions which were also associated with BD. Higher BMI in people with BD indicated more pronounced brain alterations. BMI is important for understanding the neuroanatomical changes in BD and the effects of psychiatric medications on the brain.

The clinical correlation between Alzheimer's disease and epilepsy

Alzheimer's disease and epilepsy are common nervous system diseases in older adults, and their incidence rates tend to increase with age. Patients with mild cognitive impairment and Alzheimer's disease are more prone to have seizures. In patients older than 65 years, neurodegenerative conditions accounted for ~10% of all late-onset epilepsy cases, most of which are Alzheimer's disease. Epilepsy and seizure can occur in the early and late stages of Alzheimer's disease, leading to functional deterioration and behavioral alterations. Seizures promote amyloid-β and tau deposits, leading to neurodegenerative processes. Thus, there is a bi-directional association between Alzheimer's disease and epilepsy. Epilepsy is a risk factor for Alzheimer's disease and, in turn, Alzheimer's disease is an independent risk factor for developing epilepsy in old age. Many studies have evaluated the shared pathogenesis and clinical relevance of Alzheimer's disease and epilepsy. In this review, we discuss the clinical associations between Alzheimer's disease and epilepsy, including their incidence, clinical features, and electroencephalogram abnormalities. Clinical studies of the two disorders in recent years are summarized, and new antiepileptic drugs used for treating Alzheimer's disease are reviewed.

[11C]Martinostat PET analysis reveals reduced HDAC I availability in Alzheimer's disease

Alzheimer’s disease (AD) is characterized by the brain accumulation of amyloid-β and tau proteins. A growing body of literature suggests that epigenetic dysregulations play a role in the interplay of hallmark proteinopathies with neurodegeneration and cognitive impairment. Here, we aim to characterize an epigenetic dysregulation associated with the brain deposition of amyloid-β and tau proteins. Using positron emission tomography (PET) tracers selective for amyloid-β, tau, and class I histone deacetylase (HDAC I isoforms 1–3), we find that HDAC I levels are reduced in patients with AD. HDAC I PET reduction is associated with elevated amyloid-β PET and tau PET concentrations. Notably, HDAC I reduction mediates the deleterious effects of amyloid-β and tau on brain atrophy and cognitive impairment. HDAC I PET reduction is associated with 2-year longitudinal neurodegeneration and cognitive decline. We also find HDAC I reduction in the postmortem brain tissue of patients with AD and in a transgenic rat model expressing human amyloid-β plus tau pathology in the same brain regions identified in vivo using PET. These observations highlight HDAC I reduction as an element associated with AD pathophysiology.

The link between amyloid and tau proteins with Alzheimer’s disease progression remains unclear. Here, the authors propose HDACs I downregulation as an element linking the deleterious effects of brain proteinopathies with disease progression.

The role of mTORC1 activation in seizure-induced exacerbation of Alzheimer's disease

The risk of seizures is 10-fold higher in patients with Alzheimer's disease than the general population, yet the mechanisms underlying this susceptibility and the effects of these seizures are poorly understood. To elucidate the proposed bidirectional relationship between Alzheimer's disease and seizures, we studied human brain samples (n = 34) from patients with Alzheimer's disease and found that those with a history of seizures (n = 14) had increased amyloid-β and tau pathology, with upregulation of the mechanistic target of rapamycin (mTOR) pathway, compared with patients without a known history of seizures (n = 20). To establish whether seizures accelerate the progression of Alzheimer's disease, we induced chronic hyperexcitability in the five times familial Alzheimer's disease mouse model by kindling with the chemoconvulsant pentylenetetrazol and observed that the mouse model exhibited more severe seizures than the wild-type. Furthermore, kindled seizures exacerbated later cognitive impairment, Alzheimer's disease neuropathology and mTOR complex 1 activation. Finally, we demonstrated that the administration of the mTOR inhibitor rapamycin following kindled seizures rescued enhanced remote and long-term memory deficits associated with earlier kindling and prevented seizure-induced increases in Alzheimer's disease neuropathology. These data demonstrated an important link between chronic hyperexcitability and progressive Alzheimer's disease pathology and suggest a mechanism whereby rapamycin may serve as an adjunct therapy to attenuate progression of the disease.

[Alzheimer disease and epilepsy]

Alzheimer Disease (AD) is a progressive neurodegenerative disorder characterized by loss of memory, difficulty in thinking, changes in behavior and personality disorders. The risk of developing epileptic seizures (ES) in patients with AD increases significantly. Animal and human studies have shown a close relationship between the pathogenesis of ES and AD. The exact prevalence of ES in AD remains unclear due to methodological difficulties, in particular, detection of ES in patients with cognitive impairment. EP types differ in sporadic and hereditary forms of AD. Antiepileptic therapy in AD has its own characteristics. Certain antiepileptic drugs can have a positive effect on cognitive function.

Association between body mass index and subcortical brain volumes in bipolar disorders-ENIGMA study in 2735 individuals

Individuals with bipolar disorders (BD) frequently suffer from obesity, which is often associated with neurostructural alterations. Yet, the effects of obesity on brain structure in BD are under-researched. We obtained MRI-derived brain subcortical volumes and body mass index (BMI) from 1134 BD and 1601 control individuals from 17 independent research sites within the ENIGMA-BD Working Group. We jointly modeled the effects of BD and BMI on subcortical volumes using mixed-effects modeling and tested for mediation of group differences by obesity using nonparametric bootstrapping. All models controlled for age, sex, hemisphere, total intracranial volume, and data collection site. Relative to controls, individuals with BD had significantly higher BMI, larger lateral ventricular volume, and smaller volumes of amygdala, hippocampus, pallidum, caudate, and thalamus. BMI was positively associated with ventricular and amygdala and negatively with pallidal volumes. When analyzed jointly, both BD and BMI remained associated with volumes of lateral ventricles  and amygdala. Adjusting for BMI decreased the BD vs control differences in ventricular volume. Specifically, 18.41% of the association between BD and ventricular volume was mediated by BMI (Z = 2.73, p = 0.006). BMI was associated with similar regional brain volumes as BD, including lateral ventricles, amygdala, and pallidum. Higher BMI may in part account for larger ventricles, one of the most replicated findings in BD. Comorbidity with obesity could explain why neurostructural alterations are more pronounced in some individuals with BD. Future prospective brain imaging studies should investigate whether obesity could be a modifiable risk factor for neuroprogression.

Electrical status epilepticus in sleep: The role of thalamus in etiopathogenesis

PURPOSE

In patients diagnosed with epilepsy, decreased ratio of N-acetyl aspartate to creatine (NAA/Cr) measured in magnetic resonance spectroscopy (MRS) has been accepted as a sign of neuronal cell loss or dysfunction. In this study, we aimed to determine whether a similar neuronal cell loss is present in a group of encephalopathy with electrical status epilepticus in sleep (ESES) patients METHODS: We performed this case-control study at a tertiary pediatric neurology center with patients with ESES. Inclusion criteria for the patient group were as follows: 1) a spike-wave index of at least 50%, 2) acquired neuropsychological regression, 3) normal cranial MRI. Eventually, a total of 21 patients with ESES and 17 control subjects were enrolled in the study. MRI of all control subjects was also within normal limits. 3D Slicer program was used for the analysis of thalamic and brain volumes. LCModel spectral fitting software was used to analyze single-voxel MRS data from the right and left thalamus of the subjects.

RESULTS

The mean age was 8.0 ± 1.88 years and 8.3 ± 1.70 years in ESES patients and the control subjects. After correcting for the main potential confounders (age and gender) with a linear regression model, NAA/Creatine ratio of the right thalamus was significantly lower in the ESES patient group compared to the healthy control group (p = 0.026). Likewise, the left thalamus NAA/Cr ratio was significantly lower in the ESES patient group than the healthy control group (p = 0.007). After correcting for age and gender, right thalamic volume was not statistically significantly smaller in ESES patients than in healthy controls (p = 0.337), but left thalamic volume was smaller in ESES patients than in healthy controls (p = 0.024).

CONCLUSION

In ESES patients, the NAA/Creatine ratio, which is an indicator of neuronal cell loss or dysfunction in the right and left thalamus, which appears regular on MRI, was found to be significantly lower than the healthy control group. This metabolic-induced thalamic dysfunction, which was reported for the first time up to date, may play a role in ESES epileptogenesis.

Neuropsychiatric symptoms in early stage of Alzheimer's and non-Alzheimer's dementia, and the risk of progression to severe dementia

BACKGROUND

Neuropsychiatric symptoms (NPSs) in early dementia have been suggested to predict a higher risk of dementia progression. However, the literature is not yet clear whether the risk is similar across Alzheimer's dementia (AD) and non-Alzheimer's dementia (non-AD), as well as across different NPSs. This study examined the association between NPSs in early dementia and the risk of progression to severe dementia, specifically in AD and non-AD, as well as across various NPSs.

METHOD

This cohort study included 7,594 participants who were ≥65 years and had early dementia (global Clinical Dementia Rating [CDR] = 1). Participants completed Neuropsychiatric-Inventory-Questionnaire at baseline and were followed-up almost annually for progression to severe dementia (global CDR = 3) (median follow-up = 3.5 years; interquartile range = 2.1-5.9 years). Cox regression was used to examine progression risk, stratified by AD and non-AD.

RESULTS

The presence of NPSs was associated with risk of progression to severe dementia, but primarily in AD (HR 1.4, 95% confidence interval [CI]: 1.1-1.6) and not in non-AD (HR 0.9, 95% CI: 0.5-1.5). When comparing across various NPSs, seven NPSs in AD were associated with disease progression, and they were depression, anxiety, apathy, delusions, hallucinations, irritability and motor disturbance (HR 1.2-1.6). In contrast, only hallucinations and delusions were associated with disease progression in non-AD (HR 1.7-1.9).

CONCLUSIONS

NPSs in early dementia-especially among individuals with AD-can be useful prognostic markers of disease progression. They may inform discussion on advanced care planning and prompt clinical review to incorporate evidence-based interventions that may address disease progression.

Tau Protein Interaction Partners and Their Roles in Alzheimer's Disease and Other Tauopathies

Tau protein plays a critical role in the assembly, stabilization, and modulation of microtubules, which are important for the normal function of neurons and the brain. In diseased conditions, several pathological modifications of tau protein manifest. These changes lead to tau protein aggregation and the formation of paired helical filaments (PHF) and neurofibrillary tangles (NFT), which are common hallmarks of Alzheimer's disease and other tauopathies. The accumulation of PHFs and NFTs results in impairment of physiological functions, apoptosis, and neuronal loss, which is reflected as cognitive impairment, and in the late stages of the disease, leads to death. The causes of this pathological transformation of tau protein haven't been fully understood yet. In both physiological and pathological conditions, tau interacts with several proteins which maintain their proper function or can participate in their pathological modifications. Interaction partners of tau protein and associated molecular pathways can either initiate and drive the tau pathology or can act neuroprotective, by reducing pathological tau proteins or inflammation. In this review, we focus on the tau as a multifunctional protein and its known interacting partners active in regulations of different processes and the roles of these proteins in Alzheimer's disease and tauopathies.

Sodium valproate increases activity of the sirtuin pathway resulting in beneficial effects for spinocerebellar ataxia-3 in vivo

Machado-Joseph disease (MJD, also known as spinocerebellar ataxia type 3) is a fatal neurodegenerative disease that impairs control and coordination of movement. Here we tested whether treatment with the histone deacetylase inhibitor sodium valproate (valproate) prevented a movement phenotype that develops in larvae of a transgenic zebrafish model of the disease. We found that treatment with valproate improved the swimming of the MJD zebrafish, affected levels of acetylated histones 3 and 4, but also increased expression of polyglutamine expanded human ataxin-3. Proteomic analysis of protein lysates generated from the treated and untreated MJD zebrafish also predicted that valproate treatment had activated the sirtuin longevity signaling pathway and this was confirmed by findings of increased SIRT1 protein levels and sirtuin activity in valproate treated MJD zebrafish and HEK293 cells expressing ataxin-3 84Q, respectively. Treatment with resveratrol (another compound known to activate the sirtuin pathway), also improved swimming in the MJD zebrafish. Co-treatment with valproate alongside EX527, a SIRT1 activity inhibitor, prevented induction of autophagy by valproate and the beneficial effects of valproate on the movement in the MJD zebrafish, supporting that they were both dependent on sirtuin activity. These findings provide the first evidence of sodium valproate inducing activation of the sirtuin pathway. Further, they indicate that drugs that target the sirtuin pathway, including sodium valproate and resveratrol, warrant further investigation for the treatment of MJD and related neurodegenerative diseases.

Amyloid-β: a potential link between epilepsy and cognitive decline

People with epilepsy - in particular, late-onset epilepsy of unknown aetiology - have an elevated risk of dementia, and seizures have been detected in the early stages of Alzheimer disease (AD), supporting the concept of an epileptic AD prodrome. However, the relationship between epilepsy and cognitive decline remains controversial, with substantial uncertainties about whether epilepsy drives cognitive decline or vice versa, and whether shared pathways underlie both conditions. Here, we review evidence that amyloid-β (Aβ) forms part of a shared pathway between epilepsy and cognitive decline, particularly in the context of AD. People with epilepsy show an increased burden of Aβ pathology in the brain, and Aβ-mediated epileptogenic alterations have been demonstrated in experimental studies, with evidence suggesting that Aβ pathology might already be pro-epileptogenic at the soluble stage, long before plaque deposition. We discuss the hypothesis that Aβ mediates - or is at least a major determinant of - a continuum spanning epilepsy and cognitive decline. Serial cognitive testing and assessment of Aβ levels might be worthwhile to stratify the risk of developing dementia in people with late-onset epilepsy. If seizures are a clinical harbinger of dementia, people with late-onset epilepsy could be an ideal group in which to implement preventive or therapeutic strategies to slow cognitive decline.

Efficacy and safety of pharmacotherapy for Alzheimer's disease and for behavioural and psychological symptoms of dementia in older patients with moderate and severe functional impairments: a systematic review of controlled trials

BACKGROUND

Many patients with Alzheimer's disease (AD) are physically frail or have substantial functional impairments. There is growing evidence that such patients are at higher risk for medication-induced adverse events. Furthermore, frailty seems to be more predictive of poor clinical outcomes than chronological age alone. To our knowledge, no systematic review of clinical trials examining drug therapy of AD or behavioural and psychological symptoms of dementia (BPSD) has specifically focused on the topic of physical frailty. Our objective was to evaluate the efficacy and safety of pharmacotherapy in AD patients with frailty or significant functional impairments.

METHODS

We performed a systematic literature search in MEDLINE, Embase and the Cochrane Central Register of Controlled Trials (CENTRAL) for randomized controlled trials (RCTs) of drug therapy of AD and BPSD in patients with significant functional impairments according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and Cochrane research criteria. Significant functionally impaired patient populations were identified using the recommendations of the Medication and Quality of Life in frail older persons (MedQoL) Research Group. Screening, selection of studies, data extraction and risk of bias assessment were performed independently by two reviewers. Outcomes including functional status, cognitive function, changes in BPSD symptoms, clinical global impression and quality of life were analysed. For assessing harm, we assessed adverse events, drop-outs as a proxy for treatment tolerability and death. Results were analysed according to Cochrane standards and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

RESULTS

Of 45,045 search results, 38,447 abstracts and 187 full texts were screened, and finally, 10 RCTs were included in the systematic review. Selected articles evaluated pharmacotherapy with acetylcholinesterase-inhibitors (AChEI), anticonvulsants, antidepressants and antipsychotics. Studies of AChEIs suggested that patients with significant functional impairments had slight but significant improvements in cognition and that AChEIs were generally well tolerated. Studies of antidepressants did not show significant improvements in depressive symptoms. Antipsychotics and anticonvulsants showed small effects on some BPSD items but also higher rates of adverse events. However, due to the very small number of identified trials, the quality of evidence for all outcomes was low to very low. Overall, the small number of eligible studies demonstrates that significantly functional impaired older patients have not been adequately taken into consideration in most clinical trials investigating drug therapy of AD and BPSD.

CONCLUSION

Due to lack of evidence, it is not possible to give specific recommendations for drug therapy of AD and BSPD in frail older patients or older patients with significant functional impairments. Therefore, clinical trials focussing on frail older adults are urgently required. A standardized approach to physical frailty in future clinical studies is highly desirable.

"Don't Phos Over Tau": recent developments in clinical biomarkers and therapies targeting tau phosphorylation in Alzheimer's disease and other tauopathies

Phosphorylation is one of the most prevalent post-translational modifications found in aggregated tau isolated from Alzheimer’s disease (AD) patient brains. In tauopathies like AD, increased phosphorylation or hyperphosphorylation can contribute to microtubule dysfunction and is associated with tau aggregation. In this review, we provide an overview of the structure and functions of tau protein as well as the physiologic roles of tau phosphorylation. We also extensively survey tau phosphorylation sites identified in brain tissue and cerebrospinal fluid from AD patients compared to age-matched healthy controls, which may serve as disease-specific biomarkers. Recently, new assays have been developed to measure minute amounts of specific forms of phosphorylated tau in both cerebrospinal fluid and plasma, which could potentially be useful for aiding clinical diagnosis and monitoring disease progression. Additionally, multiple therapies targeting phosphorylated tau are in various stages of clinical trials including kinase inhibitors, phosphatase activators, and tau immunotherapy. With promising early results, therapies that target phosphorylated tau  could be useful at slowing tau hyperphosphorylation and aggregation in AD and other tauopathies.

Treatment of epilepsy for people with Alzheimer's disease

BACKGROUND

Any type of seizure can be observed in Alzheimer's disease. Antiepileptic drugs seem to prevent the recurrence of epileptic seizures in most people with Alzheimer's disease. There are pharmacological and non-pharmacological treatments for epilepsy in people with Alzheimer's disease, however there are no current systematic reviews to evaluate the efficacy and tolerability of these treatments. This review aims to investigate these different modalities. This is an updated version of the Cochrane Review previously published in 2018.

OBJECTIVES

To assess the efficacy and tolerability of pharmacological or non-pharmacological interventions for the treatment of epilepsy in people with Alzheimer's disease (including sporadic Alzheimer's disease and dominantly inherited Alzheimer's disease).

SEARCH METHODS

For the latest update, on 3 August 2020 we searched the Cochrane Register of Studies (CRS Web) and MEDLINE (Ovid, 1946 to 31 July 2020). CRS Web includes randomized or quasi-randomized controlled trials from PubMed, EMBASE, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform (ICTRP), the Cochrane Central Register of Controlled Trials (CENTRAL), and the Specialized Registers of Cochrane Review Groups, including Cochrane Epilepsy. In an effort to identify further published, unpublished and ongoing trials, we searched ongoing trials registers, reference lists and relevant conference proceedings; we also contacted trial authors and pharmaceutical companies.

SELECTION CRITERIA

We included randomized and quasi-randomized controlled trials investigating treatment for epilepsy in people with Alzheimer's disease, with the primary outcomes of proportion of participants with seizure freedom and proportion of participants experiencing adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the titles and abstracts of identified records, selected studies for inclusion, extracted data, cross-checked the data for accuracy and assessed the methodological quality. We performed no meta-analyses due to there being limited available data.

MAIN RESULTS

We included one randomized controlled trial (RCT) on pharmacological interventions; the trial included 95 participants. No studies were found for non-pharmacological interventions. Concerning the proportion of participants with seizure freedom, no significant differences were found for the comparisons of levetiracetam versus lamotrigine (RR) 1.20, 95% CI 0.53 to 2.71; 67 participants; very low-certainty evidence), levetiracetam versus phenobarbital (RR 1.01, 95% CI 0.47 to 2.19; 66 participants; very low-certainty evidence), or lamotrigine versus phenobarbital (RR 0.84, 95% CI 0.35 to 2.02; 57 participants; very low-certainty evidence). It seemed that levetiracetam could improve cognition and lamotrigine could relieve depression, while phenobarbital and lamotrigine could worsen cognition, and levetiracetam and phenobarbital could worsen mood. The risk of bias relating to allocation, blinding and selective reporting was unclear. We judged the certainty of the evidence for all outcomes to be very low.

AUTHORS' CONCLUSIONS

This review does not provide sufficient evidence to support levetiracetam, phenobarbital or lamotrigine for the treatment of epilepsy in people with Alzheimer's disease. Regarding efficacy and tolerability, no significant differences were found between levetiracetam, phenobarbital and lamotrigine. Large RCTs with a double-blind, parallel-group design are required to determine the efficacy and tolerability of treatment for epilepsy in people with Alzheimer's disease.

Alzheimer's Disease and Epilepsy: A Perspective on the Opportunities for Overlapping Therapeutic Innovation

Early-onset Alzheimer's disease (AD) is associated with variants in amyloid precursor protein (APP) and presenilin (PSEN) 1 and 2. It is increasingly recognized that patients with AD experience undiagnosed focal seizures. These AD patients with reported seizures may have worsened disease trajectory. Seizures in epilepsy can also lead to cognitive deficits, neuroinflammation, and neurodegeneration. Epilepsy is roughly three times more common in individuals aged 65 and older. Due to the numerous available antiseizure drugs (ASDs), treatment of seizures has been proposed to reduce the burden of AD. More work is needed to establish the functional impact of seizures in AD to determine whether ASDs could be a rational therapeutic strategy. The efficacy of ASDs in aged animals is not routinely studied, despite the fact that the elderly represents the fastest growing demographic with epilepsy. This leaves a particular gap in understanding the discrete pathophysiological overlap between hyperexcitability and aging, and AD more specifically. Most of our preclinical knowledge of hyperexcitability in AD has come from mouse models that overexpress APP. While these studies have been invaluable, other drivers underlie AD, e.g. PSEN2. A diversity of animal models should be more frequently integrated into the study of hyperexcitability in AD, which could be particularly beneficial to identify novel therapies. Specifically, AD-associated risk genes, in particular PSENs, altogether represent underexplored contributors to hyperexcitability. This review assesses the available studies of ASDs administration in clinical AD populations and preclinical studies with AD-associated models and offers a perspective on the opportunities for further therapeutic innovation.

Key Disease Mechanisms Linked to Alzheimer's Disease in the Entorhinal Cortex

Alzheimer’s disease (AD) is a chronic, neurodegenerative brain disorder affecting millions of Americans that is expected to increase in incidence with the expanding aging population. Symptomatic AD patients show cognitive decline and often develop neuropsychiatric symptoms due to the accumulation of insoluble proteins that produce plaques and tangles seen in the brain at autopsy. Unexpectedly, some clinically normal individuals also show AD pathology in the brain at autopsy (asymptomatic AD, AsymAD). In this study, SWItchMiner software was used to identify key switch genes in the brain’s entorhinal cortex that lead to the development of AD or disease resilience. Seventy-two switch genes were identified that are differentially expressed in AD patients compared to healthy controls. These genes are involved in inflammation, platelet activation, and phospholipase D and estrogen signaling. Peroxisome proliferator-activated receptor γ (PPARG), zinc-finger transcription factor (YY1), sterol regulatory element-binding transcription factor 2 (SREBF2), and early growth response 1 (EGR1) were identified as transcription factors that potentially regulate switch genes in AD. Comparing AD patients to AsymAD individuals revealed 51 switch genes; PPARG as a potential regulator of these genes, and platelet activation and phospholipase D as critical signaling pathways. Chemical–protein interaction analysis revealed that valproic acid is a therapeutic agent that could prevent AD from progressing.

Temporal Lobe Epilepsy and Alzheimer's Disease: From Preclinical to Clinical Evidence of a Strong Association

Increasing evidence coming from both experimental and humans' studies strongly suggest the existence of a link between epilepsy, in particular temporal lobe epilepsy (TLE), and Alzheimer's disease (AD). Patients with mild cognitive impairment and AD are more prone to have seizures, and seizures seem to facilitate amyloid-β and tau deposits, thus promoting neurodegenerative processes. Consistent with this view, long-lasting drug-resistant TLE and AD have been shown to share several pathological and neuroimaging features. Even if studies addressing prevalence of interictal and subclinical epileptiform activity in these patients are not yet conclusive, their findings raise the possibility that epileptiform activity might negatively impact memory and hasten cognitive decline, either directly or by association with unrecognized silent seizures. In addition, data about detrimental effect of network hyperexcitability in temporal regions in the premorbid and early stages ofADopen up newtherapeutic opportunities for antiseizure medications and/or antiepileptic strategies that might complement or enhance existing therapies, and potentially modify disease progression. Here we provide a review of evidence linking epileptiform activity, network hyperexcitability, and AD, and their role promoting and accelerating neurodegenerative process. Finally, the effects of antiseizure medications on cognition and their optimal administration in patients with AD are summarized.

Anti-seizure medication correlated changes of cortical morphology in childhood epilepsy with centrotemporal spikes

To investigate the morphological changes of cerebral cortex correlating with anti-seizure medication in Childhood Epilepsy with Centrotemporal Spikes (CECTS), and their relationships with seizure control. This study included a total of 188 children, including 62 patients with CECTS taking anti-seizure drugs, 56 patients with drug-naive, and 70 healthy controls. A portion of cases were also followed-up for longitudinal analysis. Cortical morphological parameters were quantitatively measured by applying surface-based morphometry analysis to high-resolution three-dimension T1 weighted images. Among the three groups, the morphological indices were compared to quantify any cortical changes affected by seizures and medication. The relationships among anti-seizure medication, seizure controls and cortical morphometry were investigated using causal mediator analysis. The Rolandic cortex of the drug-naive patients showed abnormal cortical thickness by comparing with that of healthy controls, and thinning by comparing with that of patients with medication. The cortical thickness in the Rolandic regions was negatively correlated with duration of medication and duration of seizure-free. Longitudinal analysis further demonstrated that the thickness of Rolandic cortex thinned in post-medication state relative to the pre-medication state. Mediation analysis revealed that morphological alteration of the Rolandic cortex might act as a mediator in the path of anti-seizure medication on seizure control. Our findings highlighted that anti-seizure medication was associated with regression of abnormal increment of cortical thickness in the Rolandic regions in CECTS. The neuroanatomical alteration might be a mediating factor in the process of seizure control by anti-seizure medication.

Propionate and Alzheimer's Disease

Propionate, a short-chain fatty acid, serves important roles in the human body. However, our review of the current literature suggests that under certain conditions, excess levels of propionate may play a role in Alzheimer's disease (AD). The cause of the excessive levels of propionate may be related to the Bacteroidetes phylum, which are the primary producers of propionate in the human gut. Studies have shown that the relative abundance of the Bacteroidetes phylum is significantly increased in older adults. Other studies have shown that levels of the Bacteroidetes phylum are increased in persons with AD. Studies on the diet, medication use, and propionate metabolism offer additional potential causes. There are many different mechanisms by which excess levels of propionate may lead to AD, such as hyperammonemia. These mechanisms offer potential points for intervention.

Glia-Driven Neuroinflammation and Systemic Inflammation in Alzheimer's Disease

The neuroinflammatory hypothesis of Alzheimer's disease (AD) was proposed more than 30 years ago. The involvement of the two main types of glial cells microglia and astrocytes, in neuroinflammation, was suggested early on. In this review, we highlight that the exact contributions of reactive glia to AD pathogenesis remain difficult to define, likely due to the heterogeneity of glia populations and alterations in their activation states through the stages of AD progression. In the case of microglia, it is becoming apparent that both beneficially and adversely activated cell populations can be identified at various stages of AD, which could be selectively targeted to either limit their damaging actions or enhance beneficial functions. In the case of astrocytes, less information is available about potential subpopulations of reactive cells; it also remains elusive whether astrocytes contribute to the neuropathology of AD by mainly gaining neurotoxic functions or losing their ability to support neurons due to astrocyte damage. We identify L-type calcium channel blocker, nimodipine, as a candidate drug for AD, which potentially targets both astrocytes and microglia. It has already shown consistent beneficial effects in basic experimental and clinical studies. We also highlight the recent evidence linking peripheral inflammation and neuroinflammation. Several chronic systemic inflammatory diseases, such as obesity, type 2 diabetes mellitus, and periodontitis, can cause immune priming or adverse activation of glia, thus exacerbating neuroinflammation and increasing risk or facilitating the progression of AD. Therefore, reducing peripheral inflammation is a potentially effective strategy for lowering AD prevalence.

Modulation of Brain Hyperexcitability: Potential New Therapeutic Approaches in Alzheimer's Disease

People with Alzheimer's disease (AD) have significantly higher rates of subclinical and overt epileptiform activity. In animal models, oligomeric Aβ amyloid is able to induce neuronal hyperexcitability even in the early phases of the disease. Such aberrant activity subsequently leads to downstream accumulation of toxic proteins, and ultimately to further neurodegeneration and neuronal silencing mediated by concomitant tau accumulation. Several neurotransmitters participate in the initial hyperexcitable state, with increased synaptic glutamatergic tone and decreased GABAergic inhibition. These changes appear to activate excitotoxic pathways and, ultimately, cause reduced long-term potentiation, increased long-term depression, and increased GABAergic inhibitory remodelling at the network level. Brain hyperexcitability has therefore been identified as a potential target for therapeutic interventions aimed at enhancing cognition, and, possibly, disease modification in the longer term. Clinical trials are ongoing to evaluate the potential efficacy in targeting hyperexcitability in AD, with levetiracetam showing some encouraging effects. Newer compounds and techniques, such as gene editing via viral vectors or brain stimulation, also show promise. Diagnostic challenges include identifying best biomarkers for measuring sub-clinical epileptiform discharges. Determining the timing of any intervention is critical and future trials will need to carefully stratify participants with respect to the phase of disease pathology.

BACE inhibition causes rapid, regional, and non-progressive volume reduction in Alzheimer's disease brain

In the phase 3 EPOCH trial (Clinicaltrials.gov; NCT01739348), treatment with the BACE inhibitor verubecestat failed to improve cognition in patients with mild-to-moderate Alzheimer's disease, but was associated with reduced hippocampal volume after 78 weeks as assessed by MRI. The aims of the present exploratory analyses were to: (i) characterize the effect of verubecestat on brain volume by evaluating the time course of volumetric MRI changes for a variety of brain regions; and (ii) understand the mechanism through which verubecestat might cause hippocampal (and other brain region) volume loss by assessing its relationship to measures of amyloid, neurodegeneration, and cognition. Participants were aged 55-85 years with probable Alzheimer's disease dementia and a Mini Mental State Examination score ≥15 and ≤26. MRIs were obtained at baseline and at Weeks 13, 26, 52 and 78 of treatment. MRIs were segmented using Freesurfer and analysed using a tensor-based morphometry method. PET amyloid data were obtained with 18F-flutemetamol (Vizamyl®) at baseline and Week 78. Standardized uptake value ratios were generated with subcortical white matter as a reference region. Neurofilament light chain in the CSF was assessed as a biomarker of neurodegeneration. Compared with placebo, verubecestat showed increased MRI brain volume loss at Week 13 with no evidence of additional loss through Week 78. The verubecestat-related volumetric MRI loss occurred predominantly in amyloid-rich brain regions. Correlations between amyloid burden at baseline and verubecestat-related volumetric MRI reductions were not significant (r = 0.05 to 0.26, P-values > 0.27). There were no significant differences between verubecestat and placebo in changes from baseline in CSF levels of neurofilament light chain at Week 78 (increases of 7.2 and 14.6 pg/ml for verubecestat versus 19.7 pg/ml for placebo, P-values ≥ 0.1). There was a moderate correlation between volumetric MRI changes and cognitive decline in all groups including placebo at Week 78 (e.g. r = -0.45 to -0.55, P < 0.001 for whole brain), but the correlations were smaller at Week 13 and significant only for the verubecestat groups (e.g. r = -0.15 and -0.11, P < 0.04 for whole brain). Our results suggest that the verubecestat-associated MRI brain volume loss is not due to generalized, progressive neurodegeneration, but may be mediated by specific effects on BACE-related amyloid processes.

Recurrent limbic seizures do not cause hippocampal neuronal loss: A prolonged laboratory study

PURPOSE

It remains controversial whether neuronal damage and synaptic reorganization found in some forms of epilepsy are the result of an initial injury and potentially contributory to the epileptic condition or are the cumulative affect of repeated seizures. A number of reports of human and animal pathology suggest that at least some neuronal loss precedes the onset of seizures, but there is debate over whether there is further damage over time from intermittent seizures. In support of this latter hypothesis are MRI studies in people that show reduced hippocampal volumes and cortical thickness with longer durations of the disease. In this study we addressed the question of neuronal loss from intermittent seizures using kindled rats (no initial injury) and rats with limbic epilepsy (initial injury).

METHODS

Supragranular mossy fiber sprouting, hippocampal neuronal densities, and subfield area measurements were determined in rats with chronic limbic epilepsy (CLE) that developed following an episode of limbic status epilepticus (n = 25), in kindled rats (n = 15), and in age matched controls (n = 20). To determine whether age or seizure frequency played a role in the changes, CLE and kindled rats were further classified by seizure frequency (low/high) and the duration of the seizure disorder (young/old).

RESULTS

Overall there was no evidence for progressive neuronal loss from recurrent seizures. Compared with control and kindled rats, CLE animals showed increased mossy fiber sprouting, decreased neuronal numbers in multiple regions and regional atrophy. In CLE, but not kindled rats: 1) Higher seizure frequency was associated with greater mossy fiber sprouting and granule cell dispersion; and 2) greater age with seizures was associated with decreased hilar densities, and increased hilar areas. There was no evidence for progressive neuronal loss, even with more than 1000 seizures.

CONCLUSION

These findings suggest that the neuronal loss associated with limbic epilepsy precedes the onset of the seizures and is not a consequence of recurrent seizures. However, intermittent seizures do cause other structural changes in the brain, the functional consequences of which are unclear.

Human Brain Neuropharmacology: A Platform for Translational Neuroscience

Central nervous system (CNS) drug development has been plagued by a failure to translate effective therapies from the lab to the clinic. There are many potential reasons for this, including poor understanding of brain pharmacokinetic (PK) and pharmacodynamic (PD) factors, preclinical study flaws, clinical trial design issues, the complexity and variability of human brain diseases, as well as species differences. To address some of these problems, we have developed a platform for CNS drug discovery comprising: drug screening of primary adult human brain cells; human brain tissue microarray analysis of drug targets; and high-content phenotypic screening methods. In this opinion, I summarise the theoretical basis and the practical development and use of this platform in CNS drug discovery.

Targeting tau: Clinical trials and novel therapeutic approaches

Tauopathies are a group of over 20 clinicopathological neurodegenerative diseases including Alzheimer's disease (AD), the most common type of dementia, progressive supranuclear palsy, Pick's disease, corticobasal degeneration, among others. Tauopathies are defined by neurodegeneration and the presence of tau aggregates in affected brains regions. Interestingly, regional tau aggregation burden correlates with clinical phenotype and predicts cognitive status. Autosomal dominant mutations in the MAPT gene lead to tau deposition and clinical FTD syndromes with cognitive, behavioral, and motor impairment. Polymorphisms in or around the MAPT gene have also been strongly linked to other proteinopathies including synucleinopathies. Taken together these findings suggests that tau plays a critical role in neurodegeneration and proteinopathies, supporting the idea that tau targeted approaches can be disease-modifying and lead to clinically meaningful benefits in slowing or reversing disease progression. Increasingly, human clinical trials are testing this hypothesis. This article reviews tau-targeted therapies tested in clinical trials as well as agents currently in active development based on publicly disclosed information. We describe the therapeutic approaches of these trials based on the potential pathogenic mechanism they target.

Valproate Use Is Associated With Posterior Cortical Thinning and Ventricular Enlargement in Epilepsy Patients

Valproate is a drug widely used to treat epilepsy, bipolar disorder, and occasionally to prevent migraine headache. Despite its clinical efficacy, prenatal exposure to valproate is associated with neurodevelopmental impairments and its use in children and adults was associated with rare cases of reversible brain atrophy and ventricular enlargement. To determine whether valproate use is related with structural brain changes we examined through a cross-sectional study cortical and subcortical structures in a group of 152 people with epilepsy and a normal clinical brain MRI. Patients were grouped into those currently using valproate (n = 54), those taking drugs other than valproate (n = 47), and drug-naïve patients (n = 51) at the time of MRI, irrespectively of their epilepsy syndrome. Cortical thickness and subcortical volumes were analyzed using Freesurfer, version 5.0. Subjects exposed to valproate (either in mono- or polytherapy) showed reduced cortical thickness in the occipital lobe, more precisely in the cuneus bilaterally, in the left lingual gyrus, and in left and right pericalcarine gyri when compared to patients who used other antiepileptic drugs, to drug-naïve epilepsy patients, and to healthy controls. Considering the subgroup of patients using valproate monotherapy (n = 25), both comparisons with healthy controls and drug-naïve groups confirmed occipital lobe cortical thickness reduction. Moreover, patients using valproate showed increased left and right lateral ventricle volume compared to all other groups. Notably, subjects who were non-valproate users at the time of MRI, but who had valproate exposure in the past (n = 27) did not show these cortical or subcortical brain changes. Cortical changes in the posterior cortex, particularly in the visual cortex, and ventricular enlargement, are present in people with epilepsy using valproate, independently from clinical and demographical variables. These findings are relevant both for the efficacy and adverse events profile of valproate use in people with epilepsy.

Efficacy and safety of valproic acid in dementia: A systematic review with meta-analysis

INTRODUCTION

The neuroprotective effect of valproic acid has been observed in the animal models of neurodegeneration, which suggests it as a potential candidate for clinical trials. In this paper, we aimed to systematically analyze the efficacy and safety of valproic acid in the treatment of dementia.

METHODS

We searched the electronic databases PubMed, EMBASE, CINAHL, Cochrane Library and China National Knowledge Infrastructure until March 2020 for the eligible randomized controlled trials, as well as the unpublished and ongoing trials. We pooled the results using a random-effects model.

RESULTS

We included seven studies with 770 randomized patients with dementia, which compared valproic acid with placebo. Indeed, there were no significant differences found in the scores of Mini-mental State Examination, Cohen-Mansfield Agitation Inventory and number of patients with adverse events. Valproic acid is generally well-tolerated in patients with dementia, even in long-term therapy for 24 months.

CONCLUSION

Insufficient evidences are found to support valproic acid in the treatment of dementia for cognitive, psychiatric symptoms or disease-modifying. The anticipations for a success in the trial of valproic acid for dementia in the future look not optimistic based on the available evidence.

Long-term and in vivo assessment of Aβ protein-induced brain atrophy in a zebrafish model by optical coherence tomography

In this study, a neurotoxicity model of zebrafish induced by amyloid beta (Aβ) protein was developed and evaluated in vivo by optical coherence tomography (OCT). Aβ protein and phosphate buffer saline (PBS) were separately injected into the head of two groups of adult zebrafish (n = 6 per group). Congo-red staining results confirmed that Aβ protein had penetrated into brain tissue. All zebrafish were imaged with OCT on the 0th, 5th, 10th, 15th and 20th day postinjection. OCT images showed that PBS is not toxic to brain tissue. However, significant brain atrophy could be seen in the OCT images of zebrafish injected with Aβ-protein that was verified by histological consequences. In addition, zebrafish in the model group showed memory decline in behavioral tests. This study verified the feasibility of in vivo long-term assessment of Aβ protein-induced brain atrophy in adult zebrafish by OCT that has great potential to be applied in the neurological diseases research.

Combination Drug Therapy for the Management of Alzheimer's Disease

Alzheimer's disease (AD) is the leading cause of dementia worldwide. Even though the number of AD patients is rapidly growing, there is no effective treatment for this neurodegenerative disorder. At present, implementation of effective treatment approaches for AD is vital to meet clinical needs. In AD research, priorities concern the development of disease-modifying therapeutic agents to be used in the early phases of AD and the optimization of the symptomatic treatments predominantly dedicated to the more advanced AD stages. Until now, available therapeutic agents for AD treatment only provide symptomatic treatment. Since AD pathogenesis is multifactorial, use of a multimodal therapeutic intervention addressing several molecular targets of AD-related pathological processes seems to be the most practical approach to modify the course of AD progression. It has been demonstrated through numerous studies, that the clinical efficacy of combination therapy (CT) is higher than that of monotherapy. In case of AD, CT is more effective, mostly when started early, at slowing the rate of cognitive impairment. In this review, we have covered the major studies regarding CT to combat AD pathogenesis. Moreover, we have also highlighted the safety, tolerability, and efficacy of CT in the treatment of AD.

Epilepsy and aging

The intersection of epilepsy and aging has broad, significant implications. Substantial increases in seizures occur both in the elderly population, who are at a higher risk of developing new-onset epilepsy, and in those with chronic epilepsy who become aged. There are notable gaps in our understanding of aging and epilepsy at the basic and practical levels, which have important consequences. We are in the early stages of understanding the complex relationships between epilepsy and other age-related brain diseases such as stroke, dementia, traumatic brain injury (TBI), and cancer. Furthermore, the clinician must recognize that the presentation and treatment of epilepsy in the elderly are different from those of younger populations. Given the developing awareness of the problem and the capabilities of contemporary, multidisciplinary approaches to advance understanding about the biology of aging and epilepsy, it is reasonable to expect that we will unravel some of the intricacies of epilepsy in the elderly; it is also reasonable to expect that these gains will lead to further improvements in our understanding and treatment of epilepsy for all age groups.

Gene expression changes induced by valproate in the process of rat hippocampal neural stem cells differentiation

Valproate (VPA), an effective clinical approved anti-epileptic drug and mood stabilizer, has been believed to induce neuronal differentiation at the expense of inhibiting astrocytic and oligodendrocytic differentiation. Nevertheless, the involving mechanisms of it remain unclear yet. In the present study, we explored the global gene expression changes of fetus rat hippocampal neural stem cells following VPA treatment by high-throughput microarray. We obtained 874 significantly upregulated genes and 258 obviously downregulated genes (fold change > 2 and P < 0.05). Then, we performed gene ontology and pathway analyses of these differentially expressed genes and chose several genes associated with nervous system according to gene ontology analysis to conduct expression analysis to validate the reliability of the array results as well as reveal possible mechanisms of VPA. To get a better comprehension of the differentially regulated genes by VPA, we conducted protein-protein association analysis of these genes, which offered a source for further studies. In addition, we made the overlap between the VPA-downregulated genes and the predicted target genes of VPA-upregulated microRNAs (miRNAs), which were previously demonstrated. These overlapped genes may provide a source to find functional VPA/miRNA/mRNA axes during neuronal differentiation. This study first constructed a comprehensive potential downstream gene map of VPA in the process of neuronal differentiation.

Safety and Efficacy of Edonerpic Maleate for Patients With Mild to Moderate Alzheimer Disease: A Phase 2 Randomized Clinical Trial

Importance

Edonerpic maleate (T-817MA) protects against Aβ40-induced neurotoxic effects and memory deficits, promotes neurite outgrowth, and preserves hippocampal synapses and spatial memory in tau transgenic mice. These effects may be mediated via sigma-1 receptor activation, delivery of synaptic AMPA receptors, or modulation of microglial function and may benefit patients with Alzheimer disease.

Objective

To assess the efficacy, safety, and tolerability of edonerpic for patients with mild to moderate Alzheimer disease.

Design, Setting, and Participants

Randomized, double-blind, placebo-controlled, parallel-group, phase 2 clinical trial conducted over 52 weeks from June 2, 2014, to December 14, 2016, at 52 US clinical and academic centers. Of 822 outpatients screened, 484 met the following criteria and were randomly assigned to treatment: 55 to 85 years of age, probable Alzheimer disease, Mini-Mental State Examination scores from 12 to 22, and taking stable doses of donepezil or rivastigmine with or without memantine.

Interventions

Random assignment (1:1:1 allocation) to placebo or 224 mg or 448 mg of edonerpic maleate, once per day.

Main Outcomes and Measures

Coprimary outcomes were scores on the Alzheimer Disease Assessment Scale-Cognitive Subscale (ADAS-cog) and Alzheimer's Disease Cooperative Study-Clinical Impression of Change (ADCS-CGIC) at week 52. Biomarkers were brain, lateral ventricular, and hippocampal volumes, as determined on magnetic resonance imaging, and cerebrospinal fluid Aβ40, Aβ42, total tau, and phospho-tau181. The primary efficacy analysis was performed on the coprimary end points for the modified intention-to-treat population.

Results

Of 482 participants in the safety population, 140 of 158 participants (88.6%) assigned to placebo, 117 of 166 participants (70.5%) to 224 mg of edonerpic maleate, and 120 of 158 participants (76.0%) to 448 mg of edonerpic maleate completed the trial. The mean ADAS-cog score change at week 52 was 7.91 for the placebo group, 7.45 for the 224-mg group, and 7.08 for the 448-mg group. Mean differences from placebo were -0.47 (95% CI, -2.36 to 1.43; P = .63) for the 224-mg group and -0.84 (95% CI, -2.75 to 1.08; P = .39) for the 448-mg group. Mean ADCS-CGIC scores were 5.22 for the placebo group, 5.24 for the 224-mg group, and 5.25 for the 448-mg group, with mean differences from placebo of 0.03 (95% CI, -0.20 to 0.25; P = .81) for the 224-mg group and 0.04 (95% CI, -0.19 to 0.26; P = .76) for the 448-mg group. In the safety population, a total of 7 of 158 participants (4.4%) in the placebo group, 23 of 166 participants (13.9%) in the 224-mg group, and 23 of 158 participants (14.6%) in the 448-mg group discontinued because of adverse events. The most frequent adverse events were diarrhea and vomiting.

Conclusions and Relevance

Edonerpic maleate appeared to be safe and tolerable, with expected gastrointestinal symptoms occurring early but without evidence for a clinical effect among patients with mild to moderate Alzheimer disease.

Trial Registration

ClinicalTrials.gov identifier: NCT02079909.

The overlap between epilepsy and Alzheimer's disease and the consequences for treatment

Introduction: Alzheimer's disease may be associated with both clinical and subclinical epileptic seizure activity. Once regarded as an epiphenomenon, epileptiform activity may, in fact, be an integral part of the Alzheimer's phenotype, and may be not only a symptomatic therapeutic target but also a possible mechanism to retard or prevent disease progression. Areas covered: The authors review clinical research articles with a focus on the semiology, epidemiology, and treatment of seizures in Alzheimer's disease, and also look at some experimental animal model studies which have informed clinical thinking on seizure aetiopathogenesis. The evidence base for treatment decisions is sparse. A brief overview of the clinical assessment of Alzheimer's disease patients considering relevant differential diagnoses and diagnostic pitfalls is presented. Expert opinion: Studies of epileptic seizures in Alzheimer's disease have become more frequent over the last 5-10 years. Understanding of seizure semiology, epidemiology, and possible pathogenesis has increased. However, the optimal management of seizures in this context remains unknown, largely due to the paucity of studies sufficient to examine this question. Clearly, such studies will be required, not only to inform clinicians about symptomatic control of seizures in Alzheimer's disease but also to investigate whether this might impact on disease progression.