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Harrison TM, Chadwick T, Pezzoli S, Lee J, Landau SM, Jagust WJ. Cognitive Trajectories and Alzheimer Disease Biomarkers: From Successful Cognitive Aging to Clinical Impairment. Ann Neurol 2024; 96:378-389. [PMID: 38747315 PMCID: PMC11236492 DOI: 10.1002/ana.26964] [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] [Received: 03/21/2024] [Revised: 04/26/2024] [Accepted: 04/29/2024] [Indexed: 07/11/2024]
Abstract
OBJECTIVE Cross-sectional definitions of successful cognitive aging have been widely utilized, but longitudinal measurements can identify people who do not decline. We performed this study to contrast maintenance with declining trajectories, including clinical conversion. METHODS We included baseline cognitively unimpaired Alzheimer's Disease Neuroimaging Initiative participants with 3 or more cognitive testing sessions (n = 539, follow-up 6.1 ± 3.5 years) and calculated slopes of an episodic memory composite (MEM) to classify them into two groups: maintainers (slope ≥ 0) and decliners (slope < 0). Within decliners, we examined a subgroup of individuals who became clinically impaired during follow-up. These groups were compared on baseline characteristics and cognitive performance, as well as both cross-sectional and longitudinal Alzheimer disease (AD) biomarker measures (beta-amyloid [Aβ], tau, and hippocampal volume). RESULTS Forty-one percent (n = 221) of the cohort were MEM maintainers, and 33% (n = 105) of decliners converted to clinical impairment during follow-up. Compared to those with superior baseline scores, maintainers had lower education and were more likely to be male. Maintainers and decliners did not differ on baseline MEM scores, but maintainers did have higher non-MEM cognitive scores. Maintainers had lower baseline global Aβ, lower tau pathology, and larger hippocampal volumes than decliners, even after removing converters. There were no differences in rates of change of any AD biomarkers between any cognitive trajectory groups except for a higher rate of hippocampal atrophy in clinical converters compared to maintainers. INTERPRETATION Using longitudinal data to define cognitive trajectory groups reduces education and sex bias and reveals the prognostic importance of early onset of accumulation of AD pathology. ANN NEUROL 2024;96:378-389.
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Affiliation(s)
- Theresa M Harrison
- Neuroscience Department, University of California, Berkeley, Berkeley, CA, USA
| | - Trevor Chadwick
- Neuroscience Department, University of California, Berkeley, Berkeley, CA, USA
| | - Stefania Pezzoli
- Neuroscience Department, University of California, Berkeley, Berkeley, CA, USA
- Molecular Biophysics and Integrated Bioimaging Department, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - JiaQie Lee
- Neuroscience Department, University of California, Berkeley, Berkeley, CA, USA
| | - Susan M Landau
- Neuroscience Department, University of California, Berkeley, Berkeley, CA, USA
| | - William J Jagust
- Neuroscience Department, University of California, Berkeley, Berkeley, CA, USA
- Molecular Biophysics and Integrated Bioimaging Department, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
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Diamond BR, Sridhar J, Maier J, Martersteck AC, Rogalski EJ. SuperAging functional connectomics from resting-state functional MRI. Brain Commun 2024; 6:fcae205. [PMID: 38978723 PMCID: PMC11228547 DOI: 10.1093/braincomms/fcae205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 04/12/2024] [Accepted: 06/17/2024] [Indexed: 07/10/2024] Open
Abstract
Understanding the relationship between functional connectivity (FC) of higher-order neurocognitive networks and age-related cognitive decline is a complex and evolving field of research. Decreases in FC have been associated with cognitive decline in persons with Alzheimer's disease and related dementias (ADRD). However, the contributions of FC have been less straightforward in typical cognitive aging. Some investigations suggest relatively robust FC within neurocognitive networks differentiates unusually successful cognitive aging from average aging, while others do not. Methodologic limitations in data processing and varying definitions of 'successful aging' may have contributed to the inconsistent results to date. The current study seeks to address previous limitations by optimized MRI methods to examine FC in the well-established SuperAging phenotype, defined by age and cognitive performance as individuals 80 and older with episodic memory performance equal to or better than 50-to-60-year-olds. Within- and between-network FC of large-scale neurocognitive networks were compared between 24 SuperAgers and 16 cognitively average older-aged control (OACs) with stable cognitive profiles using resting-state functional MRI (rs-fMRI) from a single visit. Group classification was determined based on measures of episodic memory, executive functioning, verbal fluency and picture naming. Inclusion criteria required stable cognitive status across two visits. First, we investigated the FC within and between seven resting-state networks from a common atlas parcellation. A separate index of network segregation was also compared between groups. Second, we investigated the FC between six subcomponents of the default mode network (DMN), the neurocognitive network commonly associated with memory performance and disrupted in persons with ADRD. For each analysis, FCs were compared across groups using two-sample independent t-tests and corrected for multiple comparisons. There were no significant between-group differences in demographic characteristics including age, sex and education. At the group-level, within-network FC, between-network FC, and segregation measurements of seven large-scale networks, including subcomponents of the DMN, were not a primary differentiator between cognitively average aging and SuperAging phenotypes. Thus, FC within or between large-scale networks does not appear to be a primary driver of the exceptional memory performance observed in SuperAgers. These results have relevance for differentiating the role of FC changes associated with cognitive aging from those associated with ADRD.
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Affiliation(s)
- Bram R Diamond
- Mesulam Center for Cognitive Neurology and Alzheimer's Disease, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
- Healthy Aging & Alzheimer's Research Care (HAARC) Center, Department of Neurology, The University of Chicago, Chicago, IL 60637, USA
| | - Jaiashre Sridhar
- Mesulam Center for Cognitive Neurology and Alzheimer's Disease, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Jessica Maier
- Department of Psychology, Florida State University, 1107 W Call St, Tallahassee, FL 32304, USA
| | - Adam C Martersteck
- Healthy Aging & Alzheimer's Research Care (HAARC) Center, Department of Neurology, The University of Chicago, Chicago, IL 60637, USA
| | - Emily J Rogalski
- Healthy Aging & Alzheimer's Research Care (HAARC) Center, Department of Neurology, The University of Chicago, Chicago, IL 60637, USA
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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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Palimariciuc M, Oprea DC, Cristofor AC, Florea T, Dobrin RP, Dobrin I, Gireadă B, Gavril R, Mawas I, Bejenariu AC, Knieling A, Ciobica A, Chiriță R. The Effects of Transcranial Direct Current Stimulation in Patients with Mild Cognitive Impairment. Neurol Int 2023; 15:1423-1442. [PMID: 38132971 PMCID: PMC10745513 DOI: 10.3390/neurolint15040092] [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: 09/25/2023] [Revised: 11/20/2023] [Accepted: 11/21/2023] [Indexed: 12/23/2023] Open
Abstract
Transcranial direct current stimulation (tDCS) came into consideration in recent years as a promising, non-invasive form of neuromodulation for individuals suffering from mild cognitive impairment (MCI). MCI represents a transitional stage between normal cognitive aging and more severe cognitive decline, which appears in neurodegenerative diseases, such as Alzheimer's disease. Numerous studies have shown that tDCS can have several useful effects in patients with MCI. It is believed to enhance cognitive functions, including memory and attention, potentially slowing down the progression of neurodegeneration and cognitive decline. tDCS is believed to work by modulating neuronal activity and promoting synaptic plasticity in the brain regions associated with cognition. Moreover, tDCS is generally considered safe and well-tolerated, making it an attractive option for long-term therapeutic use in MCI. However, further research is needed to determine the optimal stimulation parameters and long-term effects of tDCS in this population, as well as its potential to serve as a complementary therapy alongside other interventions for MCI. In this review, we included 16 randomized clinical trials containing patients with MCI who were treated with tDCS. We aim to provide important evidence for the cognitive enhancement using tDCS in patients with MCI, summarizing the effects and conclusions found in several clinical trials, and discuss its main mechanisms.
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Affiliation(s)
- Matei Palimariciuc
- Department of Medicine III, Faculty of Medicine, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 700115 Iasi, Romania; (M.P.); (D.C.O.); (A.C.C.); (T.F.); (I.D.); (B.G.); (R.G.); (I.M.); (A.C.B.); (R.C.)
- Institute of Psychiatry “Socola”, 36 Bucium Street, 700282 Iasi, Romania
| | - Dan Cătălin Oprea
- Department of Medicine III, Faculty of Medicine, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 700115 Iasi, Romania; (M.P.); (D.C.O.); (A.C.C.); (T.F.); (I.D.); (B.G.); (R.G.); (I.M.); (A.C.B.); (R.C.)
- Institute of Psychiatry “Socola”, 36 Bucium Street, 700282 Iasi, Romania
| | - Ana Caterina Cristofor
- Department of Medicine III, Faculty of Medicine, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 700115 Iasi, Romania; (M.P.); (D.C.O.); (A.C.C.); (T.F.); (I.D.); (B.G.); (R.G.); (I.M.); (A.C.B.); (R.C.)
- Institute of Psychiatry “Socola”, 36 Bucium Street, 700282 Iasi, Romania
| | - Tudor Florea
- Department of Medicine III, Faculty of Medicine, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 700115 Iasi, Romania; (M.P.); (D.C.O.); (A.C.C.); (T.F.); (I.D.); (B.G.); (R.G.); (I.M.); (A.C.B.); (R.C.)
- Institute of Psychiatry “Socola”, 36 Bucium Street, 700282 Iasi, Romania
| | - Romeo Petru Dobrin
- Department of Medicine III, Faculty of Medicine, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 700115 Iasi, Romania; (M.P.); (D.C.O.); (A.C.C.); (T.F.); (I.D.); (B.G.); (R.G.); (I.M.); (A.C.B.); (R.C.)
- Institute of Psychiatry “Socola”, 36 Bucium Street, 700282 Iasi, Romania
| | - Irina Dobrin
- Department of Medicine III, Faculty of Medicine, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 700115 Iasi, Romania; (M.P.); (D.C.O.); (A.C.C.); (T.F.); (I.D.); (B.G.); (R.G.); (I.M.); (A.C.B.); (R.C.)
- Institute of Psychiatry “Socola”, 36 Bucium Street, 700282 Iasi, Romania
| | - Bogdan Gireadă
- Department of Medicine III, Faculty of Medicine, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 700115 Iasi, Romania; (M.P.); (D.C.O.); (A.C.C.); (T.F.); (I.D.); (B.G.); (R.G.); (I.M.); (A.C.B.); (R.C.)
- Institute of Psychiatry “Socola”, 36 Bucium Street, 700282 Iasi, Romania
| | - Radu Gavril
- Department of Medicine III, Faculty of Medicine, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 700115 Iasi, Romania; (M.P.); (D.C.O.); (A.C.C.); (T.F.); (I.D.); (B.G.); (R.G.); (I.M.); (A.C.B.); (R.C.)
- Institute of Psychiatry “Socola”, 36 Bucium Street, 700282 Iasi, Romania
| | - Iasmin Mawas
- Department of Medicine III, Faculty of Medicine, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 700115 Iasi, Romania; (M.P.); (D.C.O.); (A.C.C.); (T.F.); (I.D.); (B.G.); (R.G.); (I.M.); (A.C.B.); (R.C.)
| | - Andreea Cristina Bejenariu
- Department of Medicine III, Faculty of Medicine, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 700115 Iasi, Romania; (M.P.); (D.C.O.); (A.C.C.); (T.F.); (I.D.); (B.G.); (R.G.); (I.M.); (A.C.B.); (R.C.)
- Institute of Psychiatry “Socola”, 36 Bucium Street, 700282 Iasi, Romania
| | - Anton Knieling
- Institute of Forensic Medicine, 700455 Iași, Romania;
- Forensic Science Department, Faculty of Medicine, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 700115 Iasi, Romania
| | - Alin Ciobica
- Department of Biology, Faculty of Biology, Alexandru Ioan Cuza University, B-dul Carol I No. 11, 700506 Iasi, Romania;
- Academy of Romanian Scientists, Splaiul Independentei Nr. 54, Sector 5, 050094 Bucuresti, Romania
- Centre of Biomedical Research, Romanian Academy, B-dul Carol I No. 8, 700506 Iasi, Romania
- Preclinical Department, Apollonia University, Păcurari Street 11, 700511 Iași, Romania
| | - Roxana Chiriță
- Department of Medicine III, Faculty of Medicine, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 700115 Iasi, Romania; (M.P.); (D.C.O.); (A.C.C.); (T.F.); (I.D.); (B.G.); (R.G.); (I.M.); (A.C.B.); (R.C.)
- Institute of Psychiatry “Socola”, 36 Bucium Street, 700282 Iasi, Romania
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