Statin treatment intensity and cerebral vasomotor reactivity response in patients with ischemic stroke.

BACKGROUND AND PURPOSE: Cerebral vasomotor reactivity (VMR) is vital for regulating brain blood flow and maintaining neurological function. Impaired cerebral VMR is linked to a higher risk of stroke and poor post-stroke outcomes. This study explores the relationship between statin treatment intensity and VMR in patients with ischemic stroke. METHODS: Seventy-four consecutive patients (mean age 69.3 years, 59.4% male) with recent ischemic stroke were included. VMR levels were assessed 4 weeks after the index stroke using transcranial Doppler, measuring the breath-holding index (BHI) as an indicator of the percentage increase in middle cerebral artery blood flow (higher BHI signifies higher VMR). Multistep multivariable regression models, adjusted for demographic and cerebrovascular risk factors, were employed to examine the association between statin intensity treatment and BHI levels. RESULTS: Forty-one patients (55%) received high-intensity statins. Patients receiving high-intensity statins exhibited a mean BHI of 0.85, whereas those on low-intensity statins had a mean BHI of 0.67 (mean difference 0.18, 95% confidence interval: 0.13-0.22, p-value<.001). This significant difference persisted in the fully adjusted model (adjusted mean values: 0.84 vs. 0.68, p-value: .008). No significant differences were observed in BHI values within patient groups on high-intensity or low-intensity statin therapy (all p-values>.05). Furthermore, no significant association was found between baseline low-density lipoprotein (LDL) levels and BHI. CONCLUSIONS: High-intensity statin treatment post-ischemic stroke is linked to elevated VMR independent of demographic and clinical characteristics, including baseline LDL level. Further research is needed to explore statin therapy's impact on preserving brain vascular function beyond lipid-lowering effects.

Post-Stroke Brain Health Monitoring and Optimization: A Narrative Review.

Significant advancements have been made in recent years in the acute treatment and secondary prevention of stroke. However, a large proportion of stroke survivors will go on to have enduring physical, cognitive, and psychological disabilities from suboptimal post-stroke brain health. Impaired brain health following stroke thus warrants increased attention from clinicians and researchers alike. In this narrative review based on an open timeframe search of the PubMed, Scopus, and Web of Science databases, we define post-stroke brain health and appraise the body of research focused on modifiable vascular, lifestyle, and psychosocial factors for optimizing post-stroke brain health. In addition, we make clinical recommendations for the monitoring and management of post-stroke brain health at major post-stroke transition points centered on four key intertwined domains: cognition, psychosocial health, physical functioning, and global vascular health. Finally, we discuss potential future work in the field of post-stroke brain health, including the use of remote monitoring and interventions, neuromodulation, multi-morbidity interventions, enriched environments, and the need to address inequities in post-stroke brain health. As post-stroke brain health is a relatively new, rapidly evolving, and broad clinical and research field, this narrative review aims to identify and summarize the evidence base to help clinicians and researchers tailor their own approach to integrating post-stroke brain health into their practices.

Diffusion Restriction in the Splenium: A Comparative Study of Cytotoxic Lesions of the Corpus Callosum (CLOCCs) versus Lesions of Vascular Etiology.

Cytotoxic lesions of the corpus callosum (CLOCCs) have broad differential diagnoses. Differentiating these lesions from lesions of vascular etiology is of high clinical significance. We compared the clinical and radiological characteristics and outcomes between vascular splenial lesions and CLOCCs in a retrospective cohort study. We examined the clinical and radiologic characteristics and outcomes in 155 patients with diffusion restriction in the splenium of the corpus callosum. Patients with lesions attributed to a vascular etiology (N = 124) were older (64.1 vs. 34.6 years old, p < 0.001) and had >1 vascular risk factor (91.1% vs. 45.2%, p < 0.001), higher LDL and A1c levels, and echocardiographic abnormalities (all p ≤ 0.05). CLOCCs (N = 31) more commonly had midline splenial involvement (p < 0.001) with only splenial diffusion restriction (p < 0.001), whereas vascular etiology lesions were more likely to have multifocal areas of diffusion restriction (p = 0.002). The rate of in-hospital mortality was significantly higher in patients with vascular etiology lesions (p = 0.04). Across vascular etiology lesions, cardio-embolism was the most frequent stroke mechanism (29.8%). Our study shows that corpus callosum diffusion restricted lesions of vascular etiology and CLOCCs are associated with different baseline, clinical, and radiological characteristics and outcomes. Accurately differentiating these lesions is important for appropriate treatment and secondary prevention.

Intracranial Atherosclerosis Disease Associated With Cognitive Impairment and Dementia: Systematic Review and Meta-Analysis.

BACKGROUND: Intracranial atherosclerosis disease (ICAD) alters cerebrovascular hemodynamics and brain structural integrity. Multiple studies have evaluated the link between ICAD and cognitive impairment, with mixed results. This study aims to systematically review and summarize the current evidence on this link. METHODS AND RESULTS: PubMed, EMBASE, PsycInfo, and Web of Science were searched from 2000 to 2023 without language restriction. Cross-sectional and prospective cohort studies as well as postmortem studies were included. Studies containing data on the link between ICAD, defined as at least 50% stenosis in 1 intracranial vessel, and cognitive impairment and dementia were screened by 2 independent reviewers. A total of 22 (17 observational and 5 postmortem) unique studies, comprising 11 184 individuals (average age range, 59.8-87.6 years; 45.7% women; 36.5% Asian race), were included in the systematic review. Seven of 10 cross-sectional studies and 5 of 7 prospective studies showed a significant association between ICAD and cognitive impairment. In the pooled analysis, ICAD was associated with greater cognitive impairment (measure of association, 1.87 [95% CI, 1.49-2.35]). Meta-regression analyses did not show a significant impact of age, sex, and race. All postmortem studies showed that patients with Alzheimer disease and vascular dementia had a higher burden of ICAD compared with controls. CONCLUSIONS: This study shows that ICAD is associated with cognitive impairment and dementia across age, sex, and race groups. Our findings may underscore the need to develop individualized dementia preventive care plans in patients with ICAD.

Diffusion-Restricted Lesions of the Splenium: Clinical Presentation, Radiographic Patterns, and Patient Outcomes.

Background and Objectives: Diffusion-restricted (DR) lesions of the splenium are encountered in a wide variety of pathologies, and their significance is often unclear. We sought to report the spectrum of clinical presentations, neuroimaging patterns, and the predictors of radiographic and clinical outcomes from DR splenial lesions. Methods: This was a single-center, retrospective cohort study from January 1, 2009, to August 1, 2020. A consecutive sample of 3,490 individuals who underwent brain MRI with reported corpus callosum lesions during the study period were evaluated for DR lesions in the corpus callosum. DR lesions were defined as increased signal intensity on diffusion-weighted imaging sequences with decreased signal intensity on apparent diffusion coefficient. Patients with prior neurosurgical procedures, hemorrhage-associated DR, anoxic brain injury, and chronic or previously known or characterized disease processes in the corpus callosum were excluded. Clinical and radiologic outcomes were ascertained, including readmissions within 1 year, in-hospital mortality rates, and resolution of DR at first follow-up imaging. Outcomes were defined a priori. Results: Two hundred patients met criteria for inclusion. The average age was 57 years (standard deviation 19 years). Near half of the patients were women (47%). Encephalopathy (55%), focal weakness (46.5%), and cortical signs (44%) were the most common presenting clinical features. Thirty-five cases (17.5%) had features consistent with cytotoxic lesions of the corpus callosum (CLOCCs). Vascular causes were most frequent (61%), followed by malignancy-related (15%) and trauma (8%). In-hospital mortality occurred in 8.5% of cases, 46.5% were readmitted to the hospital within 1 year, and 49.1% of patients had resolution of the splenial DR at the next scan. Backward stepwise regression models showed that mass effect was negatively associated with splenial DR resolution (odds ratio [OR]: 0.12, confidence interval [CI] 0.03-0.46, p = 0.002). Encephalopathy was significantly associated with in-hospital mortality (OR: 4.50, CI 1.48-17.95, p = 0.007). Patients with a CLOCC had less frequent readmissions at 1-year compared with patients without a CLOCC, p = 0.015. Discussion: Vascular DR lesions of the splenium were more common than CLOCCs and other etiologies in this cohort. While splenial DR lesions can present a clinical challenge, their associated clinical and radiographic characteristics may predict outcome and guide prognosis.

The role of population-level preventive care for brain health in ageing.

Over the past several decades, a worldwide demographic transition has led to an increasing number of older adults with chronic neurological conditions. These conditions, which have a profound effect on the cognitive function and physical ability of older adults, also have a long preclinical phase. This feature provides a unique opportunity to implement preventive measures for high-risk groups and the population as a whole, and therefore to reduce the burden of neurological diseases. The concept of brain health has emerged as the overarching theme to define overall brain function independently of underlying pathophysiological processes. We review the concept of brain health from the ageing and preventive care perspectives, discuss the mechanisms underpinning ageing and brain ageing, highlight the interplay of various forces resulting in deviation from brain health towards brain disease, and provide an overview of strategies to promote brain health with a life-course approach.

Weight loss, visit-to-visit body weight variability and cognitive function in older individuals.

OBJECTIVE: to investigate the association between variability and loss of body weight with subsequent cognitive performance and activities of daily living in older individuals. DESIGN: cross-sectional cohort study. SETTING: PROspective Study of Pravastatin in the Elderly at Risk, multicentre trial with participants from Scotland, Ireland and the Netherlands. SUBJECTS: 4,309 participants without severe cognitive dysfunction (mean age 75.1 years, standard deviation (SD) = 3.3), at higher risk for cardiovascular disease (CVD). METHODS: body weight was measured every 3 months for 2.5 years. Weight loss was defined as an average slope across all weight measurements and as ≥5% decrease in baseline body weight during follow-up. Visit-to-visit variability was defined as the SD of weight measurements (kg) between visits. Four tests of cognitive function were examined: Stroop test, letter-digit coding test (LDCT), immediate and delayed picture-word learning tests. Two measures of daily living activities: Barthel Index (BI) and instrumental activities of daily living (IADL). All tests were examined at month 30. RESULTS: both larger body weight variability and loss of ≥5% of baseline weight were independently associated with worse scores on all cognitive tests, but minimally with BI and IADL. Compared with participants with stable weight, participants with significant weight loss performed 5.83 seconds (95% CI 3.74; 7.92) slower on the Stroop test, coded 1.72 digits less (95% CI -2.21; -1.13) on the LDCT and remembered 0.71 pictures less (95% CI -0.93; -0.48) on the delayed picture-word learning test. CONCLUSION: in older people at higher risk for CVD, weight loss and variability are independent risk-factors for worse cognitive function.

The Burden of Dementia Spectrum Disorders and Associated Comorbid and Demographic Features.

Dementia spectrum disorders (DSDs) are a major cause of mortality and disability worldwide. DSDs encompass a large group of medical conditions that all ultimately lead to major functional and cognitive decline and disability. Demographic and comorbid conditions that are associated with DSDs have significant prognostic and preventive implications. In this article, we will discuss the global and regional burden of DSDs and cover key demographic and clinical conditions linked with DSDs. In the absence of disease-modifying treatments, the role of primary prevention has become more prominent. Implementation of preventive measures requires an understanding of predisposing and exacerbating factors.

Primary Prevention of Ischemic Stroke.

Ischemic stroke is by far the most common type of cerebrovascular event and remains a major cause of death and disability globally. Despite advancements in acute stroke care, primary prevention is still the most cost-effective approach in reducing the burden of ischemic stroke. The two main strategies for primary stroke prevention include population-wide versus high-risk group interventions. Interventions such as increasing access to primary care, regulation of salt and sugar contents in processed foods, public education, and campaigns to control cerebrovascular risk factors are examples of population-wide interventions. High-risk group interventions, on the other hand, focus on recognition of individuals at risk and aim to modify risk factors in a timely and multifaceted manner. This article provides an overview on conventional modifiable risk factors for ischemic stroke and highlights the emerging risk factors and approaches for high-risk group identification and treatment.

Opinion & Special Article: Preventive Neurology: An Emerging Field Toward Brain Health.

With the rapid aging of populations, neurologic disorders have become among the leading causes of disability and mortality worldwide. Most neurologic conditions have a prolonged prodromal phase-even if they tend to manifest with an acute syndrome such as stroke-and can lead to a relentless, often deleterious course creating a major burden on patients, caregivers, and society. This unique nature of neurologic diseases signifies the strong need for equally effective primary and secondary prevention strategies and focus on brain health before brain diseases ensue. The field of preventive neurology applies both universal and selective primary prevention strategies to promote brain health both at the public and personal levels. The preventive neurology approach aims to identify and target high-risk individuals and protect them from reaching a critical point where overt clinical symptoms are present and disease progression is irreversible. Universal and selective prevention training, along with dovetailed clinical and public health research, are 3 essential pillars of preventive neurology. The burgeoning field of preventive neurology aims to assess neurologic care needs in a society, promote the participation of neurologists in restructuring of the health care policies to promote brain health, and identify medium- and high-risk individuals to prevent or delay future neurologic events.

Neurovascular-glymphatic dysfunction and white matter lesions.

Cerebral white matter lesions (WML) represent a spectrum of age-related structural changes that are identified as areas of white matter high signal intensity on brain magnetic resonance imaging (MRI). Preservation of white matter requires proper functioning of both the cerebrovascular and glymphatic systems. The cerebrovascular safeguards adequate cerebral blood flow to supply oxygen, energy, and nutrients through a dynamic process of cerebral autoregulation and neurovascular coupling to keep up with global and regional demands of the brain. The glymphatic system maintains white matter integrity by preserving flow of interstitial fluid, exchanging metabolic waste and eventually its clearance into the venous circulation. Here, we argue that these two systems should not be considered separate entities but as one single physiologically integrated unit to preserve brain health. Due to the process of aging, damage to the neurovascular-glymphatic system accumulates over the life course. It is an insidious process that ultimately leads to the disruption of cerebral autoregulation, to the neurovascular uncoupling, and to the accumulation of metabolic waste products. As cerebral white matter is particularly vulnerable to hypoxic, inflammatory, and metabolic insults, WML are the first recognized pathologies of neurovascular-glymphatic dysfunction. A better understanding of the underlying pathophysiology will provide starting points for developing effective strategies to prevent a wide range of clinical disorders among which there are gait disturbances, functional dependence, cognitive impairment, and dementia.

Contributions of Cerebral Blood Flow to Associations Between Blood Pressure Levels and Cognition: The Age, Gene/Environment Susceptibility-Reykjavik Study.

[Figure: see text].

Central nervous system vascular malformations: A clinical review.

CNS vascular malformation is an umbrella term that encompasses a wide variety of pathologies, with a wide range of therapeutic and diagnostic importance. This range spans lesions with a risk of devastating neurological compromise to lesions with a slow, static or benign course. Advances in neurovascular imaging along with increased utilization of these advances, have resulted in more frequent identification of these lesions. In this article, we provide an overview on definitions and classifications of CNS vascular malformations and outline the etiologic, diagnostic, prognostic, and therapeutic features for each entity. This review covers intracranial and spinal cord vascular malformations and discusses syndromes associated with CNS vascular malformations.

COVID-19 Respiratory Illness and Subsequent Cerebrovascular Events, the Initial Iranian Experience.

OBJECTIVES: COVID-19 disproportionately affects older adults and individuals with cardiovascular co-morbidities. This report presents fifteen patients who had COVID-19 respiratory illness followed by cerebrovascular events. MATERIALS AND METHODS: A call by the Iranian Neurological Association gathered cases across the country who developed neurological symptoms attributed to hemorrhagic or ischemic stroke after a definite or probable Covid-19 respiratory illness. Definite cases were those with a typical respiratory illness, positive nasopharyngeal Covid-19 PCR test, and chest CT consistent with Covid-19 infection. Probable cases were defined by a typical respiratory illness, history of contacts with a Covid-19 case, and chest CT characteristic for Covid-19 infection. RESULTS: Fifteen patients (12 men and 3 women) with an age range of 38 to 93 years old (median: 65 years old) were included. Fourteen patients had a first-ever acute ischemic stroke and one patient had a subarachnoid hemorrhage. Eleven patients (73%) had previous cardiovascular comorbidities. The median time between respiratory symptoms and neurological symptoms was seven days (range 1-16 days). Stroke severity in two patients was mild (NIHSS ≤ 6), in six patients moderate (NIHSS: 7-12), and in seven patients severe (NIHSS ≥13). One patient received intravenous tissue plasminogen activator ( IV-tPA) with improved neurological symptoms. Six out of 15 patients (40%) died. All but one of those who survived had significant disability assessed by a modified ranking scale >2. The majority of patients in this case series had vascular risk factors and their stroke was associated with severe disability and death. CONCLUSION: This report highlights the need for further investigation of the links between Covid-19 and cerebrovascular events.

Association of circulating metabolites in plasma or serum and risk of stroke: Meta-analysis from seven prospective cohorts.

OBJECTIVE: To conduct a comprehensive analysis of circulating metabolites and incident stroke in large prospective population-based settings. METHODS: We investigated the association of metabolites with risk of stroke in seven prospective cohort studies including 1,791 incident stroke events among 38,797 participants in whom circulating metabolites were measured by Nuclear Magnetic Resonance (1H-NMR) technology. The relationship between metabolites and stroke was assessed using Cox proportional hazards regression models. The analyses were performed considering all incident stroke events and ischemic and hemorrhagic events separately. RESULTS: The analyses revealed ten significant metabolite associations. Amino acid histidine (hazard ratio (HR) per standard deviation (SD) = 0.90, 95% confidence interval (CI): 0.85, 0.94; P = 4.45×10-5), glycolysis-related metabolite pyruvate (HR per SD = 1.09, 95% CI: 1.04, 1.14; P = 7.45×10-4), acute phase reaction marker glycoprotein acetyls (HR per SD = 1.09, 95% CI: 1.03, 1.15; P = 1.27×10-3), cholesterol in high-density lipoprotein (HDL) 2 and several other lipoprotein particles were associated with risk of stroke. When focusing on incident ischemic stroke, a significant association was observed with phenylalanine (HR per SD = 1.12, 95% CI: 1.05, 1.19; P = 4.13×10-4) and total and free cholesterol in large HDL particles. CONCLUSIONS: We found association of amino acids, glycolysis-related metabolites, acute phase reaction markers, and several lipoprotein subfractions with the risk of stroke. These findings support the potential of metabolomics to provide new insights into the metabolic changes preceding stroke.

N-Terminal Pro Brain, N-Terminal Pro Atrial Natriuretic Peptides, and Dynamic Cerebral Autoregulation.

Background Elevated natriuretic peptides (NP) are associated with adverse cerebrovascular conditions including stroke, cerebral small vessel disease, and dementia. However, the mechanisms underlying these associations remain unclear. In this study, we examined the relationship of NT-proBNP (N-terminal pro brain NP) and NT-proANP (N-terminal pro atrial NP) with cerebrovascular function, measured by cerebral autoregulation. Methods and Results We included 154 participants (mean age 56±4 years old) from the CARDIA (Coronary Artery Risk Development in Young Adults) cohort. NT-proBNP and NT-proANP were measured in blood samples from the year 25 examination using electrochemiluminescence Immunoassay and enzyme-linked immunoassay, respectively. Dynamic cerebral autoregulation (dCA) was assessed at the year 30 examination by transcranial Doppler ultrasound, using transfer function analysis (phase and gain) of spontaneous blood pressure and flow velocity oscillations, where lower phase and higher gain reflect less efficient cerebral autoregulation. We used multivariable linear regression models adjusted for demographics, vascular risk factors, and history of kidney and cardiac diseases. Higher NT-proBNP levels at year 25 were associated with lower phase (ß [95% CI]=-5.30 lower degrees of phase [-10.05 to -0.54]) and higher gain (ß [95% CI]=0.06 higher cm/s per mm Hg of gain [0.004-0.12]) at year 30. Similarly, higher NT-proANP levels were associated with lower phase (ß [95% CI]=-9.08 lower degrees of phase [-16.46 to -1.70]). Conclusions Higher circulating levels of NT-proBNP and NT-proANP are associated with less efficient dCA 5 years later. These findings link circulating NP to cerebral autoregulation and may be one mechanism tying NP to adverse cerebrovascular outcomes.

Ventricular Repolarization is Associated with Cognitive Function, but Not with Cognitive Decline and Brain Magnetic Resonance Imaging (MRI) Measurements in Older Adults.

We aimed to investigate the cross-sectional and longitudinal associations of electrocardiogram (ECG)-based QT, QTc, JT, JTc, and QRS intervals with cognitive function and brain magnetic resonance imaging (MRI) measurements in a cohort of older individuals at increased risk for cardiovascular disease, but free of known arrhythmias. We studied 4627 participants (54% female, mean age 75 years) enrolled in the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER). Ten-second ECGs were conducted at baseline. Cognitive function was tested at baseline and repeated during a mean follow-up time of 3.2 years. Structural MRIs were conducted in a subgroup of 535 participants. Analyses were performed with multivariable (repeated) linear regression models and adjusted for cardiovascular risk-factors, co-morbidities, and cardiovascular drug use. At baseline, longer QT, JT, JTc-but not QTc and QRS intervals-were associated with a worse cognitive performance. Most notably, on the Stroop Test, participants performed 3.02 (95% CI 0.31; 5.73) seconds worse per standard deviation higher QT interval, independent of cardiovascular risk factors and medication use. There was no association between longer ventricular de- or repolarization and structural brain measurements. Therefore, specifically ventricular repolarization was associated with worse cognitive performance in older individuals at baseline but not during follow-up.

A Case of Covid-19 Respiratory Illness with Subsequent Seizure and Hemiparesis.

BACKGROUND: Neurological manifestations and complications are common in viral infections, and they are significant sources for clinical deterioration and poor clinical outcomes. Case report: The current report presents a 38year-old man with Covid-19 respiratory illness who subsequently developed neurological complications and clinical worsening leading to death. This patient sought medical attention after five days of progressive cough, fever, and dyspnea. On arrival in the emergency room, he was found to have hypoxic respiratory failure resulting in intubation and intensive care unit (ICU) admission. Chest CT scan was characteristic for Covid-19 infection, and PCR test on tracheal samples confirmed the diagnosis. On day nine of admission, he developed generalized tonic colonic seizure associated with deterioration of mental status and hemiparesis. Repeated brain CT scans showed subcortical hypoattenuation with associated sulcal effacement in the left occipital and posterior parietal lobes concerning for ischemic changes. The patient passed away on day 17 despite supportive measures. CONCLUSION: This observation and recent evidence on Covid-19 CNS involvement highlight the need for further studies on early recognition of neurological complications in Covid-19 patients.

Profile of and risk factors for poststroke cognitive impairment in diverse ethnoregional groups.

OBJECTIVE: To address the variability in prevalence estimates and inconsistencies in potential risk factors for poststroke cognitive impairment (PSCI) using a standardized approach and individual participant data (IPD) from international cohorts in the Stroke and Cognition Consortium (STROKOG) consortium. METHODS: We harmonized data from 13 studies based in 8 countries. Neuropsychological test scores 2 to 6 months after stroke or TIA and appropriate normative data were used to calculate standardized cognitive domain scores. Domain-specific impairment was based on percentile cutoffs from normative groups, and associations between domain scores and risk factors were examined with 1-stage IPD meta-analysis. RESULTS: In a combined sample of 3,146 participants admitted to hospital for stroke (97%) or TIA (3%), 44% were impaired in global cognition and 30% to 35% were impaired in individual domains 2 to 6 months after the index event. Diabetes mellitus and a history of stroke were strongly associated with poorer cognitive function after covariate adjustments; hypertension, smoking, and atrial fibrillation had weaker domain-specific associations. While there were no significant differences in domain impairment among ethnoracial groups, some interethnic differences were found in the effects of risk factors on cognition. CONCLUSIONS: This study confirms the high prevalence of PSCI in diverse populations, highlights common risk factors, in particular diabetes mellitus, and points to ethnoracial differences that warrant attention in the development of prevention strategies.

Repeat variations in polyglutamine disease-associated genes and cognitive function in old age.

Although the heritability of cognitive function in old age is substantial, genome-wide association studies have had limited success in elucidating its genetic basis, leaving a considerable amount of "missing heritability." Aside from single nucleotide polymorphisms, genome-wide association studies are unable to assess other large sources of genetic variation, such as tandem repeat polymorphisms. Therefore, here, we studied the association of cytosine-adenine-guanine (CAG) repeat variations in polyglutamine disease-associated genes (PDAGs) with cognitive function in older adults. In a large cohort consisting of 5786 participants, we found that the CAG repeat number in 3 PDAGs (TBP, HTT, and AR) were significantly associated with the decline in cognitive function, which together accounted for 0.49% of the variation. Furthermore, in an magnetic resonance imaging substudy, we found that CAG repeat polymorphisms in 4 PDAGs (ATXN2, CACNA1A, ATXN7, and AR) were associated with different imaging characteristics, including brain stem, putamen, globus pallidus, thalamus, and amygdala volumes. Our findings indicate that tandem repeat polymorphisms are associated with cognitive function in older adults and highlight the importance of PDAGs in elucidating its missing heritability.