Search

Cerebral small vessel disease (CSVD) encompasses a broad clinical spectrum united by pathology of the small vessels of the brain. CSVD is commonly identified using brain magnetic resonance imaging with well characterized markers including covert infarcts, white matter hyperintensities, enlarged perivascular spaces, and cerebral microbleeds. The pathophysiology of CSVD is complex involving genetic determinants, environmental factors, and their interactions. While the role of vascular risk factors in CSVD is well known and its management is pivotal in mitigating the clinical effects, recent research has identified novel genetic factors involved in CSVD. Delineating genetic determinants can promote the understanding of the disease and suggest effective treatments and preventive measures of CSVD at the individual level. Here we review CSVD focusing on recent advances in the genetics of CSVD. The knowledge gained has advanced understanding of the pathophysiology of CSVD, offered promising early results that may improve subtype identification of small vessel strokes, has led to additional identification of mendelian forms of small vessel strokes, and is getting closer to influencing clinical care through pharmacogenetic studies.

Supplemental material, sj-docx-1-wso-10.1177_17474930231155816 for Pleiotropy analysis between lobar intracerebral hemorrhage and CSF β-amyloid highlights new and established associations by Sandro Marini, Jaeyoon Chung, Xudong Han, Xinyu Sun, Livia Parodi, Lindsay A Farrer, Jonathan Rosand, Jose Rafael Romero and Christopher D Anderson in International Journal of Stroke

Supplemental material, sj-docx-1-wso-10.1177_17474930231155816 for Pleiotropy analysis between lobar intracerebral hemorrhage and CSF β-amyloid highlights new and established associations by Sandro Marini, Jaeyoon Chung, Xudong Han, Xinyu Sun, Livia Parodi, Lindsay A Farrer, Jonathan Rosand, Jose Rafael Romero and Christopher D Anderson in International Journal of Stroke

Background and purposeStroke is the leading cause of death and long-term disability worldwide. Previous genome-wide association studies identified 51 loci associated with stroke (mostly ischemic) and its subtypes among predominantly European populations. Using whole-genome sequencing in ancestrally diverse populations from the Trans-Omics for Precision Medicine (TOPMed) Program, we aimed to identify novel variants, especially low-frequency or ancestry-specific variants, associated with all stroke, ischemic stroke and its subtypes (large artery, cardioembolic, and small vessel), and hemorrhagic stroke and its subtypes (intracerebral and subarachnoid).MethodsWhole-genome sequencing data were available for 6833 stroke cases and 27 116 controls, including 22 315 European, 7877 Black, 2616 Hispanic/Latino, 850 Asian, 54 Native American, and 237 other ancestry participants. In TOPMed, we performed single variant association analysis examining 40 million common variants and aggregated association analysis focusing on rare variants. We also combined TOPMed European populations with over 28 000 additional European participants from the UK BioBank genome-wide array data through meta-analysis.ResultsIn the single variant association analysis in TOPMed, we identified one novel locus 13q33 for large artery at whole-genome-wide significance (P

Background and objectives Cerebral microbleeds (CMBs) are a neuroimaging expression of small vessel disease (SVD). We investigated in a cohort of SVD patients with mild cognitive impairment (MCI): 1) the reliability of the Microbleed Anatomical Rating Scale (MARS); 2) the burden and location of CMBs and their association with cognitive performances, independent of other clinical and neuroimaging features. Methods Patients underwent clinical, neuropsychological (4 cognitive domains), and MRI assessments. CMBs were assessed by three raters. Results Out of the 152 patients (57.2% males; mean age ± SD: 75.5 ± 6.7 years) with gradient-echo (GRE) sequences, 41 (27%) had at least one CMB. Inter-rater agreement for number and location of CMBs ranged from good to very good [multi-rater Fleiss kappa (95%CI): 0.70–0.95]. Lacunar infarcts and some clinical variables (e.g., hypertension and physical activity) were associated with CMBs in specific regions. Total number of CMBs and of those in deep and lobar regions were associated with attention/executive and fluency domains. Discussion MARS is a reliable instrument to assess CMBs in SVD patients with MCI. Nearly one third of these patients had at least one CMB. Total CMBs burden was associated with attention/executive functions and fluency domains impairment, lacunar infarcts, and with some potentially modifiable risk factors.

Background and objective Vascular cognitive impairment may have a selective neuropsychological profile. We developed a battery for assessing mild cognitive impairment (MCI) in patients with small vessel disease (SVD), its applicability, and psychometric properties. Methods Among those proposed by the 2006 NINDS-CSN Consensus Conference, we selected tests for which norms based on healthy Italians and equivalent scores methodology were available. Confirmatory factor analysis was applied to ascertain the fit of the theoretically assumed dimensions to empirical data and to derive each cognitive dimension compound measures. Results The entire battery was applied to 146 out of a cohort of 201 patients with MCI and SVD. Most tests showed good applicability. Fifty-five patients, who were older and cognitively more impaired, proved unable to complete the Trail Making Test part B, the Rey-Osterrieth Complex Figure, and the Stroop test, and were excluded from the analysis. Among the remaining patients, Mini-Mental State Examination proved largely normal, while Rey-Osterrieth Complex Figure, Symbol digit modalities test, and Trail Making Test part B were most frequently abnormal. Confirmatory factor analysis showed a good fit of the 4-factor theoretical model to empirical data. Praxis domain resulted in the highest percentage of abnormal performance (65%), followed by Memory and Attention/EF domains (19% and 15%), and Language (8%). Conclusions Our battery proved to be comprehensive, robust, and applicable. Attention-executive dysfunction and impaired memory and visuo-constructional abilities, were the prominent features. The assessment of the Consensus Conference, that included Trial Making Test, looks poorly applicable to older and cognitively impaired patients.

We aimed to characterize the genetics of endothelial function and how this influences risk for cardiovascular diseases such as ischemic stroke. We integrated genetic data from a study of ultrasound flow-mediated dilatation of brachial artery in adolescents from ALSPAC (Avon Longitudinal Study of Parents and Children; n=5214) with a study of ischemic stroke (MEGASTROKE: n=60 341 cases and 452 969 controls) to identify variants that confer risk of ischemic stroke through altered endothelial function. We identified a variant in PDE3A (Phosphodiesterase 3A), encoding phosphodiesterase 3A, which was associated with flow-mediated dilatation in adolescents (9-12 years of age; β[SE], 0.38 [0.070]; P=3.8×10-8) and confers risk of ischemic stroke (odds ratio, 1.04 [95% CI, 1.02-1.06]; P=5.2×10-6). Bayesian colocalization analyses showed the same underlying variation is likely to lead to both associations (posterior probability, 97%). The same variant was associated with flow-mediated dilatation in a second study in young adults (age, 24-27 years; β[SE], 0.47 [0.23]; P=0.047) but not in older adults (β[SE], -0.012 [0.13]; P=0.89). We conclude that a genetic variant in PDE3A influences endothelial function in early life and leads to increased risk of ischemic stroke. Subtle, measurable changes to the vasculature that are influenced by genetics also influence risk of ischemic stroke.

Aims: The DSM-5 introduced the term “major neurocognitive disorders” (NCDs) to replace the previous term “dementia.” However, psychometric and functional definitions of NCDs are missing. We aimed to apply the DSM-5 criteria for diagnosing the transition to NCD to patients with mild cognitive impairment (MCI) and small vessel disease (SVD), and to define clinically significant thresholds for this transition. Methods: The functional and cognitive features of the NCD criteria were evaluated as change from baseline and operationalized according to hierarchically ordered psychometric rules. Results: According to the applied criteria, out of 138 patients, 44 were diagnosed with major NCD (21 with significant cognitive worsening in ≥1 additional cognitive domain), 84 remained stable, and 10 reverted to normal. Single-domain MCI patients were the most likely to revert to normal, and none progressed to major NCD. The amnestic multiple-domain MCI patients had the highest rate of progression to NCD. Conclusion: We provide rules for the DSM-5 criteria for major NCD based on cognitive and functional changes over time, and define psychometric thresholds for clinically significant worsening to be used in longitudinal studies. According to these operationalized criteria, one-third of the MCI patients with SVD progressed to major NCD after 2 years, but only within the multiple-domain subtypes.