Cerebellar Grey Matter Volumes in Reactive Aggression and Impulsivity in Healthy Volunteers.

Several lines of evidence point towards the involvement of the cerebellum in reactive aggression. In addition to the posterior cerebellar hemisphere, the vermis has been suggested to play a prominent role in impulse regulation. In the present study, we set out to further examine the relationships between cerebellar grey matter volumes, aggression, and impulsivity in 201 healthy volunteers. 3 T structural magnetic resonance imaging scans were acquired to investigate grey matter volumes of the cerebellar vermis and the anterior and posterior lobules. Aggression was assessed with the Buss-Perry Aggression Questionnaire and impulsivity was measured with the Barratt Impulsiveness Scale-11. Results showed that impulsivity was positively associated with grey matter volumes of the cerebellar vermis and inversely correlated with grey matter volumes of the right posterior lobule. In addition, smaller volumes of the right posterior lobules were associated with higher physical aggression. Exploratory analyses indicated that for the right hemisphere, this association was driven by grey matter volumes of lobules VIIb and VIIIa. Our findings provide correlational evidence in healthy volunteers for the involvement of the cerebellar vermis and posterior lobules in a cortico-limbic-cerebellar circuit of aggression.

Microvascular Dysfunction Is Associated With Worse Cognitive Performance: The Maastricht Study.

Microvascular dysfunction may be associated with worse cognitive performance. Most previous studies did not adjust for important confounders, evaluated only individual measures of microvascular dysfunction, and showed inconsistent results. We evaluated the association between a comprehensive set of measures of microvascular dysfunction and cognitive performance in the population-based Maastricht Study. We used cross-sectional data including 3011 participants (age 59.5±8.2; 48.9% women; 26.5% type 2 diabetes mellitus [oversampled by design]). Measures of microvascular dysfunction included magnetic resonance imaging features of cerebral small vessel disease, plasma biomarkers of microvascular dysfunction, albuminuria, flicker light-induced retinal arteriolar and venular dilation response and heat-induced skin hyperemia. These measures were summarized into a microvascular dysfunction composite score. Cognitive domains assessed were memory, processing speed, and executive function. A cognitive function score was calculated as the sum of the scores on these 3 cognitive domains. The microvascular dysfunction score was associated with a worse cognitive function score (standardized ß, -0.087 [95% CI, -0.127 to -0.047]), independent of age, education level, sex, type 2 diabetes mellitus, smoking, alcohol use, hypertension, total/HDL (high-density lipoprotein) cholesterol ratio, triglycerides, lipid-modifying medication, prior cardiovascular disease, depression and plasma biomarkers of low-grade inflammation. The fully adjusted ß-coefficient of the association between the microvascular dysfunction score and the cognitive function score was equivalent to 2 (range, 1-3) years of aging for each SD higher microvascular dysfunction score. The microvascular dysfunction score was associated with worse memory and processing speed but not with worse executive function. The present study shows that microvascular dysfunction is associated with worse cognitive performance.