The cerebellar cognitive affective syndrome

TLDR

Neuroimaging studies indicate the cerebellum contributes to higher‑order functions, yet few clinical cases have explored this role. The authors define the newly identified clinical entity as the “cerebellar cognitive affective syndrome.” They examined 20 patients with isolated cerebellar disease using neurological exams, bedside mental state tests, neuropsychological assessments, and anatomical imaging to evaluate the nature and severity of neurological and mental changes. Patients with posterior cerebellar and vermian lesions show prominent deficits in executive, spatial, affective, and language domains, while anterior lobe lesions produce only minor executive and visual‑spatial impairments, suggesting that cerebellar modulation of prefrontal, parietal, temporal, and limbic circuits underlies the syndrome.

Abstract

Anatomical, physiological and functional neuroimaging studies suggest that the cerebellum participates in the organization of higher order function, but there are very few descriptions of clinically relevant cases that address this possibility. We performed neurological examinations, bedside mental state tests, neuropsychological studies and anatomical neuroimaging on 20 patients with diseases confined to the cerebellum, and evaluated the nature and severity of the changes in neurological and mental function. Behavioural changes were clinically prominent in patients with lesions involving the posterior lobe of the cerebellum and the vermis, and in some cases they were the most noticeable aspects of the presentation. These changes were characterized by: impairment of executive functions such as planning, set-shifting, verbal fluency, abstract reasoning and working memory; difficulties with spatial cognition including visual-spatial organization and memory; personality change with blunting of affect or disinhibited and inappropriate behaviour; and language deficits including agrammatism and dysprosodia. Lesions of the anterior lobe of the cerebellum produced only minor changes in executive and visual-spatial functions. We have called this newly defined clinical entity the 'cerebellar cognitive affective syndrome'. The constellation of deficits is suggestive of disruption of the cerebellar modulation of neural circuits that link prefrontal, posterior parietal, superior temporal and limbic cortices with the cerebellum.