Cognition in cerebellar disorders: What's in the profile? A systematic review and meta-analysis

This systematic review and meta-analysis aim to examine the profile and extent of cognitive deficits in patients with cerebellar disorders, and to provide a complete overview of the cognitive domains that might be affected in the Cerebellar Cognitive Affective Syndrome (CCAS).

MEDLINE, Embase, PsycINFO, and Web of Science were systematically searched to 17-07-2024. Studies were considered if the participants were adult patients with a clinical diagnosis of cerebellar disorder and were neuropsychological assessed. Outcomes were grouped into the domains of processing speed, language, social cognition, executive function, visuospatial skills, episodic memory, verbal intelligence, attention, and working memory. All aetiologies were included for first evaluation and patients were assigned to one of two groups (focal vs. degenerative) for secondary evaluation. Random-effects models were employed for the meta-analyses.

129 studies with a total of 3140 patients with cerebellar disorders were included. Patients performed significantly worse compared to control/standardized data in all domains. Deficits were most pronounced in processing speed, ES [95% CI] = - 0.83 [- 1.04, - 0.63], language, ES [95% CI] = - 0.81 [- 0.94, - 0.67], and social cognition, ES [95% CI] = - 0.81 [- 1.19, - 0.42]. Cognitive impairment varied between patients with focal cerebellar lesions and degenerative cerebellar disorders, but was overall worse in the degenerative group.

Cerebellar disorders can impact many cognitive domains, extending beyond executive functioning, visuospatial skills, and language. These outcomes contribute to a broader understanding of the cerebellum's role in cognition and sheds light on the cognitive deficits associated with cerebellar disorders.