Twenty-four young adults with infratentorial infarcts were evaluated by MRI and angiography and assessed by neuropsychological tests, acutely and at 4 and 12 months after the stroke, in a prospective study at the University of Umea, Sweden. Twenty two had a favorable outcome, but most performed worse than controls on tasks of attention, visuospatial skills, working memory, and cognitive flexibility. IQ scores were related to size of infarct, and early post-stroke, block design task performance predicted maximal work performance at 12 months. Standard tests of intelligence and episodic memory were unchanged, and the neurologic examination was normal. However, only 57% of patients were at work full-time 1 year after the stroke. Headache, fatigue, anxiety, and memory disturbance contributed to the disability. 
COMMENT. Cerebellar damage from infarcts in young adults impairs attention, working memory, and visuospatial skills, while sparing, intelligence and episodic memory. Working memory involves short-term, temporary, and recalled experiences used to support other mental functions. Whereas digit and word span tasks requiring passive repetition are unaffected by cerebellar damage, a more demanding and complex listening span task, requiring repetition of words while simultaneously trying to analyze sentences, is significantly impaired.
Hypoplasia of the cerebellar vermis following cranial irradiation for acute leukemia has been correlated with cognitive deficits involving visuospatial coordination and memory while sparing language and verbal processing (see Progress in Pediatric Neurology III, 1997; pp423-4). The cerebellum and/or its connections with fronto-striate regions have important cognitive functions.