Cerebellar cognitive affective syndrome (Schmahmann syndrome) following isolated cerebellar infarction.

The cerebellum plays an important role in higher-order cognition through cerebrocerebellar networks. Lesions affecting this structure may result in cerebellar cognitive affective syndrome (CCAS), which is frequently underrecognized by routine cognitive screening tools. We reported a 69-year-old right-handed man who presented with 18 months of forgetfulness, impaired concentration, and irritability following a documented left cerebellar infarction. Neurological examination revealed cerebellar signs without cortical deficits. Brain magnetic resonance imaging (MRI) demonstrated a left cerebellar infarct with hemorrhagic transformation. While the Mini-Mental State Examination (MMSE) was normal and the Montreal Cognitive Assessment (MoCA) showed mild impairment, detailed neuropsychological assessment using CCAS Scale (CCAS-S) confirmed definite CCAS. This case highlights the importance of cerebellum-specific cognitive assessment in patients with isolated cerebellar stroke, as conventional screening tools might underestimate multidomain cognitive and affective disturbances.