Cerebellar Cognitive Affective Syndrome in the Context of Crossed Cerebellar Diaschisis Post Pontine Infarction

Crossed cerebellar diaschisis (CCD) is characterized by reduced blood flow and hypometabolism in the cerebellum secondary to a supratentorial lesion in the contralateral cerebral hemisphere. Although CCD due to an infratentorial lesion, particularly a pontine infarction, is rare, it has been previously described. We report a case of a middle-aged man with left paramedian pontine infarction who developed new-onset cognitive dysfunction. Neuropsychological assessment revealed deficits consistent with cerebellar cognitive affective syndrome (CCAS). Brain single-photon emission computed tomography showed hypometabolism in the posterior right cerebellar hemisphere, consistent with CCD. We hypothesize that the cognitive dysfunction, compatible with CCAS following the left pontine infarction, can be explained by CCD-related hypometabolism in the right cerebellum. This case contributes to the limited literature on CCD from infratentorial lesions, emphasizing the potential for CCAS to arise from pontine infarction.