Chance Encounter of Mega Cisterna Magna in a Case with Cerebellar Diaschisis following Ischemic Stroke

Mega Cisterna Magna (MCM) has been known as a developmental abnormality within the Dandy-Walker complex, characterized by an expanded cisterna magna exceeding 10 mm. While MCM often presents asymptomatically, it has been associated with mental disorders and cognitive decline. Differential diagnosis between MCM and arachnoid cyst is crucial due to their shared embryonic origin. Crossed Cerebellar Diaschisis (CCD) denotes functional decline in the contralateral cerebellar hemisphere due to a supratentorial lesion. CCD has associations with postural disturbance and complex regional pain syndrome. Notably, no literature discusses the co-occurrence of MCM and CCD. Here, we present a unique case involving underscore the significance and rarity of the change encounter of MCM and CCD. To our knowledge, this is the first case linking CCD to MCM, highlighting the need for further research elucidating their relationship and impact on clinical outcomes.