Abstract
Bilateral cerebellar infarction due to unilateral occlusion of the posterior inferior cerebellar artery (PICA) is extremely rare, particularly when a bihemispheric PICA variant is present. We report the case of an 81-year-old male with a history of hypertension and diabetes who presented with recurrent vomiting and gait disturbance, eventually progressing to a comatose state. MRI revealed bilateral cerebellar infarctions sparing the brainstem and ventricular enlargement consistent with obstructive hydrocephalus. Magnetic resonance angiography (MRA) demonstrated occlusion of the right PICA, while an earlier MRA had identified a bihemispheric PICA variant originating from the right vertebral artery and supplying both cerebellar hemispheres. Echocardiography did not reveal any embolic source. This case underscores the clinical importance of early recognition of rare vascular anomalies, such as the bihemispheric PICA variant, which is critical for optimal stroke management and the prevention of complications like obstructive hydrocephalus.