A 41-year-old woman with untreated hyperlipidemia and a history of cigarette smoking was evaluated at the emergency room 3 days previously because of new-onset nausea, vomiting, and disequilibrium. Diagnosed with flu and depression, she was sent home in a wheelchair, to be readmitted a day later because of occipital headaches and increasing gait unsteadiness.

Our patient had an acute cerebellar infarction involving the territory of the PICA. Fortunately, despite the initial misdiagnosis, she had a good clinical outcome.

The brainstem, cerebellum, and labyrinths are supplied by the vertebrobasilar arterial system. The areas of the cerebellum supplied by the PICA are extremely variable. There are several different patterns of PICA territory cerebellar infarctions. If the medial branch is affected, involving the vermis and vestibulocerebellum, the clinical findings include prominent vertigo, ataxia, and nystagmus. If the lateral cerebellar hemisphere is involved,
patients can have vertigo, gait ataxia, limb dysmetria and ataxia, nausea, vomiting, conjugate or dysconjugate gaze palsies, miosis, and dysarthria.