Visual hallucinations following a left-sided unilateral tuberothalamic artery infarction.

A 20-year-old man presented with realistic visual hallucinations and no motor or sensory neurological findings. The absence of motor or sensory deficits on physical examination made for a diagnostic challenge, but an altered mental status with dysnomic word-finding difficulty was the clue to the existence of an encephalopathy that resulted in evaluation for structural pathology. Brain imaging revealed an infarction in the territory of the left tuberothalamic artery. A head magnetic resonance imaging scan identified the neuropathology that led to immediately starting treatment for stroke.