An 81-year-old female presented with a right pontine infarct and later developed recurrent vivid hallucinations. After a workup for delirium and hallucinosis was unrevealing, a diagnosis of peduncular hallucinosis (PH) was proposed. Treatment with quetiapine and, later, adjunctive nightly melatonin resulted in return to cognitive baseline. An array of etiologies can be responsible for visual hallucinations, including PH. Herein, we review several disorders of hallucinosis and their diagnostic workup. Additionally, we explore the pathophysiology of PH and its association with the pontine-geniculate-occipital (PGO) pathway and propose why correction of the sleep-wake cycle may benefit patients with PH.
Keywords: Peduncular hallucinosis; melatonin; pontine-geniculate-occipital pathway; stroke; visual hallucinations.