Peduncular hallucinosis following microvascular decompression for trigeminal neuralgia: report of a case.

Peduncular hallucinosis usually presents as a visual disorder and is often a genuine hallucination associated with mesencephalic lesions. A 62-year-old woman with trigeminal neuralgia underwent microvascular decompression for facial pain through a lateral suboccipital approach. The pain completely disappeared after surgery, but a visual hallucination developed on the second postoperative day and continued for 5 days. Magnetic resonance imaging confirmed the lesions around the mesencephalon.