Reversible Palinacousis From Intracranial Metastases

Palinacousis is an auditory illusion consisting of perseveration or echoing of an external auditory stimulus after it has ceased. This rare clinical symptom has been reported in ictal (seizure), postictal, and nonictal states, and causative lesions have been most consistently found in or near the temporal lobes. It is distinct from the auditory hallucinations seen in psychiatric illness. We report the case of a 61-year-old man who experienced several days of palinacousis while undergoing treatment for newly diagnosed metastatic lung adenocarcinoma. Palinacousis was presumed to be triggered by intracranial metastases near the auditory cortex. An electroencephalogram showed bilateral theta slowing over the left greater than right temporal lobes without epileptiform activity. Palinacousis remitted with corticosteroid and whole brain radiation therapy.