Hyperekplexia: report of a nonfamilial adult onset case associated with obstructive sleep apnea and abnormal brain nuclear tomography.

We report the unique occurrence of hyperekplexia and obstructive sleep apnea (OSA) in a 48-year-old male. Polysomnography and multiple sleep latency testing excluded cataplexy, which can be confused with startle attacks. A new imaging finding was a nuclear tomography abnormality in the left frontal lobe. We postulate that this finding may represent a functional cortical lesion of a descending pathway that normally inhibits the startle reflex. Serious complications of pharmacotherapy with clonazepam, the drug of choice for hyperekplexia, can be avoided by first evaluating for OSA.