Myoclonus associated with megestrol acetate

Abstract

Myoclonus is a clinical sign characterized by brief, involuntary, jerky contraction or lapse of contraction of a muscle or a group of muscles, which can be associated with cerebral disorders, epileptic disorders, and drugs. Megestrol acetate (MGA) is a synthetic derivative of progestin, which has been widely used in clinical practice for increasing appetite in patients with severe anorexia associated with malignancies. We experienced a 68-year-old female patient who experienced myoclonus after administration of MGA and herein report the case. Our case indicated that MGA may be a cause of reversible myoclonus. Cryptogenic myoclonus can be encountered in patients with wasting syndromes associated with malignancies. It may be a cause of unexplained myoclonus in such patients.