Spinal segmental myoclonus related to pregnancy.

A 33-year-old pregnant woman (gestational age, 39 weeks and 2 days) presented with a one-day history of abdominal rhythmic myoclonus. Gynecological examination revealed that the cervix was unfavorable with irregular contractions that were ineffective. Electroencephalography, MRI of the dorsal spine and blood biochemical, examinations were normal. Electrophysiological recordings from the rectus abdominis muscles with surface electrodes showed 2 Hz rhythmic myoclonic activity bursts. On the same day, the delivery was induced and the frequency and severity of involuntary contractions decreased and disappeared in two days. This is the first case of abdominal myoclonus developed as a complication of pregnancy or delivery.