A Case with Dopamine-Antagonist Responsive Repetitive Head Punching as Rhythmic Movement Disorder during Sleep
A 17-year-old male presented with recurrent rhythmic movement since the age of five. He repetitively tapped his brow or chin with the right fist only during sleep. The duration of this rhythmic movement ranged from 10 seconds to five minutes. Sometimes he repetitively punched the brow hard enough to render skin reddish discoloration. This behavior recurred almost every day. Upon admission, video-EEG monitoring demonstrated that the patient struck his brow with the right fist for one minute during the light sleep. The frequency of tapping during the monitoring was 2 Hz. There was no EEG change. Previously, under the impression of frontal lobe complex partial seizure, various ant-epileptic drugs including oxcarbazepine, zonisamide, levetiracetam and clobazam had been administered to control this symptom without any significant improvement. With the diagnosis of the rhythmic movement during sleep, clonazepam was prescribed before night time sleep. The dose of clonazepam was increased up to three mg per day. Clonazepam could not alter the symptom and induced only daytime drowsiness as an adverse event. Levodopa 250 mg plus carbidopa 25 mg were administered as a therapeutic challenge. Surprisingly this rhythmic movement increased dramatically in intensity and duration. The patient more or less violently punched his brow for four or five hours every night. With the hint of aggravating symptom by dopamine-agonist, haloperidol was chosen. One mg of haloperidol could markedly suppress the symptom to one-tenth degree in the intensity and duration compared with the symptom of the initial presentation. To avoid long-term adverse events, haloperidol was switched to pimozide two mg just before the night time sleep. After five days of administration, the rhythmic movement was completely disappeared for the following two months. The symptom reappeared after two months. However, the intensity was very mild and the duration was very short, which the parents could not notice the movement without careful observation for a whole night.