Repeated transcranial magnetic stimulation (rTMS) has been suggested to be a therapeutic approach for rehabilitation after stroke. Generally, it is considered a safe and well-tolerated procedure, however, it can cause some adverse. In this article, we report a case of choreic movement as an adverse effect of rTMS in the patient with thalamic pain after stroke.

Case report: a 65-year-old female was admitted to our rehabilitation department for management of thalamic pain after stroke. We tried many pharmacologic treatments to relieve her thalamic pain, however it was not successful. We applied rTMS to her pain. RTMS was applied over the left M1 area using a navigation system. She received 10 rTMS sessions for 2 weeks. Each session was consisted of a total of 1000 pulses at 10Hz with intensity of 90% of resting motor threshold (RMT) for 20minutes.

After 5 therapeutic rTMS sessions, her pain and hand function were improved. The pain was reduced and the right thumb opposition became possible that she could not perform before rTMS. After 8 sessions, she reported an abnormal involuntary movement of the right-hand, lasts less than 10seconds, once a day. After 10 sessions, her pain and hand function were more improved. However, frequency and intensity of the abnormal involuntary hand movement were increased while the improvements in thalamic pain and hand function were maintained. We consulted the neurologist about the symptom with a video. The neurologist diagnosed it as an episodic choreic movement of the hand and recommended haloperidol if the symptom worsens. The episodic choreic movement gradually decreased without medication, and it disappeared after one month.

This is the first report of rTMS related choreic movement as an adverse effect of rTMS after stroke.