LAUSR

An estimated 1% of professional musicians are affected by dystonia, and many experience dystonia exclusively while playing an instrument. The common musical instruments associated with musician’s dystonia are the piano, guitar, and the brass instruments [1]. Musician’s dystonia with a traditional musical instrument, however, has rarely been reported [2]. Herein, we report a 33-year-old male patient with left arm dystonic tremor while playing a Korean traditional woodwind instrument, the “Piri.” The patient, a bandsman of the Korean Musical Orchestra, complained of evolving tremor of the left arm that occurred exclusively while playing the Piri. His unilateral, task-specific, upper limb tremor emerged 4 years ago when he began to practice a new skill to improve his playing. Piri musicians voluntarily move the instrument back and forth while playing to make reverberated sounds (Fig. 1a and b). They intentionally flex and extend their forearms to alter the pitch of their playing. The patient had been trained to play the instrument using the right arm for more than 10 years to vibrate the flow of the sound, but he decided to switch the technique to the left arm. The symptom occurred after spending hours of focused training of the left arm for several months. The patient noticed insidious painless fatigue and awkwardness of his left arm, but it was ignorable at the beginning. After 2 years of practicing, the patient noticed aggravation of his left arm tremor, forcing him to exert more effort to perform the task. The symptoms began at the start of his musical performance and stopped immediately after he removed the Piri from his mouth. The tremor did not appear at the preparatory stage; it arose only when he placed his lips on the mouthpiece and started to blow. When the patient alternately played the Piri with each arm, only the left arm displayed tremor. Furthermore, his left arm trembled even while playing the Piri with his right hand when the left was not in contact with the instrument (Video Segment 1). The tremors were typically short-lived as long as he was not playing. A few months prior to his visit to our clinic, the patient noticed that his left arm shook while he was drinking from a cup (Video Segment 2). He had no past medical history and denied exposure to any medications, including neuroleptics. The patient never suffered any orthopedic problem with his limbs. He did not have any family members with hyperkinetic or hypokinetic disorders. Attempted treatment with a beta-blocker (propranolol) and a benzodiazepine did not alleviate his symptoms. Neurologic examinations did not reveal any abnormality. Neither spontaneous nor postural tremor were observed, and his muscle tone was normal. He did not describe any pain that might have caused the symptoms. Laboratory examinations, including measurements of serum ceruloplasmin, copper levels, thyroid function, and biochemical screenings, were unremarkable. His brain magnetic resonance imaging, including nigrosome 1 and neuromelanin imaging did not display any abnormalities. A genetic study of DYT1 and whole exome sequencing did not find any abnormalities. Surface electromyography (sEMG) was performed to evaluate the nature of the tremor. At the resting position, there were not any subclinical activations of the recorded left biceps and triceps and right biceps muscles (Fig. 1c). At the preparatory posture without the instrument, neither abnormal co-contractions nor oscillatory muscle activations were provoked (Fig. 1d). sEMG revealed rhythmical co-contractions of the left biceps and triceps, predominantly the biceps, of 6 Hz when he played the Piri (Fig. 1e). The amplitudes were inconstant. * Joong-Seok Kim [email protected]