A young man with a jerky hand

CASE PRESENTATION A 17-year-old right-handed man with a previous history of a complex partial seizure disorder since age 5 years presented to an outside institution with 'jerky' movements limited to the left upper extremity. These movements were predominantly in the fingers, wrist, and elbow. He had been seizure-free for 3 years prior to presentation and was on therapeutic levels of valproate. One week following presentation he noticed his left upper extremity was developing a flexed posture at the wrist, elbow, and fingers. He continued to experience twitching as well as jerks of his left proximal and distal upper extremity (see video, Case 84). There was no alteration in consciousness associated with the symptoms. He was tried on multiple anticonvulsants, including gabapentin 1500 mg three times daily and tiagabine 16 mg three times daily, but they failed to improve the movements. His electroencephalogram (EEG) and magnetic resonance imaging (MRI) of the head were reportedly normal at the time of initial examination. After failing therapy with antiepileptic medications, an alternative diagnosis of myoclonus - dystonia syndrome was presumptively assigned, and he was tried on maximal doses of anticholinergics, beta-blockers, levodopa, and botulinum toxin, all of which failed to result in benefit. Deep brain stimulation of the right globus pallidus was also unsuccessful at improving his symptoms.