A 12-year-old girl presenting with writer’s cramp as the first manifestation of basal ganglia arteriovenous malformation (AVM) is reported from the Department of Neurosurgery, University of Tokyo, Japan. Difficulty in writing caused by too firm a pen grasp developed at 9 years of age and progressively worsened until at 11 years, she had weakness and involuntary movements of the right hand. At 12 years, she had severe headache with nausea and vomiting. MRI showed an unruptured left basal ganglia AVM localized to the globus pallidus and putamen, and extending to the left frontal lobe white matter. Cerebral angiography revealed a large high-flow AVM fed by lenticulostriate arteries. Treated conservatively, the dystonic cramp and weakness have not progressed during one year follow-up. 
COMMENT. AV malformation presenting as writer’s cramp is a novel case-report. The location and size of the lesion appear to have prompted conservative management. A review of the literature in 1994 revealed that AVM mortality was 23-57% with conservative management versus 8.5-11% postoperatively. The smaller the AVM, the higher the risk of hemorrhage and the greater the indication for surgery. (See Progress in Pediatric Neurology III, PNB Publ, 1997;p458).