Dystonia in ataxia telangiectasia: report of a case with putaminal lesions and decreased striatal [123I]iodobenzamide binding.

A 6-year-old girl with ataxia telangiectasia and severe progressive dystonic posturing is presented. Magnetic resonance imaging showed cerebellar atrophy and a right-sided putaminal lesion. A single-photon emission computed tomography study of cerebral dopamine-(D2)-receptor binding with [123I]iodobenzamide showed a decreased tracer uptake in the striatum bilaterally. Dystonia deteriorated with levodopa treatment, whereas trihexyphenidyl led to significant improvement. Although dystonic symptoms have been repeatedly described in ataxia telangiectasia, this is the first report demonstrating structural and functional basal ganglia abnormalities in this disorder.