Imaging techniques in Parkinson's disease

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.

The detection of preclinical Parkinson's disease: what is the role of positron emission tomography?

On clinical criteria alone, the diagnosis of early Parkinson's disease can be difficult and, by definition, the prospective recognition of preclinical Parkinson's disease is impossible. Positron emission tomography (PET) using [18F]dopa as tracer has been proposed as a means of identifying patients with preclinical disease. The number of subjects detected to date has been few; most have been identified by serendipity or during the course of family studies. This review examines the significance of a single abnormal scan in an apparently healthy subject in terms of the relationship between normal and abnormal values and the time course of the disease.