Asymmetry of basal ganglia perfusion in Tourette's syndrome shown by technetium-99m-HMPAO SPECT.

Our study involved performing brain perfusion SPECT scans on Tourette's subjects to observe any common perfusion abnormalities involving the cerebral cortex or subcortical structures. Six patients with Tourette's syndrome and nine normal control subjects underwent a brain SPECT study with 99mTc-HMPAO. Regions of interest were generated over the cerebral cortex, basal ganglia, thalamus and cerebellum to evaluate any relative perfusion abnormalities or asymmetry in the Tourette's subjects. Five of the six Tourette's subjects demonstrated a significant decrease in right basal ganglia activity which was not present in any of the normal control subjects. Our study suggests an etiology for Tourette's syndrome involving the right basal ganglia. Furthermore, brain SPECT may be useful in the evaluation of these patients if it proves to be sufficiently sensitive and specific in larger study populations.