Technetium-99m-HMPAO in Tourette's syndrome on neuroleptic therapy and after withdrawal

Both decreased and increased perfusion and metabolism have been described with PET and SPECT in different areas of the brain in patients with Gilles de la Tourette's syndrome, The aim of this study was to define the regional cerebral perfusion pattern in drug-free patients and the changes in perfusion with the usual neuroleptic treatment, Methods: A group of 13 normal control subjects and 15 unmedicated Gilles de la Tourette's syndrome patients were studied with Tc-99m-HMPAO brain SPECT. Thirteen of the initial group of patients were retested on neuroleptic treatment. A semiquantitative analysis of the images was performed. Results: Decreased perfusion in orbital and anterior medial regions of both frontal lobes as well as in both temporal lobes was observed in the nontreated group compared with control subjects, With treatment, a perfusion increase in these frontal regions and in the left medial temporal cortex was observed. Conclusion: Neuroleptic treatment could decrease the hyperactivity of the dopaminergic system leading to improvement of the clinical symptoms and reperfusion of some previously hypoperfused regions.