BRAIN PERFUSION ABNORMALITIES IN GILLES-DE-LA-TOURETTES SYNDROME

Background. functional brain imaging with technetium-99m d,l-hexamethy l propyleneamine oxime (HMPAO) Single Photon Emission Tomography (SPET ) allows us to explore the cerebral pathophysiology of Gilles de la To urette's Syndrome (GTS).Method. Fifty patients and 20 controls were ex amined. Patients were rated for tic severity and mood. Scans were anal ysed quantitatively using internal ratios to the occipital cortex. Res ults. Patients differed from controls on measures of relative blood fl ow to the left caudate, anterior cingulate cortex and the left dorsola teral prefrontal cortex. Severity of ties was related to hypoperfusion of the left caudate and cingulate and a left medial temporal region. Hypoperfusion in the left dorsolateral prefrontal region was related t o mood. Conclusions. The areas found to be hypoperfused in this study are consistent with known functions of fronto-striatal circuits. A wid e range of perfusion patterns is seen, however, and no characteristic patterns for behavioural subgroups has been documented with this techn ique.