Tourette's Syndrome: Clinical and Neurochemical Correlates

Forty-six patients with Tourette's syndrome (TS), aged 7 to 45 years, were evaluated clinically and neurochemically. Patients with more severe total symptoms had lower plasma homovanillic acid (pHVA) levels. Analysis of individual items on the Tourette Syndrome Global Scale (TSGS) revealed significant inverse correlations between mean pHVA levels and motor restlessness and school/work function. There were no significant correlations between pHVA levels and individual tic items, although the correlation between mean pHVA levels and simple motor tics approached significance. Plasma 3-methyoxy-4-hydroxyphenylglycol (pMHPG) levels did not correlate significantly with TSGS scores. Pretreatment levels of pHVA or pMHPG did not predict treatment response to clonidine. These data suggest that TS patients with more severe non-tic symptomatology have lower morning pHVA levels. This relationship is of interest because earlier studies showed that TS patients have lower CSF HVA levels compared with contrast and control groups. J. Am. Acad. Child Adolesc. Psychiatry, 1988, 27, 4:409–412.