Thermal sensitivity in Tourette syndrome: Preliminary report

The effects of heat on tic symptoms were studied in a sample of 78 adults with Tourette syndrome. 62 men and 16 women completed a survey concerning the type, onset, and four se of their ties. 10 adult male subjects also participated in a thermal challenge during which ambient temperature was raised from 22 degreesC to 35 degreesC following a control period. Of the 78, 23% or 19 reported increased ties upon exposure to heat. Compared to the remaining 59 subjects, there were no differences in sex distribution, current age, or overall course of illness. In the thermal challenge, there Miss general increase in ties that was correlated with sweat rate (r =.55, p = .001). This effect was prominent in 5 of 10 subjects (rs = 29 to.63). There were no mean differences in current age, age of onset, or current severity of symptoms between the five subjects of each group. Tic symptoms in a subgroup of patients with Tourette syndrome may be sensitive to heat. Abnormal heat regulation is not a likely explanation tor the observed increase in ties. The increase may be due to normal heat-loss mechanisms through dopaminergic pathways.