Thermal sensitivity in Tourette syndrome: Preliminary report

The effects oi heat on tic symptoms were studied in a sample of 78 adults w ith Tourette syndrome. 62 men and 16 women completed a survey concerning th e type, onset, and four se of their ties. 10 adult male subjects also parti cipated 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 remain ing 59 subjects, there were no differences in sex distribution, current age , or overall course of illness. In the thermal challenge, there Miss genera l 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 n o mean differences in current age, age of onset, or current severity of sym ptoms between the five subjects of each group. Tic symptoms in a subgroup o f patients with Tourette syndrome may be sensitive to heat. Abnormal heat r egulation is not a likely explanation tor tile observed increase in ties. T he increase may be due to normal heat-loss mechanisms through dopaminergic pathways.