Heart Rate, Blood Pressure Regulation and Neurotransmitter Balance in Tourette's Syndrome

The mean cardiointerval (CI) (M ± S.E.M.: 0.808 ± 0.019 sec) in 24 children and adolescents with Tourette's syndrome (TS) proved to be significantly higher than in agematched contrast groups with temporal lobe epilepsy (0.718 ± 0.022, N=20), schizophrenia (0.754 ± 0.028, N=15), residual organicity (0.690 ± 0.066, N=6) and myoclonic epilepsy (0.713 ± 0.012, N=7). The individual mean CI values in the TS group were higher than the respective normative age data in 20 of 24 cases. The mean deviation from the respective normative age data for all 24 patients was +10.9 ± 2.5% (p<0.001). The variability of CI values (0.076 ± 0.007, mean group standard deviation ± s.E.M.) was significantly higher in TS than in the contrast groups with temporal lobe epilepsy (0.044 ± 0.006, p<0.001), schizophrenia (0.044 ± 0.005, p<0.001), residual organicity (0.045 ± 0.016, p<0.10), and myoclonic epilepsy (0.051 ± 0.005, p<0.01). Slower and more variable heart rate in TS reflects enhanced vagal tonus in heart regulation. In contrast, increased eye-blinking rate in TS was confirmed, suggesting dopaminergic hyperactivity. The issues of the disturbed neurotransmitter balance in TS (including cholinergic, dopaminergic, serotonergic and noradrenergic mechanisms) and some essential neurophysiological aspects of TS are discussed.