The pathogenesis of Tourette's syndrome. A possible role for hormonal and excitatory neurotransmitter influences in brain development
R. Kurlan
Department of Neurology, University of Rochester, School of Medicine and Dentistry, NY 14642.
Tourette's syndrome (TS) is associated with prominent gender differences in
clinical expression, tics with a sexual content, and a stabilization or
improvement of symptoms after puberty. It is herein hypothesized that some
tics can be viewed as inappropriately expressed (normally inhibited)
fragments of primitive motor and vocal programs involved in reproductive
activity. The brain regions involved in TS (basal ganglia and limbic
system) are proposed to be counterparts in humans of those functioning in
primitive reproductive behavior whose development and organization are
under sex hormone control. It is further hypothesized that sex hormone
action is mediated by excitatory neurotransmitter mechanisms such that an
excessive trophic effect occurs early in development and a neurotoxic
environment emerges later on. The defective gene in TS is hypothesized to
influence these developmental processes. This hypothesis has implications
for the investigation of the pathogenesis of TS and for experimental
therapeutics of the disorder.
