Brain Monoamines and Amino Acids in Gilles de la Tourette's Syndrome: A Preliminary Study of Subcortical Regions

To the Editor. —  We have measured levels of monoamines, monoamine metabolites, amino acids, and neurotransmitter-related enzymes in subcortical regions of postmortem tissue obtained from brains of four individuals who had Gilles de la Tourette's syndrome (TS). Although the study was limited by the small number of available brains and other concomitants of postmortem analyses, several suggestive differences were seen between the brains of subjects with TS and those of the control group. Most intriguing in terms of possible pathophysiologic significance were the observation of generally lower values of serotonin and its related compounds in the TS group, and the lower TS group means of glutamate in the three major projection areas of the subthalamic nucleus (STN): the medial globus pallidus (MGP), lateral globus pallidus (LGP), and substantia nigra reticulata (SNR).

Subjects and Methods.—  The brains of four subjects who were diagnosed before death as having TS were obtained. One