A case of Tourette's syndrome with midbrain involvement

Several hypotheses have attempted to incriminate a particular anatomical region responsible for the complex symptomatology of Tourette's syndrome (TS). Recently, Devinsky speculated that damage to the peri-aqueductal gray matter (PAG) and midbrain tegmentum may represent the major anatomical site of dysfunction in TS. A patient with TS in whom radiological evidence indicated midbrain involvement may support Devinsky's hypothesis. A 7-year-old boy exhibited motor and vocal tics since the age of four. These were associated with hyperactive behavior, stereotype body movements, abnormal sexual behavior and coprolalia. At the age of five he was placed on methylphenidate for hyperactive behavior which resulted in marked exacerbation of the tics. Family history was unremarkable. Neurological examination was normal with the exception of the tics. Endocrine evaluation, including plasma cortisol, growth hormone, prolactin and TSH were normal with the exception of reduced FSH, LH and testosterone levels. Sexual maturation was normal. MRI head scan was normal with the exception of an asymmetry of the cerebral peduncles with the left larger than the right. CSF examination was normal. While the nature of this patient's radiological abnormalities is not clear, our findings of asymmetric cerebral peduncles associated with TS may support a role for the midbrain in the pathophysiology of TS. The likelihood of the latter assumption seems to be further confirmed by a recent report in which peri-third ventricular and PAG calcifications were detected by CT scan of the head in an adult patient with TS. Further MRI investigations in other cases of TS may clarify the anatomical relationship of the midbrain to the symptomatology of TS.