Deranged modulatory midbrain opioid and gonadotrophin functions: relevance to Tourette's syndrome.

In the following communication we discuss evidence suggesting that an abnormal opioid-gonadotrophin interaction at the midbrain may be essential to the clinical expression of vocal tics in Tourette's Syndrome (TS). Data derived from animal studies and the striking similarity between the symptomatology of TS and encephalitis lethargica (EL) add further support to our hypothesis implicating an abnormal opioid-gonadotrophin interaction in the pathophysiology of TS.