The excitability of blink reflexes in patients with neurologic and psychiatric disorders.

The blink reflex and its recovery curve were studied in 12 patients with neurologic and psychiatric disorders, i.e., juvenile Parkinson's disease (case 1), Gilles de la Tourette's syndrome (case 2), anorexia nervosa (case 3), mild developmental delay (cases 4 and 5), a meningomyelocele with winking spasms (case 6), Parkinson's disease (cases 7-10) and OPCA (cases 11 and 12). The cases were divided into 4 groups on the basis of the results, (1) hyperexcitability of facial motoneurons only (case 6), (2) hyperexcitability of facial motoneurons and brainstem interneurons (case 1 and 2), (3) hyperexcitability of brainstem interneurons only (cases 4, 5 and 7-12) and (4) hypoexcitability of both sides (case 3). Therefore, as to the excitability an abnormal pattern of blink reflexes could be a neurophysiologic marker of some neurologic and psychiatric disorders.