The effect of intravenous L-5-HTP in the myoclonic encephalopathy of infants.

A 7 year old girl suffering from myoclonic encephalopathy of infants (MEI) underwent acute treatment by slow intravenous L-5-hydroxytrypthophan (L-5-HTP). The authors found a clear clinical physiological improvement of myoclonic symptoms at rest and during action, but the opsoclonus remained unchanged. The authors suggest that, at least in this case of MEI, the myoclonus was serotonin responsive, as already reported in action or intention and stimulus sensitive myoclonus.