5-Hydroxytryptophan and sleep in Down's syndrome.
Polygraphic total night sleep electroencephalographic (EEG), electro-oculographic (EOG) and electromyographic (EMG) recordings have been made in 6 mongoloid infants who received oral 5-HTP for periods extending from 12 to 36 months. The doses were adapted to the infants' age and tolerance level. The oculomotor activity of paradoxical sleep (PS) was selectively analysed. The eye-movement (EM) density was significantly decreased in non-treated mongoloids as compared with that of normal age-related infants. Out of the 5-HTP-treated patients, however, the results in only 2 were within the limits for normal age-related infants. 5-HTP failed to induce any long-term differences in the EM frequencies. In fact, the drug had a short-term effect lasting up to 8 days. An increase in muscle tone and an improvement of motor behaviour were the only long-lasting results.