Effects of a low dose of melatonin on sleep in children with Angelman syndrome

The effects of low dose melatonin therapy on sleep behavior and serum melat onin levels were studied in Angelman syndrome (AS) children suffering from insomnia. 24-hour motor activity was monitored in 13 AS children (age 2-10 yr) in their home environments for 7 days prior to melatonin treatment and for 5 days during which a 0.3 mg dose of melatonin was administered daily 0 .5-1 hour before the patient's habitual bedtime. Blood samples were withdra wn at hourly intervals over two 21-hour periods in order to measure individ ual endogenous serum melatonin levels and the levels induced by melatonin t reatment, Actigraphic recording of motor activity, confirmed by parents' re ports, showed a significant improvement in the patients' nocturnal sleep pa ttern as a result of melatonin treatment. Analysis of the group data reveal ed a significant decrease in motor activity during the total sleep period f ollowing melatonin treatment, and an increase in the duration of the total sleep period. Endogenous peak nocturnal melatonin values ranged from 19 to 177 pg/ml, The administration of melatonin elevated peak serum hormone leve ls to 128-2800 pg/ml in children of different ages and body mass. These dat a suggest that a moderate increase in circulating melatonin levels signific antly, reduces motor activity during the sleep period in Angelman syndrome children, and promotes sleep.