Melatonin secretion in relation to sleep in epileptic and control children and adolescents.

Abstract

Serum melatonin (MT) levels were measured by radioimmunoassay at 4 hour intervals from 12.00 am to 8.00 am (darkness 8.00 pm - 7.00 am) with simultaneous EEG tracing in 22 epileptic patients aged 8 to 21 years. Mean levels for all patients at 12.00 pm and 4.00 am were respectively 43±7 and 55±10 pg/ml (mean ± SEM). There was no significant difference in mean peak levels of MT at 4.00 am among non-treated (mean = 62±19 pg/ml, n = 6), valproic acid-treated (mean = 48±13 pg/ml, n = 10) and patients treated with other medications (mean 62±29 pg/ml, n = 3). Three treated patients who had epileptic discharges through the night had a mean peak of only 32±5 pg/ml and were not included in the subsequent analysis. Analysis of MT levels according to sleep stages revealed that MT values after 2 or more episodes of REM sleep (86±20 pg/ml) were significantly higher than those after no preceeding episodes (31±6 pg/ml, P<.0001) and even than those after one preceeding episode (48±8 pg/ml, P<.05). For comparison 8 normal males were studied hourly in the same fashion. Mean MT levels at 12.00 am and 4.00 am were 36±10 pg/ml and 50±9 pg/ml, respectively. Likewise, MT values at 4.00 am varied directly with the number of preceeding episodes of REM sleep although the differences were not statistically significant. These results suggest that MT secretion may be related to REM sleep.