Sleep and melatonin secretion abnormalities in children and adolescents with fetal alcohol spectrum disorders.

OBJECTIVES: Caregivers describe significant sleep disturbances in the vast majority of children and adolescents, which is diagnosed as fetal alcohol spectrum disorders (FASD), but objective data on sleep disorders in this population are almost completely lacking. Animal models suggest that intrauterine alcohol exposure may disrupt sleep wake patterns, cause sleep fragmentation, and specifically affect the suprachiasmatic nucleus, thus disrupting melatonin secretion. The objective of this pioneering study was to evaluate sleep and melatonin abnormalities in children with FASD using objective, gold-standard measures.

METHODS: Children and adolescents (N = 36, 6-18 years) with FASD participated in clinical assessments by sleep specialists, overnight polysomnography (PSG), and a dim light melatonin onset (DLMO) test in a pediatric sleep laboratory. PSG was analyzed according to standardized scoring guidelines and sleep architecture was compared with normative data. DLMOs were determined and melatonin secretion curves were evaluated qualitatively to classify melatonin profiles. Sleep disorders were evaluated according to international diagnostic criteria.

RESULTS: There was a high prevalence (58%) of sleep disorders. The most common sleep problems were parasomnias (27.9%) and insomnia (16.8%). The sleep studies showed lower than normal sleep efficiency and high rates of sleep fragmentation. Most participants (79%) had an abnormal melatonin profile.

CONCLUSIONS: This study led to the recognition that both sleep and melatonin secretion abnormalities are present in children with FASD. Therefore, to be effective in managing the sleep problems in children with FASD, one needs to consider both the sleep per se and a possible malfunction of the circadian regulation.