Diagnostic value of particularities of circadian rhythms of sleep-wake cycle in early ontogenesis

According to the data of direct electroencephalography (EEG) human fetus can develop circadian rhythm of sleep-wake cycle before birth. Healthy fetus during birth is awake and takes an active part in the delivery. The fetus sleep during birth is developed only in hypoxic states. EEG irregularities of sleep are noticed yet in fetal stage. Children aged 0-1 year develop five phases of sleep: drowsiness, active sleep, sleep of middle depth, deep sleep, paradoxical REM sleep. Maturity of superficial sleep terminates by the 10th-12th month of life. The sleep of average depth and deep sleep terminate maturity by the 2nd month of life. Duration of paradoxical sleep increases considerably by the age 12th month and is divided into 2 stages. By the age of 12 months paradoxical sleep remains immature. In children of the same age with CNS disorder the structural composition of sleep changes: active sleep is prolonged, sleep of middle depth is not changed, deep sleep does not develop, paradoxical-REM sleep is atypical.