Rapid eye movement storms in infants: rate of occurrence at 6 months predicts mental development at 1 year.

Intense rapid eye movements (REM) during sleep were investigated as a possible indication of delay in the neurodevelopment of infants. The rate of occurrence of REM storms was determined by monitoring the sleep of 15 normal, first-born infants during weeks 2 through 5 and at 3, 6, 12 months. The amount of REM within each 10-second interval of active sleep was rated on a four-point scale based on frequency and intensity of eye movements. When the babies were 12 months old, the Bayley Scales of Mental Development were administered. A significant negative correlation was found between the frequency of REM storms of 14 subjects was also studied. The negative correlation was confirmed. The findings support the suggestion that by 6 months of age REM storms express dysfunction or delay in the development of central inhibitory feedback controls for sleep organization and phasic sleep-related activities.