Delta and spindle components in compressed spectral array during nocturnal sleep in infants with cerebral palsy.

The correlations between the delta and spindle components in compressed spectral array in 21 mentally retarded children with cerebral palsy (CP) (from 4 months to 5 years of age) and 32 reference mentally retarded children of no abnormality with the exception of psychomotor retardation (from 4 months to 12 years of age) were studied throughout nocturnal sleep. In 11 (52%) out of 21 CP cases and 27 (84%) out of 32 reference cases, periodic changes of delta and spindle rhythm powers were noted in sleep EEG (group A). In 5 (24%) other cases in CP and 5 (16%) reference cases delta but not spindle rhythm powers were found (group B), and in the remaining 5 (24%) CP cases neither delta nor spindle rhythm powers were found throughout nocturnal sleep (groups C). A significant decrease in the developmental quotient (DQ) was found in group C as compared with group A in both CP and reference cases. Moreover, a significant decrease in DQ was also found in group B as compared with group A of reference cases.