Spontaneous movements in the supine position of preterm infants with intellectual disability.

OBJECTIVE: Spontaneous movements at 2 months of corrected age in preterm infants with intellectual disability (ID) were investigated by assessing individual motor elements separated from movements involving the entire body. METHODS: Video recordings of 20 preterm infants with ID (16 males, 4 females; median gestational age 26 weeks; median birth weight 810 g) were analyzed and were compared with those of 21 normal preterm infants (8 males, 13 females; median gestational age 30 weeks; median birth weight 1216 g). RESULTS: In the preterm infants with ID at 2 months corrected age, startle response, lateral decumbent position, predominant shoulder rotation, and maintaining hip adduction were more frequently observed and hand sucking, maintaining shoulder abduction, to-and-fro shoulder abduction, to-and-fro elbow flexion, isolated hip adduction, to-and-fro hip abduction, and leg lift were less frequently seen than in the normal preterm infants (Fisher's exact test, p<0.05). CONCLUSION: Abnormal spontaneous movements at 2 months of age in preterm infants with ID result from persistent immature movements and non-emergence of mature movements.

Spontaneous movements in the supine position of healthy term infants and preterm infants with or without periventricular leukomalacia.

AIM: The individual motor elements presumed to be essential for motor development were determined from spontaneous movements involving the entire body of normal term and preterm infants. Then, diagnostic items for motor abnormality in infants with periventricular leukomalacia (PVL) were investigated. METHODS: Video recordings of 24 healthy term infants, 21 normal preterm infants (8 males, 13 females; median gestational age 30 weeks; median birth weight 1216g) and 14 preterm infants with PVL (6 males, 8 females; median gestational age 30 weeks; median birth weight 1360g) were analyzed. RESULTS: In healthy term infants, predominant shoulder rotation was noticed until 1 month of age. After 2 months of age, isolated movements of the shoulder, elbow, hip, knee, and ankle frequently emerged. In preterm infants with PVL at the corrected age of 2 months, startle response and predominant shoulder rotation were more frequently seen and isolated neck, shoulder, elbow, hip, knee, and ankle movements were less frequently seen than in the normal preterm infants (Fisher's exact test, p<0.025). INTERPRETATION: At 2 months of age, isolated movements evolve, and their failure to occur is suggested to be a useful sign for the diagnosis of cerebral motor disorders.