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 30weeks; median birth weight 1216g) and 14 preterm infants with PVL (6 males, 8 females; median gestational age 30weeks; median birth weight 1360g) were analyzed. Results: In healthy term infants, predominant shoulder rotation was noticed until 1month of age. After 2months of age, isolated movements of the shoulder, elbow, hip, knee, and ankle frequently emerged. In preterm infants with PVL at the corrected age of 2months, 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 2months of age, isolated movements evolve, and their failure to occur is suggested to be a useful sign for the diagnosis of cerebral motor disorders.