Prognostic Value of the Neurologic Optimality Score at 9 and 18 months in Preterm Infants Born before 31 Weeks Gestation. Frisone MF, Mercuri E, Foglia C, et al. J Pediatr (Jan 2002) 140: 57-60.

The Hammersmith Infant Neurologic Examination was performed on a cohort of 74 preterm infants whose gestational age ranged between 24 and 30.5 weeks. The infants were examined between 9 and 18 months chronological age (6-15 months corrected age) and scored with the neurologic optimality score (NOS) system previously standardized in a cohort of low-risk term infants. The NOS were correlated with locomotor function at 2 years of age.

Results. Sixty-five of the 74 children were able to walk independently by 2 years of age, and 5 were able to sit unsupported, but unable to walk. The 4 infants who were unable to walk or sit unsupported all had NOS below 52. Four of the 5 infants who could sit but not walk at age 2 had NOS between 52 and 64, and one scored above 64. The sensitivity of NOS above 64 to predict walking at 2 years of age was 98% and the specificity was 85%. There was no significant association between the NOS and the degree of prematurity or the age at assessment.