Transient dystonias revisited: a comparative study of preterm and term children at 2 1/2 years of age.

Minor neurological dysfunctions (MND) have frequently been reported as an outcome of preterm birth. Behavioural and learning difficulties are a known feature, but coordination problems are especially described in preterm infants at later ages. All preterm infants in our study were born with a gestational age of <32 weeks and a birthweight of <1500 g. The aim of the study was to determine if in a normal clinical situation, children at risk for developing coordination problems could be detected by focusing particularly on their spontaneous, although elicited, motor performance. Forty-two children of 2 years 6 months of age were studied of whom 25 were 'low-risk' preterm and 17 were born at term. All children had been followed up since birth. In a structured, free-field situation the quality of body rotation, spontaneous reaching-out, and manipulation during parts of the Bayley Developmental Test were observed and videotaped. Body rotations were scored on a 2-point scale, and arm and hand functions on a 3-point scale. Most preterm infants showed non-optimal body rotations and borderline or non-optimal arm and hand functions in contrast to most term children. A clear connection was found between less optimal body rotations and poor arm and hand functions. Retrospectively, poor arm and hand functions at 2 years 6 months seemed to be related to those at 39 weeks. At the age of 39 weeks a clear relation had been found between poor postural control (many preterm infants could not sit independently) and earlier hyperextension of the trunk at 18 weeks and quality of arm-hand functions. In the present study at 2 years 6 months a correlation with the former hyperextension could no longer be found, but there was a significant relation between poor trunk rotation and arm and hand function and the earlier arm and hand functions at 39 weeks.