Martha C. Piper

Serial magnetic resonance imaging in neonatal hypoxic-ischemic encephalopathy

We prospectively performed magnetic resonance imaging (MRI) studies during the neonatal period, and at 4 and 8 months of age, on 15 term infants with hypoxic-ischemic encephalopathy, and compared the results with their neurodevelopmental outcome at 18 months of age. Cerebral palsy developed in nine infants, two infants were classified as having abnormalities of tone and delayed motor milestones that were suggestive of cerebral palsy, and four infants were normal. Structural abnormalities, delayed myelination, or a combination of the two were detected with MRI at 8 months of age in all nine infants with later development of cerebral palsy. Three of the four normal infants and one infant with suggestive abnormalities had normal serial MRI findings. Each of the remaining two infants (one normal, one with suggestive abnormalities) had isolated persistent ventricular dilation on all three MRI studies. Our results suggest that 8 months appears to be the earliest time at which MRI findings correlate well with later adverse neurodevelopmental outcome in this population.

GROSS AND FINE MOTOR DEVELOPMENT OF PRETERM INFANTS AT EIGHT AND 12 MONTHS OF AGE

Forty‐five neurologically normal preterm infants were allocated to one of two groups according to their gestational age at birth (< 32 weeks; 32 to 36 weeks). Their gross and fine motor development was assessed at eight and 12 months chronological age and eight and 12 months adjusted age. At eight months chronological age the two groups differed significantly in both gross and fine motor development, but at eight and 12 months adjusted age and 12 months chronological age they differed significantly only in fine motor development.

Resolution of neurological symptoms in high-risk infants during the first two years of life.

115 high‐risk infants were identified and followed prospectively over the first 24 months of life. All infants underwent neurological assessments at 12 and 24 months and developmental assessments at six and 12 months. Approximately one‐quarter of the infants were considered to be ‘neurologically suspicious’ at 12 months of age, of whom slighly more than one‐half were deemed normal by 24 months. Children who were classified as being either normal or abnormal at 12 months were highly likely to have their classification confirmed at 24 months. Abnormal and suspicious neurological outcomes at 12 and 24 months were inversely correlated with birthweight and were not affected by the infants being given early physical therapy. Children who were suspicious at 12 months and who either remained suspicious or became abnormal at 24 months had lower personal–social quotients at six and 12 months and lower hearing–speech quotients at 12 months than the suspicious children who became normal.

Effect of gestational age on neurological functioning of the very low-birthweight infant at 40 weeks

A cohort of 97 very low‐birthweight infants who had had prolonged care in two neonatal units was identified prospectively and subdivided into three groups according to gestational age at birth (23 to 27, 28 to 31 and 32 to 36 weeks). The neurological status of the three groups was compared at 40 weeks gestational age. The effects of various medical complications also were analyzed by comparing the neurological performances at term of (1) nine ‘at‐risk’ fullterm infants with ‘complicateď’ preterm infants, and (2) 15 ‘normaL’ fullterm infants with ‘healthy’ preterm infants. After controlling for medical complications, no significant difference in neurological scores was found between the three preterm groups, nor between the preterm groups and the ‘at‐risk’ fullterm group. However, ‘healthy’ preterm infants had significantly lower scores than fullterm ‘normaL’ infants. Item analyses also showed significant differences between the three preterm groups; those with gestations between 23 and 27 weeks were more likely to exhibit tremors than the other two groups; and those with gestations of 32 to 36 weeks were more likely to have opisthotonic postures, overshooting movements, hypertonus and exaggerated responses.

Early Motor development of breech- and cephalic-presenting infants

Objective This study was conducted to determine whether breech-presenting infants have a different pattern of early neuromotor development than cephalic-presenting infants—regardless of mode of delivery—thus explaining both the failure to assume cephalic version at the end of gestation and the higher rates of childhood motor impairments associated with breech presentation. Methods Ninety morphologically normal, term, breech-presenting singletons with birthweights greater than 2500 g were paired with a similar cephalic-presenting infant, matched for gender and mode of delivery (n = 180; 100 delivered abdominally and 80 delivered vaginally). Data on neurological status (Neurological Assessment of the Preterm and Full-term Newborn Infant) and motor performance (Alberta Infant Motor Scale, Peabody Developmental Motor Scales, and age of walking) were collected prospectively over the first 18 months of life. This study was designed with a power of .80 to detect a “medium” effect size for motor development using the Alberta Infant Motor Scale. The data were analyzed using analysis of variance techniques. Results Breech-presenting infants had minor transient differences compared with cephalic-presenting infants. First, they had more open popliteal angles at birth (P < .001). Second, they had significantly lower motor scores at 6 weeks than the normative sample (P < .001). At 18 months, three infants were diagnosed with neurological problems, all of whom were delivered electively in the cesarean-breech group. Conclusion As a group, breech-presenting infants do not have a persistent, inherently different pattern of motor development than cephalic-presenting infants. Mode of delivery did not explain the excess neuromotor impairment detected in the subgroup of breech infants.

Early developmental screening : sensitivity and specificity of chronological and adjusted scores

The motor development of 75 preterm infants was assessed at 4 months chronological and 4 months adjusted ages using the Movement Assessment of Infants (MAI). Infants were followed until 18 months old when neurological and motor outcomes were assessed by a developmental pediatrician, and outcomes were classified as normal, suspicious, or abnormal. Sensitivity, specificity, and positive and negative predictive values were calculated at the two points in time using a variety of cutoff MAI scores. At 4 months, the practice of adjusting for prematurity resulted in the better combination of screening rates for the detection of both neurologically abnormal and neurologically abnormal/suspicious children. To obtain comparable rates, different cutoff MAI scores were used to identify the neurologically abnormal versus the neurologically abnormal/suspicious children. The optimal combination of sensitivity, specificity, positive and negative predictive values varies according to the age of assessment, the disorders being identified, and the cutoff scores employed. J Dev Behav Pediatr 13:95–101, 1992.

Primitive reflexes and the determination of fetal presentation at birth.

Ninety term breech-presenting singletons with birth weights greater than 2500 g and no congenital anomalies were matched with similar cephalic-presenting infants on gender and mode of delivery (n = 180). Thirteen primitive reflexes were examined at birth, 6 weeks and 3 and 5 months. No significant differences in the intensity of the asymmetrical tonic neck, symmetrical tonic neck, positive support tonic labyrinthine (prone and supine), segmental rolling (head-on-body and body-on-body), Galant, Moro, upper and lower extremity grasp, lower extremity placing and stepping reflexes were observed between these two groups of infants. Infants delivered vaginally, regardless of presentation, had weaker Moro reflexes at 5 months than infants delivered by cesarean section. The popular notion that precursors to early motor behaviors, such as the placing and stepping reflexes, are determinants of fetal presentation at the end of pregnancy is not supported by these results. Instead, spontaneously generated active whole body movements may be more significant influences of fetal orientation at the time of birth.

Neuromotor Development of Preterm Infants Through the First Year of Life

Physical and occupational therapists monitor the development of preterm infants graduating form neonatal intensive care units and frequently use the neuromotor development of fullterm infants as the criterion against which normality is judged. Despite the methodological problems of comparison on non-homogeneous groups, poor matching, inadequate measurement tools, and expectancy bias, the literature suggests that preterm infants develop differently from full term infants. Neither the extent nor reasons for differences and suggestions for future research are proposed. Knowledge of the variability of preterm infant neuromotor behavior should be useful to pediatric therapists aiming to identify those infants who truly are developing abnormally.

Effect of early environmental experience on the motor development of the preterm infant

A cohort of normally developing preterm infants was subdivided into two gestational age groups (<32 weeks and 32-36 weeks) for the purpose of assessing the impact of the early extrauterine environment on motor development. The motor development of the two groups of infants was assessed and compared at seven points in time: term, 4, 8, and 12 months chronologic age and 4, 8, and 12 months adjusted age. Analyses revealed that certain components of early motor development are biologically driven, whereas other components are affected by the extrauterine environment. The impact of the environment also varied according to the age of the infant. Implications for therapeutic interventions for infants with motor disorders are discussed.

Developmental outcome in very low birth weight infants 6 to 36 months old.

A cohort of 78 infants weighing less than 1500 g at birth was followed prospectively to determine the impact of birth weight, age of assessment, and skill area on their developmental performance. Five skill areas were tested using the Griffiths Mental Scales of Development at 6, 12, 24, and 36 months of age. Infants were divided into three birth weight groups: <750 g, 750–1000 g, and 1001–1500 g. A significant age and skill interaction was found, with the locomotor and eye-hand skills decreasing consistently over time, and the personal-social and hearing and speech skills initially decreasing and then rising from 12 to 36 months. Infants born at <1000 g consistently performed more poorly than those born at 1001–1500 g. Explanations for the variation in scores and the implications of these findings to the evaluation of low birth weight infants are discussed.