Relationship between mother-infant mutual dyadic responsiveness and premature infant development as measured by the Bayley III at 6 weeks corrected age.

BACKGROUND: The quality of mother-preterm infant interaction has been identified as a key factor in influencing the infant's later development and language acquisition. The relationship between mother-infant responsiveness and later development may be evident early in infancy, a time period which has been understudied. AIM: Describe the relationship between mother-infant mutual dyadic responsiveness and premature infant development. DESIGN: This study employed a secondary analysis of data from the 6-week corrected age (CA) follow-up visit of the Hospital-Home Transition: Optimizing Prematures' Environment (H-HOPE) study, a randomized clinical trial testing the efficacy of a mother- and infant- focused intervention for improving outcomes among premature infants. SUBJECTS: Premature infants born between 29 and 34 weeks gestational age and their mothers who had social-environmental risks. OUTCOME MEASURES: At 6-weeks corrected age, a play session was coded for the quality of mutual responsiveness (Dyadic Mutuality Code). Development was assessed via the Bayley Scales of Infant and Toddler Development, 3rd edition. RESULTS: Of 137 mother-infant dyads, high, medium and low mutual responsiveness was observed for 35.8%, 34.3% and 29.9%, respectively. Overall motor, language and cognitive scores were 115.8 (SD = 8.2), 108.0 (7.7) and 109.3 (7.9). Multivariable linear models showed infants in dyads with high versus low mutual responsiveness had higher scores on the motor (ß = 3.07, p = 0.06) and language (ß = 4.47, p = 0.006) scales. CONCLUSION: High mutual responsiveness in mother-premature infant dyads is associated with significantly better language development and marginally better motor development.

Behavior During Tethered Kicking in Infants With Periventricular Brain Injury.

PURPOSE: To describe behavior of children with periventricular brain injury (PBI) in a tethered-kicking intervention. METHODS: Sixteen infants with PBI were randomly assigned to exercise or no-training in a longitudinal pilot study. Frequencies of leg movements and interlimb coordination were described from videos at 2 and 4 months' corrected age (CA). RESULTS: Eight of the 13 children (62%) with longitudinal data increased the frequency of leg movements while tethered to a mobile between 2 and 4 months' CA. Movement frequency was correlated with scores on the Test of Infant Motor Performance, but no differences between experimental groups were found. Children with typical development at 12 months' CA increased the proportion of leg movements that were synchronous between 2 and 4 months, as did a child with cerebral palsy in the experimental group. CONCLUSIONS: The tethered-kicking intervention facilitates movement in infants with PBI, but effects on development remain to be demonstrated.

Correlation between fractional anisotropy and motor outcomes in one-year-old infants with periventricular brain injury.

PURPOSE: To determine whether motor outcomes of an exercise intervention beginning at 2 months corrected age (CA) in children with periventricular brain injury (PBI) are correlated with fractional anisotropy (FA) measures derived from diffusion tensor imaging (DTI) at 12 months CA. MATERIALS AND METHODS: DTI was performed in eight infants with PBI who were randomly assigned to kicking and treadmill stepping exercise or a no-training condition. Development was assessed using the Alberta Infant Motor Scale (AIMS) and the Gross Motor Function Classification System (GMFCS). FA values were derived from regions of interest (ROIs) in the middle third of the posterior limb of the internal capsule (PLIC) and the posterior thalamic radiation (PTR). RESULTS: Significant correlations were observed between motor development and FA measures. For PLIC, the correlation coefficients were 0.82 between FA and AIMS, and -0.92 between FA and GMFCS, while for PTR the corresponding correlation coefficients were 0.73 and -0.80, respectively. CONCLUSION: Results of this study suggest that quantitative evaluation of white matter tracts using DTI at 12 months CA may be useful for assessment of brain plasticity in children.

Concurrent validity of the TIMP and the Bayley III scales at 6 weeks corrected age.

PURPOSE: Examine agreement between the Test of Infant Motor Performance (TIMP) and the Bayley III. METHODS: One hundred forty-five infants born at 29 to 34 weeks gestation with socioenvironmental risk factors were tested on the TIMP and Bayley III at 6 weeks corrected age (CA). Scores were correlated to assess convergence/divergence of content. Decision analysis using a cutoff of the mean on the Bayley Motor Composite and -0.5 and -1 SD from the mean on the TIMP assessed agreement on delay/nondelay. RESULTS: The TIMP-Bayley Motor Composite correlation was 0.546, with Cognitive was 0.310, and with Language was 0.281. Nine percent of infants scored less than -1.0 SD on the TIMP, while no child scored less than -1 SD on the Bayley Motor scale (sensitivity, 31%). CONCLUSIONS: Convergent validity between the TIMP and the Bayley Motor scale was demonstrated, but no infant showed delay on any Bayley scale. The TIMP is preferred for early assessment of infants.

Effects on motor development of kicking and stepping exercise in preterm infants with periventricular brain injury: a pilot study.

BACKGROUND: Preterm infants with periventricular brain injury (PBI) have a high incidence of atypical development and leg movements. OBJECTIVE: Determine whether kicking and treadmill stepping intervention beginning at 2 months corrected age (CA) in children with PBI improves motor function at 12 months CA when compared with control subjects. METHOD: In a multi-center pilot study for a controlled clinical trial, sixteen infants with PBI were randomly assigned to home exercise consisting of kicking and treadmill stepping or a no-training control condition. Development was assessed at 2, 4, 6, 10, and 12 months CA with the Alberta Infant Motor Scale (AIMS). At 12 months children were classified as normal, delayed, or with cerebral palsy (CP). RESULTS: At 12 months CA 3 of 7 (43%) of the exercise group children walked alone or with one hand held versus 1 of 9 (11%) in the control group (p=0.262), but no significant differences in AIMS scores were found at any age. Half of the subjects had CP or delay; the outcomes of these infants were not improved by exercise. Compliance with the home program was lower than requested and may have affected results. CONCLUSION: Although not statistically significant with a small sample size, self-produced kicking and treadmill exercise may lower age at walking in infants with normal development following PBI, but improvements of the protocol to increase and document compliance are needed before a larger study is implemented.

Validity of the TIMPSI for estimating concurrent performance on the test of infant motor performance.

PURPOSE: The TIMPSI, a short version of the Test of Infant Motor Performance (TIMP), is used for screening. The project was designed to compare concurrent TIMPSI scores with those on the TIMP and recommend cutscores for clinical decision making. METHODS: Infants (n = 990) were recruited reflecting the race/ethnicity of US infants with low birth weight. From 67 to 97 infants were tested in 2-week age groups ranging from 34 to 35 weeks postmenstrual age through 16 to 17 weeks post-term. Rasch analysis of raw scores was used. TIMPSI cutscores ranging from the mean to -1.00 standard deviation (SD) were compared with performance above/below -0.5 SD on the TIMP to assess accuracy of classification. RESULTS: The TIMPSI was a valid screening instrument when compared with concurrent performance on the TIMP. CONCLUSION: A cutscore of -0.25 SD appears useful in predicting the best combination of false negatives (5.8%) and false positives (12.5%) with overall accuracy of classification of 81.7%.

Population-based age standards for interpreting results on the test of motor infant performance.

PURPOSE: The goals of this study were establishment of age standards for the Test of Infant Motor Performance (TIMP) and evaluation of possible group differences based on sex, medical risk for poor developmental outcome, and race/ethnicity. SUBJECTS: Subjects were 990 infants with a range of risk for poor outcome from 11 geographic locations across the United States that were recruited to reflect the distribution of race/ethnicity in the US population of low birth weight infants. METHODS: Between 67 and 97 infants were tested in each two-week age range from 34-35 weeks' postconceptional age through 16-17 weeks after term. Boys made up 52% of the subjects. Fifty-eight percent of the sample was white, 25% black, and the remainder were of other ethnicities. Scores for all infants in each age group were averaged to form age expectations for each two-week period. Multiple regression was used to explore the effect on TIMP scores of sex, risk, and race/ethnicity. RESULTS: Means ranged from 49 (standard deviation = 15) at 34-35 weeks' postconceptional age through 120 (standard deviation = 16) at 16-17 weeks after term. High-risk infants scored significantly lower than other infants (beta = -0.133, P < 0.0001). Latino infants scored lower than infants of all other ethnicities (beta = -0.052, p < 0.006). Performance did not differ by sex. CONCLUSIONS/CLINICAL IMPLICATIONS: These standards for performance on the TIMP can be used to identify infants with delayed motor development.

Annotated bibliography: effects of sleep position and play position on motor development in early infancy.

The prevalence of prone sleeping has decreased dramatically since the American Academy of Pediatrics (AAP) published sleep position guidelines and launched the Back to Sleep Campaign in 1992. One aspect of the guidelines, which suggests placing infants in the prone position for supervised play time, is often overlooked. This review summarizes published articles related to the effects of sleep/play position on motor development and provides considerations for physical and occupational therapy practice in early infancy. The study results suggested that delays in the attainment of gross motor milestones in the prone position could be observed in infants whose predominant sleep position was supine, but the delays in motor development disappeared later in life. Some studies also found a reverse order of the rolling development. Therapists should educate parents about the less known advised rules of supervised play time in the prone position by the AAP, and include activities in the prone position as part of the home program in early infancy.