Transient tone abnormalities in high risk infants and cognitive outcome at five years

Analysis of the prevalence of asymmetry and muscle tone disorders in the first year of life among youth with idiopathic scoliosis: A retrospective case-control study

BACKGROUND

Not much is known about developmental motor disorders in the first year of life of children diagnosed with idiopathic scoliosis (IS).

OBJECTIVE

This study aimed to compare the occurrence of asymmetry or muscle tone disorders in the first year of life in adolescents with IS and their healthy counterparts.

METHODS

The parents of adolescents with IS and without scoliosis completed a survey on the occurrence of asymmetry, abnormal muscle tone, and physiotherapy in their children in the first year of life. Pearson's chi square test and Cramer's coefficient were used.

RESULTS

The final analysis included 527 surveys completed by parents of adolescents with idiopathic scoliosis (150) and without scoliosis (377). A significantly higher frequency of asymmetry (p= 0.001) and muscle tone disorders (p= 0.001) was noted in adolescents with idiopathic scoliosis. The results also revealed a significant association between scoliosis and asymmetry (p= 0.001), as well as muscle tone (p= 0.001).

CONCLUSIONS

Developmental asymmetry or improper muscle tone in the first year of life could be considered a potential factor in the development of scoliosis; however, this hypothesis should be confirmed in future studies. Infants diagnosed with developmental disorders require systematic observation.

Development of muscle tone impairments in high-risk infants: Associations with cerebral palsy and cystic periventricular leukomalacia

AIM

To assess the prevalence and development of muscle tone impairments in infants at high risk of developmental disorders, and their associations with cerebral palsy (CP) and cystic periventricular leukomalacia (cPVL).

METHOD

Longitudinal exploration of muscle tone in 39 infants at high risk of CP (LEARN2MOVE 0-2 project) mostly due to an early lesion of the brain. Muscle tone was assessed ≥4 times between 0 and 21 months corrected age (CA) with the Touwen Infant Neurological Examination. Diagnosis of CP was determined at 21 months CA. Neonatal neuro-imaging was available. Developmental trajectories were calculated using generalized linear mixed effect models.

RESULTS

Infants showed atypical muscle tone in three or four body parts in 93% (172/185) of the assessments. The most prevalent muscle tone pattern was hypotonia of neck and trunk with hypertonia of the limbs (28%). From 7 months CA onwards hypertonia of the arms was associated with CP. Asymmetric arm tone during infancy was associated with unilateral CP. At 18-21 months CA ankle hypertonia was associated with CP at 21 months; leg hypertonia in infancy was not associated with CP. Leg hypertonia was associated with cPVL, regardless of age.

INTERPRETATION

High-risk infants due to an early lesion of the brain often present with muscle tone impairment. In these infants, hypertonia and asymmetric muscle tone of the arms were from 7 months onwards associated with the diagnosis of CP at 21 months; hypertonia of the legs was not.

Predictive Validity of the Bayley-III Cognitive Scores at 6 Months for Cognitive Outcomes at 24 Months in Very-Low-Birth-Weight Infants

Purpose: To assess the predictive validity of the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) cognitive scores at 6 months of corrected age (CA) for cognitive outcomes at 24 months of CA in very-low-birth-weight (VLBW) infants and investigate the predictors of change in cognitive outcomes. Methods: We retrospectively evaluated VLBW children enrolled in the Taiwan Premature Infant Follow-up Network between 2010 and 2015 and completed the Bayley-III at CA of 6 and 24 months. The predictive validity of the cognitive performance at 6-month CA for the cognitive outcomes at 24-month CA was analyzed. The positive and negative predictive factors were also evaluated using logistic regression. Cut-off scores of <70 and <85 were used to identify lower functioning groups based on the Bayley-III definition. Results: A total of 2,972 VLBW children, born with a mean weight of 1116.4 ± 257.5 g and mean gestational age of 29.0 ± 2.8 weeks, were evaluated. A cognitive score of <70 at 6-month CA had a positive predictive value (PPV) of 27.4% (95% confidence interval [CI]: 19.2-35.7%) for a cognitive score of <70 at 24-month CA, while the negative predictive value (NPV) was 97.3% (95% CI: 96.7-97.9%). A cut-off score of 85 had a PPV of 33.6% (95% CI: 28.1-39.0%) and an NPV of 87.7% (95% CI: 86.4-88.9%). Abnormal muscle tone at 6 months was a risk factor for cognitive function decline at 24 months for both Bayley-III cognitive cut-off scores: scores of 70 (adjusted odds ratio [AOR]: 2.8; 95% CI: 1.5-5.5) and 85 (AOR: 2.6; 95% CI: 1.6-4.1). Lower maternal socioeconomic status was associated with a worsening of the cognitive function in infants at 24 months who scored ≥85 at 6 months (AOR: 1.6; 95% CI: 1.2-2.0). Conclusion: Subnormal Bayley-III cognitive scores at 6-month CA were not predictive of subnormal cognitive function at 24-month CA. In children with normal cognition during early infancy, abnormal muscle tone and lower maternal socioeconomic status may influence the cognitive developing process; this highlighted the importance of early identification of high risk infants and complete preterm infant-associated public health policies to promote an improved neurodevelopmental outcome.

Transient tone anomalies in very preterm infants: Association with term-equivalent brain magnetic resonance imaging and neurodevelopment at 18 months

BACKGROUND

Very preterm (VPT) infants are at risk for neurodevelopmental impairments and early clinical findings such as transient tone anomalies (TTA) might represent potential predictive indicators.

AIMS

The aims of this study were to assess 1) the prevalence of TTA at 6 months corrected age in a population of VPT infants, 2) the association with term-equivalent age (TEA) brain MRI and 3) the neurodevelopmental outcome at 18 months corrected age.

STUDY DESIGN AND SUBJECTS

A prospective case-control cohort of 103 VPT infants (<29 weeks of gestation) was followed up at 6 months and classified into TTA+ or TTA-. TTA+ was defined by the presence of ≥2 criteria among anomalies of posture, anomalies of tone and hyperreflexia.

OUTCOME MEASURES

Conventional and diffusion-weighted MRIs at TEA were analyzed according to a semi-quantitative MRI scoring system and apparent diffusion coefficients (ADC) and fractional anisotropy (FA) were measured in frontal, occipital white matter and posterior limb of the internal capsule (PLIC). Neurodevelopment was assessed at 18 months using Bayley-II scales (Psychomotor Developmental Index: PDI; Mental Developmental Index: MDI).

RESULTS

TTA+ infants represented 29.1% of the total population. They had: 1) significantly higher ADC values in 3 regions of interest (p < 0.001), 2) significant lower FA in the PLIC (p < 0.001), and 3) significant lower PDI score (p < 0.05). No differences were observed regarding MDI scores. Interaction of TTA by cerebellum score was related to lower MDI scores.

CONCLUSIONS

In VPT infants, TTA at 6 months and/or structural brain abnormality at TEA are associated with poorer neurodevelopmental outcome at 18 months.

Early school outcomes for extremely preterm infants with transient neurological abnormalities

AIM

To determine if transient neurological abnormalities (TNA) at 9 months corrected age predict cognitive, behavioral, and motor outcomes at 6 years of age in extremely preterm infants.

METHOD

A cohort of 124 extremely preterm infants (mean gestational age 25.5wks; 55 males, 69 females), admitted to our unit between 2001 and 2003, were classified based on the Amiel-Tison Neurological Assessment at 9 months and 20 months corrected age as having TNA (n=17), normal neurological assessment (n=89), or neurologically abnormal assessment (n=18). The children were assessed at a mean age of 5 years 11 months (SD 4mo) on cognition, academic achievement, motor ability, and behavior.

RESULTS

Compared with children with a normal neurological assessment, children with TNA had higher postnatal exposure to steroids (35% vs 9%) and lower adjusted mean scores on spatial relations (84 [standard error {SE} 5] vs 98 [SE 2]), visual matching (79 [SE 5] vs 91 [SE 2]), letter-word identification (97 [SE 4] vs 108 [SE 1]), and spelling (76 [SE 4] vs 96 [SE 2]) (all p<0.05).

INTERPRETATION

Despite a normalized neurological assessment, extremely preterm children with a history TNA are at higher risk for lower cognitive and academic skills than those with normal neurological findings during their first year of school.

Hypotonia, jaundice, and Chiari malformations: relationships to executive functions

This article postulates that movement and action control are the underpinning of executive functioning. We selectively examine brain regions that have traditionally been almost exclusively understood as critical to the control and expression of movement-namely, the basal ganglia and the cerebellum. We first describe the relationship between movement and cognition. This is followed by a review of common developmental disorders that are known to exhibit abnormal executive functions and movement anomalies. Against that background, we examine hypotonia, neonatal jaundice, and Chiari I malformation, and we demonstrate why these are "at-risk" factors for neurodevelopmental disorders that can feature both motor control and executive function abnormalities. Our goal is to prepare the clinical neuropsychologist for gathering information about these features of a child's birth and developmental histories, while using this as a framework for interpreting test results and applying test data in a useful, practical way to guide descriptive diagnosis and treatment.