Brain Characteristics Noted Prior to and Following Cranial Orthotic Treatment

Methodological considerations on diffusion MRI tractography in infants aged 0-2 years: a scoping review

Diffusion MRI (dMRI) enables studying the complex architectural organization of the brain's white matter (WM) through virtual reconstruction of WM fiber tracts (tractography). Despite the anticipated clinical importance of applying tractography to study structural connectivity and tract development during the critical period of rapid infant brain maturation, detailed descriptions on how to approach tractography in young infants are limited. Over the past two decades, tractography from infant dMRI has mainly been applied in research settings and focused on diffusion tensor imaging (DTI). Only few studies used techniques superior to DTI in terms of disentangling information on the brain's organizational complexity, including crossing fibers. While more advanced techniques may enhance our understanding of the intricate processes of normal and abnormal brain development and extensive knowledge has been gained from application on adult scans, their applicability in infants has remained underexplored. This may partially be due to the higher technical requirements versus the need to limit scan time in young infants. We review various previously described methodological practices for tractography in the infant brain (0-2 years-of-age) and provide recommendations to optimize advanced tractography approaches to enable more accurate reconstructions of the brain WM's complexity. IMPACT: Diffusion tensor imaging is the technique most frequently used for fiber tracking in the developing infant brain but is limited in capability to disentangle the complex white matter organization. Advanced tractography techniques allow for reconstruction of crossing fiber bundles to better reflect the brain's complex organization. Yet, they pose practical and technical challenges in the fast developing young infant's brain. Methods on how to approach advanced tractography in the young infant's brain have hardly been described. Based on a literature review, recommendations are provided to optimize tractography for the developing infant brain, aiming to advance early diagnosis and neuroprotective strategies.

Three-Dimensional Analysis of the Cranial Base Structure in Patients with Facial Asymmetry

Facial asymmetry is often seen in patients with skeletal mandibular prognathism and is associated with deformities in the maxillofacial and head regions. The maxillofacial deviation is three-dimensional and affects not only the lateral deviation of the mandible and midface, but also the cranium. This study conducted a three-dimensional morphological evaluation of the cranial base morphology of patients with skeletal mandibular prognathism (ANB < 0°, Wits < 0 mm) with the aim of examining the relationship between deformities of the head region and facial asymmetry. Data obtained from computed tomography conducted during the initial examination of patients with and without skeletal mandibular prognathism with facial asymmetry were used. Differences in the position of structures present in the cranial base were measured, and the association between cranial deformities and mandibular deviation was assessed. The middle cranial base area and the lateral deviation of the mandibular fossa were significantly larger in patients with facial asymmetry compared to those without facial asymmetry. In addition, a correlation between the amount of mandibular deviation and the area of the anterior cranial base was identified in patients with significant cranial deformity (p = 0.012). Given the identified association between the structure of the head region and facial asymmetry, further studies are needed to determine the factors implicated in the growth process.

Neurocognitive Outcomes in Deformational Plagiocephaly: Is There an Association between Morphologic Severity and Results?

BACKGROUND

The neurodevelopmental effects of skull asymmetry and orthotic helmet therapy for deformational plagiocephaly (DP) have had limited investigation. This study assessed the long-term neurocognitive outcomes in patients with DP and their association with orthotic helmet therapy and head shape abnormality.

METHODS

A total of 138 school-age children with a history of DP, 108 of whom received helmet therapy, were tested with a neurocognitive battery assessing academic achievement, intelligence quotient, and visual-motor function. Severity of presenting plagiocephaly was calculated using anthropometric and photometric measurements. Analysis of covariance was used to compare outcomes between helmeted and nonhelmeted cohorts, unilateral plagiocephaly and concomitant brachycephaly, and left-sided and right-sided plagiocephaly. The association between severity of plagiocephaly and neurocognitive outcome was assessed through a residualized change approach.

RESULTS

There were no significant differences in neurocognitive outcomes between the helmeted and nonhelmeted DP cohorts or the unilateral plagiocephaly and brachycephaly cohorts. Participants with left-sided DP had significantly lower motor coordination scores than participants with right-sided DP (84.8 versus 92.7; effect size = -0.50; P = 0.03). There was a significant laterality by cephalic index interaction, with a negative association between cephalic index and reading comprehension and spelling for participants with left-sided DP. No significant associations were found between severity of presenting or posttreatment deformity and neurocognitive outcome.

CONCLUSIONS

Pretreatment and posttreatment severity of plagiocephaly were not correlated with neurocognitive function at school age. Helmet therapy was not associated with better or worse long-term neurocognitive function. However, participants with left-sided DP demonstrated worse neurocognitive outcomes than participants with right-sided DP in the domains of motor coordination and some types of academic achievement.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Negative versus withdrawn maternal behavior: Differential associations with infant gray and white matter during the first 2 years of life

Distinct neural effects of threat versus deprivation emerge by childhood, but little data are available in infancy. Withdrawn versus negative parenting may represent dimensionalized indices of early deprivation versus early threat, but no studies have assessed neural correlates of withdrawn versus negative parenting in infancy. The objective of this study was to separately assess the links of maternal withdrawal and maternal negative/inappropriate interaction with infant gray matter volume (GMV), white matter volume (WMV), amygdala, and hippocampal volume. Participants included 57 mother-infant dyads. Withdrawn and negative/inappropriate aspects of maternal behavior were coded from the Still-Face Paradigm at four months infant age. Between 4 and 24 months (M age = 12.28 months, SD = 5.99), during natural sleep, infants completed an MRI using a 3.0 T Siemens scanner. GMV, WMV, amygdala, and hippocampal volumes were extracted via automated segmentation. Diffusion weighted imaging volumetric data were also generated for major white matter tracts. Maternal withdrawal was associated with lower infant GMV. Negative/inappropriate interaction was associated with lower overall WMV. Age did not moderate these effects. Maternal withdrawal was further associated with reduced right hippocampal volume at older ages. Exploratory analyses of white matter tracts found that negative/inappropriate maternal behavior was specifically associated with reduced volume in the ventral language network. Results suggest that quality of day-to-day parenting is related to infant brain volumes during the first two years of life, with distinct aspects of interaction associated with distinct neural effects.