Quantitative brain morphological analysis in CHARGE syndrome

Brain morphometric changes in children born as small for gestational age without catch up growth

Introduction

Most infants born as small for gestational age (SGA) demonstrate catch up growth by 2-4 years, but some fail to do so. This failure is associated with several health risks, including neuropsychological development issues. However, data on the morphological characteristics of the brains of infants born as SGA without achieving catch up growth are lacking. This study aims to determine the structural aspects of the brains of children born as SGA without catch up growth.

Methods

We conducted voxel- and surface-based morphometric analyses of 1.5-T T1-weighted brain images scanned from eight infants born as SGA who could not achieve catch up growth by 3 years and sixteen individuals with idiopathic short stature (ISS) to exclude body size effects. Growth hormone (GH) secretion stimulation tests were used to rule out GH deficiency in all SGA and ISS cases. The magnetic resonance imaging data were assessed using Levene's test for equality of variances and a two-tailed unpaired t-test for equality of means. The Benjamini-Hochberg procedure was used to apply discovery rate correction for multiple comparisons.

Results

Morphometric analyses of both t-statical map and surface-based analyses using general linear multiple analysis determined decreased left insula thickness and volume in SGA without catch up growth compared with ISS.

Conclusion

The brain scans of patients with SGA who lack catch up growth indicated distinct morphological disparities when compared to those with ISS. The discernible features of brain morphology observed in patients born as SGA without catch up growth may improve understanding of the association of SGA without catch up growth with both intellectual and psychological outcomes.

A Brain Morphometry Study with Across-Site Harmonization Using a ComBat-Generalized Additive Model in Children and Adolescents

Regional anatomical structures of the brain are intimately connected to functions corresponding to specific regions and the temporospatial pattern of genetic expression and their functions from the fetal period to old age. Therefore, quantitative brain morphometry has often been employed in neuroscience investigations, while controlling for the scanner effect of the scanner is a critical issue for ensuring accuracy in brain morphometric studies of rare orphan diseases due to the lack of normal reference values available for multicenter studies. This study aimed to provide across-site normal reference values of global and regional brain volumes for each sex and age group in children and adolescents. We collected magnetic resonance imaging (MRI) examinations of 846 neurotypical participants aged 6.0-17.9 years (339 male and 507 female participants) from 5 institutions comprising healthy volunteers or neurotypical patients without neurological disorders, neuropsychological disorders, or epilepsy. Regional-based analysis using the CIVET 2.1.0. pipeline provided regional brain volumes, and the measurements were across-site combined using ComBat-GAM harmonization. The normal reference values of global and regional brain volumes and lateral indices in our study could be helpful for evaluating the characteristics of the brain morphology of each individual in a clinical setting and investigating the brain morphology of ultra-rare diseases.

Brain structure alterations in girls with central precocious puberty

Purpose

Central precocious puberty (CPP) is puberty that occurs at an unusually early age with several negative psychological outcomes. There is a paucity of data on the morphological characteristics of the brain in CPP. This study aimed to determine the structural differences in the brain of patients with CPP.

Methods

We performed voxel- and surface-based morphometric analyses of 1.5 T T1-weighted brain images scanned from 15 girls with CPP and 13 age-matched non-CPP controls (NC). All patients with CPP were diagnosed by gonadotropin-releasing hormone (GnRH) stimulation test. The magnetic resonance imaging (MRI) data were evaluated using Levene's test for equality of variances and a two-tailed unpaired t-test for equality of means. False discovery rate correction for multiple comparisons was applied using the Benjamini-Hochberg procedure.

Results

Morphometric analyses of the brain scans identified 33 candidate measurements. Subsequently, increased thickness of the right precuneus was identified in the patients with CPP using general linear models and visualizations of cortical thickness with a t-statistical map and a random field theory map.

Conclusion

The brain scans of the patients with CPP showed specific morphological differences to those of the control. The features of brain morphology in CPP identified in this study could contribute to further understanding the association between CPP and detrimental psychological outcomes.

Pervasive cortical and white matter anomalies in a mouse model for CHARGE syndrome

CHARGE (Coloboma of the eye, Heart defects, Atresia of the choanae, Retardation of growth, Genital anomalies and Ear abnormalities) syndrome is a disorder caused by mutations in the gene encoding CHD7, an ATP dependent chromatin remodelling factor, and is characterised by a diverse array of congenital anomalies. These include a range of neuroanatomical comorbidities which likely underlie the varied neurodevelopmental disorders associated with CHARGE syndrome, which include intellectual disability, motor coordination deficits, executive dysfunction, and autism spectrum disorder. Cranial imaging studies are challenging in CHARGE syndrome patients, but high-throughput magnetic resonance imaging (MRI) techniques in mouse models allow for the unbiased identification of neuroanatomical defects. Here, we present a comprehensive neuroanatomical survey of a Chd7 haploinsufficient mouse model of CHARGE syndrome. Our study uncovered widespread brain hypoplasia and reductions in white matter volume across the brain. The severity of hypoplasia appeared more pronounced in posterior areas of the neocortex compared to anterior regions. We also perform the first assessment of white matter tract integrity in this model through diffusion tensor imaging (DTI) to assess the potential functional consequences of widespread reductions in myelin, which suggested the presence of white matter integrity defects. To determine if white matter alterations correspond to cellular changes, we quantified oligodendrocyte lineage cells in the postnatal corpus callosum, uncovering reduced numbers of mature oligodendrocytes. Together, these results present a range of promising avenues of focus for future cranial imaging studies in CHARGE syndrome patients.

Phenotypic characteristics and variability in CHARGE syndrome: a PRISMA compliant systematic review and meta-analysis

BACKGROUND

CHARGE syndrome (OMIM #214800) is a phenotypically complex genetic condition characterised by multi-system, multi-sensory impairments. Behavioural, psychological, cognitive and sleep difficulties are not well delineated and are likely associated with biopsychosocial factors.

METHODS

This meta-analysis investigated the prevalence of clinical features, physical characteristics and conditions, behavioural, psychological, cognitive and sleep characteristics in CHARGE syndrome, and statistically evaluated directional associations between these characteristics. Pooled prevalence estimates were calculated using reliable, prespecified quality weighting criteria, and meta-regression was conducted to identify associations between characteristics.

RESULTS

Of the 42 eligible studies, data could be extracted for 1675 participants. Prevalence estimates were highest for developmental delay (84%), intellectual disability (64%), aggressive behaviour (48%), self-injurious behaviour (44%) and sleep difficulties (45%). Meta-regression indicated significant associations between intellectual disability and choanal atresia, intellectual disability and inner ear anomalies, sleep difficulties and growth deficiency, and sleep difficulties and gross motor difficulties.

CONCLUSIONS

Our comprehensive review of clinical features, behavioural, psychological, cognitive and physical characteristics, conditions and comorbidities in CHARGE syndrome provides an empirically based foundation to further research and practice.

MRI studies of brain size and growth in individuals with congenital heart disease

Congenital heart disease (CHD) is the most frequent congenital abnormality. Most infants born with CHD now survive. However, survivors of CHD are at increased risk of neurodevelopmental impairment, which may be due to impaired brain development in the fetal and neonatal period. Magnetic resonance imaging (MRI) provides objective measures of brain volume and growth. Here, we review MRI studies assessing brain volume and growth in individuals with CHD from the fetus to adolescence. Smaller brain volumes compared to healthy controls are evident from around 30 weeks gestation in fetuses with CHD and are accompanied by increased extracerebral cerebrospinal fluid. This impaired brain growth persists after birth and throughout childhood to adolescence. Risk factors for impaired brain growth include reduced cerebral oxygen delivery in utero, longer time to surgery and increased hospital stay. There is increasing evidence that smaller total and regional brain volumes in this group are associated with adverse neurodevelopmental outcome. However, to date, few studies have assessed the association between early measures of cerebral volume and neurodevelopmental outcome in later childhood. Large prospective multicentre studies are required to better characterise the relationship between brain volume and growth, clinical risk factors and subsequent cognitive, motor, and behavioural impairments in this at-risk population.

Quantitative analyses of high-angular resolution diffusion imaging (HARDI)-derived long association fibers in children with sensorineural hearing loss

Sensorineural hearing loss (SNHL) is the most common developmental sensory disorder due to a loss of function within the inner ear or its connections to the brain. While successful intervention for auditory deprivation with hearing amplification and cochlear implants during a sensitive early developmental period can improve spoken-language outcomes, SNHL patients can suffer several cognitive dysfunctions including executive function deficits, visual cognitive impairment, and abnormal visual dominance in speaking perception even after successful intervention. To evaluate whether long association fibers are involved in the pathogenesis of impairment on the extra-auditory cognitive process in SNHL participants, we quantitatively analyzed high-angular resolution diffusion imaging (HARDI) tractography-derived fibers in participants with SNHL. After excluding cases with congenital disorders, perinatal brain damage, or premature birth, we enrolled 17 participants with SNHL aged under 10 years old. Callosal pathways (CP) and six types of cortico-cortical association fibers (arcuate fasciculus [AF], inferior longitudinal fasciculus [ILF], inferior fronto-occipital fasciculus [IFOF], uncinate fasciculus [UF], cingulum fasciculus [CF], and fornix [Fx]) in both hemispheres were identified and visualized. The ILF and IFOF were partly undetected in three profound SNHL participants. Compared to age- and gender-matched neurotypical controls (NC), decreased volumes, increased lengths, and high apparent diffusion coefficient (ADC) values without difference in fractional anisotropy (FA) values were identified in multiple types of fibers in the SNHL group. The impairment of long association fibers in SNHL may partly be related to the association of cognitive dysfunction with SNHL.