Correlations between sleep disturbance and brain cortical morphometry in healthy children

Background While the importance of adequate sleep duration to normal brain development is well known, more studies are needed to characterize how undiagnosed sleep disturbance other than suboptimal sleep duration may impact brain development. In this study we aim to understand the relationships between sleep disturbance measures and cortical morphometry in typically-developing children without previous diagnoses of sleep pathology. Methods Healthy 8-year-old children (30 boys, 37 girls) without clinical diagnosis of sleep disorders were prospectively recruited for brain MRI and their parents completed the Children’s Sleep Habits Questionnaire (CSHQ). Total sleep disturbance score, as well as 8 subscales including bedtime resistance, sleep onset delay, sleep duration, sleep anxiety, night waking, parasomnias, sleep disordered breathing, and daytime sleepiness were calculated, and their relationships with cortical morphometry features including cortical gray matter volume, cortical thickness, and surface area were investigated, controlled for total cortical volume and sex. Results The CSHQ total sleep disturbance score significantly correlated with cortical surface area in a cluster in the left middle temporal gyrus (P < 0.001, R = -0.54). In addition, the bedtime resistance subscale negatively correlated with cortical surface area in a cluster in the right fusiform gyrus (P < 0.001, R = -0.50). No other clusters showed significant relationships between CSHQ total score or subscales and cortical features for this cohort. Conclusion Significant relationships between sleep disturbance scores in typically-developing children without clinical diagnosis of sleep pathology and their brain cortical surface area in two temporal lobe regions were identified, suggesting that undiagnosed sleep disturbance may potentially impact brain development even in healthy children.

Antipsychotics effects on network-level reconfiguration of cortical morphometry in first-episode schizophrenia

BackgroundCortical thickness reductions are evident in patients with schizophrenia. Associations between antipsychotic medications (APMs) and cortical morphometry have been explored in schizophrenia patients. This raises the question of whether the reconfiguration of morphological architecture by APM plays potential compensatory roles for abnormalities in the cerebral cortex.MethodsStructural MRI were obtained from 127 medication-naive first-episode schizophrenia (FES) patients and 133 matched healthy controls. Patients received 12 weeks of APM and were categorized as responders (n=75) or nonresponders (n=52) at follow-up. Using surface-based morphometry and structural covariance analysis, this study investigated the short-term effects of antipsychotics on cortical thickness and cortico-cortical connectivity. Global efficiency was computed to characterize network integration of the large-scale structural connectome. The relationship between connectivity and cortical thinning was examined by the structural covariance analysis among top-n regions with thickness reduction.ResultsWidespread cortical thickness reductions were observed in pre-APM patients. Post-APM patients showed more reductions in cortical thickness, even in the frontotemporal regions without baseline reductions. Covariance analysis revealed strong cortico-cortical connectivity and higher network integration in responders than in nonresponders. Notably, the nonresponders lacked key nodes of the prefrontal and temporal regions for the covariance network between top-n regions with cortical thickness reductions.ConclusionsAntipsychotic effects are not restricted to a single brain region but rather exhibit a network-level covariance pattern. Neuroimaging connectomics highlights the positive effects of antipsychotics on the reconfiguration of brain architecture, suggesting that abnormalities in regional morphology may be compensated by increasing interregional covariance when symptoms are controlled by antipsychotics.

A Multi-Modal MRI Analysis of Cortical Structure in Relation to Gender Dysphoria, Sexual Orientation, and Age in Adolescents

Gender dysphoria (GD) is characterized by distress due to an incongruence between experienced gender and sex assigned at birth. Sex-differentiated brain regions are hypothesized to reflect the experienced gender in GD and may play a role in sexual orientation development. Magnetic resonance brain images were acquired from 16 GD adolescents assigned female at birth (AFAB) not receiving hormone therapy, 17 cisgender girls, and 14 cisgender boys (ages 12–17 years) to examine three morphological and microstructural gray matter features in 76 brain regions: surface area (SA), cortical thickness (CT), and T1 relaxation time. Sexual orientation was represented by degree of androphilia-gynephilia and sexual attraction strength. Multivariate analyses found that cisgender boys had larger SA than cisgender girls and GD AFAB. Shorter T1, reflecting denser, macromolecule-rich tissue, correlated with older age and stronger gynephilia in cisgender boys and GD AFAB, and with stronger attractions in cisgender boys. Thus, cortical morphometry (mainly SA) was related to sex assigned at birth, but not experienced gender. Effects of experienced gender were found as similarities in correlation patterns in GD AFAB and cisgender boys in age and sexual orientation (mainly T1), indicating the need to consider developmental trajectories and sexual orientation in brain studies of GD.