Human total brain size is consistently reported to be ~8-10% larger in males, although consensus on regionally-specific differences is weak. Here, in the largest longitudinal pediatric neuroimaging study reported to date (829 scans from 387 subjects, ages 3 to 27 years), we demonstrate the importance of examining size-by-age trajectories of brain development rather than group averages across broad age ranges when assessing sexual dimorphism. Using magnetic resonance imaging (MRI) we found robust male/female differences in the shapes of trajectories with total cerebral volume peaking at age 10.5 in females and 14.5 in males. White matter increases throughout this 24 year period with males having a steeper rate of increase during adolescence. Both cortical and subcortical gray matter trajectories follow an inverted U shaped path with peak sizes 1 to 2 years earlier in females. These sexually dimorphic trajectories confirm the importance of longitudinal data in studies of brain development and underline the need to consider sex matching in studies of brain development.

Background: Treatments for childhood cancer have evolved in recent decades, with the goal of maximizing cure rates while minimizing the adverse effects of therapy. We aimed to evaluate incidence patterns of serious chronic health conditions in long-term survivors of childhood cancer across three decades of diagnosis and treatment. Methods: We used data from the Childhood Cancer Survivor Study, a retrospective cohort with prospective follow-up of 5-year survivors of childhood cancer diagnosed from 1970-1999 in North America. We examined the cumulative incidence of severe to fatal chronic health conditions occurring up to 20 years post-diagnosis among survivors, compared by diagnosis decade. Multivariable regression models estimated hazard ratios per diagnosis decade, and addition of treatment variables assessed whether treatment changes attenuated associations between diagnosis decade and chronic disease risk. Findings: Among 23,601 survivors (median age 28, range 5-63 years; 46% female), the 20-year cumulative incidence of at least one grade 3-5 chronic condition decreased significantly from 33·2% (95% CI, 32·0%-34·3%) in those diagnosed 1970-1979 to 29·3% (95% CI, 28·4%-30·2%, p<0·0001) in 1980-1989, and 27·5% (95% CI, 26·4%-28·6%, p=0·012 vs. 1980-1989) in 1990-1999. By comparison, the 20-year cumulative incidence of at least one grade 3-5 condition among 5,051 siblings was 4·6% (95% CI,3·9%-5·2%). The 15-year cumulative incidence of at least one grade 3-5 condition was lower for survivors diagnosed 1990-1999 compared to 1970-1979 for Hodgkin lymphoma (17·7% vs. 26·4%, p<0·0001), non-Hodgkin lymphoma (16·9% vs. 23·8%, p=0.0053), astrocytoma (30·5% vs. 47·3%, p<0·0001), Wilms tumor (11·9% vs. 17·6%, p=0·034), soft tissue sarcoma (28·3% vs. 36·5%, p=0·021), and osteosarcoma (65·6% vs. 87·5%, p<0·0001). In contrast, the 15-year cumulative incidence of at least one grade 3-5 condition was higher (1990-1999 vs. 1970-1979) for medulloblastoma/PNET (58·9% vs. 42·9%, p=0·00060) and neuroblastoma (25·0% vs. 18·0%, p=0·0045). Results were consistent with changes in treatment as a mediator of the association between diagnosis decade and risk of grade 3-5 chronic conditions for astrocytoma, Hodgkin lymphoma, and non-Hodgkin lymphoma. Temporal decreases were observed for endocrinopathies, subsequent malignant neoplasms, musculoskeletal conditions, and gastrointestinal conditions, while hearing loss increased. Interpretation: Our results provide novel evidence that more recently treated survivors of childhood cancer have experienced improvements in health outcomes, consistent with efforts over the same time period to modify childhood cancer treatment regimens to maximize cure while reducing risk of late effects. Continuing advances in cancer therapy offer promise of further reducing the risk of late effects. However, achieving a cure for childhood cancer continues to come at a cost for many survivors, emphasizing the importance of long-term follow-up care for this population. Funding: National Cancer Institute and t...

OBJECTIVE. An extra X chromosome in males (XXY), known as Klinefelter syndrome, is associated with characteristic physical, cognitive, and behavioral features of variable severity. The objective of this study was to examine possible neuroanatomical substrates of these cognitive and behavioral features during childhood and adolescence. METHODS. MRI brain scans were acquired for 42 XXY and 87 healthy XY age-matched control males. We compared these 2 groups on regional brain volumes and cortical thickness. RESULTS. Total cerebral volume and all lobar volumes except parietal white matter were significantly smaller in the XXY group, whereas lateral-ventricle volume was larger. Consistent with the cognitive profile, the cortex was significantly thinner in the XXY group in left inferior frontal, temporal, and superior motor regions. CONCLUSION. The brain-imaging findings of preferentially affected frontal, temporal, and motor regions and relative sparing of parietal regions are consistent with observed cognitive and behavioral strengths and weaknesses in XXY subjects.

Key Points Question What are the most effective treatments for N -methyl- d -aspartate receptor (NMDAR) antibody encephalitis? Findings In this meta-analysis of individual patient data including 1550 cases, treatment factors at first event that were significantly associated with good functional outcome 12 months from disease onset included first-line treatment with therapeutic apheresis alone, corticosteroids in combination with intravenous immunoglobulin (IVIG), or corticosteroids in combination with IVIG and therapeutic apheresis, while lack of immunotherapy within 30 days of disease onset was significantly associated with poor outcome. Rituximab and long-term IVIG use were significantly associated with nonrelapsing disease course. Meaning Separate treatment factors are associated with functional outcomes and relapsing disease biology in those with NMDAR antibody encephalitis.