Early-onset psychosis disorders are serious mental disorders arising before the age of 18 years. Here, we investigate the largest neuroimaging dataset, to date, of patients with early-onset psychosis and healthy controls for differences in intracranial and subcortical brain volumes. The sample included 263 patients with early-onset psycho-
Objective
Abnormal blood lipid levels are common in bipolar disorder (BD) and correlate with mood symptoms and neurocognition. However, studies have not examined the lipid–brain structure association in BD or youth.
Methods
This study examined low‐density lipoprotein (LDL‐C), high‐density lipoprotein (HDL‐C), triglycerides, and total cholesterol (TC) levels in relation to brain structure utilizing T1‐weighted images, among participants ages 13–20 with BD (n = 55) and healthy controls (HC; n = 47). General linear models investigated group differences in the association of lipids with anterior cingulate cortex (ACC), hippocampus, and inferior parietal lobe structure, controlling for age, sex, body mass index, and intracranial volume. For significant associations, post hoc within‐group analyses were undertaken. Exploratory vertex‐wise analyses further investigated group differences in the lipid–brain structure association.
Results
There were significant group differences in the association of LDL‐C (β = −0.29 p = 0.001), and TC (β = −0.21 p = 0.016), with hippocampal volume, and triglycerides with ACC volume (β = −0.25 p = 0.01) and area (β = −0.26 p = 0.004). Elevated lipids were associated with smaller brain structure to a significantly greater extent in BD vs HC. Post hoc analyses revealed that elevated LDL‐C (β = −0.27 p = 0.007) and reduced HDL‐C (β = 0.24 p = 0.01) were associated with smaller hippocampal volume in the BD group. Exclusion of BD second‐generation antipsychotic users did not alter these results. Vertex‐wise analyses further showed that elevated lipids were associated with smaller brain structure to a significantly greater extent in BD vs HC, across the cortex.
Conclusion
Elevated lipids are associated with smaller brain structure in BD. Research evaluating lipid–brain structure associations prospectively and whether lipid optimization has salutary effects on brain structure is necessary.
Background: Regional cerebral blood flow (CBF) is reportedly altered in both adolescents and adults with bipolar disorder (BD). Whether these CBF differences are part of an overall imbalance in cerebral energy homeostasis remains unknown. Therefore, we examined global cerebral metabolic rate of oxygen consumption (CMRO2) as a physiological index of brain metabolism in adolescents with and without BD.
Methods: One hundred and fifteen adolescents (mean age 17.3 ± 1.4 years), including 58 BD (type I, II, or not otherwise specified [NOS]) and 57 age-matched healthy controls (HCs) participated in this magnetic resonance imaging (MRI) study. Global estimates for venous blood oxygenation (Yv) and grey matter CBF were measured using T2-relaxation-under-spin-tagging (TRUST) and arterial spin labeling (ASL) MRI, respectively. CMRO2 was calculated using the Fick principle of arteriovenous difference to test for a group difference. We also examined CMRO2 in relation to mood states (i.e. euthymic, depressed, or hypomanic/mixed).
Results: Although CBF was significantly higher in BD compared to HCs, there was no group difference in global CMRO2, nor Yv. Meanwhile, Yv significantly decreased with age, and females tended to have greater CBF and CMRO2 in comparison to males. Lastly, there was no significant association between CMRO2 and mood states.
Conclusions: Our results indicate a potential mismatch between cerebral blood supply and oxygen metabolism in BD, suggesting inefficiency in energy homeostasis in the brain. Mapping CMRO2 would provide the spatial resolution to investigate regional alterations in metabolism, particularly in the brain regions where CBF is increased.
In albinism, the number of ipsilaterally projecting retinal ganglion cells (RGCs) is significantly reduced. The retina and optic chiasm have been proposed as candidate sites for misrouting. Since a correlation between the number of lateral geniculate nucleus (LGN) relay neurons and LGN size has been shown, and based on previously reported reductions in LGN volumes in human albinism, we suggest that fiber projections from LGN to the primary visual cortex (V1) are also reduced. Studying structural differences in the visual system of albinism can improve the understanding of the mechanism of misrouting and subsequent clinical applications. Diffusion data and tractography are useful for mapping the OR (optic radiation). This manuscript describes two algorithms for OR reconstruction in order to compare brain connectivity in albinism and controls.An MRI scanner with a 32-channel head coil was used to acquire structural scans. A T1-weighted 3D-MPRAGE sequence with 1 mm(3) isotropic voxel size was used to generate high-resolution images for V1 segmentation. Multiple proton density (PD) weighted images were acquired coronally for right and left LGN localization. Diffusion tensor imaging (DTI) scans were acquired with 64 diffusion directions. Both deterministic and probabilistic tracking methods were run and compared, with LGN as the seed mask and V1 as the target mask. Though DTI provides relatively poor spatial resolution, and accurate delineation of OR may be challenging due to its low fiber density, tractography has been shown to be advantageous both in research and clinically. Tract based spatial statistics (TBSS) revealed areas of significantly reduced white matter integrity within the OR in patients with albinism compared to controls. Pairwise comparisons revealed a significant reduction in LGN to V1 connectivity in albinism compared to controls. Comparing both tracking algorithms revealed common findings, strengthening the reliability of the technique.
Background
Oxidative stress is implicated in the neuropathology of bipolar disorder (BD). We investigated the association of single-nucleotide polymorphisms (SNPs) in the antioxidative genes superoxide dismutase 2 (SOD2) and glutathione peroxidase 3 (GPX3) with structural neuroimaging phenotypes in youth BD.
Methods
SOD2 rs4880 and GPX3 rs3792797 SNP genotypes, along with structural magnetic resonance imaging, were obtained from 147 youth (BD=75; healthy controls (HC)=72). Images were processed using FreeSurfer, yielding surface area, volume, and thickness values for regions of interest (ROI; prefrontal cortex (PFC), caudal anterior cingulate cortex (cACC), hippocampus) and for vertex-wise whole brain analysis. Analyses controlled for age, sex, race, and intracranial volume for volume area, and thickness analyses.
Result
ROI analyses revealed diagnosis-by-SOD2 rs4880 interaction effects for cACC volume and surface area, and PFC volume; in each case, there was lower volume/area in the BD GG genotype group vs. the HC GG genotype group. There was a significant BD diagnosis x GPX3 rs3793797 interaction effect for PFC surface area, where area was lower in the BD A-allele carrier group vs. the other genotype groups. Vertex-wise analyses revealed significant interaction effects in frontal, temporal, and parietal regions, related to smaller brain structure in the BD SOD2 rs4880 GG group and BD GPX3 rs3793797 A-allele carrier group.
Conclusion
We found preliminary evidence that SOD2 rs4880 and GPX3 rs3792797 are differentially associated with brain structure in youth with BD, in regions that are relevant to BD. Further studies incorporating additional neuroimaging phenotypes and blood levels of oxidative stress markers are warranted.
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