Brain charts for the human lifespan.

Over the past few decades, neuroimaging has become a ubiquitous tool in basic research and clinical studies of the human brain. However, no reference standards currently exist to quantify individual differences in neuroimaging metrics over time, in contrast to growth charts for anthropometric traits such as height and weight1. Here we assemble an interactive open resource to benchmark brain morphology derived from any current or future sample of MRI data ( http://www.brainchart.io/ ). With the goal of basing these reference charts on the largest and most inclusive dataset available, acknowledging limitations due to known biases of MRI studies relative to the diversity of the global population, we aggregated 123,984 MRI scans, across more than 100 primary studies, from 101,457 human participants between 115 days post-conception to 100 years of age. MRI metrics were quantified by centile scores, relative to non-linear trajectories2 of brain structural changes, and rates of change, over the lifespan. Brain charts identified previously unreported neurodevelopmental milestones3, showed high stability of individuals across longitudinal assessments, and demonstrated robustness to technical and methodological differences between primary studies. Centile scores showed increased heritability compared with non-centiled MRI phenotypes, and provided a standardized measure of atypical brain structure that revealed patterns of neuroanatomical variation across neurological and psychiatric disorders. In summary, brain charts are an essential step towards robust quantification of individual variation benchmarked to normative trajectories in multiple, commonly used neuroimaging phenotypes.

The Heimann-Bielschowsky phenomenon after optic neuritis.

A 32-year-old woman with relapsing-remitting multiple sclerosis and a right optic neuritis with incomplete remission presented with unique neuro-ophthalmologic abnormality consisting of a spontaneous, pendular, vertical movement of the right eye consistent with the Heimann-Bielschowsky phenomenon (HBP). This rare form of dissociated nystagmus probably reflects a "dual abnormality mechanism" comprising the coexistence of an asymmetric conduction delay in the optic nerve and a strategic network disruption in brainstem gaze holding centres. For the clinician it is important to recognize this rare neuro-ophthalmologic syndrome and be aware of its benign nature.

Proxy evidence for state-dependence of climate sensitivity in the Eocene greenhouse.

Despite recent advances, the link between the evolution of atmospheric CO2 and climate during the Eocene greenhouse remains uncertain. In particular, modelling studies suggest that in order to achieve the global warmth that characterised the early Eocene, warmer climates must be more sensitive to CO2 forcing than colder climates. Here, we test this assertion in the geological record by combining a new high-resolution boron isotope-based CO2 record with novel estimates of Global Mean Temperature. We find that Equilibrium Climate Sensitivity (ECS) was indeed higher during the warmest intervals of the Eocene, agreeing well with recent model simulations, and declined through the Eocene as global climate cooled. These observations indicate that the canonical IPCC range of ECS (1.5 to 4.5 °C per doubling) is unlikely to be appropriate for high-CO2 warm climates of the past, and the state dependency of ECS may play an increasingly important role in determining the state of future climate as the Earth continues to warm.

Functional DNA methylation signatures for autism spectrum disorder genomic risk loci: 16p11.2 deletions and CHD8 variants.

BACKGROUND: Autism spectrum disorder (ASD) is a common and etiologically heterogeneous neurodevelopmental disorder. Although many genetic causes have been identified (> 200 ASD-risk genes), no single gene variant accounts for > 1% of all ASD cases. A role for epigenetic mechanisms in ASD etiology is supported by the fact that many ASD-risk genes function as epigenetic regulators and evidence that epigenetic dysregulation can interrupt normal brain development. Gene-specific DNAm profiles have been shown to assist in the interpretation of variants of unknown significance. Therefore, we investigated the epigenome in patients with ASD or two of the most common genomic variants conferring increased risk for ASD. Genome-wide DNA methylation (DNAm) was assessed using the Illumina Infinium HumanMethylation450 and MethylationEPIC arrays in blood from individuals with ASD of heterogeneous, undefined etiology (n = 52), and individuals with 16p11.2 deletions (16p11.2del, n = 9) or pathogenic variants in the chromatin modifier CHD8 (CHD8+/-, n = 7). RESULTS: DNAm patterns did not clearly distinguish heterogeneous ASD cases from controls. However, the homogeneous genetically-defined 16p11.2del and CHD8+/- subgroups each exhibited unique DNAm signatures that distinguished 16p11.2del or CHD8+/- individuals from each other and from heterogeneous ASD and control groups with high sensitivity and specificity. These signatures also classified additional 16p11.2del (n = 9) and CHD8 (n = 13) variants as pathogenic or benign. Our findings that DNAm alterations in each signature target unique genes in relevant biological pathways including neural development support their functional relevance. Furthermore, genes identified in our CHD8+/- DNAm signature in blood overlapped differentially expressed genes in CHD8+/- human-induced pluripotent cell-derived neurons and cerebral organoids from independent studies. CONCLUSIONS: DNAm signatures can provide clinical utility complementary to next-generation sequencing in the interpretation of variants of unknown significance. Our study constitutes a novel approach for ASD risk-associated molecular classification that elucidates the vital cross-talk between genetics and epigenetics in the etiology of ASD.

Disentangling balance impairments in spinal and bulbar muscular atrophy.

Spinal and bulbar muscular atrophy (Kennedy's disease) has been associated with balance dysfunction and falls. However, postural control has not been studied quantitatively. Here, we quantified upright stance and aimed to disentangle the role of vestibular, proprioceptive and oculomotor deficits. Static balance was assessed in Kennedy patients (n = 7) during quiet stance on a force platform under different visual and proprioceptive feedback conditions. Vestibular function was assessed with the video head impulse test. Sural nerve neurography was employed to evaluate the severity of peripheral neuropathy. Also, horizontal saccades were recorded and quantified by the main sequence relationship. Posturographic analyses revealed significantly increased body sway, more pronounced in conditions with closed eyes, which was also reflected in the calculated Romberg indices. Horizontal vestibulo-ocular reflex gains were normal, i.e. > 0.75. In contrast, compound sensory nerve action potentials were markedly decreased in all patients (mean = 2.4 µV). Two patients showed slow saccades with increased exponential main sequence constants. We conclude that Kennedy patients exhibit severe deficits in quiet stance. Postural instability is greatest in conditions of absent vision with reduced proprioception being the main determinant of unsteadiness. Some patients show slowed saccadic eye movements suggesting a nuclear abducens neuronopathy.

Postural instability during attacks of migraine without aura.

BACKGROUND AND PURPOSE: Migraine has long been associated with unsteadiness and dizziness but postural control has not been studied in the ictal state. Here, the stability of upright stance during migraine attacks was measured. METHODS: Static balance was assessed prospectively in migraine patients (n = 30) during quiet stance for 40 s on a posturographic force platform. Recordings were performed both ictally and in the pain-free interval. Subjects were assessed under four different conditions yielding different visual and proprioceptive feedback environments. Both ictal and interictal data were compared with age-matched healthy controls (n = 30). RESULTS: Postural instability increased significantly under all experimental conditions during migraine attacks. Whilst standing on a foam pad with eyes closed, median sway area was 353 mm2 in control subjects, 318 mm2 in migraineurs in the pain-free period and 618 mm2 in the ictal state. However, Romberg and vestibular Romberg quotients were not altered during migraine attacks. Spectral analyses of postural sway also showed similar profiles in migraineurs and controls. The severity of headache was inversely correlated to Romberg quotients. CONCLUSIONS: The demonstrated pattern of balance disorder during migraine attacks suggests a transient cerebellar dysfunction. Our findings also indicate that intense headache induces a re-weighting of sensory processing toward less dependence on visual and proprioceptive information.

Indices of repetitive behaviour are correlated with patterns of intrinsic functional connectivity in youth with autism spectrum disorder.

The purpose of the current study was to examine how repetitive behaviour in Autism Spectrum Disorder (ASD) is related to intrinsic functional connectivity patterns in a number of large-scale, neural networks. Resting-state fMRI scans from thirty subjects with ASD and thirty-two age-matched, typically developing control subjects were analysed. Seed-to-voxel and ROI-to-ROI functional connectivity analyses were used to examine resting-state connectivity in a number of cortical and subcortical neural networks. Bivariate correlation analysis was performed to examine the relationship between repetitive behaviour scores from the Repetitive Behaviour Scale - Revised and intrinsic functional connectivity in ASD subjects. Compared to control subjects, ASD subjects displayed marked over-connectivity of the thalamus with several cortical sensory processing areas, as well as over-connectivity of the basal ganglia with somatosensory and motor cortices. Within the ASD group, significant correlations were found between functional connectivity patterns and total RBS-R scores as well as one principal component analysis-derived score from the RBS-R. These results suggest that thalamocortical resting-state connectivity is altered in individuals with ASD, and that resting-state functional connectivity is associated with ASD symptomatology.

Effect of common antivertiginous agents on the high velocity vestibulo-ocular reflex.

OBJECTIVE: It has long been suggested that antivertiginous medications exert their symptomatic effect through inhibition of the vestibulo-ocular reflex (VOR). We tested this hypothesis by directly measuring the VOR after administration of three agents from different substance classes: an antihistamine, a benzodiazepine and a calcium channel antagonist. METHODS: The gain and the variability of the high velocity VOR was assessed using video head impulses (vHIT) under the following conditions: baseline, after dimenhydrinate, after diazepam and after cinnarizine. RESULTS: We found that all three medications did not change any VOR gain or variability parameter: At 60ms, the gain was 0.95 at baseline, 0.99 under dimenhydrinate, 0.99 under diazepam and 0.96 under cinnarizine. The gain variability across repetitive head impulses remained also uninfluenced. CONCLUSIONS: The human high frequency VOR remains robust to pharmacological perturbations at common clinical doses and the assumption that symptomatic vertigo relief is achieved merely through impairment of the VOR requires re-examination. SIGNIFICANCE: Alternative mechanisms of pharmacological action might be operant, such as the modulation of vestibulo-cortical pathways, a differential effect on the low frequency VOR and an altered sensitivity to drugs in acute unilateral vestibulopathy.

Immunohistochemical investigation of metabolic markers fatty acid synthase (FASN) and glucose transporter 1 (GLUT1) in normal endometrium, endometrial hyperplasia, and endometrial malignancy.

BACKGROUND: Cancer cells present higher metabolic needs in comparison to their normal, non-neoplastic counterparts, consuming carbohydrates as a source of energy. Moreover, increased fatty acid biosynthesis is noted in many malignancies. In this regard, we investigated specific metabolic markers, the fatty acid synthase (FASN) which catalyzes fatty acid synthesis and the glucose transporter 1 (GLUT1) which promotes glucose transport through the cellular membrane, in normal endometrium, endometrial hyperplasia, and endometrial malignancy. METHODS: We examined the immunohistochemical expression of GLUT1 and FASN in 43 cases of endometrioid adenocarcinoma, 15 cases of serous endometrial carcinoma, eight cases of clear cell endometrial carcinoma, 11 cases of atypical hyperplasia / endometrial intraepithelial neoplasia, 17 cases of simple hyperplasia, and 20 cases of normal endometrium. RESULTS: We observed a gradual increase in the expression of both markers, progressing from benign clinical conditions to malignancy. The most notable finding concerned the difference of FASN immunoreactivity between atypical hyperplasia and grade 1 endometrioid adenocarcinoma (p =0.01). CONCLUSION: GLUT1 and FASN expression demonstrated a gradual increase when advancing from endometrial hyperplasia to carcinoma. These findings suggest that both GLUT1 and FASN immunohistochemistry might be used as an adjunct in the differentiation between atypical endometrial hyperplasia and endometrial carcinoma in complex cases. HIPPOKRATIA 2017, 21(4): 169-174.

Widespread White Matter Differences in Children and Adolescents with Autism Spectrum Disorder.

Diffusion tensor imaging studies show white matter (WM) abnormalities in children with autism spectrum disorder (ASD). However, investigations are often limited by small samples, particularly problematic given the heterogeneity of ASD. We explored WM using DTI in a large sample of 130 children and adolescents (7-15 years) with and without ASD, whether age-related changes differed between ASD and control groups, and the relation between DTI measures and ASD symptomatology. Reduced fractional anisotropy and axial diffusivity were observed in ASD in numerous WM tracts, including the corpus callosum and thalamocortical fibres-tracts crucial for interhemispheric connectivity and higher order information processing. Widespread WM compromise in ASD is consistent with the view that ASD is a disorder of generalized complex information processing.

Addition of low-dose hCG to rFSH during ovarian stimulation for IVF/ICSI: is it beneficial?

PURPOSE: The aim of the study was to assess the eftect ot the addition or iow-cose numan cnononic gonauoiropm (hCG) to ovarian stimulation with recombinant follicle stimulating hormone (rFSH) on in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) outcome. MATERIALS AND METHODS: This retrospective clinical study was conducted on 141 women undergoing ICSI through a short GnRH-agonist protocol with rFSH and the addition of low-dose (100 IU/day) hCG. The control group consisted of 124 women undergoing ovarian stimulation with a similar protocol devoid of hCG. Statistical analysis in the study population along with a subgroup analysis for age 35 years and 36 years was performed. RESULTS: Women in hCG group were statistically significant older and with higher basal FSH compared to control group. This can be attributed to the Centre's latent tendency to add hCG in the stimulation protocol in poor prognosis patients. Despite this fact and the fact that several ovarian stimulation parameters, such as peak estradiol levels, number of oocytes retrieved, number of mature oocytes, and fertilization rates were in favor of the control group, the quality of transferred embryos and pregnancy rates were in favor of hCG group. Similar results were obtained in the subgroup analyses apart from peak estradiol levels, which did not differ among the study groups. CONCLUSIONS: The addition of hCG to rFSH may be associated with better quality embryos and higher pregnancy rates, even in women of advanced reproductive age with higher basal FSH levels, which are often considered to have poorer ovarian reserve.

The autism puzzle: Diffuse but not pervasive neuroanatomical abnormalities in children with ASD.

Autism Spectrum Disorder (ASD) is a clinically diagnosed, heterogeneous, neurodevelopmental condition, whose underlying causes have yet to be fully determined. A variety of studies have investigated either cortical, subcortical, or cerebellar anatomy in ASD, but none have conducted a complete examination of all neuroanatomical parameters on a single, large cohort. The current study provides a comprehensive examination of brain development of children with ASD between the ages of 4 and 18 years who are carefully matched for age and sex with typically developing controls at a ratio of one-to-two. Two hundred and ten magnetic resonance images were examined from 138 Control (116 males and 22 females) and 72 participants with ASD (61 males and 11 females). Cortical segmentation into 78 brain-regions and 81,924 vertices was conducted with CIVET which facilitated a region-of-interest- (ROI-) and vertex-based analysis, respectively. Volumes for the cerebellum, hippocampus, striatum, pallidum, and thalamus and many associated subregions were derived using the MAGeT Brain algorithm. The study reveals cortical, subcortical and cerebellar differences between ASD and Control group participants. Diagnosis, diagnosis-by-age, and diagnosis-by-sex interaction effects were found to significantly impact total brain volume but not total surface area or mean cortical thickness of the ASD participants. Localized (vertex-based) analysis of cortical thickness revealed no significant group differences, even when age, age-range, and sex were used as covariates. Nonetheless, the region-based cortical thickness analysis did reveal regional changes in the left orbitofrontal cortex and left posterior cingulate gyrus, both of which showed reduced age-related cortical thinning in ASD. Our finding of region-based differences without significant vertex-based results likely indicates non-focal effects spanning the entirety of these regions. The hippocampi, thalamus, and globus pallidus, were smaller in volume relative to total cerebrum in the ASD participants. Various sub-structures showed an interaction of diagnosis-by-age, diagnosis-by-sex, and diagnosis-by-age-range, in the case where age was divided into childhood (age < 12) and adolescence (12 < age < 18). This is the most comprehensive imaging-based neuro-anatomical pediatric and adolescent ASD study to date. These data highlight the neurodevelopmental differences between typically developing children and those with ASD, and support aspects of the hypothesis of abnormal neuro-developmental trajectory of the brain in ASD.