Sex differences in the pleiotropy of hearing difficulty with imaging-derived phenotypes: a brain-wide investigation.

Hearing difficulty (HD) is a major health burden in older adults. While ageing-related changes in the peripheral auditory system play an important role, genetic variation associated with brain structure and function could also be involved in HD predisposition. We analysed a large-scale HD genome-wide association study (GWAS; ntotal = 501 825, 56% females) and GWAS data related to 3935 brain imaging-derived phenotypes (IDPs) assessed in up to 33 224 individuals (52% females) using multiple MRI modalities. To investigate HD pleiotropy with brain structure and function, we conducted genetic correlation, latent causal variable, Mendelian randomization and multivariable generalized linear regression analyses. Additionally, we performed local genetic correlation and multi-trait co-localization analyses to identify genomic regions and loci implicated in the pleiotropic mechanisms shared between HD and brain IDPs. We observed a widespread genetic correlation of HD with 120 IDPs in females, 89 in males and 171 in the sex-combined analysis. The latent causal variable analysis showed that some of these genetic correlations could be due to cause-effect relationships. For seven of them, the causal effects were also confirmed by the Mendelian randomization approach: vessel volume→HD in the sex-combined analysis; hippocampus volume→HD, cerebellum grey matter volume→HD, primary visual cortex volume→HD and HD→fluctuation amplitudes of node 46 in resting-state functional MRI dimensionality 100 in females; global mean thickness→HD and HD→mean orientation dispersion index in superior corona radiata in males. The local genetic correlation analysis identified 13 pleiotropic regions between HD and these seven IDPs. We also observed a co-localization signal for the rs13026575 variant between HD, primary visual cortex volume and SPTBN1 transcriptomic regulation in females. Brain structure and function may have a role in the sex differences in HD predisposition via possible cause-effect relationships and shared regulatory mechanisms.

Functional brain activity is highly associated with cortical myelination in neonates.

Functional organization of the human cerebral cortex is highly constrained by underlying brain structures, but how functional activity is associated with different brain structures during development is not clear, especially at the neonatal stage. Since long-range functional connectivity is far from mature in the dynamically developing neonatal brain, it is of great scientific significance to investigate the relationship between different structural and functional features at the local level. To this end, for the first time, correlation and regression analyses were performed to examine the relationship between cortical morphology, cortical myelination, age, and local brain functional activity, as well as functional connectivity strength using high-resolution structural and resting-state functional MRI data of 177 neonates (29-44 postmenopausal weeks, 98 male and 79 female) from both static and dynamic perspectives. We found that cortical myelination was most strongly associated with local brain functional activity across the cerebral cortex than other cortical structural features while controlling the age effect. These findings suggest the crucial role of cortical myelination in local brain functional development at birth, providing valuable insights into the fundamental biological basis of functional activity at this early developmental stage.

Reorganization of brain connectivity across the spectrum of clinical cognitive decline.

Clinical cognitive decline, leading to Alzheimer's Disease Dementia (ADD), has long been interpreted as a disconnection syndrome, hindering the information flow capacity of the brain, hence leading to the well-known symptoms of ADD. The structural and functional brain connectome analyses play a central role in studies of brain from this perspective. However, most current research implicitly assumes that the changes accompanying the progression of cognitive decline are monotonous in time, whether measured across the entire brain or in fixed cortical regions. We investigate the structural and functional connectivity-wise reorganization of the brain without such assumptions across the entire spectrum. We utilize nodal assortativity as a local topological measure of connectivity and follow a data-centric approach to identify and verify relevant local regions, as well as to understand the nature of underlying reorganization. The analysis of our preliminary experimental data points to statistically significant, hyper and hypo-assortativity regions that depend on the disease's stage, and differ for structural and functional connectomes. Our results suggest a new perspective into the dynamic, potentially a mix of degenerative and compensatory, topological alterations that occur in the brain as cognitive decline progresses.

The neuro-pathophysiology of temporomandibular disorders-related pain: a systematic review of structural and functional MRI studies.

Chronic pain surrounding the temporomandibular joints and masticatory muscles is often the primary chief complaint of patients with temporomandibular disorders (TMD) seeking treatment. Yet, the neuro-pathophysiological basis underlying it remains to be clarified. Neuroimaging techniques have provided a deeper understanding of what happens to brain structure and function in TMD patients with chronic pain. Therefore, we performed a systematic review of magnetic resonance imaging (MRI) studies investigating structural and functional brain alterations in TMD patients to further unravel the neurobiological underpinnings of TMD-related pain. Online databases (PubMed, EMBASE, and Web of Science) were searched up to August 3, 2019, as complemented by a hand search in reference lists. A total of 622 papers were initially identified after duplicates removed and 25 studies met inclusion criteria for this review. Notably, the variations of MRI techniques used and study design among included studies preclude a meta-analysis and we discussed the findings qualitatively according to the specific neural system or network the brain regions were involved in. Brain changes were found in pathways responsible for abnormal pain perception, including the classic trigemino-thalamo-cortical system and the lateral and medial pain systems. Dysfunction and maladaptive changes were also identified in the default mode network, the top-down antinociceptive periaqueductal gray-raphe magnus pathway, as well as the motor system. TMD patients displayed altered brain activations in response to both innocuous and painful stimuli compared with healthy controls. Additionally, evidence indicates that splint therapy can alleviate TMD-related symptoms by inducing functional brain changes. In summary, MRI research provides important novel insights into the altered neural manifestations underlying chronic pain in TMD.

Discussion on Brain Structure and Function in Schizophrenia by Multimodal Magnetic Resonance Imaging.

In order to explore the relationship between hippocampal structure changes and performance symptoms as well as cognitive function in adolescent schizophrenia, taking the brain response signals of psychiatric patients as the research object, the relationship between hippocampal volume drawn by schizophrenia and language memory of negative symptoms is explored based on morphological analysis method. It is found that the left hippocampal volume of schizophrenic patients is abnormal when the whole brain volume is returned, which is significantly lower than that of normal people. It is also found that the left hippocampus volume of schizophrenic patients is a mediator between negative symptoms and speech memory. The results show that the left hippocampus of schizophrenic patients plays an important role in the pathogenesis of schizophrenia.

Dissociation and Alterations in Brain Function and Structure: Implications for Borderline Personality Disorder.

Dissociation involves disruptions of usually integrated functions of consciousness, perception, memory, identity, and affect (e.g., depersonalization, derealization, numbing, amnesia, and analgesia). While the precise neurobiological underpinnings of dissociation remain elusive, neuroimaging studies in disorders, characterized by high dissociation (e.g., depersonalization/derealization disorder (DDD), dissociative identity disorder (DID), dissociative subtype of posttraumatic stress disorder (D-PTSD)), have provided valuable insight into brain alterations possibly underlying dissociation. Neuroimaging studies in borderline personality disorder (BPD), investigating links between altered brain function/structure and dissociation, are still relatively rare. In this article, we provide an overview of neurobiological models of dissociation, primarily based on research in DDD, DID, and D-PTSD. Based on this background, we review recent neuroimaging studies on associations between dissociation and altered brain function and structure in BPD. These studies are discussed in the context of earlier findings regarding methodological differences and limitations and concerning possible implications for future research and the clinical setting.

The design and rationale of a multicenter clinical trial comparing two strategies for control of systolic blood pressure: the Systolic Blood Pressure Intervention Trial (SPRINT).

BACKGROUND: High blood pressure is an important public health concern because it is highly prevalent and a risk factor for adverse health outcomes, including coronary heart disease, stroke, decompensated heart failure, chronic kidney disease, and decline in cognitive function. Observational studies show a progressive increase in risk associated with blood pressure above 115/75 mm Hg. Prior research has shown that reducing elevated systolic blood pressure lowers the risk of subsequent clinical complications from cardiovascular disease. However, the optimal systolic blood pressure to reduce blood pressure-related adverse outcomes is unclear, and the benefit of treating to a level of systolic blood pressure well below 140 mm Hg has not been proven in a large, definitive clinical trial. PURPOSE: To describe the design considerations of the Systolic Blood Pressure Intervention Trial (SPRINT) and the baseline characteristics of trial participants. METHODS: The Systolic Blood Pressure Intervention Trial is a multicenter, randomized, controlled trial that compares two strategies for treating systolic blood pressure: one targets the standard target of <140 mm Hg, and the other targets a more intensive target of <120 mm Hg. Enrollment focused on volunteers of age ≥50 years (no upper limit) with an average baseline systolic blood pressure ≥130 mm Hg and evidence of cardiovascular disease, chronic kidney disease, 10-year Framingham cardiovascular disease risk score ≥15%, or age ≥75 years. The Systolic Blood Pressure Intervention Trial recruitment also targeted three pre-specified subgroups: participants with chronic kidney disease (estimated glomerular filtration rate <60 mL/min/1.73 m(2)), participants with a history of cardiovascular disease, and participants 75 years of age or older. The primary outcome is first the occurrence of a myocardial infarction (MI), acute coronary syndrome, stroke, heart failure, or cardiovascular disease death. Secondary outcomes include all-cause mortality, decline in kidney function or development of end-stage renal disease, incident dementia, decline in cognitive function, and small-vessel cerebral ischemic disease. RESULTS: Between 8 November 2010 and 15 March 2013, Systolic Blood Pressure Intervention Trial recruited and randomized 9361 people at 102 clinics, including 3331 women, 2648 with chronic kidney disease, 1877 with a history of cardiovascular disease, 3962 minorities, and 2636 ≥75 years of age. LIMITATIONS: Although the overall recruitment target was met, the numbers recruited in the high-risk subgroups were lower than planned. CONCLUSIONS: The Systolic Blood Pressure Intervention Trial will provide important information on the risks and benefits of intensive blood pressure treatment targets in a diverse sample of high-risk participants, including those with prior cardiovascular disease, chronic kidney disease, and those aged ≥75 years.

Epigenetic mechanisms underlying sex differences in the brain and behavior.

Sex differences are found across brain regions, behaviors, and brain diseases. Sexual differentiation of the brain is initiated prenatally but it continues throughout life, as a result of the interaction of three major factors: gonadal hormones, sex chromosomes, and the environment. These factors are thought to act, in part, via epigenetic mechanisms which control chromatin and transcriptional states in brain cells. In this review, we discuss evidence that epigenetic mechanisms underlie sex-specific neurobehavioral changes during critical organizational periods, across the estrous cycle, and in response to diverse environments throughout life. We further identify future directions for the field that will provide novel mechanistic insights into brain sex differences, inform brain disease treatments and women's brain health in particular, and apply to people across genders.

Brain Structural and Functional Damage Network Localization of Suicide.

BACKGROUND: Extensive neuroimaging research on brain structural and functional correlates of suicide has produced inconsistent results. Despite increasing recognition that damage in multiple different brain locations that causes the same symptom can map to a common brain network, there is still a paucity of research investigating network localization of suicide. METHODS: To clarify this issue, we initially identified brain structural and functional damage locations in relation to suicide from 63 published studies with 2135 suicidal and 2606 nonsuicidal individuals. By applying novel functional connectivity network mapping to large-scale discovery and validation resting-state functional magnetic resonance imaging datasets, we mapped these affected brain locations to 3 suicide brain damage networks corresponding to different imaging modalities. RESULTS: The suicide gray matter volume damage network comprised widely distributed brain areas primarily involving the dorsal default mode, basal ganglia, and anterior salience networks. The suicide task-induced activation damage network was similar to but less extensive than the gray matter volume damage network, predominantly implicating the same canonical networks. The suicide resting-state activity damage network manifested as a localized set of brain regions encompassing the orbitofrontal cortex and middle cingulate cortex. CONCLUSIONS: Our findings not only may help reconcile prior heterogeneous neuroimaging results, but also may provide insights into the neurobiological mechanisms of suicide from a network perspective, which may ultimately inform more targeted and effective strategies to prevent suicide.

Changes in Brain Structure and Function in a Multisport Cohort of Retired Female and Male Athletes, Many Years after Suffering a Concussion: Implications for Neuroplasticity and Neurodegenerative Disease Pathogenesis.

Background: Cumulative effects of traumatic brain injury is of increasing concern, especially with respect to its role in the etiology and pathogenesis of neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. Objective: Compare regional brain volume and connectivity between athletes with a history of concussion and controls. Methods: We evaluated whole-brain volumetric effects with Bayesian regression models and functional connectivity with network-based statistics, in 125 retired athletes (a mean of 11 reported concussions) and 36 matched controls. Results: Brain regions significantly lower in volume in the concussed group included the middle frontal gyrus, hippocampus, supramarginal gyrus, temporal pole, and inferior frontal gyrus. Conversely, brain regions significantly larger included the hippocampal and collateral sulcus, middle occipital gyrus, medial orbital gyrus, caudate nucleus, lateral orbital gyrus, and medial postcentral gyrus. Functional connectivity analyses revealed increased edge strength, most marked in motor domains. Numerous edges of this network strengthened in athletes were significantly weakened with concussion. Aligned to meta-analytic neuroimaging data, the observed changes suggest functional enhancement within the motor, sensory, coordination, balance, and visual processing domains in athletes, attenuated by concussive head injury with a negative impact on memory and language. Conclusions: These findings suggest that engagement in sport may benefit the brain across numerous domains, but also highlights the potentially damaging effects of concussive head injury. Future studies with longitudinal cohorts including autopsy examination are needed to determine whether the latter reflects tissue loss from brain shearing, or the onset of a progressive Alzheimer's disease like proteinopathy.

Predicting motor and cognitive outcomes from MRIs of brain structure in children with acquired brain injury: A pilot study.

BACKGROUND: Acquired Brain Injury (ABI) describes a range of brain injuries occurring after birth, including tumor, traumatic brain injury or stroke. Although MRIs are routinely used for diagnosis, prediction of outcome following brain injury is challenging. Quantitative structural information from brain images may provide an opportunity to predict patient outcomes; however, due to the high prevalence of severe pathology in children with ABI, quantitative approaches must be robust to injury severity. METHODS: In this pilot cross-sectional study, automated quantitative measures were extracted from the MRIs of a cohort of children with ABI (n = 30, 8-16 years, follow up MRI taken 1.8-13.4 years after time of injury) as well as 36 typically developing controls with no brain injury (7-17 years) using a pathology-robust technique. Measures of brain volume, lesion volume and cortical morphology were associated with concurrent motor, behavioral, visual and communicative function using Least Absolute Shrinkage and Selection Operator (LASSO) regression. RESULTS: These regression models were validated on a separate test set (n = 8 of the ABI cohort), which revealed significant correlations between measures of brain structure with motor, cognitive, visual and communicative function (r = 0.65-0.85, all p < 0.01). Furthermore, comparisons of the structural measures to the typically developing cohort revealed overall reductions in global grey matter volume among the ABI cohort, as well as cortical thinning in several cortical areas. CONCLUSIONS: These preliminary associations reveal that motor and behavioral function can be estimated from MRI alone, highlighting the potential utility of the proposed pathology-robust MRI quantification tools to provide estimates of long-term clinical prognosis of children with ABI following injury.

Habenula Volume and Functional Connectivity Changes Following Laparoscopic Sleeve Gastrectomy for Obesity Treatment.

BACKGROUND: Neuroimaging studies have revealed alterations in habenular (Hb) structure and functional connectivity (FC) in psychiatric conditions. The Hb plays a particularly critical role in regulating negative emotions, which trigger excessive food intake and obesity. However, obesity and weight loss intervention (i.e., laparoscopic sleeve gastrectomy [LSG])-associated changes in Hb structure and FC have not been studied. METHODS: We used voxel-based morphometry analysis to measure changes in gray matter volume (GMV) in the Hb in 56 patients with obesity at pre-LSG and 12 months post-LSG and in 78 normal-weight (NW) control participants. Then, we conducted Hb seed-based resting-state FC (RSFC) to examine obesity-related and LSG-induced alterations in RSFC. Finally, we used mediation analysis to characterize the interrelationships among Hb GMV, RSFC, and behaviors. RESULTS: Compared with NW participants, Hb GMV was smaller in patients at pre-LSG and increased at 12 months post-LSG to levels equivalent to that of NW; in addition, increases in Hb GMV were correlated with reduced body mass index (BMI). Compared with NW participants, pre-LSG patients showed greater RSFCs of the Hb-insula, Hb-precentral gyrus, and Hb-rolandic operculum and weaker RSFCs of the Hb-thalamus, Hb-hypothalamus, and Hb-caudate; LSG normalized these RSFCs. Decreased RSFC of the Hb-insula was correlated with reduced BMI, Yale Food Addiction Scale rating, and emotional eating; reduced hunger levels were correlated with increased RSFCs of the Hb-thalamus and Hb-hypothalamus; and reduced BMI and Yale Food Addiction Scale ratings were correlated with increased RSFCs of the Hb-thalamus and Hb-hypothalamus, respectively. The bidirectional relationships between Hb GMV and RSFC of the Hb-insula contributed to reduced BMI. CONCLUSIONS: These findings indicate that LSG increased Hb GMV and that its related improvement in RSFC of the Hb-insula may mediate long-term benefits of LSG for eating behaviors and weight loss.

Transcriptional substrates of brain structural and functional impairments in drug-naive first-episode patients with major depressive disorder.

BACKGROUND: Despite remarkable success in identifying genetic risk factors for depression, there are still open questions about the exact genetic mechanisms underlying certain disease phenotypes, such as brain structural and functional impairments. METHODS: Comprehensive multi-modal neuroimaging meta-analyses were conducted to examine changes in brain structure and function in drug-naive first-episode patients with major depressive disorder (DF-MDD). Combined with the Allen Human Brain Atlas, transcriptome-neuroimaging spatial association analyses were performed to identify genes whose expression related to these brain structural and functional changes, followed by a range of gene functional signature analyses. RESULTS: Meta-analyses revealed gray matter atrophy in the insula, temporal pole, cerebellum and postcentral gyrus, and a complex pattern of hyper-function in the temporal pole and hypo-function in the cuneus/precuneus, angular gyrus and lingual gyrus in DF-MDD. Moreover, these brain structural and functional changes were spatially associated with the expression of 1194 and 1733 genes, respectively. Importantly, there were commonalities and differences in the two gene sets and their functional signatures including functional enrichment, specific expression, behavioral relevance, and constructed protein-protein interaction networks. LIMITATIONS: The results merit further verification using a large sample of DF-MDD. CONCLUSIONS: Our findings not only corroborate the polygenic nature of depression, but also suggest common and distinct genetic modulations of brain structural and functional impairments in this disorder.

Gut Microbiome, Inflammation, and Cerebrovascular Function: Link Between Obesity and Cognition.

Obesity affects 13% of the adult population worldwide and this number is only expected to increase. Obesity is known to have a negative impact on cardiovascular and metabolic health, but it also impacts brain structure and function; it is associated with both gray and white matter integrity loss, as well as decreased cognitive function, including the domains of executive function, memory, inhibition, and language. Especially midlife obesity is associated with both cognitive impairment and an increased risk of developing dementia at later age. However, underlying mechanisms are not yet fully revealed. Here, we review recent literature (published between 2010 and March 2021) and discuss the effects of obesity on brain structure and cognition, with a main focus on the contributions of the gut microbiome, white adipose tissue (WAT), inflammation, and cerebrovascular function. Obesity-associated changes in gut microbiota composition may cause increased gut permeability and inflammation, therewith affecting cognitive function. Moreover, excess of WAT in obesity produces pro-inflammatory adipokines, leading to a low grade systemic peripheral inflammation, which is associated with decreased cognition. The blood-brain barrier also shows increased permeability, allowing among others, peripheral pro-inflammatory markers to access the brain, leading to neuroinflammation, especially in the hypothalamus, hippocampus and amygdala. Altogether, the interaction between the gut microbiota, WAT inflammation, and cerebrovascular integrity plays a significant role in the link between obesity and cognition. Future research should focus more on the interplay between gut microbiota, WAT, inflammation and cerebrovascular function to obtain a better understanding about the complex link between obesity and cognitive function in order to develop preventatives and personalized treatments.

Deep Fusion of Brain Structure-Function in Mild Cognitive Impairment.

Multimodal fusion of different types of neural image data provides an irreplaceable opportunity to take advantages of complementary cross-modal information that may only partially be contained in single modality. To jointly analyze multimodal data, deep neural networks can be especially useful because many studies have suggested that deep learning strategy is very efficient to reveal complex and non-linear relations buried in the data. However, most deep models, e.g., convolutional neural network and its numerous extensions, can only operate on regular Euclidean data like voxels in 3D MRI. The interrelated and hidden structures that beyond the grid neighbors, such as brain connectivity, may be overlooked. Moreover, how to effectively incorporate neuroscience knowledge into multimodal data fusion with a single deep framework is understudied. In this work, we developed a graph-based deep neural network to simultaneously model brain structure and function in Mild Cognitive Impairment (MCI): the topology of the graph is initialized using structural network (from diffusion MRI) and iteratively updated by incorporating functional information (from functional MRI) to maximize the capability of differentiating MCI patients from elderly normal controls. This resulted in a new connectome by exploring "deep relations" between brain structure and function in MCI patients and we named it as Deep Brain Connectome. Though deep brain connectome is learned individually, it shows consistent patterns of alteration comparing to structural network at group level. With deep brain connectome, our developed deep model can achieve 92.7% classification accuracy on ADNI dataset.

Neurologic Factors in Patients with Vascular Mild Cognitive Impairment Based on fMRI.

This study focused on the application of functional magnetic resonance imaging and neuropsychology in diagnosis of vascular mild cognitive impairment (MCI) and the exploration of its relevant factors. The study enrolled 28 patients with vascular MCI in an observation group and 30 healthy individuals in a control group. All patients underwent magnetic resonance imaging. An automatic segmentation algorithm based on graph theory was adopted to process the images. Age, sex, disease course, Montreal Cognitive Assessment score, regional homogeneity, and amplitude of low-frequency fluctuation levels were recorded. There were no significant differences in age, gender, and course of disease between the observation group and the control group (P > 0.05). The level of regional homogeneity in the left posterior cerebellum in the observation group was significantly higher than that in the control group (P < 0.05).The regional homogeneity level of bilateral cingulate cortex was negatively correlated with Montreal Cognitive Assessment score (P < 0.05). The amplitude of low-frequency fluctuation of bilateral inferior parietal lobe, parietal lobe, and prefrontal lobe in the observation group was significantly lower than that in the control group, and the amplitude of low-frequency fluctuation of bilateral anterior cingulate gyrus, superior medial frontal gyrus, orbital frontal gyrus, right middle frontal gyrus, and right auxiliary motor area was higher than that in the control group (P < 0.05). Heart disease, such as myocardial infarction and atrial fibrillation, is a high risk factor for vascular MCI. Functional magnetic resonance imaging combined with an automatic segmentation algorithm can noninvasively observe the changes of a patient's brain tissue, which can be used in the recognition of vascular MCI. The global network attributes of patients with depression tend to be more randomized and have stronger resilience under targeted attacks.

Is Ejaculation Frequency in Men Related to General and Mental Health? Looking Back and Looking Forward.

Despite its relevance for human sexuality, literature on potential effects of ejaculation frequency and masturbation on general and mental health outcomes is sparse. Reasons for this knowledge gap include a general lack of interest, but also methodological challenges and still existing superstition. This paper reconciles literature from various fields to extract relevant information on how ejaculation frequency effects general and mental health outcomes. Culture-bound syndromes have been reported in countries still strictly tabooing or condemning masturbation. Masturbatory guilt describes a phenomenon in individuals experiencing a discrepancy between moral standards and own behavior with respect to masturbation. Abstinence is one aspect under study in the area of fertility treatment. Specific time frames and their respective implications on quality of sperm remain inconclusive. Limited temporal resolution capacities hamper the precise study of brain structures directly activated during ejaculation. The relation between ejaculation frequency and hormonal influences remains poorly understood. Future research that specifically addresses ejaculation frequency and potential mental and general health outcomes is needed. In contrast to extracting knowledge as a byproduct from other studies with a different focus, this enables sound study designs and could provide evidence-based results which could then be further discussed and interpreted.

Brainstem Abnormalities in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Scoping Review and Evaluation of Magnetic Resonance Imaging Findings.

Background: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a multisystem medical condition with heterogeneous symptom expression. Currently, there is no effective cure or treatment for the standard care of patients. A variety of ME/CFS symptoms can be linked to the vital life functions of the brainstem, the lower extension of the brain best known as the hub relaying information back and forth between the cerebral cortex and various parts of the body. Objective/Methods: Over the past decade, Magnetic Resonance Imaging (MRI) studies have emerged to understand ME/CFS with interesting findings, but there has lacked a synthesized evaluation of what has been found thus far regarding the involvement of the brainstem. We conducted this study to review and evaluate the recent MRI findings via a literature search of the MEDLINE database, from which 11 studies met the eligibility criteria. Findings: Data showed that MRI studies frequently reported structural changes in the white and gray matter. Abnormalities of the functional connectivity within the brainstem and with other brain regions have also been found. The studies have suggested possible mechanisms including astrocyte dysfunction, cerebral perfusion impairment, impaired nerve conduction, and neuroinflammation involving the brainstem, which may at least partially explain a substantial portion of the ME/CFS symptoms and their heterogeneous presentations in individual patients. Conclusions: This review draws research attention to the role of the brainstem in ME/CFS, helping enlighten future work to uncover the pathologies and mechanisms of this complex medical condition, for improved management and patient care.

Relationship between brain structure and Cerebral Visual Impairment in children with Cerebral Palsy: A systematic review.

BACKGROUND: Cerebral Visual Impairment (CVI) is very common yet often unrecognised visual dysfunction in children with Cerebral Palsy (CP). Magnetic Resonance Imaging (MRI) is the diagnostic tool in the investigation of brain lesions in children with CP and CVI. AIM: The aim of this systematic review is to evaluate the relationship between brain structure and CVI, as determined by MRI in children with CP. METHODS AND PROCEDURES: A comprehensive search of 5 database (PubMed, EMBASE, SCOPUS, CINAHL and Cochrane Database) was undertaken up until June 2019. The PRISMA checklist was then utilised to report on the process of selecting eligible papers. A total of 30 observational studies met the full inclusion criteria. Further, STROBE checklist was employed to report on the observational studies. OUTCOMES AND RESULTS: Periventricular leucomalacia on MRI was found to have a strong association with CVI in all 30 studies. Only 13 (43 %) studies described dorsal and/ ventral stream dysfunction. There was ambiguity in the definition of CVI. CONCLUSIONS AND IMPLICATIONS: The overall level of evidence correlating different patterns of CVI and CP (based on GMFCS, motor type and distribution) and MRI was low. Further studies utilising advances in MRI are needed to understand brain reorganisation and patterns of CVI and suggest rehabilitation therapy inclusive of vision.

Structural and Functional Alterations in the Contralesional Medial Temporal Lobe in Glioma Patients.

BACKGROUND: The human brain has an extraordinary ability to functionally change or reorganize its structure in response to disease. The aim of this study is to assess the structural and functional plasticity of contralesional medial temporal lobe (MTL) in patients with unilateral MTL glioma. METHODS: Sixty-eight patients with unilateral MTL glioma (left MTL glioma, n = 33; right MTL glioma, n = 35) and 40 healthy controls were recruited and scanned with 3D T1 MRI and rest-fMRI. We explored the structure of the contralesional MTL using voxel-based morphometry (VBM) and assessed the memory networks of the contralesional hemisphere using resting-state functional connectivity (rs-FC). The association between FC and cognitive function was assessed with partial correlation analysis. RESULTS: Compared with healthy controls, both patient groups exhibited (1) a large cluster of voxels with gray matter (GM) volume decrease in the contralesional MTL using region of interest (ROI)-based VBM analysis (cluster level p < 0.05, FDR corrected); and (2) decreased intrahemispheric FC between the posterior hippocampus (pHPC) and posterior cingulate cortex (PCC) (p < 0.01, Bonferroni corrected). Intrahemispheric FC between the pHPC and PCC was positively correlated with cognitive function in both patient groups. CONCLUSION: Using multi-modality brain imaging tools, we found structural and functional changes in the contralesional MTL in patients with unilateral MTL glioma. These findings suggest that the contralesional cortex may have decompensation of structure and function in patients with unilateral glioma, except for compensatory structural and functional adaptations. Our study provides additional insight into the neuroanatomical and functional network changes in the contralesional cortex in patients with glioma.