Country-level gender inequality is associated with structural differences in the brains of women and men.

Gender inequality across the world has been associated with a higher risk to mental health problems and lower academic achievement in women compared to men. We also know that the brain is shaped by nurturing and adverse socio-environmental experiences. Therefore, unequal exposure to harsher conditions for women compared to men in gender-unequal countries might be reflected in differences in their brain structure, and this could be the neural mechanism partly explaining women's worse outcomes in gender-unequal countries.

Systemic inflammation and cortical neurochemistry in never-medicated first episode-psychosis individuals.

Studies of cellular and cytokine profiles have contributed to the inflammation hypothesis of schizophrenia; however, precise markers of inflammatory dysfunction remain elusive. A number of proton magnetic resonance spectroscopy (1H-MRS) studies in patients with first-episode psychosis (FEP) have shown higher brain levels of metabolites such as glutamate, myo-inositol (mI) and choline-containing compounds (tCho), suggesting neuroinflammation. Here, we present peripheral inflammatory profiles in antipsychotic-naive FEP patients and age-and-sex matched healthy controls, as well as cortical glutamate, mI and tCho levels using 1H-MRS.

Variability and magnitude of brain glutamate levels in schizophrenia: a meta and mega-analysis.

Glutamatergic dysfunction is implicated in schizophrenia pathoaetiology, but this may vary in extent between patients. It is unclear whether inter-individual variability in glutamate is greater in schizophrenia than the general population. We conducted meta-analyses to assess (1) variability of glutamate measures in patients relative to controls (log coefficient of variation ratio: CVR); (2) standardised mean differences (SMD) using Hedges g; (3) modal distribution of individual-level glutamate data (Hartigan's unimodality dip test).

Dysconnectivity in Schizophrenia Revisited: Abnormal Temporal Organization of Dynamic Functional Connectivity in Patients With a First Episode of Psychosis.

Background And Hypothesis: Abnormal functional connectivity between brain regions is a consistent finding in schizophrenia, including functional magnetic resonance imaging (fMRI) studies. Recent studies have highlighted that connectivity changes in time in healthy subjects. We here examined the temporal changes in functional connectivity in patients with a first episode of psychosis (FEP).

Involuntary Emotional Expression Disorder in a Patient With Toluene Leukoencephalopathy.

Objective: Inhalant users may develop toluene leukoencephalopathy, a devastating neuropsychiatric disorder. We present a case of toluene-induced damage to the corticospinal and the corticonuclear tracts, which presented with involuntary emotional expression disorder.

Methods: Case study of a 20-year-old man with a 3-year history of frequent solvent abuse was admitted to the Neuropsychiatry Unit of the National Institute of Neurology and Neurosurgery because "he could not speak or walk" but would keep "laughing and crying without reason".

Striatal glutamate, subcortical structure and clinical response to first-line treatment in first-episode psychosis patients.

Introduction: Recent studies have observed that patients with treatment-resistant schizophrenia as well as patients with schizophrenia who do not respond within a medication trial exhibit excess activity of the glutamate system. In this study we sought to replicate the within-trial glutamate abnormality and to investigate the potential for structural differences and treatment-induced changes to improve identification of medication responders and non-responders.

Methods: We enrolled 48 medication-naïve patients in a 4-week trial of risperidone and classified them retrospectively into responders and non-responders using clinical criteria.

Involuntary Emotional Expression Disorder in a Patient With Toluene Leukoencephalopathy.

Objective: Inhalant users may develop toluene leukoencephalopathy, a devastating neuropsychiatric disorder. We present a case of toluene-induced damage to the corticospinal and the corticonuclear tracts, which presented with involuntary emotional expression disorder.

Methods: Case study of a 20-year-old man with a 3-year history of frequent solvent abuse was admitted to the Neuropsychiatry Unit of the National Institute of Neurology and Neurosurgery because "he could not speak or walk" but would keep "laughing and crying without reason".

Reconversion of neurosurgical practice in times of the SARS-CoV-2 pandemic: a narrative review of the literature and guideline implementation in a Mexican neurosurgical referral center.

Objective: The coronavirus disease 2019 (COVID-19) pandemic has forced the modification of surgical practice worldwide. Medical centers have been adapted to provide an efficient arrangement of their economic and human resources. Although neurosurgeons are not in the first line of management and treatment of COVID-19 patients, they take care of patients with neurological pathology and potential severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

Structural brain abnormalities in schizophrenia in adverse environments: examining the effect of poverty and violence in six Latin American cities.

Background: Social and environmental factors such as poverty or violence modulate the risk and course of schizophrenia. However, how they affect the brain in patients with psychosis remains unclear.

Aims: We studied how environmental factors are related to brain structure in patients with schizophrenia and controls in Latin America, where these factors are large and unequally distributed.

White matter alterations and the conversion to psychosis: A combined diffusion tensor imaging and glutamate H MRS study.

Introduction: Widespread white matter abnormalities and alterations in glutamate levels have been reported in patients with schizophrenia. We hypothesized that alterations in white matter integrity and glutamate levels in individuals at clinical high risk (CHR) for psychosis are associated with the subsequent development of psychosis.

Methods: Participants included 33 antipsychotic naïve CHR (Female 7/Male 26, Age 19.

Cognitive Impairment in Never-Medicated Individuals on the Schizophrenia Spectrum.

This cohort study examines cognition in never-medicated individuals at different stages of the illness.

An imaging-based risk calculator for prediction of conversion to psychosis in clinical high-risk individuals using glutamate H MRS.

Risk calculators for prediction of conversion of Clinical High-Risk (CHR) individuals to syndromal psychosis have recently been developed and have generated considerable clinical use and research interest. Predictor variables in these calculators have been clinical rather than biological, and our goal was to incorporate a neurochemical imaging measure into this framework and assess its impact on prediction. We combined striatal glutamate H MRS data with the SIPS symptoms identified by the Columbia Risk Calculator as having the greatest predictive value in order to develop an imaging-based risk calculator for conversion to psychosis.

Striatal Glutathione in First-episode Psychosis Patients Measured In Vivo with Proton Magnetic Resonance Spectroscopy.

Deficits of brain glutathione (GSH), the most abundant and primary antioxidant in living tissue, and associated redox imbalance are postulated to be implicated in schizophrenia. This pilot clinical study compared the levels of striatal GSH, measured in vivo with proton magnetic resonance spectroscopy (H MRS) at 3T, in 10 drug-naïve, first-episode psychosis (FEP) patients with those in 9 matched healthy control subjects. The results revealed a significant GSH deficit in FEP patients (0.

Imaging Social and Environmental Factors as Modulators of Brain Dysfunction: Time to Focus on Developing Non-Western Societies.

Social and environmental factors are known risk factors and modulators of mental health disorders. We here conducted a nonsystematic review of the neuroimaging literature studying the effects of poverty, urbanicity, and community violence, highlighting the opportunities of studying non-Western developing societies such as those in Latin America. Social and environmental factors in these communities are widespread and have a large magnitude, as well as an unequal distribution, providing a good opportunity for their characterization.

Prefrontal and Striatal Gamma-Aminobutyric Acid Levels and the Effect of Antipsychotic Treatment in First-Episode Psychosis Patients.

Background: Abnormally elevated levels of gamma-aminobutyric acid (GABA) in the medial prefrontal cortex (mPFC) have been reported in antipsychotic-free patients with schizophrenia. Whether such GABA elevations are also present in other brain regions and persist after antipsychotic treatment has not been previously investigated.

Methods: Twenty-eight antipsychotic-naïve patients with first-episode psychosis (FEP) and 18 healthy control subjects completed the study.

Glutamatergic Metabolites, Volume and Cortical Thickness in Antipsychotic-Naive Patients with First-Episode Psychosis: Implications for Excitotoxicity.

Neuroimaging studies investigating patients with schizophrenia often report appreciable volumetric reductions and cortical thinning, yet the cause of these deficits is unknown. The association between subcortical and cortical structural alterations, and glutamatergic neurometabolites is of particular interest due to glutamate's capacity for neurotoxicity; elevated levels may be related to neuroanatomical compromise through an excitotoxic process. To this end, we explored the relationships between glutamatergic neurometabolites and structural measures in antipsychotic-naive patients experiencing their first non-affective episode of psychosis (FEP).

Proton Magnetic Resonance Spectroscopy Changes in Parkinson's Disease With and Without Psychosis.

Background: Psychosis prevalence in Parkinson's disease is estimated at 8-30%. Proton magnetic resonance spectroscopy measures specific metabolites as markers of cell functioning.

Objective: To study N-acetyl-aspartate and glutamate levels in the caudate and putamen nuclei in subjects with Parkinson's disease with and without psychosis.

Cortico-Striatal GABAergic and Glutamatergic Dysregulations in Subjects at Ultra-High Risk for Psychosis Investigated with Proton Magnetic Resonance Spectroscopy.

Background: Dysregulations of the major inhibitory and excitatory amino neurotransmitter systems of γ-aminobutyric acid and glutamate, respectively, have been described in patients with schizophrenia. However, it is unclear whether these abnormalities are present in subjects at ultra-high risk for psychosis.

Methods: Twenty-three antipsychotic naïve subjects at ultra-high risk and 24 healthy control subjects, matched for age, sex, handedness, cigarette smoking, and parental education, underwent proton magnetic resonance spectroscopy scans in the dorsal caudate bilaterally and the medial prefrontal cortex at 3T.

Elevated Myo-Inositol, Choline, and Glutamate Levels in the Associative Striatum of Antipsychotic-Naive Patients With First-Episode Psychosis: A Proton Magnetic Resonance Spectroscopy Study With Implications for Glial Dysfunction.

Glial disturbances are highly implicated in the pathophysiology of schizophrenia and may be linked with glutamatergic dysregulation. Myo-inositol (mI), a putative marker of glial cells, and choline (Cho), representative of membrane turnover, are both present in larger concentrations within glial cells than in neurons, and their elevation is often interpreted to reflect glial activation. Proton magnetic resonance spectroscopy ((1)H-MRS) allows for the evaluation of mI, Cho, glutamate, glutamate + glutamine (Glx), and N-acetylaspartate (NAA).

Abnormal white matter integrity in antipsychotic-naïve first-episode psychosis patients assessed by a DTI principal component analysis.

Introduction: Diffusion tensor imaging (DTI) studies in patients with schizophrenia have shown abnormalities in the microstructure of white matter tracts. Specifically, reduced fractional anisotropy (FA) has been described across multiple white matter tracts, in studies that have mainly included patients treated with antipsychotic medications.

Objective: To compare FA in antipsychotic-naïve patients experiencing a first episode of psychosis (FEP) to FA in healthy controls to demonstrate that the variance of FA can be grouped, in a coincidental manner, in four predetermined factors in accordance with a theoretical partition of the white matter tracts, using a principal components analysis (PCA).

Personality features in ultra-high risk for psychosis: a comparative study with schizophrenia and control subjects using the Temperament and Character Inventory-Revised (TCI-R).

Several variables have been identified as risk factors for conversion to overt psychosis in ultra-high risk for psychosis (UHR) individuals. Although almost two-thirds of them do not experience a transition to psychosis, they still exhibit functional disabilities. Other subjective developmental features may be useful for a more precise identification of individuals at UHR.