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. Levels of γ-aminobutyric acid and of the combined resonance of glutamate and glutamine (Glx) were obtained using the standard J-editing technique and expressed as peak area ratios relative to the synchronously acquired unsuppressed voxel water signal.Results:Higher levels of γ-aminobutyric acid (P<.001) and Glx (P=.007) were found in the dorsal caudate of the subjects at ultra-high risk than in the healthy controls. In the medial prefrontal cortex, likewise, both γ-aminobutyric acid (P=.03) and Glx (P=.006) levels were higher in the ultra-high risk group than in the healthy controls. No group differences were found for any of the other metabolites (N-acetylaspartate, total choline, or total creatine) in the 2 regions of interest.Conclusions:This study presents the first evidence of abnormal elevations, in subjects at ultra-high risk, of γ-aminobutyric acid and Glx in 2 brain regions that have been implicated in the pathophysiology of psychosis, warranting longitudinal studies to assess whether these neurotransmitter abnormalities can serve as noninvasive biomarkers of conversion risk to psychosis as well as of illness progression and treatment response.

The results of the present study documented elevations of GABA levels both in the mPFC and, for the first time, in the dorsal caudate of antipsychotic-naïve patients with FEP, which normalized in both regions following 4 weeks of antipsychotic treatment.

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). Methods Thirty-five antipsychotic-naïve FEP patients and 35 age- and gender-matched healthy controls underwent DTI at 3T. Analysis was performed using a tract-based spatial statistics (TBSS) method and exploratory PCA. Results DTI analysis showed extensive FA reduction in white matter tracts in FEP patients compared with the control group. The PCA grouped the white matter tracts into four factors explaining 66% of the total variance. Comparison of the FA values within each factor highlighted the differences between FEP patients and controls. Discussion Our study confirms extensive white matter tracts anomalies in patients with schizophrenia, more specifically, in drug-naïve FEP patients. The results also indicate that a small number of white matter tracts share common FA anomalies that relate to deficit symptoms in FEP patients. Our study adds to a growing body of literature emphasizing the need for treatments targeting white matter function and structure in FEP patients.

Introduction. Delirium is a neurocognitive disorder, frequently present in advanced cancer patients. It morbidity, mortality, health expenditure, and causes distress to patients, family members, and health care professionals. Despite its impact, the disorder is still underdiagnosed, and consequently, mistreated. Objective. To describe the prevalence, clinical features, impact on the survival and percentage of missed diagnosis of delirium, in palliative care inpatients treated in a tertiary center. Method. We conducted a prospective study, including all the inpatients referred to the Palliative Care Service of the Instituto Nacional de Cancerología in Mexico, from August, 2014 to March, 2015. As a first step, we collected clinical and sociodemographic data, and determined the presence/absence of delirium, using the Confusion Assessment Method. Then, we reviewed the clinical file to determine if a previous delirium diagnosis was stablished by the primary referring team. Finally, thirty days after the initial assessment, we contacted the patients in order to know their survival status (alive/death). We performed a survival analysis to compare mortality among patients with delirium/non-delirium, and reported the percentage of delirium missed diagnosis. Results. We included 174 patients, 40.2% were diagnosed with delirium. Mean survival time in patients with delirium was 11 days, while in non-delirium patient’s mean survival time was 21 days; Log Rank 23.50, p < .001. We found a 73% of missed delirium diagnosis by the primary referring team. Discussion and conclusion. Prevalence of delirium in this population is similar to that observed in other palliative care populations. Also, delirium is the principal determinant of short-term mortality, and it is frequently underdiagnosed. Preventive strategies and early identification could help to reduce its burden.