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Oral and maxillofacial surgeons (OMS) treat adult and pediatric patients with obstructive sleep apnea (OSA). Objective 1 assessed sleep apnea–related education, knowledge, and professional behavior of OMS residents in the United States. Objective 2 was to compare the responses of junior versus senior residents and residents in single‐ versus dual‐degree programs. OMS residents in the United States received a recruitment email with a link to an anonymous online survey; 81 residents responded. The survey included 20 questions to assess respondents’ OSA‐related education, knowledge, attitudes, and professional behavior. Respondents generally agreed that they had received OSA‐related didactic‐based education (5‐point scale with “5” = agree strongly: mean = 3.62) and clinical training (mean = 3.75). Clinical and classroom educational gaps were identified in relation to treatment with oral appliances and hypoglossal nerve stimulation. The residents scored on average 10.38 out of 18 (58%) possible correct answer points for the knowledge questions. Findings about pediatric OSA suggest that only 43.8% of residents understand diagnostic criteria for pediatric OSA, with only 26.6% screening pediatric patients for OSA. A case analysis showed that only 1.5% of residents correctly identified an apnea–hypopnea index of 17 as moderate sleep apnea. This survey found knowledge gaps in several areas that can be improved upon. It identifies deficiency in objective knowledge about OSA among OMS residents and a specific lack of clinical training and confidence with hypoglossal nerve stimulation and management of pediatric patients with OSA. Junior and senior residents and single‐ and dual‐degree residents showed no statistically significant differences in any category except senior residents in regard to surgical management of OSA, particularly with maxillomandibular advancement.

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). MEDLINE and EMBASE databases were searched from inception to September 2022 for proton magnetic resonance spectroscopy (1H-MRS) studies reporting glutamate, glutamine or Glx in schizophrenia. 123 studies reporting on 8256 patients and 7532 controls were included. Compared with controls, patients demonstrated greater variability in glutamatergic metabolites in the medial frontal cortex (MFC, glutamate: CVR = 0.15, p< 0.001; glutamine: CVR = 0.15, p= 0.003; Glx: CVR = 0.11, p= 0.002), dorsolateral prefrontal cortex (glutamine: CVR = 0.14, p= 0.05; Glx: CVR = 0.25, p< 0.001) and thalamus (glutamate: CVR = 0.16, p= 0.008; Glx: CVR = 0.19, p= 0.008). Studies in younger, more symptomatic patients were associated with greater variability in the basal ganglia (BG glutamate with age: z= −0.03, p= 0.003, symptoms: z= 0.007, p= 0.02) and temporal lobe (glutamate with age: z= −0.03, p= 0.02), while studies with older, more symptomatic patients associated with greater variability in MFC (glutamate with age: z= 0.01, p= 0.02, glutamine with symptoms: z= 0.01, p= 0.02). For individual patient data, most studies showed a unimodal distribution of glutamatergic metabolites. Meta-analysis of mean differences found lower MFC glutamate (g= −0.15, p= 0.03), higher thalamic glutamine (g= 0.53, p< 0.001) and higher BG Glx in patients relative to controls (g= 0.28, p< 0.001). Proportion of males was negatively associated with MFC glutamate (z= −0.02, p< 0.001) and frontal white matter Glx (z= −0.03, p= 0.02) in patients relative to controls. Patient PANSS total score was positively associated with glutamate SMD in BG (z= 0.01, p= 0.01) and temporal lobe (z= 0.05, p= 0.008). Further research into the mechanisms underlying greater glutamatergic metabolite variability in schizophrenia and their clinical consequences may inform the identification of patient subgroups for future treatment strategies.

Abnormalities within frontal lobe gray and white matter of bipolar disorder (BD) patients have been consistently reported in adult and pediatric studies, yet little is known about the neurochemistry of the anterior white matter (AWM) in pediatric BD and how medication status may affect it. The present cross-sectional 3T 1H MRS study is the first to use a multivoxel approach to study the AWM of BD youth. Absolute metabolite levels from four bilateral AWM voxels were collected from 49 subjects between the ages of 8 and 18 (25 healthy controls (HC); 24 BD) and quantified. Our study found BD subjects to have lower levels of N-acetylaspartate (NAA) and glycerophosphocholine plus phosphocholine (GPC + PC), metabolites that are markers of neuronal viability and phospholipid metabolism and have also been implicated in adult BD. Further analysis indicated that the observed patterns were mostly driven by BD subjects who were medicated at the time of scanning and had an ADHD diagnosis. Although limited by possible confounding effects of mood state, medication, and other mood comorbidities, these findings serve as evidence of altered neurochemistry in BD youth that is sensitive to medication status and ADHD comorbidity.

Existing data on altered membrane phospholipid metabolism in schizophrenia are diverse. We conducted a meta-analysis of studies of phosphorus magnetic resonance spectroscopy, a noninvasive imaging approach that can assess molecular biochemistry of cortex by measuring phosphomonoester (PME) and phosphodiester (PDE) levels, which can provide evidence of altered biochemical processes involved in neuropil membrane expansion and contraction in schizophrenia.

With a growing population of elderly patients in the United States seeking treatment for obstructive sleep apnea, age is becoming an increasingly important consideration for sleep surgeons. The effects of obstructive sleep apnea on elderly patients may be different for older patients, specifically when it comes to the cardiovascular and mortality risk observed in younger patient populations. Recent reports indicate that traditional structural surgery for elderly patients may be less effective and that postoperative complication rates are higher. In contrast, early reports on upper airway stimulation therapy suggest improved efficacy with increasing age. Although advanced age itself is not a contraindication for surgery, the balance of risks vs benefits should be carefully weighed in the elderly patient population. [ABSTRACT FROM AUTHOR]

Objective: Magnetic Resonance Spectroscopy (MRS) is a noninvasive in vivo technique extensively applied to assess the levels of neural metabolites in the brain. We aimed to summarize the findings of proton spectroscopy (1H MRS) studies addressing neuro-metabolite findings in the Basal Ganglia (BG) of patients with Bipolar Disorders (BD). Method: A search of PubMed and Ovid databases was conducted to identify ¹H MRS studies since 1990 reporting N-acetylaspartate (NAA), phosphocholine plus glycerophosphocholine (PC+GPC), and creatine plus phosphocreatine (Cr+PCr) levels in the BG of patients with BD. Results: Ten original studies were included in this review. Three studies involved BD patients with depressed mood, six studied euthymic BD patients, and one study looked at manic subjects. In depressed BD patients, three studies reported elevated PC+GPC and Cr+PCr levels in the caudate and putamen. NAA levels were found to be elevated in two of the studies, while one reported no change. In euthymic BD patients, five studies reported no group differences with respect to any metabolites, and one study found differences in PC+GPC/Cr+PCr associated with lithium treatment. In mania, lower PC+GPC, lower NAA levels, and increased Cr+PCr levels were described in the caudate of BD patients compared to HC. Conclusion: This review suggests that abnormalities in NAA, GPC+PC, and Cr+PCr levels in the BG might be associated with mood state among BD patients. In addition, the methodological issues involved in the heterogeneity of 1H MRS findings in BD, as well as the potential role of 1H MRS findings as biomarkers for BD, are discussed.

Previous studies have found increased levels of choline-containing compounds (ie, glycerophosphocholine plus phosphocholine (GPC+PC)) in bipolar disorder using in vivo proton magnetic resonance spectroscopy (1H MRS), especially in bipolar I disorder (BD-I). Increased levels of GPC+PC suggest alterations in the membrane phospholipids metabolism in bipolar disorder. Rapid cycling (RC) bipolar disorder is considered as a severe course of bipolar disorder, but it is unclear whether rapid cycling bipolar disorder is linked to highly altered membrane phospholipid metabolism. The purpose of this study was to investigate whether the regional extent of elevated GPC+PC were greater in BD-I patients with rapid cycling compared to BD-I patients without rapid cycling and healthy controls. Using a multi-voxel 1H MRS approach at 3 Tesla with high spatial resolution and absolute quantification, GPC+PC levels from the anterior cingulate cortex (ACC), caudate and putamen of 16 RC BD-I, 34 non-RC BD-I and 44 healthy controls were assessed. We found significantly elevated GPC+PC levels in ACC, putamen and caudate of RC BD-I patients compared to healthy controls (P<0.005) and in ACC compared to non-RC BD-I patients (P<0.05). These results suggest greater alteration of membrane phospholipid metabolisms in rapid cycling BD-I compared to non-rapid-cycling BD-I.

To assess a new measure of positive airway pressure (PAP) effectiveness, the Effective AHI, which accounts for sleep disordered breathing events during the time PAP is (PAP On) and is not (PAP Off) being used. A secondary aim was to test the accuracy of the Watch-PAT 200 (WP) portable monitor for measurement of the Effective AHI.

Neuropathological studies suggest neuropil reduction in schizophrenia. Altered synaptic pruning is proposed to underlie neuropil reduction. Underlying factors and clinical correlates of synaptic pruning are poorly understood. Using phosphorus magnetic resonance spectroscopy, it is feasible to assess membrane phospholipid (MPL) metabolites in the brain that specifically and sensitively reflect neuropil expansion (elevated MPL precursors) or contraction (elevated MPL catabolites).

To identify the role of end-tidal carbon dioxide (EtCO2) monitoring during polysomnography in evaluation of children with obstructive sleep apnea syndrome (OSAS), including the correlation of EtCO2 with other measures of OSAS and prediction of changes in cognition and behavior after adenotonsillectomy.

Brain-derived neurotrophic factor val66met polymorphism has been implicated in the pathophysiology of bipolar disorder. We investigated the neurochemistry of the left dorsolateral prefrontal cortex of bipolar disorder and healthy participants in relation to the brain-derived neurotrophic factor val66met polymorphism using 1H-magnetic resonance spectroscopy. Absolute N-acetyl-aspartate, phosphocreatinecreatine (PCrCr), choline-containing compounds, myo-inositol, and glutamate levels were measured. Bipolar disorder met-carriers had lower PCrCr levels than bipolar disorder valval patients, and bipolar disorder valval patients had higher PCrCr levels than valval healthy controls. These results indicate that bipolar disorder met-carriers have abnormal energy metabolism in the left dorsolateral prefrontal cortex.

In vivo magnetic resonance spectroscopy (MRS) is the only noninvasive imaging technique that can directly assess the living biochemistry in localized brain regions. In the past decade, spectroscopy studies have shown biochemical alterations in various neuropsychiatric disorders. These first-generation studies have, in most cases, been exploratory but have provided insightful biochemical information that has furthered our understanding of different brain disorders. This review provides a brief description of spectroscopy, followed by a literature review of key spectroscopy findings in schizophrenia, affective disorders, and autism.In schizophrenia, phosphorus spectroscopy studies have shown altered metabolism of membrane phospholipids (MPL) during the early course of the illness, which is consistent with a neurodevelopmental abnormality around the critical period of adolescence when the illness typically begins. Children and adolescents who are at increased genetic risk for schizophrenia show similar MPL alterations, suggesting that schizophrenia subjects with a genetic predisposition may have a premorbid neurodevelopmental abnormality.Independent of medication status, bipolar subjects in the depressive state tended to have higher MPL precursor levels and a deficit of high-energy phosphate metabolites, which also is consistent with major depression, though these results varied. Further bipolar studies are needed to investigate alterations at the early stage.Lastly, associations between prefrontal metabolism of high-energy phosphate and MPL and neuropsychological performance and reduced N-acetylaspartate in the temporal and cerebellum regions have been reported in individuals with autism. These findings are consistent with developmental alterations in the temporal lobe and in the cerebellum of persons with autism. This paper discusses recent findings of new functions of N-acetylaspartate.