ABSTRACT
Emergency physicians are highly trained to deliver acute unscheduled care. The emergency physician core skillset gained during emergency medicine residency can be applied to many other roles that benefit patients and extend and diversify emergency physician careers. In 2022, the American College of Emergency Physicians (ACEP) convened the New Practice Models Task Force to describe new care models and emergency physician opportunities outside the 4 walls of the emergency department. The Task Force consisted of 21 emergency physicians with broad experience and 2 ACEP staff. Fifty-nine emergency physician roles were identified (21 established clinical roles, 16 emerging clinical roles, 9 established nonclinical roles, and 13 emerging nonclinical roles). A strength-weakness-opportunity-threat (SWOT) analysis was performed for each role. Using the analysis, the Task Force made recommendations for guiding ACEP internal actions, advocacy, education, and research opportunities. Emphasis was placed on urgent care, rural medicine, telehealth/virtual care, mobile integrated health care, home-based services, emergency psychiatry, pain medicine, addiction medicine, and palliative care as roles with high or rising demand that draw on the emergency physician skillset. Advocacy recommendations focused on removing state and federal regulatory and legislative barriers to the expansion of new and emerging roles. Educational recommendations focused on aggregating available resources, developing a centralized resource for career guidance, and new educational content for emerging roles. The Task Force also recommended promoting research on potential advantages (eg, improved outcomes, lower cost) of emergency physicians in certain roles and new care models (eg, emergency physician remote supervision in rural settings).
Subject(s)
Emergency Medicine , Physicians , Telemedicine , Humans , United States , Emergency Medicine/education , Emergency Service, Hospital , Palliative CareABSTRACT
The effects of acute sleep deprivation on ß-amyloid (Aß) clearance in the human brain have not been documented. Here we used PET and 18F-florbetaben to measure brain Aß burden (ABB) in 20 healthy controls tested after a night of rested sleep (baseline) and after a night of sleep deprivation. We show that one night of sleep deprivation, relative to baseline, resulted in a significant increase in Aß burden in the right hippocampus and thalamus. These increases were associated with mood worsening following sleep deprivation, but were not related to the genetic risk (APOE genotype) for Alzheimer's disease. Additionally, baseline ABB in a range of subcortical regions and the precuneus was inversely associated with reported night sleep hours. APOE genotyping was also linked to subcortical ABB, suggesting that different Alzheimer's disease risk factors might independently affect ABB in nearby brain regions. In summary, our findings show adverse effects of one-night sleep deprivation on brain ABB and expand on prior findings of higher Aß accumulation with chronic less sleep.
Subject(s)
Amyloid beta-Peptides/metabolism , Hippocampus/metabolism , Sleep Deprivation/diagnostic imaging , Sleep Deprivation/metabolism , Thalamus/metabolism , Adult , Aged , Alzheimer Disease/diagnostic imaging , Alzheimer Disease/genetics , Alzheimer Disease/metabolism , Amyloid beta-Peptides/genetics , Apolipoproteins E/genetics , Female , Genotype , Hippocampus/diagnostic imaging , Humans , Male , Middle Aged , Risk Factors , Sleep Deprivation/genetics , Thalamus/diagnostic imagingABSTRACT
The role of sleep in brain physiology is poorly understood. Recently rodent studies have shown that the glymphatic system clears waste products from brain more efficiently during sleep compared to wakefulness due to the expansion of the interstitial fluid space facilitating entry of cerebrospinal fluid (CSF) into the brain. Here, we studied water diffusivity in the brain during sleep and awake conditions, hypothesizing that an increase in water diffusivity during sleep would occur concomitantly with an expansion of CSF volume - an effect that we predicted based on preclinical findings would be most prominent in cerebellum. We used MRI to measure slow and fast components of the apparent diffusion coefficient (ADC) of water in the brain in 50 healthy participants, in 30 of whom we compared awake versus sleep conditions and in 20 of whom we compared rested-wakefulness versus wakefulness following one night of sleep-deprivation. Sleep compared to wakefulness was associated with increases in slow-ADC in cerebellum and left temporal pole and with decreases in fast-ADC in thalamus, insula, parahippocampus and striatal regions, and the density of sleep arousals was inversely associated with ADC changes. The CSF volume was also increased during sleep and was associated with sleep-induced changes in ADCs in cerebellum. There were no differences in ADCs with wakefulness following sleep deprivation compared to rested-wakefulness. Although we hypothesized increases in ADC with sleep, our findings uncovered both increases in slow ADC (mostly in cerebellum) as well as decreases in fast ADC, which could reflect the distinct biological significance of fast- and slow-ADC values in relation to sleep. While preliminary, our findings suggest a more complex sleep-related glymphatic function in the human brain compared to rodents. On the other hand, our findings of sleep-induced changes in CSF volume provide preliminary evidence that is consistent with a glymphatic transport process in the human brain.
Subject(s)
Brain/metabolism , Cerebrospinal Fluid/metabolism , Glymphatic System/physiology , Sleep/physiology , Adult , Diffusion Magnetic Resonance Imaging , Female , Humans , MaleABSTRACT
OBJECTIVE: Cephalic arch stenosis (CAS) is a frequent and challenging failure mode of brachiocephalic fistulas. Natural tortuosity of the cephalic arch requires special consideration in selecting a treatment modality. Typical percutaneous angioplasty and bare-metal stent (BMS) treatments provide a short-term treatment solution for CAS without a durable effect. This study assessed Viabahn (W. L. Gore & Associates, Flagstaff, Ariz) stent grafts (SGs) as a first-line percutaneous option to provide a durable treatment for CAS. METHODS: SG data were collected at a free-standing physician office between July 10, 2009, and January 26, 2011. A single-arm, prospective, observational study was conducted of 50 consecutive CAS patients treated with angioplasty followed by deployment of Viabahn SGs. Outcomes included target lesion primary patency and reintervention rates as well as secondary access patency. Results were compared with historic cohorts of percutaneous balloon angioplasty (N = 50) and angioplasty followed by BMS deployment (N = 50). The cohorts were treated between May 5, 2005, and May 20, 2010, and assessed in chronologic order. RESULTS: The SG cohort target lesion primary patency reported at 3, 6, and 12 months was 90% ± 7%, 74% ± 12%, and 60% ± 14% (±95% confidence interval), respectively. Compared with historic cohorts, the SG cohort demonstrated statistically superior target lesion primary patency (P < .001), with a reduced reintervention rate per access-year (P < .001). Secondary access patency was statistically superior compared with the percutaneous balloon angioplasty cohort (P = .034) but not statistically different from the BMS cohort when assessed during a 2.5-year period. The secondary access patency for the SG cohort at 5 years was 80% ± 15%. CONCLUSIONS: In treatment of a CAS, the Viabahn SG study group demonstrated superior target lesion primary patency and required fewer subsequent interventions compared with historic cohorts treated with angioplasty or angioplasty followed by BMS placement. Given the significant improvement in target lesion primary patency, future studies should challenge Viabahn SGs as a primary percutaneous treatment modality vs durable surgical alternatives.
Subject(s)
Arteriovenous Shunt, Surgical/adverse effects , Blood Vessel Prosthesis Implantation/instrumentation , Blood Vessel Prosthesis , Endovascular Procedures/instrumentation , Graft Occlusion, Vascular/surgery , Renal Dialysis , Stents , Upper Extremity/blood supply , Angiography , Angioplasty, Balloon/instrumentation , Blood Vessel Prosthesis Implantation/adverse effects , Endovascular Procedures/adverse effects , Graft Occlusion, Vascular/diagnostic imaging , Graft Occlusion, Vascular/etiology , Graft Occlusion, Vascular/physiopathology , Humans , Kaplan-Meier Estimate , Prospective Studies , Prosthesis Design , Recurrence , Risk Factors , Time Factors , Treatment Outcome , Vascular PatencyABSTRACT
Thrombosed immature fistulas have historically been considered unsalvageable. However, advances in procedure and balloon catheter technologies have expanded the scope of endovascular treatments. This study investigates the efficacy, functionality, and cost associated with the use of percutaneous techniques for the salvage of thrombosed immature fistulas. Over a 2-year period and from a population of 18,000 patients on hemodialysis, 140 consecutive patients with thrombosed immature fistulas underwent attempts at salvage via thrombectomy procedures. All fistulas had thrombosed following access creation and had never been used for hemodialysis. Multiple approaches were utilized to gain access to the fistula, including trans-fistula cannulation, distal arterial puncture, and proximal retrograde venous access. Thrombectomy was performed via balloon maceration and aspiration. Accelerated maturation was achieved through sequential angioplasty of diffusely stenotic veins and elimination of competing branch vessels. Primary access, primary assisted, and secondary access patencies were calculated at 3, 6, 12, and 24 months. A cost analysis was performed based on procedure statistics and the 2009 Medicare reimbursement schedule and compared with data from the 2009 United States Renal Data Survey. Thrombectomy was successful in 119 (85%) immature clotted fistulas, and hemodialysis adequacy was achieved in 111 (79%) fistulas. The average maturation time from thrombectomy to cannulation for dialysis was 46.4 days, with an average of 2.64 interventions per patient. There were 5 (3.5%) cases of angioplasty-induced rupture, all of which were treated with stent placement. Clinically significant pseudoaneurysm formation occurred in 4 (2.8%) patients. At 12 months, secondary access patency of salvaged accesses was 90%. Based on 2009 Medicare outpatient billing rates per patient per initial access-year and the maturation times observed in the New York area, percutaneous salvage of thrombosed immature fistulas costs $4881 to $14,998 less than access abandonment and new access creation. Endovascular techniques can be used for the salvage of thrombosed nonmaturing fistulas. When analyzed within the initial access-year, this approach yields significant cost savings over access abandonment.
Subject(s)
Angioplasty, Balloon/methods , Arteriovenous Shunt, Surgical , Renal Dialysis/methods , Thrombectomy/methods , Thrombosis/therapy , Adolescent , Adult , Aged , Aged, 80 and over , Angiography , Follow-Up Studies , Humans , Male , Retrospective Studies , Thrombosis/diagnosis , Thrombosis/etiology , Treatment Outcome , Young AdultABSTRACT
Maintenance of hemodialysis vascular access is increasingly performed on an outpatient basis by physicians trained in interventional techniques. The adoption of guidelines by national reputable organizations will help identify patients eligible for such outpatient treatments and help optimize the safety and efficacy of their procedures in the outpatient setting.
Subject(s)
Ambulatory Care Facilities/standards , Ambulatory Care/standards , Kidney Failure, Chronic/therapy , Practice Guidelines as Topic , Renal Dialysis/standards , Humans , Outpatients , United StatesABSTRACT
PRCIS: Myopic glaucoma suspects, particularly with high myopia, experience thinning of nontemporal parameters of retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL), without change in optic nerve head (ONH) parameters. PURPOSE: The aim was to assess the effect of myopia on RNFL, GCIPL, and ONH parameters in glaucoma suspects. MATERIALS AND METHODS: Seventy-six eyes of glaucoma suspects studied with Cirrus high definition optical coherence tomography were divided into low (n=27), moderate (n=25), and high myopia (n=24) groups. Optical coherence tomography parameters were correlated with spherical equivalent (SE) and evaluated with areas under the receiver operating characteristic curve for quantifying diagnostic ability to differentiate high myopia from nonhigh myopia. RESULTS: In high myopia, SE was positively correlated with thinning of average, minimum, and nontemporal GCIPL and thinning of average and nontemporal RNFL (P<0.05 for all), but not for inferior RNFL (P=0.28). In moderate myopia, SE was correlated with thinning of inferonasal and minimum GCIPL as well as superior and inferior RNFL (P<0.05 for all). SE was not correlated with ONH parameters in moderate or high myopia (P>0.05). The largest areas under the receiver operating characteristic curve for RNFL and GCIPL parameters were for superior (0.82) and superonasal (0.80) regions, respectively, with comparable diagnostic ability (P=0.74). CONCLUSION: High myopia, in particular, is associated with thinning of average RNFL, average and minimum GCIPL, and nontemporal parameters of both RNFL and GCIPL, warranting consideration of refractive status in glaucoma suspects.
Subject(s)
Glaucoma , Myopia , Optic Disk , Glaucoma/diagnosis , Humans , Intraocular Pressure , Myopia/diagnosis , Nerve Fibers , Retinal Ganglion Cells , Tomography, Optical CoherenceABSTRACT
OBJECTIVE: Our study sought to determine whether there was a change in emergency department (ED) length of stay (LOS) during the coronavirus disease 2019 (COVID-19) pandemic compared to prior years. METHODS: We performed a retrospective analysis using ED performance data 2018-2020 from 56 EDs across the United States. We used a generalized estimating equation (GEE) model to assess differences in ED LOS for admitted (LOS-A) and discharged (LOS-D) patients during the COVID-19 pandemic period compared to prior years. RESULTS: GEE modeling showed that LOS-A and LOS-D were significantly higher during the COVID-19 period compared to the pre-COVID-19 period. LOS-A during the COVID-19 period was 10.3% higher compared to the pre-COVID-19 time period, which represents a higher geometric mean of 28 minutes. LOS-D during the COVID-19 period was 2.8% higher compared to the pre-COVID-19 time period, which represents a higher geometric mean of 2 minutes. CONCLUSIONS: ED LOS-A and LOS-D were significantly higher in the COVID-19 period compared to the pre-COVID-19 period despite a lower volume of patients in the COVID-19 period.
ABSTRACT
We evaluated the efficacy of the Minimally Invasive Limited Ligation Endoluminal-Assisted Revision (MILLER) banding procedure in treating dialysis-associated steal syndrome or high-flow access problems. A retrospective analysis was conducted, evaluating banding of 183 patients of which 114 presented with hand ischemia (Steal) and 69 with clinical manifestations of pathologic high access flow such as congestive heart failure. Patients were assessed for technical success and symptomatic improvement, primary and secondary access patency, and primary band patency. Overall, 183 patients underwent a combined 229 bandings with technical success achieved in 225. Complete symptomatic relief (clinical success) was attained in 109 Steal patients and in all high-flow patients. The average follow-up time was 11 months with a 6-month primary band patency of 75 and 85% for Steal and high-flow patients, respectively. At 24 months the secondary access patency was 90% and the thrombotic event rates for upper-arm fistulas, forearm fistulas, and grafts were 0.21, 0.10, and 0.92 per access-year, respectively. Hence, the minimally invasive MILLER procedure appears to be an effective and durable option for treating dialysis access-related steal syndrome and high-flow-associated symptoms.
Subject(s)
Arteriovenous Shunt, Surgical/adverse effects , Hand/blood supply , Ischemia/etiology , Ischemia/therapy , Renal Dialysis , Aged , Female , Humans , Ligation/methods , Male , Middle Aged , Retrospective StudiesABSTRACT
INTRODUCTION: The novel coronavirus 2019 (COVID-19) pandemic in the United States (US) prompted widespread containment measures such as shelter-in-place (SIP) orders. The goal of our study was to determine whether there was a significant change in overall volume and proportion of emergency department (ED) encounters since SIP measures began. METHODS: This was a retrospective, observational, cross-sectional study using billing data from January 1, 2017-April 20, 2020. We received data from 141 EDs across 16 states, encompassing a convenience sample of 26,223,438 ED encounters. We used a generalized least squares regression approach to ascertain changes for overall ED encounters, hospital admissions, and New York University ED visit algorithm categories. RESULTS: ED encounters decreased significantly in the post-SIP period. Overall, there was a 39.6% decrease in ED encounters compared to expected volume in the pre-SIP period. Emergent encounters decreased by 35.8%, while non-emergent encounters decreased by 52.1%. Psychiatric encounters decreased by 30.2%. Encounters related to drugs and alcohol decreased the least, by 9.3% and 27.5%, respectively. CONCLUSION: There was a significant overall reduction in ED utilization in the post-SIP period. There was a greater reduction in lower acuity encounters than higher acuity encounters. Of all subtypes of ED encounters, substance abuse- and alcohol-related encounters reduced the least, and injury-related encounters reduced the most.
Subject(s)
COVID-19/epidemiology , Emergency Service, Hospital/statistics & numerical data , Adolescent , Adult , Age Distribution , Aged , Child , Child, Preschool , Cross-Sectional Studies , Female , Humans , Infant , Male , Middle Aged , Quarantine/legislation & jurisprudence , Retrospective Studies , SARS-CoV-2 , Sex Distribution , United States/epidemiology , Young AdultABSTRACT
The coronavirus disease 2019 (COVID-19) pandemic has rapidly evolved and now dominates the attention and full efforts of the emergency medicine community, both domestic and abroad. Seattle is the site of the initial diagnosed COVID-19 cases and fatalities in the United States. We provide an overview of the system-level response of 6 Seattle emergency departments and the Washington state chapter of the American College of Emergency Physicians (ACEP) to the COVID-19 pandemic. Local efforts involved the spectrum of emergency response including on- and off-site triage strategies, an approach to personal protective equipment, testing and reporting protocols, early treatments, communication strategies, the impact on front-line providers, and ongoing work.
ABSTRACT
PURPOSE: To establish a standardized approach for the maturation of non-maturing arteriovenous fistulae. METHODS: Consecutive patients (n=122) with non-maturing fistulae presented to our outpatient vascular access center for percutaneous interventions to assist in maturation. The techniques used included flow rerouting, competing branch vein elimination, staged balloon angioplasty, and limited controlled extravasation. RESULTS: Successful fistula maturations were achieved in 118/122 patients. Fistulae were divided into two classes according to initial vessel size: class 1 (6.0-8.0 mm diameter, >6 mm deep) and class 2 (2.0-5.0 mm diameter) fistulae were evaluated for differences in technical procedures and clinically successful fistula maturation. Class 1 and class 2 fistulae were evaluated for mean number of procedures to maturation (1.6 and 2.6, respectively), and time to maturation (5 and 7 weeks, respectively). Follow-up for 109 of the initial 118 patients was achieved (mean=24 months, range=0.25-60 months). Class 1 and class 2 fistulae had primary patencies of 17 and 39% at 6 months; and secondary patencies of 72 and 77% at 12 months, 53 and 61% at 24 months, and 42 and 32% at 36 months, respectively. Primary and secondary patencies (Mann-Whitney test, p=0.44 and p=0.38, respectively) of class 1 and class 2 fistulae did not differ significantly, and secondary patencies were comparable to other fistula salvage studies. CONCLUSION: Fistula salvage attempts should not be limited by factors such as a diffusely small diameter or an inaccessibly deep position.
Subject(s)
Angioplasty, Balloon , Arteriovenous Shunt, Surgical , Graft Occlusion, Vascular/therapy , Salvage Therapy , Upper Extremity/blood supply , Angioplasty, Balloon/adverse effects , Constriction, Pathologic , Female , Follow-Up Studies , Graft Occlusion, Vascular/diagnostic imaging , Graft Occlusion, Vascular/etiology , Graft Occlusion, Vascular/physiopathology , Humans , Male , Regional Blood Flow , Retrospective Studies , Time Factors , Treatment Failure , Ultrasonography , Vascular PatencyABSTRACT
INTRODUCTION: The short-term return visit rate among patients discharged from emergency departments (ED) is a quality metric and target for interventions. The ability to accurately identify which patients are more likely to revisit the ED could allow EDs and health systems to develop more focused interventions, but efforts to reduce revisits have not yet found success. Whether patients with a high number of ED visits are at increased risk of a return visit remains underexplored. METHODS: This was a population-based, retrospective, cohort study using administrative data from a large physician partnership. We included patients discharged from EDs from 80 hospitals in seven states from July 2014 - June 2016. We performed multivariable logistic regression of short-term return visits on patient, visit, hospital, and community characteristics. The primary outcome was the proportion of patients who had a return visit within 14 days of an index ED visit. RESULTS: Among 6,699,717 index visits, the overall risk of 14-day revisit was 12.6%. Frequent visitors accounted for 18.7% of all visits and 40.2% of all 14-day revisits. Frequent visitor status was associated with the highest odds of a revisit (odds ratio [OR] 3.06; 95% confidence interval [CI], 3.041 - 3.073). Other predictors of revisits were cellulitis (OR 2.131; 95% CI, 2.106 - 2.156), alcohol-related disorders (OR 1.579; 95%CI, 1.548 - 1.610), congestive heart failure (OR 1.175; 95% CI, 1.126 - 1.226), and public insurance (Medicaid OR 1.514; 95% CI, 1.501 - 1.528; Medicare OR 1.601; 95% CI, 1.583 - 1.620). CONCLUSION: Previous ED use - even a single previous visit - was a stronger predictor of a return visit than any other patient, hospital, or community characteristic. Clinicians should consider previous ED use when considering treatment decisions and risk of return visit, as should stakeholders targeting patients at risk of a return visit.
Subject(s)
Emergency Service, Hospital/statistics & numerical data , Patient Acceptance of Health Care/statistics & numerical data , Patient Readmission/statistics & numerical data , Adult , Aged , Female , Health Services Research , Humans , Male , Middle Aged , Retrospective Studies , United States/epidemiologyABSTRACT
Numerous studies have documented cognitive impairments in multiple domains in patients with an alcohol use disorder (AUD), including perceptuomotor, executive, and visuospatial functions. Although the neural underpinnings of cognitive deficits in AUD have been studied extensively, the neural basis of attention deficits in AUD remains relatively unexplored. Here, we investigated neural responses to a visual attention task (VAT) in 19 recently abstinent patients with AUD and 23 healthy control participants (HC) using functional MRI (fMRI). AUD had a mean number of 62 ± 34SD drinks per week and 29 ± 13 years' history of alcohol use. Results show that there were no behavioral differences (accuracy or reaction time) between groups during the VAT. For both groups, the VAT activated brain areas associated with visual attention load (i.e., parietal and prefrontal cortices) and visual processing (i.e., occipital cortex), which is in line with previous reports on the same task in healthy volunteers. Despite similar behavioral performances, AUD participants showed decreased VAT activation in regions of the dorsal and ventral attention networks, including parietal and prefrontal cortices, and in the insula as compared to controls. These findings corroborate differences in attention networks in AUD compared to HC that might underlie attention deficits in AUD, whereas impairments in the insula could reflect a disruption of interoception processing as found in other addictions.
Subject(s)
Alcoholism/diagnostic imaging , Attention/physiology , Brain/diagnostic imaging , Visual Perception/physiology , Adult , Alcoholism/physiopathology , Brain/physiopathology , Brain Mapping , Cognition/physiology , Female , Functional Neuroimaging , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Reaction Time/physiologyABSTRACT
Drugs and food both exert a rewarding effect through the firing of dopamine neurons in the ventral tegmental area, resulting in the release of dopamine into the nucleus accumbens and effects on the mesolimbic pathway. Here, we review the neuroimaging literature to consider the validity of food addiction and the common neurobiological mechanisms that overlap in food and drug addiction. This review paper focuses on findings from Positron Emission Tomography (PET), functional Magnetic Resonance Imaging (fMRI) and structural imaging studies, as well as evidence from neuroimaging studies of bariatric surgery and pharmacological interventions on obese individuals. We examine not only functional and structural changes in the mesolimbic pathways, but also in other frontal areas shown to be involved in drug addiction, including the prefrontal cortex, orbitofrontal cortex and anterior cingulate cortex, as well as changes in neurotransmitter systems beyond dopaminergic systems.
Subject(s)
Brain/diagnostic imaging , Food Addiction/diagnostic imaging , Neuroimaging/methods , Substance-Related Disorders/diagnostic imaging , Animals , Bariatric Surgery , Brain/physiopathology , Dopamine/metabolism , Dopaminergic Neurons/metabolism , Food Addiction/physiopathology , Humans , Obesity/diagnostic imaging , Obesity/physiopathology , Obesity/surgery , Substance-Related Disorders/physiopathologyABSTRACT
Neuroinflammation appears to contribute to neurotoxicity observed with heavy alcohol consumption. To assess whether chronic alcohol results in neuroinflammation we used PET and [11C]PBR28, a ligand that binds to the 18-kDa translocator protein (TSPO), to compare participants with an alcohol use disorder (AUD: n = 19) with healthy controls (HC: n = 17), and alcohol-dependent (n = 9) with -nondependent rats (n = 10). Because TSPO is implicated in cholesterol's transport for steroidogenesis, we investigated whether plasma cholesterol levels influenced [11C]PBR28 binding. [11C]PBR28 binding did not differ between AUD and HC. However, when separating by TSPO genotype rs6971, we showed that medium-affinity binders AUD participants showed lower [11C]PBR28 binding than HC in regions of interest (whole brain, gray and white matter, hippocampus, and thalamus), but no group differences were observed in high-affinity binders. Cholesterol levels inversely correlated with brain [11C]PBR28 binding in combined groups, due to a correlation in AUD participants. In rodents, we observed no differences in brain [11C]PBR28 uptake between alcohol-dependent and -nondependent rats. These findings, which are consistent with two previous [11C]PBR28 PET studies, may indicate lower activation of microglia in AUD, whereas failure to observe alcohol effects in the rodent model indicate that species differences do not explain the discrepancy with prior rodent autoradiographic studies reporting increases in TSPO binding with chronic alcohol. However, reduced binding in AUD participants could also reflect competition from endogenous TSPO ligands such as cholesterol; and since the rs6971 polymorphism affects the cholesterol-binding domain of TSPO this could explain why differences were observed only in medium-affinity binders.
Subject(s)
Alcoholism/metabolism , Brain/metabolism , Carrier Proteins/metabolism , Cholesterol/metabolism , Receptors, GABA-A/metabolism , Receptors, GABA/metabolism , Acetamides , Alcoholism/diagnostic imaging , Alcoholism/genetics , Animals , Brain/diagnostic imaging , Brain/drug effects , Central Nervous System Depressants/administration & dosage , Ethanol/administration & dosage , Female , Humans , Male , Middle Aged , Positron-Emission Tomography , Protein Binding , Pyridines , Radiopharmaceuticals , Rats, Wistar , Receptors, GABA/geneticsSubject(s)
Anesthesiology , Anesthetists , Australia , Blood Transfusion , Humans , New Zealand , Surveys and QuestionnairesABSTRACT
It remains unclear whether resting state functional magnetic resonance imaging (rfMRI) networks are associated with underlying synchrony in energy demand, as measured by dynamic 2-deoxy-2-[18F]fluoroglucose (FDG) positron emission tomography (PET). We measured absolute glucose metabolism, temporal metabolic connectivity (t-MC) and rfMRI patterns in 53 healthy participants at rest. Twenty-two rfMRI networks emerged from group independent component analysis (gICA). In contrast, only two anti-correlated t-MC emerged from FDG-PET time series using gICA or seed-voxel correlations; one included frontal, parietal and temporal cortices, the other included the cerebellum and medial temporal regions. Whereas cerebellum, thalamus, globus pallidus and calcarine cortex arose as the strongest t-MC hubs, the precuneus and visual cortex arose as the strongest rfMRI hubs. The strength of the t-MC linearly increased with the metabolic rate of glucose suggesting that t-MC measures are strongly associated with the energy demand of the brain tissue, and could reflect regional differences in glucose metabolism, counterbalanced metabolic network demand, and/or differential time-varying delivery of FDG. The mismatch between metabolic and functional connectivity patterns computed as a function of time could reflect differences in the temporal characteristics of glucose metabolism as measured with PET-FDG and brain activation as measured with rfMRI.
Subject(s)
Brain/metabolism , Energy Metabolism , Glucose/metabolism , Adult , Brain Mapping , Female , Fluorodeoxyglucose F18/metabolism , Humans , Magnetic Resonance Imaging , Male , Metabolic Networks and Pathways , Middle Aged , Nerve Net/metabolism , Oxidation-Reduction , Positron-Emission Tomography , RestSubject(s)
Adenoma/complications , Optic Chiasm/diagnostic imaging , Pituitary Neoplasms/complications , Retinal Ganglion Cells/pathology , Tomography, Optical Coherence/methods , Humans , Nerve Compression Syndromes/diagnostic imaging , Nerve Compression Syndromes/pathology , Optic Chiasm/pathology , Visual Fields , Visual Pathways/pathologyABSTRACT
Neuroimaging techniques to measure the function and biochemistry of the human brain such as positron emission tomography (PET), proton magnetic resonance spectroscopy ((1)H MRS), and functional magnetic resonance imaging (fMRI), are powerful tools for assessing neurobiological mechanisms underlying the response to treatments in substance use disorders. Here, we review the neuroimaging literature on pharmacological and behavioral treatment in substance use disorder. We focus on neural effects of medications that reduce craving (e.g., naltrexone, bupropion hydrochloride, baclofen, methadone, varenicline) and that improve cognitive control (e.g., modafinil, N-acetylcysteine), of behavioral treatments for substance use disorders (e.g., cognitive bias modification training, virtual reality, motivational interventions) and neuromodulatory interventions such as neurofeedback and transcranial magnetic stimulation. A consistent finding for the effectiveness of therapeutic interventions identifies the improvement of executive control networks and the dampening of limbic activation, highlighting their values as targets for therapeutic interventions in substance use disorders.