A reciprocal inhibition model of alternations between under-/overemotional modulatory states in patients with PTSD.

Patients with posttraumatic stress disorder (PTSD) appear to manifest two opposing tendencies in their attentional biases and symptoms. However, whether common neural mechanisms account for their opposing attentional biases and symptoms remains unknown. We here propose a model in which reciprocal inhibition between the amygdala and ventromedial prefrontal cortex (vmPFC) predicts synchronized alternations between emotional under- and overmodulatory states at the neural, behavioral, and symptom levels within the same patients. This reciprocal inhibition model predicts that when the amygdala is dominant, patients enter an emotional undermodulatory state where they show attentional bias toward threat and manifest re-experiencing symptoms. In contrast, when the vmPFC is dominant, patients are predicted to enter an emotional overmodulatory state where they show attentional bias away from threat and avoidance symptoms. To test the model, we performed a behavioral meta-analysis (total N = 491), analyses of own behavioral study (N = 20), and a neuroimaging meta-analysis (total N = 316). Supporting the model, we found the distributions of behavioral attentional measurements to be bimodal, suggesting alternations between the states within patients. Moreover, attentional bias toward threat was related to re-experiencing symptoms, whereas attentional bias away from threat was related with avoidance symptoms. We also found that the increase and decrease of activity in the left amygdala activity was related with re-experiencing and avoidance symptoms, respectively. Our model may help elucidate the neural mechanisms differentiating nondissociative and dissociative subtypes of PTSD, which usually show differential emotional modulatory levels. It may thus provide a new venue for therapies targeting each subtype.

Dexmedetomidine versus propofol for prolonged sedation in critically ill trauma and surgical patients.

BACKGROUND: and Purpose: Currently, dexmedetomidine versus propofol has primarily been studied in medical and cardiac surgery patients with outcomes indicating safe and effective sedation. The purpose of this study was to assess the efficacy of dexmedetomidine versus propofol for prolonged sedation in trauma and surgical patients. METHODS: This was a single-center prospective study conducted in the Trauma/Surgical Intensive Care Unit (ICU) at a Level I academic trauma center. It included patients 18 years of age or older requiring mechanical ventilation who were randomly assigned based on unit bed location to receive either dexmedetomidine or propofol. The primary outcome was duration of mechanical ventilation. Secondary outcomes included mortality; proportion of time in target sedation; incidence of delirium, hypotension, and bradycardia; and ICU and hospital length of stay (LOS). RESULTS: A total of 57 patients were included. Baseline characteristics were similar between groups. There was no significant difference in duration of mechanical ventilation (median [IQR]) between the dexmedetomidine (78.5[125] hours) and propofol (105[130] hours; p = 0.15) groups. There was no difference between groups in ICU mortality, ICU and hospital LOS, or incidence of delirium. Safety outcomes were also similar. Patients in the dexmedetomidine group spent a significantly greater percentage of time in target sedation (98[8] %) compared to propofol group (92[10] %; p = 0.02). CONCLUSIONS: Our results suggest that, similar to medical and cardiac surgery patients, dexmedetomidine and propofol are safe and effective sedation agents in critically ill trauma and surgical patients; however, dexmedetomidine achieves target sedation better than propofol for this specific population.

Quetiapine for delirium prophylaxis in high-risk critically ill patients.

BACKGROUND: Delirium is common in patients admitted to the surgical trauma intensive care unit (ICU), and the risk factors for these patients differ from medical patients. Given the morbidity and mortality associated with delirium, efforts to prevent it may improve patient outcomes, but previous efforts pharmacologically have been limited by side effects and insignificant results. We hypothesized that scheduled quetiapine could reduce the incidence of delirium in this population. METHODS: The study included 71 adult patients who were at high-risk for the development of delirium (PRE-DELIRIC Score ≥50%, history of dementia, alcohol misuse, or drug abuse). Patients were randomized to receive quetiapine 12.5 mg every 12 h for delirium or no pharmacologic prophylaxis within 48 h of admission to the ICU. The primary end point was the incidence of delirium during admission to the ICU. Secondary end points included time to onset of delirium, ICU and hospital length of stay (LOS), ICU and hospital mortality, duration of mechanical ventilation, and adverse events. RESULTS: The incidence of delirium during admission to the ICU was 45.5% (10/22) in the quetiapine group and 77.6% (38/49) in the group that did not receive pharmacological prophylaxis. The mean time to onset of delirium was 1.4 days for those who did not receive prophylaxis versus 2.5 days for those who did (p = 0.06). The quetiapine group significantly reduced ventilator duration from 8.2 days to 1.5 days (p = 0.002). CONCLUSIONS: The findings suggested that scheduled, low-dose quetiapine is effective in preventing delirium in high-risk, surgical trauma ICU patients.

Obesity and Associated Outcomes for Blunt vs Penetrating Mechanism in Trauma Laparotomy Patients.

Obesity in trauma patients is an established risk factor contributing to postoperative complications, but the relationship between body mass index (BMI) and trauma patient outcomes is not well-defined, especially when stratified by mechanism of injury. We surveyed the trauma laparotomy registry at an academic level 1 trauma center over a 3-year period to identify mortality, injury severity score, and hospital length of stay (hLOS) outcome measures across BMI classes, with further stratification by mechanism of injury: blunt vs penetrating trauma. A total of 442 patients were included with mean age 44.6 (SD = 18.7) and mean BMI 28.55 (SD = 7.37). These were subdivided into blunt trauma (n = 313) and penetrating trauma (n = 129). Within the blunt trauma subgroup, the hLOS among patients who survived hospitalization significantly increased 9% for each successive BMI class (P = .022, 95% CI = 1.29-17.5). We conclude that successive increase in BMI class is associated with longer hospital stay for blunt trauma patient survivors requiring laparotomy, though additional analysis is needed to establish this relationship to other outcome measures and among penetrating trauma patients.

Outcomes From a Level 1 Trauma and Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program Center of Excellence.

Trauma patients with obesity experience disparity in various outcomes. Similar to trauma centers, vetted credentialing is in practice for bariatric services. This study evaluates outcomes of trauma patients with obesity at a Level 1 Trauma Center and verified bariatric surgery center of excellence (BSCOE). The trauma registry was reviewed for individuals admitted between January 1, 2008 to December 31, 2020 who were age 19 years or older and stratified by World Health Organization body mass index (BMI). Various morbidity and mortality outcomes were examined. There were 20 788 patients included in this analysis. Intensive care unit (ICU) length of stay (LOS) was found to be statistically longer for patients with BMI >40. Overall results suggest that the infrastructure associated with this BSCOE may improve care for this specialized patient population.

Obesity Associated With Increased Mortality and Hospital Length of Stay in Trauma Laparotomy Patients.

Although obesity in trauma patients is accepted as a risk factor for postoperative complications, recent literature offers conflicting evidence regarding the effect of body mass index (BMI) on mortality in trauma patients undergoing laparotomy. To address this question, we examined the patient population of a Level 1 Trauma Center during a 3-year period to compare mortality rates and other outcomes between BMI groups undergoing laparotomy. Through retrospective chart review of electronic medical records, with subsequent stratification of data based on BMI, we found that mortality, injury severity score, and hospital length of stay all increase significantly with each incremental increase in BMI class. From these data, we concluded that higher BMI class leads to greater morbidity and mortality in trauma patients undergoing laparotomy at this institution.

Perisplenitis ("Sugar Spleen") Associated With Malrotation of the Intestine in an Elderly Man.

Intestinal non-rotation is an exceedingly rare clinical entity, especially as the etiology for small bowel obstruction following open-heart surgery in an elderly patient. Perisplenitis (also known as "sugar spleen") is also rarely identified during exploratory laparotomy, and is more often encountered post-mortem due to its benign disease course. These two entities were encountered in the same acutely decompensating patient, and while unrelated, serve as a reminder of the importance of recognizing variations in anatomy and understanding subsequent clinical significance.

Inferior Vena Cava Ligation and Pancreaticoduodenectomy in a Patient With Penetrating Abdominal Trauma.

INTRODUCTION: Injury to the inferior vena cava (IVC) is often fatal. Pancreaticoduodenectomy for trauma is also rare. This case describes a patient who underwent both procedures. CASE PRESENTATION: A 30-year-old male presented status post gunshot to the abdomen. He was taken to the operating room and found to have 6 cm defect in the IVC, which was ligated. Despite resuscitation, the patient required emergent return to the OR where bleeding from the pancreaticoduodenal artery was noted in addition to injuries in the stomach, duodenum, and pancreas. He subsequently underwent a pancreaticoduodenectomy. He was discharged after a month-long hospital stay. CONCLUSIONS: This case demonstrates that IVC ligation is a form of damage of control surgery. Pancreaticoduodenectomy is rarely performed during the index operation for trauma patients. Patient with injuries to the pancreaticoduodenal complex can be life-threatening if not rapidly controlled. This patient is a rare example of someone who survived two morbid trauma surgery interventions.

Corrigendum: An Evolutionarily Threat-Relevant Odor Strengthens Human Fear Memory.

[This corrects the article DOI: 10.3389/fnins.2020.00255.].

An Evolutionarily Threat-Relevant Odor Strengthens Human Fear Memory.

Olfaction is an evolutionary ancient sense, but it remains unclear to what extent it can influence routine human behavior. We examined whether a threat-relevant predator odor (2-methyl-2-thiazoline) would contextually enhance the formation of human fear memory associations. Participants who learned to associate visual stimuli with electric shock in this predator odor context later showed stronger fear responses to the visual stimuli than participants who learned in an aversiveness-matched control odor context. This effect generalized to testing in another odor context, even after extinction training. Results of a separate experiment indicate that a possible biological mechanism for this effect may be increased cortisol levels in a predator odor context. These results suggest that innate olfactory processes can play an important role in human fear learning. Modulatory influences of odor contexts may partly explain the sometimes maladaptive persistence of human fear memory, e.g., in post-traumatic stress disorders.

GLOBE Observer Data: 2016-2019.

This technical report summarizes the GLOBE Observer data set from 1 April 2016 to 1 December 2019. GLOBE Observer is an ongoing NASA-sponsored international citizen science project that is part of the larger Global Learning and Observations to Benefit the Environment (GLOBE) Program, which has been in operation since 1995. GLOBE Observer has the greatest number of participants and geographic coverage of the citizen science projects in the Earth Science Division at NASA. Participants use the GLOBE Observer mobile app (launched in 2016) to collect atmospheric, hydrologic, and terrestrial observations. The app connects participants to satellite observations from Aqua, Terra, CALIPSO, GOES, Himawari, and Meteosat. Thirty-eight thousand participants have contributed 320,000 observations worldwide, including 1,000,000 georeferenced photographs. It would take an individual more than 13 years to replicate this effort. The GLOBE Observer app has substantially increased the spatial extent and sampling density of GLOBE measurements and more than doubled the number of measurements collected through the GLOBE Program. GLOBE Observer data are publicly available (at observer.globe.gov).

Reward value enhances post-decision error-related activity in the cingulate cortex.

By saying "Anyone who has never made a mistake has never tried anything new", Albert Einstein himself allegedly implied that the making and processing of errors are essential for behavioral adaption to a new or changing environment. These essential error-related cognitive and neural processes are likely influenced by reward value. However, previous studies have not dissociated accuracy and value and so the distinct effect of reward on error processing in the brain remained unknown. Therefore, we set out to investigate this at various points in decision-making. We used functional magnetic resonance imaging to scan participants while they completed a random dot motion discrimination task where reward and non-reward were associated with stimuli via classical conditioning. Pre-error activity was found in the medial frontal cortex prior to response but this was not related to reward value. At response time, error-related activity was found to be significantly greater in reward than non-reward trials in the midcingulate cortex. Finally at outcome time, error-related activity was found in the anterior cingulate cortex in non-reward trials. These results show that reward value enhances post-decision but not pre-decision error-related activities and these results therefore have implications for theories of error correction and confidence.

Dissociable functions of reward inference in the lateral prefrontal cortex and the striatum.

In a complex and uncertain world, how do we select appropriate behavior? One possibility is that we choose actions that are highly reinforced by their probabilistic consequences (model-free processing). However, we may instead plan actions prior to their actual execution by predicting their consequences (model-based processing). It has been suggested that the brain contains multiple yet distinct systems involved in reward prediction. Several studies have tried to allocate model-free and model-based systems to the striatum and the lateral prefrontal cortex (LPFC), respectively. Although there is much support for this hypothesis, recent research has revealed discrepancies. To understand the nature of the reward prediction systems in the LPFC and the striatum, a series of single-unit recording experiments were conducted. LPFC neurons were found to infer the reward associated with the stimuli even when the monkeys had not yet learned the stimulus-reward (SR) associations directly. Striatal neurons seemed to predict the reward for each stimulus only after directly experiencing the SR contingency. However, the one exception was "Exclusive Or" situations in which striatal neurons could predict the reward without direct experience. Previous single-unit studies in monkeys have reported that neurons in the LPFC encode category information, and represent reward information specific to a group of stimuli. Here, as an extension of these, we review recent evidence that a group of LPFC neurons can predict reward specific to a category of visual stimuli defined by relevant behavioral responses. We suggest that the functional difference in reward prediction between the LPFC and the striatum is that while LPFC neurons can utilize abstract code, striatal neurons can code individual associations between stimuli and reward but cannot utilize abstract code.