The presence of fear: How subjective fear, not physiological changes, shapes the experience of presence.

When we become engrossed in novels, films, games, or even our own wandering thoughts, we can feel present in a reality distinct from the real world. Although this subjective sense of presence is, presumably, a ubiquitous aspect of conscious experience, the mechanisms that produce it are unknown. Correlational studies conducted in virtual reality have shown that we feel more present when we are afraid, motivating claims that physiological changes contribute to presence; however, such causal claims remain to be evaluated. Here, we report two experiments that test the causal role of subjective and physiological components of fear (i.e., activation of the sympathetic nervous system) in generating presence. In Study 1, we validated a virtual reality simulation capable of inducing fear. Participants rated their emotions while they crossed a wooden plank that appeared to be suspended above a city street; at the same time, we recorded heart rate and skin conductance levels. Height exposure increased ratings of fear, presence, and both measures of sympathetic activation. Although presence and fear ratings were correlated during height exposure, presence and sympathetic activation were unrelated. In Study 2, we manipulated whether the plank appeared at height or at ground level. We also captured participants' movements, which revealed that alongside increases in subjective fear, presence, and sympathetic activation, participants also moved more slowly at height relative to controls. Using a mediational approach, we found that the relationship between height exposure and presence on the plank was fully mediated by self-reported fear, and not by sympathetic activation. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Association of length of hospital stay with delay to surgical fixation of hip fracture.

BACKGROUND: Previous research has shown increases in length of stay (LOS), morbidity and mortality when the standard for surgical fixation of hip fracture of 48 hours is not met. However, few investigators have analyzed LOS as a primary outcome, and most used time of diagnosis as opposed to time of fracture as the reference point. We examined the effect of time to surgical fixation of hip fracture, measured from time of fracture, on length of hospital stay; the secondary outcome was average 1-year mortality. METHODS: We conducted a retrospective cohort study of patients presenting to 1 of 2 tertiary care centres in St. John's, Newfoundland and Labrador, Canada, with a hip fracture from Jan. 1, 2014, to Dec. 31, 2018. We analyzed 3 groups based on timing of surgical fixation after fracture: less than 24 hours (group 1), 24-48 hours (group 2) and more than 48 hours (group 3). We assessed statistical significance using 1-way analysis of variance. RESULTS: Of the 692 patients included in the study, 212 (30.6%) were in group 1, 360 (52.0%) in group 2 and 120 (17.3%) in group 3. A delay to surgical fixation exceeding 48 hours was associated with a significantly longer LOS, by an average of 2.9 and 2.8 days compared to groups 1 and 2, respectively (p = 0.04); there was no significant difference in LOS between groups 1 and 2. A significant difference in average 1-year mortality was observed between groups 1 (11%) and 3 (26%) (p = 0.004), and groups 2 (13%) and 3 (p = 0.009). CONCLUSION: Surgical fixation beyond 48 hours after hip fracture resulted in significantly increased LOS and 1-year mortality. Further research should be conducted to evaluate reasons for delays to surgery and the effects of these delays on time to surgical fixation as measured from time of fracture.

Olfaction, cholinergic basal forebrain degeneration, and cognition in early Parkinson disease.

INTRODUCTION: Impaired olfaction and reduced cholinergic nucleus 4 (Ch4) volume both predict greater cognitive decline in Parkinson's disease (PD). We examined the relationship between olfaction, longitudinal change in cholinergic basal forebrain nuclei and their target regions, and cognition in early PD. METHODS: We analyzed a cohort of 97 PD participants from the Parkinson's Progression Markers Initiative with brain MRIs at baseline, 1 year, 2 years, and 4 years. Using probabilistic maps, regional grey matter density (GMD) was calculated for Ch4, cholinergic nuclei 1, 2, and 3 (Ch123), and their target regions. RESULTS: Baseline University of Pennsylvania Smell Identification Test score correlated with change in GMD of all regions of interest (all p < 0.05). Rate of change of Ch4 GMD was correlated with rate of change of Ch123 (p = 0.034), cortex (p = 0.001), and amygdala GMD (p < 0.001), but not hippocampus GMD (p = 0.38). Rate of change of Ch123 GMD was correlated with rate of change of cortex (p = 0.001) and hippocampus (p < 0.001), but not amygdala GMD (p = 0.133). In a linear regression model including change in GMD of all regions of interest and age as predictors, change in cortex GMD (߈slope= 38.2; 95 % CI: [0.47, 75.9]) and change in hippocampus GMD (߈slope= 24.8; 95 % CI: [0.80, 48.8]) were significant predictors of Montreal Cognitive Assessment score change over time. CONCLUSION: Impaired olfaction is associated with degeneration of the cholinergic basal forebrain and bilateral cortex, amygdala, and hippocampus in PD. The relationship between impaired olfaction and cognitive decline may be mediated by greater atrophy of the cortex and hippocampus.

Proactive Control of Emotional Distraction: Evidence From EEG Alpha Suppression.

Biased attention towards emotional stimuli is adaptive, as it facilitates responses to important threats and rewards. An unfortunate consequence is that emotional stimuli can become potent distractors when they are irrelevant to current goals. How can this distraction be overcome despite the bias to attend to emotional stimuli? Recent studies show that distraction by irrelevant flankers is reduced when distractor frequency is high, even if they are emotional. A parsimonious explanation is that the expectation of frequent distractors promotes the use of proactive control, whereby attentional control settings can be altered to minimize distraction before it occurs. It is difficult, however, to infer proactive control on the basis of behavioral data alone. We therefore measured neural indices of proactive control while participants performed a target-detection task in which irrelevant peripheral distractors (either emotional or neutral) could appear either frequently (on 75% of trials) or rarely (on 25% of trials). We measured alpha power during the pre-stimulus period to assess proactive control and during the post-stimulus period to determine the consequences of control for subsequent processing. Pre-stimulus alpha power was tonically suppressed in the high, compared to low, distractor frequency condition, regardless of expected distractor valence, indicating sustained use of proactive control. In contrast, post-stimulus alpha suppression was reduced in the high-frequency condition, suggesting that proactive control reduced the need for post-stimulus adjustments. Our findings indicate that a sustained proactive control strategy accounts for the reduction in both emotional and non-emotional distraction when distractors are expected to appear frequently.

Quality Improvement Focused Morbidity and Mortality Rounds: An Integrative Review.

Morbidity and mortality conference (MMC) is a century-old tradition in medicine that was initially primarily focused on the review of surgical outcomes and errors. In recent years, the value of MMC in quality improvement (QI) and patient safety initiatives has been realized and incorporated into the MMCs of some disciplines and institutions. Despite this, there is a need for a standardized structure of MMC that emphasizes both QI and patient safety. The purpose of this integrative review is to synthesize the literature on MMC structure that is reflective of QI and patient safety. An integrative literature search was carried out using PubMed and MEDLINE. Abstracts were reviewed and non-relevant articles were excluded. Exclusion criteria were no mention of MMC, analysis of specific case, no focus on QI or patient safety, and non-English language. A total of 21 articles were identified for review. Articles were reviewed in their entirety for content regarding structuring of the MMC to reflect and further develop QI and patient safety. The follwing three themes emerged that were consistently identified as being important for restructuring MMCs: (1) the importance of careful case selection, (2) the format of discussion during the conferences, and (3) the action plans reflecting QI initiatives derived from the conferences. The review suggests that one standardized method of MMC implementation that encompasses the three pivotal themes should be developed. Further research needs to focus on instituting measures of effectiveness for the new MMC model.

A Randomized Feasibility Trial of a Novel, Integrative, and Intensive Virtual Rehabilitation Program for Service Members Post-Acquired Brain Injury.

INTRODUCTION: Acquired Brain Injury, whether resulting from Traumatic brain injury (TBI) or Cerebral Vascular Accident (CVA), represent major health concerns for the Department of Defense and the nation. TBI has been referred to as the "signature" injury of recent U.S. military conflicts in Iraq and Afghanistan - affecting approximately 380,000 service members from 2000 to 2017; whereas CVA has been estimated to effect 795,000 individuals each year in the United States. TBI and CVA often present with similar motor, cognitive, and emotional deficits; therefore the treatment interventions for both often overlap. The Defense Health Agency and Veterans Health Administration would benefit from enhanced rehabilitation solutions to treat deficits resulting from acquired brain injuries (ABI), including both TBI and CVA. The purpose of this study was to evaluate the feasibility of implementing a novel, integrative, and intensive virtual rehabilitation system for treating symptoms of ABI in an outpatient clinic. The secondary aim was to evaluate the system's clinical effectiveness. MATERIALS AND METHODS: Military healthcare beneficiaries with ABI diagnoses completed a 6-week randomized feasibility study of the BrightBrainer Virtual Rehabilitation (BBVR) system in an outpatient military hospital clinic. Twenty-six candidates were screened, consented and randomized, 21 of whom completed the study. The BBVR system is an experimental adjunct ABI therapy program which utilizes virtual reality and repetitive bilateral upper extremity training. Four self-report questionnaires measured participant and provider acceptance of the system. Seven clinical outcomes included the Fugl-Meyer Assessment of Upper Extremity, Box and Blocks Test, Jebsen-Taylor Hand Function Test, Automated Neuropsychological Assessment Metrics, Neurobehavioral Symptom Inventory, Quick Inventory of Depressive Symptomatology-Self-Report, and Post Traumatic Stress Disorder Checklist- Civilian Version. The statistical analyses used bootstrapping, non-parametric statistics, and multilevel/hierarchical modeling as appropriate. This research was approved by the Walter Reed National Military Medical Center and Uniformed Services University of the Health Sciences Institutional Review Boards. RESULTS: All of the participants and providers reported moderate to high levels of utility, ease of use and satisfaction with the BBVR system (x- = 73-86%). Adjunct therapy with the BBVR system trended towards statistical significance for the measure of cognitive function (ANAM [x- = -1.07, 95% CI -2.27 to 0.13, p = 0.074]); however, none of the other effects approached significance. CONCLUSION: This research provides evidence for the feasibility of implementing the BBVR system into an outpatient military setting for treatment of ABI symptoms. It is believed these data justify conducting a larger, randomized trial of the clinical effectiveness of the BBVR system.

Developing an Undergraduate Ultrasound Curriculum: A Needs Assessment.

Background The introduction of ultrasound into the undergraduate medical school curriculum is gaining momentum in North America. At present, many institutions are teaching ultrasound to undergraduate medical students using a traditional framework designed to instruct practicing clinicians, or have modeled the curriculum on other universities. This approach is not based on educational needs or supported by evidence. Methods Using a descriptive, cross-sectional survey of stakeholder groups, we assessed the perceived relevance of various ultrasound skills and the attitude towards implementing an undergraduate ultrasound curriculum at our university. Results One hundred and fifty survey respondents representing all major stakeholder groups participated. All medical students, 97% of residents and 82% of educators agreed that the introduction of an ultrasound curriculum would enhance medical students' understanding of anatomy and physiology. All clinical medical students and residents, 92% of preclinical medical students, and 82% of educators agreed that the curriculum should also include clinical applications of ultrasound. Participants also indicated their preferences for specific curriculum content based on their perceived needs. Conclusion An integrated undergraduate ultrasound curriculum composed of specific preclinical and clinical applications was deemed appropriate for our university following a comprehensive needs assessment. Other universities planning such curricula should consider employing a needs assessment to provide direction for curriculum need and content.

Expression of connexin 26 and connexin 43 is reduced in Hirschsprung's disease.

BACKGROUND: Despite having an optimal pull-through operation, some children with Hirschsprung's disease (HSCR) continue to experience persistent bowel symptoms. Coordinated colonic electrical activity depends on intercellular communication between the enteric nerves, interstitial cells of Cajal (ICCs), smooth muscle cells, and fibroblast-like (platelet-derived growth factor receptor-alpha-positive) cells. Gap junctions are low-resistance channels composed of connexin (Cx) proteins which couple cells electrically and chemically. We aimed to evaluate the expression patterns of Cx26, Cx36, and Cx43 in the colon of children with HSCR and in healthy control colon. MATERIALS AND METHODS: Entire resected colonic specimens were collected from children undergoing pull-through surgery for HSCR (n = 10). Colonic controls were collected at colostomy closure in children with imperforate anus (n = 8). Distribution of Cx26, Cx36, and Cx43 was assessed using double-labeled immunofluorescence and confocal microscopy. Protein expression was quantified using Western blot analysis. RESULTS: Sparse punctate Cx36 expression was seen in the myenteric plexus in nerve trunks and some platelet-derived growth factor receptor-alpha-positive cell and ICC fibers. Cx26 was similarly distributed, although it was not coexpressed in ICCs. Cx43 was only coexpressed with ICCs in the myenteric plexus. Expression of Cx26 and Cx43 was markedly reduced in the aganglionic colon in HSCR compared to controls, while Cx26 expression was also moderately reduced in the ganglionic bowel in HSCR. CONCLUSIONS: Reduced expression of Cx26 and Cx43 is implicated in the pathophysiology of colonic dysmotility in the aganglionic bowel as well as, in the case of Cx26, the ganglionic bowel in HSCR.

Can We CanMEDS? Intangible Learning Through Tangible Simulation Case Development.

The Royal College CanMEDS framework has become a guide for medical school curricula. This framework aims to improve patient care by identifying and explaining seven key roles that physicians must fulfill in order to deliver high-quality healthcare to their patients. While medical schools incorporate these roles in their teaching processes, students can also apply them outside the classroom. Here, we describe a unique model developed at Memorial University of Newfoundland's Tuckamore Simulation Research Collaborative (TSRC), where students develop simulation cases with the guidance of expert mentors and apply the Royal College CanMEDS framework to writing clinical simulations.

The Impact of a Concussion-U Educational Program on Knowledge of and Attitudes about Concussion.

BACKGROUND: The diagnosis of a sports-related concussion is often dependent on the athlete self-reporting their symptoms. It has been suggested that improving youth athlete knowledge and attitudes toward concussion may increase self-reporting behaviour. The objective of this study was to determine if a novel Concussion-U educational program improves knowledge of and attitudes about concussion among a cohort of elite male Bantam and Midget AAA hockey players. METHODS: Fifty-seven male Bantam and Midget AAA-level hockey players (mean age=14.52±1.13 years) were recruited from the local community. Each participant completed a modified version of the Rosenbaum Concussion Knowledge and Attitudes Survey-Student Version immediately before and after a Concussion-U educational presentation. Follow-up sessions were arranged 4 to 6 months after the presentation, and assessed retention of knowledge and attitude changes. RESULTS: Forty-three players completed all three surveys. Concussion knowledge and attitude scores significantly (p<0.01) increased from pre- to post-presentation by 12.79 and 8.41%, respectively. At long-term follow-up, knowledge levels remained significantly (p<0.01) higher than baseline by 8.49%. Mean attitude scores were also increased at follow-up; however, this increase was not statistically significant. CONCLUSIONS: A Concussion-U educational program led to an immediate improvement in concussion knowledge and attitudes among elite male Bantam and Midget AAA hockey players. Increased knowledge was maintained at long-term follow-up, but improved attitude was not. Future studies should investigate whether similar educational programs influence symptom reporting and concussion incidence. In addition, they should focus on how to maintain improved concussion attitudes.

Altered tryptophan hydroxylase 2 expression in enteric serotonergic nerves in Hirschsprung's-associated enterocolitis.

AIM: To determine if expression of colonic tryptophan hydroxylase-2 (TPH2), a surrogate marker of neuronal 5-hydroxytryptamine, is altered in Hirschsprung's-associated enterocolitis. METHODS: Entire resected colonic specimens were collected at the time of pull-through operation in children with Hirschsprung's disease (HSCR, n = 12). Five of these patients had a history of pre-operative Hirschsprung's-associated enterocolitis (HAEC). Controls were collected at colostomy closure in children with anorectal malformation (n = 10). The distribution of expression of TPH2 was evaluated using immunofluorescence and confocal microscopy. Protein expression of TPH2 was quantified using western blot analysis in the deep smooth muscle layers. RESULTS: TPH2 was co-expressed in nitrergic and cholinergic ganglia in the myenteric and submucosal plexuses in ganglionic colon in HSCR and healthy controls. Co-expression was also seen in submucosal interstitial cells of Cajal and PDGFRα(+) cells. The density of TPH2 immuno-positive fibers decreased incrementally from ganglionic bowel to transition zone bowel to aganglionic bowel in the myenteric plexus. Expression of TPH2 was reduced in ganglionic bowel in those affected by pre-operative HAEC compared to those without HAEC and healthy controls. However, expression of TPH2 was similar or high compared to controls in the colons of children who had undergone diverting colostomy for medically refractory HAEC. CONCLUSION: Altered TPH2 expression in colonic serotonergic nerves of patients with HSCR complicated by HAEC may contribute to intestinal secretory and motor disturbances, including recurrent HAEC.

Blast From the Past: A Retrospective Analysis of Blast-induced Head Injury.

Because of the sharp increase in the number of military personnel exposed to explosive blasts in combat, research has been dedicated toward understanding the impact of explosions on the brain. It is important to consider that potential injuries that military personnel sustain may be both in the form of physical injury as well as "invisible" neuronal and psychological damage. Since the inception of the study of blast science in the Medieval and Renaissance eras, significant improvements have been made in the historical record keeping and biomedical analysis of blast injuries. This editorial comments on the evolution of blast science and the recognition of neurological sequelae from both the historical and scientific perspectives.

Thermal Burns and Smoke Inhalation: A Simulation Session.

In recent years, simulation-based training has seen increased application in medical education. Emergency medicine simulation uses a variety of educational tools to facilitate trainee acquisition of knowledge and skills in order to help achieve curriculum objectives. In this report, we describe the use of a highly realistic human patient simulator to instruct emergency medicine senior residency trainees on the management of a burn patient.

Neuromuscular fatigue of the knee extensors during repeated maximal intensity intermittent-sprints on a cycle ergometer.

INTRODUCTION: We studied the time course of neuromuscular fatigue during maximal intensity intermittent-sprint cycling. METHODS: Eight participants completed 10, 10-s sprints interspersed with 180 s of recovery. The power outputs were recorded for each sprint. Knee extensor maximum voluntary contraction (MVC) force, voluntary activation, and evoked contractile properties were recorded presprint, postsprint 5, and postsprint 10. RESULTS: Total work over the 10 sprints decreased significantly (P < 0.05) and could be described by 2 linear relationships from sprints 1-5 compared with sprints 6-10. Participants had significantly (P < 0.05) lower MVC and twitch forces postsprint 5 compared with presprint. MVC, voluntary activation, and twitch force were decreased (P < 0.05) postsprint 10 compared with postsprint 5. CONCLUSIONS: The maximal intermittent sprints induced neuromuscular fatigue. Neuromuscular fatigue in the first 5 sprints was mainly peripheral, whereas in the last 5 sprints it was both peripheral and central.

Prepubescent males are less susceptible to neuromuscular fatigue following resistance exercise.

PURPOSE: To determine if prepubescent and adult males have similar fatigue profiles following high and lower intensity knee extensions. METHODS: Ten male children and ten adults completed two sessions of three sets of high repetition (17 typical muscle endurance training) high repetition (High RM) or low repetition (seven typical strength training) maximum (Low RM) dynamic knee extensions. Voluntary and evoked contractile properties, heart rate (HR), and rating of perceived exertion (RPE) were assessed before and after each knee extension RM. RESULTS: Knee extension RM measures revealed that boys performed more (children set 2, 6.7 ± 0.5; set 3, 5.7 ± 0.5 vs. adult set 2, 5.2 ± 0.4; set 3, 3.5 ± 0.5; P < 0.001) repetitions, had a faster (children 39.9 ± 8.6 vs. adult 9.4 ± 3.7 bpm; P < 0.001) HR recovery and lower (6.4 ± 0.43; P < 0.001) RPE compared to adults (8.0 ± 0.4). Post-knee extension measures also revealed a smaller MVC force decrement (P < 0.001) with boys (94.3 % ± 6.1 vs. 76.3 % ± 4.1). Unlike adults, there were no significant decrements to children's evoked contractile properties or EMG. The greater boys' antagonist activation (children 125.7 % ± 9.2 vs. adult: 103.5 % ± 6.7; P < 0.001) post-knee extension would suggest muscle coordination changes as a primary mechanism for MVC force decrements. The lower RPE and similar agonist EMG activity may also indicate an inability of boys to perceive or produce a maximal effort. CONCLUSION: Independent of High or Low RM knee extensions, boys had greater neuromuscular fatigue resistance and recovered faster than adults.

Aerobic activity before and following short-duration static stretching improves range of motion and performance vs. a traditional warm-up.

Many activities necessitate a high degree of static joint range of motion (ROM) for an extended duration. The objective of this study was to examine whether ROM could be improved with a short duration and volume of static stretching within a warm-up, without negatively impacting performance. Ten male recreationally active participants completed 2 separate protocols to examine changes in ROM and performance, respectively, with different warm-ups. The warm-up conditions for the ROM protocol were static stretching (SS), consisting of 6 repetitions of 6 s stretches; 10 min of running prior to the SS (AS); and 5 min of running before and after the SS (ASA). The performance protocol included a control condition of 10 min of running. Measures for the ROM protocol included hip flexion ROM, passive leg extensor tension, and hamstring electromyographic (EMG) activity at pre-warm-up, and at 1, 10, 20, and 30 min post-warm-up. Performance measures included countermovement jump (CMJ) height, reaction time (RT), movement time (MT), and balance at pre-warm-up and at 1 and 10 min post-warm-up. The ASA produced greater ROM overall than the SS and AS conditions (p < 0.0001), persisting for 30 min. There were no significant alterations in passive muscle tension or EMG. For the performance protocol, there were no main effects for condition, but there was a main effect for time, with CMJ height being greater at 1 and 10 min post-warm-up (p = 0.0004). Balance ratios and MT improved at 10 min post-warm-up (p < 0.0001). Results indicate that the ASA method can provide ROM improvements for 30 min with either facilitation or no impairment in performance. This may be especially important for athletes who substitute later into a game with minimal time for a full warm-up.

Direct intracranial extension of malignant eccrine spiradenoma of the face.

UNLABELLED: Malignant eccrine spiradenomas are exceedingly rare tumours. They are aggressive tumours normally arising in long-standing benign eccrine spiradenomas. We present a case of malignant eccrine spiradenoma of the right side of the face with direct intracranial extension without distant metastasis. A 48 years old woman presented with a large exophytic tumour on the right side of her face. Radiological imaging of the head and neck region revealed extensive invasion of the facial tissues around right orbit, maxilla and extension into the middle cranial fossa involving the right temporal lobe. She underwent craniotomy and debulking of the right temporal lobe and biopsy of the facial tumour. Histopathological findings were consistent with malignant eccrine spiradenoma. This is a rare case of facial malignant eccrine spiradenoma with direct intracranial extension with no distant metastasis. A literature search revealed that it is first case to be reported of this kind. KEYWORDS: Eccrine carcinoma; Spiradenoma; Adnexal carcinoma; Malignant eccrine spiradenoma.