The persistence of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) after SARS-CoV-2 infection: A systematic review and meta-analysis.

OBJECTIVES: Long COVID-19 (LC) patients experience a number of chronic idiopathic symptoms that are highly similar to those of post-viral Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). We have therefore performed a systematic review and meta-analysis to determine the proportion of LC patients that satisfy ME/CFS diagnostic criteria. METHODS: Clinical studies published between January 2020 to May 2023 were identified using the PubMed, Web of Science, Embase and CINAHL databases. Publication inclusion/exclusion criteria were formulated using the global CoCoPop framework. Data were pooled using a random-effects model with a restricted maximum-likelihood estimator. Study quality was assessed using the Joanna Briggs Institute critical assessment tool. RESULTS: We identified 13 eligible studies that reported a total of 1,973 LC patients. Our meta-analysis indicated that 51% (95% CI, 42%-60%) of LC patients satisfied ME/CFS diagnostic criteria with fatigue, sleep disruption, and muscle/joint pain being the most common symptoms. Importantly, LC patients also experienced the ME/CFS hallmark symptom, post-exertional malaise. CONCLUSIONS: Our study not only demonstrates that LC patients exhibit similar symptom clusters to ME/CFS, but that approximately half of LC patients satisfy a diagnosis of ME/CFS. Our findings suggest that current ME/CFS criteria could be adapted to the identification of a subset of LC patients that may facilitate the standardized diagnosis, management and the recruitment for clinical studies in the future. DATA AVAILABILITY: Data available upon request.

Anconeus Exertional Compartment Syndrome and Posterolateral Rotatory Elbow Instability: A Clinical Association and Rare Cause of Elbow Pain.

Background: Anconeus compartment syndrome is a rarely reported compartment syndrome in the anconeus muscle compartment of the forearm. It has anatomic and pathophysiological associations with posterolateral rotatory instability (PLRI) of the elbow. Purpose: To present the history, management, and outcomes of 4 patients with anconeus compartment syndrome. Secondary aims were to (1) establish normative anconeus pressures and (2) measure the volume of this compartment with and without PLRI in cadavers. Study Design: Case series; Level of evidence, 4. Methods: Four patients with clinical signs of anconeus compartment syndrome (2 gymnasts, 1 swimmer, and 1 footballer/weightlifter) were identified over a 3-year period (2015-2017 inclusive). Patient history, sporting activity, physical examination, anconeus compartment pressures, and treatment outcomes were recorded. Manometry of the anconeus compartment in 2 healthy male controls was performed to establish normative compartment pressures. Anconeus volumetric anatomy and the effect of creating PLRI on compartment volume was investigated in 4 cadaveric elbows. Results: All 4 patients had microtraumatic PLRI, and 2 patients had anconeus hypertrophy. Anconeus compartment pressures at rest and at 2-minutes postexercise were median 28.0 and 67.5 mm Hg, respectively, in the patients and mean 16.5 and 18 mm Hg, respectively, in the controls. Simultaneous fasciotomy and PLRI reconstructive procedures were performed in 2 patients, with outcomes showing full return to competition. Fasciotomy alone was performed in 2 patients to allow return to competition, with both requiring later reconstruction to address PLRI. Cadaver dissection revealed that the anconeus compartment was extremely small and that creation of PLRI reduced the direct volume of the compartment and increased the distance between the anconeus origin and insertion. Conclusion: Our case series demonstrated that anconeus compartment syndrome can occur in upper limb-dominant athletes in the presence of PLRI and anconeus hypertrophy. Pain is relieved by fasciotomy, but definitive treatment of the underlying instability prevents further symptomatology.

Chronic exertional compartment syndrome of the forearm diagnosed in a wider spectrum of patients and not seldom with a history of the same diagnosis in the lower legs.

Purpose: To identify patient characteristics associated with forearm chronic exertional compartment syndrome (CECS) and to demonstrate the distribution of intramuscular pressure (IMP) values at 1 min postexercise in a cohort of patients with exercise-induced forearm pain. Methods: A consecutive series of 99 patients seeking orthopaedic consultation for chronic exertional forearm pain underwent IMP measurements between 2010 and 2023. The diagnosis of CECS was confirmed (n = 34) or ruled out (n = 65) based on the patient's history, clinical examination and IMP measurements. Results: There were significantly more male patients in the CECS group than in the group of patients where the diagnosis was ruled out. Furthermore, a significantly higher proportion of the CECS patients had been previously treated for CECS of the lower legs. The most common occupation was office worker (21%), followed by craftsperson (18%). The most common main physical activities were strength training (21%) and cycling (15%). The median (range) 1-min postexercise IMP values for patients with CECS were 34 (23-68) mmHg for the flexor compartment and 32 (25-67) mmHg for the extensor compartment. Conclusion: This study demonstrates a more general population of CECS patients compared to previous studies. Notably, more than a fifth of the CECS patients had previously been treated for CECS in the lower legs. Importantly, considering the 95% confidence interval for IMP values in patients without CECS, the most used IMP cutoff value for diagnosing CECS appears to be too high for the forearm compartments. Level of Evidence: Level II.

Hypersensitivity Pneumonitis: An Interesting Case of Acute Shortness of Breath in a Young Patient.

Hypersensitivity pneumonitis (HP) is a rare disease caused by an inflammation of the distal airway caused by an immune response to inhaled allergens. The clinical presentation and radiological and histological findings can overlap with other pulmonary conditions such as idiopathic pulmonary fibrosis. Therefore, it is essential to consider focused assessment for the patient if a diagnosis of HP is suspected. We present a case involving a young female patient who presented with symptoms of cough, flu-like illness, and dyspnea. Subsequent investigations revealed a diagnosis of nonfibrotic HP. The patient experienced acute respiratory failure and was managed with high-flow oxygen therapy. A detailed investigation determined that the patient's prior exposure to pet parrots at home was a significant factor. Following treatment with steroids and counseling regarding the removal of parrots from the home environment, the patient's condition improved, and she was successfully weaned off of oxygen therapy. This case underscores the importance of a comprehensive social history in evaluating common complaints such as dyspnea. The rarity of parrot-induced HP related to the patient's age, and exposure warrants attention.

Towards an understanding of physical activity-induced post-exertional malaise: Insights into microvascular alterations and immunometabolic interactions in post-COVID condition and myalgic encephalomyelitis/chronic fatigue syndrome.

BACKGROUND: A considerable number of patients who contracted SARS-CoV-2 are affected by persistent multi-systemic symptoms, referred to as Post-COVID Condition (PCC). Post-exertional malaise (PEM) has been recognized as one of the most frequent manifestations of PCC and is a diagnostic criterion of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Yet, its underlying pathomechanisms remain poorly elucidated. PURPOSE AND METHODS: In this review, we describe current evidence indicating that key pathophysiological features of PCC and ME/CFS are involved in physical activity-induced PEM. RESULTS: Upon physical activity, affected patients exhibit a reduced systemic oxygen extraction and oxidative phosphorylation capacity. Accumulating evidence suggests that these are mediated by dysfunctions in mitochondrial capacities and microcirculation that are maintained by latent immune activation, conjointly impairing peripheral bioenergetics. Aggravating deficits in tissue perfusion and oxygen utilization during activities cause exertional intolerance that are frequently accompanied by tachycardia, dyspnea, early cessation of activity and elicit downstream metabolic effects. The accumulation of molecules such as lactate, reactive oxygen species or prostaglandins might trigger local and systemic immune activation. Subsequent intensification of bioenergetic inflexibilities, muscular ionic disturbances and modulation of central nervous system functions can lead to an exacerbation of existing pathologies and symptoms.

No signs of mast cell involvement in long-COVID: A case-control study.

Long-COVID caused by SARS-CoV-2 infection has significant and increasing effects on human health worldwide. Although a unifying molecular or biological explanation is lacking, several pathophysiological mechanisms have been proposed. Involvement of mast cells-evolutionary old "multipurpose" innate immune cells-was reported recently in studies of acute infection and post-acute-COVID-19 syndrome. Mast cell activity has been suggested in long-COVID. In this case-control study, we compared data from 24 individuals with long-COVID (according to the NICE criteria) and 24 age- and sex-matched healthy individuals with a history of SARS-CoV-2 infection without developing sequelae. Serum levels of the proteases beta-tryptase (TPSB2) and carboxypeptidase (CPA3), which are mast cell specific, were measured using immunoassays. The values were compared between the two groups and correlated to measures of physical exertional intolerance. TPSB2 and CPA3 levels were median (range) 26.9 (2.0-1000) and 5.8 (1.5-14.0) ng/mL, respectively, in the long-COVID group. The corresponding values in the control group were 10.9 (2.0-1000) (p = 0.93) and 5.3 (3.5-12.9) ng/mL (p = 0.82). No significant correlations between TPSB2 or CPA3 levels and scores on the ten physical subscales of SF-36, 3.1-3.10 were revealed. We found no significant differences in the levels of mast cell activation markers TPSB2 and CPA3 between the long-COVID and control groups and no correlations with proxy markers of exercise intolerance. Mast cell activation does not appear to be part of long-term pathogenesis of long-COVID, at least in the majority of patients.

Diagnostic criteria of forearm Chronic Exertional Compartment Syndrome: A systematic review.

BACKGROUND: Chronic Exertional Compartment Syndrome (CECS) of the forearm is characterized by an increase of the pressure in the forearm compartments during repeated activities. Its diagnosis is challenging because of the lack of clearly established diagnostic criteria. PURPOSE: We aimed to provide a comprehensive description of the diagnostic methods used for CECS of the forearm, to assess if a more effective diagnosis strategy could be identified. METHODS: We used PubMed, Google Scholar, Cochrane Library and Science Direct databases to search articles. We carried out multiple searches using the mesh terms ("Chronic Exertional Compartment Syndrome" OR "Chronic compartment syndrome" OR "Exertional compartment") AND ("forearm" OR "upper limb"). Inclusion criteria were prospective or retrospective studies on CECS of the forearm including case reports. We used PRISMA guidelines. The included studies were critically appraised using GRADE approach. RESULTS: A total of 625 articles were screened and 33 studies were included. It represented 590 patients (505 men and 85 women), with a mean age of 26.6 years old. Among them, 282 competed at an elite level. Motorcycling and motocross were the most frequent sports (66%). Six diagnostic methods were employed. Intra-compartmental pressure (ICP) measurement was the most frequently used method in 26 studies. Magnetic resonance imaging was performed in 9 studies, while electromyography was employed in only 2 studies. One study reported the measurement of grip strength using a manual dynamometer, one study compared forearm circumference before and after effort, and one used myotonometry. Various exercise protocols were observed. Stress-testing using a hand-grip was the most common protocol in 14 studies. Exercise duration varied from 2 min to 60 min. CONCLUSION: Existing data do not provide sufficient evidence to favor an alternative diagnostic method over ICP measurements that should be used cautiously given the absence of formal validation. Non-invasive methods might be easier to use, but should be subjected to further research. LEVEL OF EVIDENCE: III.

Contribution of medical resonance imaging in the return to physical activity after exertional rhabdomyolysis a case report.

INTRODUCTION: Exertional rhabdomyolysis (ER) is the breakdown of muscle cells that occurs after intensive physical activity. Although a cautious and gradual return to physical activity (RTPA) is recommended after an episode of ER, physical sequelae are reported long afterwards. CASE REPORT: We present the case of a 31-year-old untrained amateur runner with no prior medical history who developed heat stroke, ER, and acute kidney failure on the occasion of a half-marathon. Three months later, whereas the patient was symptom-free and CK levels were normal, an MRI revealed typical signs of rhabdomyolysis, which normalized thereafter. DISCUSSION: Given that clinical and biological data inform RTPA decisions, the delay between clinical biological and MRI normalization may cause an RTPA to be initiated prior to full muscle recovery, which could account for the symptoms' prolonged persistence. In sportspeople who have recovered and their CK blood levels are returned to normal, MRI data could defer the RTPA if MRI abnormalities persist or, conversely, give it the green light.

In the event of exertional rhabdomyolysis following a race, the presence of muscular lesions on MRI, even if the patient feels healed and creatine kinase levels have returned to normal, should postpone the return to physical activity.

Exertional Heat Stroke Best Practices in U.S. Emergency Medical Services Guidelines.

BACKGROUND: Exertional heat illnesses (EHIs), specifically exertional heat stroke (EHS), are a top cause of nonaccidental death among U.S. laborers. EHS management requires coordination between Emergency Medical Services (EMS) and workplace officials to implement cold water immersion (CWI) and cool first, transport second (CFTS). OBJECTIVE: The purpose of this article was to quantify and identify existing statewide EMS guidelines, determine whether statewide EHS guidelines improved outcomes for EHIs in laborers, and examine the odds of laborer EHS fatalities when best practices are present in EMS statewide guidelines. METHODS: The Paramedic Protocol Provider database and official EMS websites were examined to determine which U.S. states had statewide EMS guidelines and, for those with statewide guidelines, a two-way χ2 analysis with associated odds ratios examined EHI outcomes. Statewide EMS guidelines underwent content analysis by three independent reviewers regarding EHS best practices. Significance was set a priori at p < 0.05. RESULTS: Among 50 states, the District of Columbia, and Puerto Rico, 57.7% (n = 30) had statewide EMS guidelines and 42.3% (n = 22) did not. There was a significant association for EHI outcome for states recommending CWI as a cooling method vs. those that did not (χ21 = 3.336; p = 0.049). The odds of EHS deaths for laborers were 3.0 times higher if CWI was not included in the EMS guidelines. There was a significant association in EHI outcomes for states without CFTS (χ21 = 5.051; p = 0.017). The odds of laborers dying from EHS were 3.7 times higher in states without CFTS. CONCLUSIONS: Laborers are 3.0 and 3.7 times less likely to die from EHS when statewide EMS guidelines include CWI and CFTS, respectively.

Concurrent Chronic Exertional Compartment Syndrome and Popliteal Artery Entrapment Syndrome.

Exertional leg pain occurs with notable frequency among athletes and poses diagnostic challenges to clinicians due to overlapping symptomatology. In this case report, we delineate the clinical presentation of a young collegiate soccer player who endured two years of progressive bilateral exertional calf pain and ankle weakness during athletic activity. The initial assessment yielded a diagnosis of chronic exertional compartment syndrome (CECS), predicated on the results of compartment testing. However, her clinical presentation was suspicious for concurrent type VI popliteal artery entrapment syndrome (PAES), prompting further radiographic testing of magnetic resonance angiography (MRA). MRA revealed severe arterial spasm with plantarflexion bilaterally, corroborating the additional diagnosis of PEAS. Given the worsening symptoms, the patient underwent open popliteal entrapment release of the right leg. Although CECS and PAES are both known phenomena that are observed in collegiate athletes, their co-occurrence is uncommon owing to their different pathophysiological underpinnings. This case underscores the importance for clinicians to be aware that the successful diagnosis of one condition does not exclude the possibility of a secondary, unrelated pathology. This case also highlights the importance of dynamic imaging modalities, including point-of-care ultrasound, dynamic MRA, and dynamic angiogram.

HMGB1 released from pyroptotic vascular endothelial cells promotes immune disorders in exertional heatstroke.

BACKGROUND AND OBJECTIVE: Exertional heatstroke (EHS) mainly occurs in healthy young people with rapid onset and high mortality. EHS immune disorders can cause systemic inflammatory responses and multiple organ failure; however, the underlying mechanisms remain unclear. As high mobility group box 1 (HMGB1) is a prototypical alarmin that activates inflammatory and immune responses, this study aimed to investigate the effect and mechanism of HMGB1 in the pathogenesis of EHS. METHODS: Peripheral blood mononuclear cell (PBMC) transcriptome sequencing of healthy volunteers, classical heatstroke patients, and EHS patients was performed. A mouse model of EHS was established and murine tissue damage was evaluated by H&E staining. HMGB1 localization and release were visualized using immunofluorescence staining. Human umbilical vein endothelial cells (HUVECs) and THP-1 cells were co-cultured to study the effects of HMGB1 on macrophages. A neutralizing anti-HMGB1 antibody was used to evaluate the efficacy of EHS treatment in mice. RESULTS: Plasma and serum HMGB1 levels were significantly increased in EHS patients or mice. EHS-induced endothelial cell pyroptosis promoted HMGB1 release in mice. HMGB1 derived from endothelial cell pyroptosis enhanced macrophage pyroptosis, resulting in immune disorders under EHS conditions. Administration of anti-HMGB1 markedly alleviated tissue injury and systemic inflammatory responses after EHS. CONCLUSIONS: The release of HMGB1 from pyroptotic endothelial cells after EHS promotes pyroptosis of macrophages and systemic inflammatory response, and HMGB1-neutralizing antibody therapy has good application prospects for EHS.

Improving quality in adult long covid services: Findings from the LOCOMOTION quality improvement collaborative.

The protracted form of COVID-19 known as 'long covid' was first described in 2020. Its symptoms, course and prognosis vary widely; some patients have a multi-system, disabling and prolonged illness. In 2021, ring-fenced funding was provided to establish 90 long covid clinics in England; some clinics were also established in Scotland and Wales. The NIHR-funded LOCOMOTION project implemented a UK-wide quality improvement collaborative involving ten of these clinics, which ran from 2021 to 2023. At regular online meetings held approximately 8-weekly, participants prioritised topics, discussed research evidence and guidelines, and presented exemplar case histories and clinic audits. A patient advisory group also held a priority-setting exercise, participated in quality meetings and undertook a service evaluation audit. The goal of successive quality improvement cycles aimed at changing practice to align with evidence was sometimes hard to achieve because definitive evidence did not yet exist in this new condition; many patients had comorbidities; and clinics were practically constrained in various ways. Nevertheless, much progress was made and a series of 'best practice' guides was produced, covering general assessment and management; breathing difficulties; orthostatic tachycardia and other autonomic symptoms; fatigue and cognitive impairment; and vocational rehabilitation. This paper summarises key findings with the frontline clinician in mind.

Cardiovascular magnetic resonance feature tracking derived strain analysis can predict return to training following exertional heatstroke.

BACKGROUND: Exertional heatstroke (EHS) is increasingly common in young trained soldiers. However, prognostic markers in EHS patients remain unclear. The objective of this study was to evaluate cardiovascular magnetic resonance (CMR) feature tracking derived left ventricle (LV) strain as a biomarker for return to training (RTT) in trained soldiers with EHS. METHODS: Trained soldiers (participants) with EHS underwent CMR cine sequences between June 2020 and August 2023. Two-dimensional (2D) LV strain parameters were derived. At 3 months after index CMR, the participants with persistent cardiac symptoms including chest pain, dyspnea, palpitations, syncope, and recurrent heat-related illness were defined as non-RTT. Multivariable logistic regression analysis was used to develop a predictive RTT model. The performance of different models was compared using the area under curve (AUC). RESULTS: A total of 80 participants (median age, 21 years; interquartile range (IQR), 20-23 years) and 27 health controls (median age, 21 years; IQR, 20-22 years) were prospectively included. Of the 77 participants, 32 had persistent cardiac symptoms and were not able to RTT at 3 months follow-up after experiencing EHS. The 2D global longitudinal strain (GLS) was significantly impaired in EHS participants compared to the healthy control group (-15.8 ± 1.7% vs -16.9 ± 1.2%, P = 0.001), which also showed significant statistical differences between participants with RTT and non-RTT (-15.0 ± 3.5% vs -16.5 ± 1.4%, P < 0.001). 2D-GLS (≤ -15.0%) (odds ratio, 1.53; 95% confidence interval: 1.08, 2.17; P = 0.016) was an independent predictor for RTT even after adjusting known risk factors. 2D-GLS provided incremental prognostic value over the clinical model and conventional CMR parameters model (AUCs: 0.72 vs 0.88, P = 0.013; 0.79 vs 0.88, P = 0.023; respectively). CONCLUSION: Two-dimensional global longitudinal strain (≤ -15.0%) is an incremental prognostic CMR biomarker to predict RTT in soldiers suffering from EHS.

Protection of Parkin over-expression on lung in rats with exertional heat stroke by activating mitophagy.

OBJECTIVE: To investigate the role of Parkin overexpression-induecd mitophagy in alleviating acute lung injury of exertional heat stroke(EHS) rats. METHODS: Eighty SD rats were divided into four groups: Control group (CON group), Control Parkin overexpression group (CON + Parkin group), exertional heat stroke group (EHS group), and exertional heat stroke Parkin overexpression group (EHS + Parkin group). Adeno-associated virus carrying the Parkin gene was intravenously injected into the rats to overexpress Parkin in the lung tissue. An exertional heat stroke rat model was established, and survival curves were plotted. Lung Micro-CT was performed, and lung coefficient and pulmonary microvascular permeability were measured. Enzyme-linked immunosorbent assays(ELISA) were used to determine the levels of interleukin-6(IL-6), interleukin-1ß(IL-1ß), Tumor necrosis factor-α(TNF-α), and reactive oxygen species(ROS). The morphology of mitochondria in type II epithelial cells of lung tissue was observed using transmission electron microscopy. The apoptosis of lung tissue, the level of mitophagy, and the co-localization of Pink1 and Parkin were determined using immunofluorescence. The expression of Pink1, Parkin, MFN2, PTEN-L, PTEN, p62, and microtubule associated protein 1 light chain 3 (LC3) in rat lung tissue was measured by western blot. RESULTS: Compared with the CON group, there were more severe lung injury and more higher levels of IL-6, IL-1ß, TNF-α in EHS rats. Both of the LC3-II/LC3-I ratio and the co-localization of LC3 and Tom20 in the lung tissue of EHS rats decreased. Compared with the EHS group, the survival rate of rats in the EHS + Parkin overexpression group was significantly increased, lung coefficient and pulmonary microvascular permeability were reduced, and pathological changes such as exudation and consolidation were significantly alleviated. The levels of IL-6, IL-1ß, TNF-α, and ROS were significantly decreased; the degree of mitochondrial swelling in type II alveolar epithelial cells was reduced, and no vacuolization was observed. Lung tissue apoptosis was reduced, and the colocalization fluorescence of Pink1 and Parkin, as well as LC3 and Tom20, were increased. The expression of Parkin and LC3-II/LC3-I ratio in lung tissue were both increased, while the expression of P62, Pink1, MFN2, and PTEN-L was decreased. CONCLUSION: Pink1/Parkin-mediated mitophagy dysfunction is one of the mechanisms underlying acute lung injury in rats with EHS, and activation of Parkin overexpression induced-mitophagy can alleviate acute lung injury caused by EHS.

Exploring the risk of heat stress in high school pre-season sports training, Johannesburg, South Africa.

There is growing concern over the increased risk of heat stress induced by the changing climate, with increased global temperatures expected to exacerbate conditions. Heat stress in school sports is a critically understudied research area in South Africa (SA). As demonstrated by several studies conducted in the global north, the stress elicited by meteorological conditions on students participating in physical education lessons and after-school sports activities could have serious consequences on their health. This paper represents the first research in the region to investigate the risk of heat stress to school students during physical activity. Meteorological data were collected at a school in Johannesburg between March and July, which encompasses the seasons of late summer, autumn, and winter. These were inputted into four heat stress indices: Humidex, Heat Index, Wet Bulb Globe Temperature, and the Universal Thermal Climate Index, together with the measured Wet Bulb Temperature to determine the level of risk of heat stress during physical education lessons and after-school sports activities between March and July. Of the 2700 index scores calculated over this period, 56% indicate some level of heat stress, with almost 6% indicating a high and very high level of risk. Heat stress is calculated to be most likely to occur between 11h00-15h00, and the danger of pre-season training, which takes place in the summer months, is demonstrated by these results. Additionally, this research finds that heat stress is far more likely on artificial surfaces than on natural grass. The findings of this research intimate that school stakeholders should consider the implications of heat stress when considering timetabling and policy-making in the interests of safeguarding their students.

Unilateral Diaphragmatic Paralysis: A Case Report of an Often Overlooked Diagnosis.

Unilateral diaphragmatic paralysis, resulting from nerve or muscle injuries, is an uncommon phenomenon often missed due to its asymptomatic nature. This condition can lead to decreased pulmonary function, particularly in patients with underlying comorbidities or cardiopulmonary issues. Identification and understanding of the underlying cause of the paralysis are essential for effective management and improved patient outcomes. Here, we present a case of a 49-year-old male who presented with left flank pain and complained of dyspnea on exertion. Further workup and a sniff test confirmed the diagnosis of left hemidiaphragm paralysis.

Nourishing Physical Productivity and Performance On a Warming Planet - Challenges and Nutritional Strategies to Mitigate Exertional Heat Stress.

PURPOSE OF REVIEW: Climate change is predicted to increase the frequency and severity of exposure to hot environments. This can impair health, physical performance, and productivity for active individuals in occupational and athletic settings. This review summarizes current knowledge and recent advancements in nutritional strategies to minimize the impact of exertional-heat stress (EHS). RECENT FINDINGS: Hydration strategies limiting body mass loss to < 3% during EHS are performance-beneficial in weight-supported activities, although evidence regarding smaller fluid deficits (< 2% body mass loss) and weight-dependent activities is less clear due to a lack of well-designed studies with adequate blinding. Sodium replacement requirements during EHS depends on both sweat losses and the extent of fluid replacement, with quantified sodium replacement only necessary once fluid replacement > 60-80% of losses. Ice ingestion lowers core temperature and may improve thermal comfort and performance outcomes when consumed before, but less so during activity. Prevention and management of gastrointestinal disturbances during EHS should focus on high carbohydrate but low FODMAP availability before and during exercise, frequent provision of carbohydrate and/or protein during exercise, adequate hydration, and body temperature regulation. Evidence for these approaches is lacking in occupational settings. Acute kidney injury is a potential concern resulting from inadequate fluid replacement during and post-EHS, and emerging evidence suggests that repeated exposures may increase the risk of developing chronic kidney disease. Nutritional strategies can help regulate hydration, body temperature, and gastrointestinal status during EHS. Doing so minimizes the impact of EHS on health and safety and optimizes productivity and performance outcomes on a warming planet.

Harlequin syndrome in a patient with probable hemicrania continua and exertional headache - is there a link? a case report.

BACKGROUND: The harlequin syndrome is a rare disorder of the autonomic nervous system characterized by unilateral diminished flushing and sweating of the face following exposure to heat or physical activity. It results from sympathetic dysfunction and most commonly occurs idiopathically. A secondary development due to an underlying pathology (e.g., carotid artery dissection, tumors) must be excluded at first appearance. There is evidence that the cranial autonomic system is involved in the pathophysiology of trigeminal autonomic headaches like hemicrania continua. Therefore, an overlap in the pathophysiology of harlequin syndrome and trigeminal autonomic headache disorders seems plausible. However, the association of a harlequin syndrome with hemicrania continua was never reported. CASE PRESENTATION: This work describes the case of a 42-year-old female patient presenting to our headache unit. The patient reported persisting unilateral headache of the right side of dragging or squeezing character accompanied by trigeminal autonomic symptoms, including lacrimation, nasal congestion, conjunctival injection and Horner's syndrome, and was responsive to treatment with 75mg/d indomethacin. Five months after the initial consultation, the patient noted that the upper right quadrant of her face was pale after jogging. A harlequin syndrome was diagnosed. Further, she developed a short-lasting, bilateral headache of pulsatile character during strenuous exercise consistent with exertional headache. Comprehensive diagnostic evaluations, encompassing cranial and cervical MRI scans, laboratory tests, and biopsies, culminated in the diagnosis of Sjögren's syndrome. This finding suggests that the trigemino-autonomic dysfunction may either be idiopathic or a direct manifestation of Sjögren's syndrome. CONCLUSIONS: This report documents the case of a rare combination of a headache resembling probable hemicrania continua and the harlequin syndrome (and even exertional headache). It illustrates the underlying anatomy of the autonomic nervous system in a clinical context and emphasizes the hypothesis of a pathophysiological link between abnormal sympathetic activity and trigeminal autonomic headaches.

Parade safety and planning: A heat balance case study of marching band artists.

Marching band (MB) artists are subject to exertional heat illnesses (EHIs) similar to other active groups like laborers and athletes. Yet, they are an understudied population with no evidence-based heat safety guidelines. Presented here is a case study of the 233rd annual Bristol, RI Independence Day Parade in 2018 that resulted in over 50 EHIs, including 25 from the Saint Anthony Village marching band (MB) from suburban Minneapolis, MN. This research aims to identify the contributing factors that led to the large number of EHIs, as well as guide ensuring the safety of MB artists in future events. A human heat balance model in conjunction with local weather data was used to simulate heat stress on MB artists. Three modeling scenarios were used to isolate the roles of clothing (band uniform vs. t-shirt and shorts), weather (July 4, 2018 vs. 30-year climatology), and metabolic rate (slow, moderate, and brisk marching pacing) on heat stress. The results identify several key factors that increased heat stress. The meteorological conditions were unusually hot, humid, and sunny for Bristol, resulting in reduced cooling from evaporation and convection, and increased radiant heating. Behavioral factors also affect heat stress. The full marching band uniforms reduced evaporative cooling by 50% and the activity levels of marching 4 km over several hours without breaks resulted in conditions that were uncompensable. Finally, it is speculated that a lack of acclimatization for participants from cooler regions may have exacerbated heat-related impacts. These findings highlight several recommendations for MB directors and race organizers, including the use of summer uniforms for anticipated hot conditions, and advance parade planning that includes providing shade/hydration before and after the parade for participants, considering cooler routes that reduce radiant heating and preparing for anticipated heat-related health impacts appropriate for anticipated hot conditions.