Updated beliefs and shaken confidence: evidence from vaccine hesitancy caused by experiencing "COVID arm".

BACKGROUND: Public health depends largely on people's knowledge, beliefs, or behaviors regarding their health and medical treatments. Although works based on the health belief model have shown that public beliefs about medical treatments affect willingness to take the treatments, little is known about the effects of changes in beliefs on attitudes toward treatment. How one's past experiences relate to one's beliefs about a given medical treatment is worth considering. METHODS: We implemented an online panel survey in February 2021 and March 2022 in Japan before and after COVID-19 vaccines were administered to the public within the country. We exploited delayed localized hypersensitivity reactions to COVID-19 vaccines, namely, "COVID arm", as an exogenous shock to investigate the relationship between past negative experiences and current beliefs about medical treatments or science. "COVID arm" was an unexpected side effect and thus likely caused updated beliefs about the vaccine. Out of the nonprobability sample of 15,000 respondents in the first wave in February 2021, 9,668 respondents also responded to the second wave conducted in March 2022. Outcome variables were whether experiencing "COVID arm" affected the respondents' 1) confidence in vaccine safety, 2) willingness to take the next dose of COVID-19 vaccines, 3) acknowledgment of the importance of vaccination, and 4) confidence in science. We measured the impact of experience with "COVID arm" on changes in the probability that survey respondents would respond affirmatively to questions posed about the issues listed above. RESULTS: Experiencing "COVID arm" significantly lowered confidence in the safety of vaccination by 4.3 percentage points, which was approximately 6% of the sample mean for the first wave, and lowered the probability of taking a second dose of the COVID-19 vaccine by 1.5 percentage points. These adverse impacts were observed after conditioning background characteristics and prior confidence in vaccination. Experiencing "COVID arm" affected neither the acknowledged importance of vaccination nor confidence in science in a statistically significant way. CONCLUSIONS: An unexpected and uncomfortable shock regarding beliefs about a treatment decreases willingness to take the treatment. An appropriate public health policy should account for this effect. TRIAL REGISTRATION: The survey was preregistered with the American Economic Association's RCT Registry (Fukai et al., 2022).

Non-Fatal Strangulation/Choking During Sex and Its Associations with Mental Health: Findings from an Undergraduate Probability Survey.

Choking/strangulation during sex is prevalent among young adults in the United States. We examined associations between having ever been choked and participants' current mental health symptoms (e.g., feeling depressed, anxious, sad, lonely) in the prior 30 days and in the prior year. Participants were 4352 randomly sampled undergraduates who completed a confidential online survey and reported lifetime partnered sexual activity. 33.6% of women and 6.0% of men reported having been choked more than five times. After adjusting for demographic characteristics, having been choked remained significantly associated with all four mental health outcomes, except for overwhelming anxiety among men.

Frequency, Method, Intensity, and Health Sequelae of Sexual Choking Among U.S. Undergraduate and Graduate Students.

Although sexual choking is now prevalent, little is known about how people engage in choking in terms of frequency, intensity, method, or potential health sequelae. In a campus-representative survey of undergraduate and graduate students, we aimed to: (1) describe the prevalence of ever having choked/been choked as part of sex; (2) examine the characteristics of choking one's sexual partners (e.g., age at first experience, number of partners, frequency, intensity, method); (3) examine the characteristics of having been choked during sex; and (4) assess immediate responses of having been choked including the extent to which frequency and method (e.g., hand, ligature, limb) of having been choked predicts the range of responses endorsed by participants. A total of 4254 randomly sampled students (2668 undergraduate, 1576 graduate) completed a confidential online survey during Spring 2021. The mean age of first choking/being choked was about 19, with more undergraduates than graduate students reporting first choking/being choked in adolescence. Women and transgender/gender non-binary participants were significantly more likely to have been choked than men. Participants more often reported the use of hands compared to limbs or ligature. Common responses to being choked were pleasurable sensations/euphoria (81.7%), a head rush (43.8%), feeling like they could not breathe (43.0%), difficulty swallowing (38.9%), unable to speak (37.6%), and watery eyes (37.2%). About 15% had noticed neck bruising and 3% had lost consciousness from being choked. Greater frequency and intensity of being choked was associated with reports of more physical responses as was use of limb (arm, leg) or ligature.

Short-Term Neurologic Manifestations of Repetitive Head Impacts Among Athletes: A Scoping Review.

OBJECTIVE: To summarize the evidence linking contact sports-related repetitive head impacts (RHIs) and short-term declines in neurologic function. METHODS: A scoping review following the guidelines in the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) and searching 3 databases (PubMed, EMBASE, and Web of Science) was performed. Peer-reviewed research articles were eligible for inclusion if they were full-length English language articles published between 1999 and 2019 examining athletes between the ages of 14 and 40 years exposed to RHIs, and reporting cognitive, vestibular, and/or oculomotor outcomes within 4 weeks of last head hit exposure. RESULTS: Fifty-two articles met criteria for review: 14 reported oculomotor outcomes, 23 reported vestibular outcomes, and 36 reported cognitive function. Short-term RHI-related declines in neurologic function were reported in 42.9% of oculomotor studies, in 20.8% of vestibular studies, and in 33.3% of cognitive studies. Most of the 52 studies involved American football, soccer, or ice hockey athletes at the collegiate ( n = 23) or high school ( n = 14) level. Twenty-four (46%) studies involved only male athletes. Wearable sensors were used to measure RHIs in 24 studies (46%), while RHIs were not measured in 26 studies (50%). In addition, many studies failed to control for attention-deficit/hyperactivity disorder/learning disability and/or concussion history. CONCLUSION: The results of this scoping review suggest that the evidence linking RHIs to short-term declines in neurologic function is relatively sparse and lacking in methodological rigor. Although most studies failed to find a link, those that did were more likely to use objective measures of RHIs and to control for confounders. More careful trial design may be needed to definitively establish a causal link between RHIs and short-term neurologic dysfunction.

Prevalence of Acute Neck Pain Following Sports-Related Concussion in High School Athletes.

OBJECTIVES: To explore the prevalence of acute neck pain in high school athletes following sports-related concussion (SRC) and to examine the role of acute neck pain in modifying or amplifying concurrent concussive symptoms. DESIGN: Retrospective observational. SETTING: High school sporting events. PARTICIPANTS: High school athletes who suffered a sports-related concussion between the 2011 and 2019 academic years academic years from the National Athletic Treatment, Injury and Outcomes Network (NATION) Study. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Prevalence of neck pain (yes/no) along with 33 other commonly reported concussion symptoms, number of symptoms reported, mechanism of injury (contact with person/surface or object), sport type (contact/noncontact), and injury history (first time/repeated injury). RESULTS: One hundred thirty-eight of 401 athletes (33.9%) indicated acute neck pain following SRC. Those with neck pain reported significantly more symptoms overall (M = 13.53, SD = 6.89) relative to their non-neck pain counterparts (M = 8.46, SD = 5.68; t [191.35] = 7.11, P < 0.001). Athletes with SRC due to contact with a surface were significantly less likely to report neck pain than those reported contact with a person. Neck pain, repeated injury, and female sex were significantly associated with a greater number of concussion symptoms in the acute phase. CONCLUSIONS: Our data suggest that acute neck pain is a frequent acute symptom following SRC and signals the necessity for additional screening to seek and identify comorbid cervical pathology. Prospective studies should seek to access the benefit of cervical therapy in the early stages in SRC patients with neck pain to reduce the risk of persistent postconcussion symptoms.

Acute Time-Course Changes in CCL11, CCL2, and IL-10 Levels After Controlled Subconcussive Head Impacts: A Pilot Randomized Clinical Trial.

OBJECTIVE: To examine changes in plasma levels of CCL11, CCL2, and IL-10 after 10 controlled soccer headers. SETTING: Laboratory setting. PARTICIPANTS: Thirty-nine healthy soccer players with at least 3 years of soccer heading experience, between 18 and 26 years old, and enrolled at a large public university. DESIGN: In this randomized clinical trial using a soccer heading model, participants were randomized into the heading (n = 22) or kicking-control (n = 17) groups to perform 10 headers or kicks. MAIN MEASURES: Plasma levels of CCL11, CCL2, and IL-10 at preintervention and 0, 2, and 24 hours postintervention. RESULTS: Mixed-effects regression models did not reveal any significant group differences in changes of plasma CCL11, CCL2, or IL-10 levels from preintervention. Within the heading group, there was a statistically significant time by years of heading experience interaction with 2.0-pg/mL increase in plasma CCL11 each year of prior experience at 24 hours postintervention (P = .001). CONCLUSION: Findings from this study suggest that 10 soccer headers do not provoke an acute inflammatory response. However, the acute CCL11 response may be influenced by prior exposure to soccer headers, providing a precedent for future field studies that prospectively track head impact exposure and changes in CCL11.

Association between Muscle Damage and Head Impacts in High School American Football.

Subconcussive head impacts (SHI), defined as impacts to the cranium that do not result in concussion symptoms, are gaining traction as a major public health concern. The contribution of physiological factors such as physical exertion and muscle damage to SHI-dependent changes in neurological measures remains unknown. A prospective longitudinal study examined the association between physiological factors and SHI kinematics in 15 high school American football players over one season. Players wore a sensor-installed mouthguard for all practices and games, recording frequency and magnitude of all head impacts. Serum samples were collected at 12 time points (pre-season, pre- and post-game for five in-season games, and post-season) and were assessed for an isoenzyme of creatine kinase (CK-MM) primarily found in skeletal muscle. Physical exertion was estimated in the form of excess post-exercise oxygen consumption (EPOC) from heart rate data captured during the five games. Mixed-effect regression models indicated that head impact kinematics were significantly and positively associated with change in CK-MM but not EPOC. There was a significant and positive association between CK-MM and EPOC. These data suggest that when examining SHI, effects of skeletal muscle damage should be considered when using outcome measures that may have an interaction with muscle damage.

Clinical Changes in Cervical Neuromuscular Control Following Subconcussive Impacts.

CONTEXT: Increased injury rates following concussive injury have been attributed to decreased neuromuscular coordination frequently documented following a concussion. However, altered integration between the vestibular system and oculomotor pathways following impacts at subconcussive thresholds implicate all sports-related impacts not just those at a concussive threshold in future musculoskeletal injury. While, several studies have explored the utility of vestibular and oculomotor clinical testing to detect altered neuromuscular control and then correlated those alterations to future injury risk, no research has explored the use of cervical clinical tests in the same capacity. OUTCOME MEASURES: Cervical joint position error test, Neck Disability Index and head acceleration. INTERVENTIONS: Soccer headers, fatigue protocol, soccer headers + fatigue. OBJECTIVE: To explore the clinical utility of a novel clinical approach to measuring changes in cervical neuromuscular control following subconcussive impacts in a controlled lab environment. PARTICIPANTS: 40 current female colligate club soccer athletes were recruited. Inclusion criteria included between the age of 18 and 25 and a minimum of 4-year soccer heading experience. SETTING: Laboratory.  Design: A repeated-measures design with 4 groups was utilized to test the hypothesis. RESULTS: A 65%, 54%, and 49% increased error was observed following the soccer heading, fatigue only, and soccer heading + fatigue interventions, respectively. Meanwhile, the controls saw a 6% decrease in neck position error. Concussion: While, cervical joint position error testing was sensitive to decreased neuromuscular coordination following soccer heading, it was not specific enough to rule out an exercise effect in the absence of subconcussive impacts. Further research is warranted to explore the clinical utility and specificity of cervical joint position error testing to measured alterations in supraspinal processing following subconcussive impacts, and how these alterations may lead to decreased coordination and movement of the body during sports-related task.

NFL blood levels are moderated by subconcussive impacts in a cohort of college football players.

INTRODUCTION: Repetitive subconcussive head impacts in contact/collision sports such as in US football are believed to contribute to long-term brain changes and chronic symptoms. However, the lack of tools to measure the effects of repeated subconcussion limits our understanding of potential contributions to neuropathological alterations including cellular damage. METHODS: We examined subconcussive head impacts using an accelerometer-embedded mouthguard on changes in blood levels of neurofilament light (NFL) chain in 18 Division I college football players. Plasma levels of NFL and clinical symptoms were assessed at pre-post practices. The frequency and linear and rotational head accelerations recorded via the mouthguard were examined in relation to NFL plasma changes. RESULTS: The frequency and magnitude of head impacts associated with increased NFL levels. The greater numbers of hits and head accelerations associated with greater pre- to post-practice NFL level increases (p < 0.05). Greater pre- to post-practice increases in NFL also associated with greater pre- to post-practice increases in S100ß (p < 0.001), but not with total tau. Years of football experience and concussion history did not associate with changes in NFL. CONCLUSION: Acute changes in NFL may be a clinically useful peripheral marker in tracking acute brain damage in collegiate football players, and other contact sports.

Measuring the impact of modern waste collection and processing service attributes on residents' acceptance of waste separation policy using a randomised conjoint field experiment in Yogyakarta Province, Indonesia.

Indonesia is one of the countries that is facing serious solid waste problems. Although the issue has been addressed in the capital city of Jakarta, many secondary cities have been left behind. This research attempts to analyse the impact of relevant waste management policy components on respondents' policy acceptance probabilities in Yogyakarta Province. Using a randomised conjoint field experiment based on the proposal of modern waste collection services, this article shows that a new waste management policy that includes waste separation with frequent organic waste collection will gain popular support, especially with the rich. Indeed, if the government introduces waste collection and processing services that consist of the most preferred levels of these attributes, including five-times-a-week organic waste collection, a majority of the residents will support this new waste management policy, which will reduce waste at its source.

An approach for the analysis of axonal neuroinflammation by measuring dual biomarkers of oligodendrocytes and inflammatory cytokine in human plasma.

The myelin sheath surrounding axons is vulnerable to mechanical stresses after head injuries, as well as autoimmune attacks and degeneration in neurological disorders. Unfortunately, there is currently no effective method to assess these axonal conditions in individual patients. We have developed a sandwich immunoassay detecting dual signals of myelin oligodendrocyte glycoprotein (MOG) and interleukin 1B (IL1B) in human plasma ([IL1B on MOG]). While IL1B is one of common inflammation markers, its lack of tissue specificity is addressed by identifying IL1B on extracellular vesicles from oligodendrocytes isolated using anti-MOG, suggesting inflammation around axons. In 77 control subjects, plasma levels of [IL1B on MOG] did not increase more than 2 fold from baseline. During the sports season, 14% (151 football players) and 22% (18 rugby players) exhibited a substantial 2-17 fold increase, despite the absence of traumatic brain injuries. This elevation demonstrated a non-random pattern, with some individuals gradually rising towards the season's end, followed by a decline. [IL1B on MOG] levels also correlated with the clinical course of a post-concussion syndrome case. These data indicate that [IL1B on MOG] blood test is a potential marker for assessing mild axonal neuroinflammation.

Effectiveness of biomedical interventions on the chronic stage of traumatic brain injury: a systematic review of randomized controlled trials.

Traumatic brain injury (TBI), in any form and severity, can pose risks for developing chronic symptoms that can profoundly hinder patients' work/academic, social, and personal lives. In the past 3 decades, a multitude of pharmacological, stimulation, and exercise-based interventions have been proposed to ameliorate symptoms, memory impairment, mental fatigue, and/or sleep disturbances. However, most research is preliminary, thus limited influence on clinical practice. This review aims to systematically appraise the evidence derived from randomized controlled trials (RCT) regarding the effectiveness of pharmacological, stimulation, and exercise-based interventions in treating chronic symptoms due to TBI. Our search results indicate that despite the largest volume of literature, pharmacological interventions, especially using neurostimulant medications to treat physical, cognitive, and mental fatigue, as well as daytime sleepiness, have yielded inconsistent results, such that some studies found improvements in fatigue (e.g., Modafinil, Armodafinil) while others failed to yield the improvements after the intervention. Conversely, brain stimulation techniques (e.g., transcranial magnetic stimulation, blue light therapy) and exercise interventions were effective in ameliorating mental health symptoms and cognition. However, given that most RCTs are equipped with small sample sizes, more high-quality, larger-scale RCTs is needed.

Associations between repetitive head impact exposure and midlife mental health wellbeing in former amateur athletes.

Introduction: Repetitive head impacts (RHI) have been suggested to increase the risk of developing a neurodegenerative disease, and many of these individuals develop a preceding mental health diagnosis. Given the lack of studies among amateur athletes, this study aimed to examine mental health outcomes in middle-aged amateur athletes who have been exposed to RHI through contact sport participation. Methods: This is a single site, cohort study involving former amateur athletes aged between 30 and 60 with at least 10 years of organized contact or non-contact sport participation. All participants completed demographic and mental health questionnaires. Mental health outcomes included symptoms related to depression, anxiety, post-traumatic stress disorder (PTSD), attention deficit hyperactive disorder (ADHD), and aggression. Self-reported data on mental health diagnoses and associated prescription were elicited and used to estimate odds ratios (OR). Results: Data from 41 contact athletes and 22 age/sex-matched non-contact athletes were available for analysis. The contact group exhibited a 2.25-fold higher likelihood of being diagnosed with mental health disorders and 1.29-fold higher likelihood of using associated medications compared to the non-contact group. The contact group reported significantly higher PTSD-related symptoms [4.61 (0.03,9.2), p=0.05] compared to the non-contact control group. While not statistically significant, the contact group showed increased depressive [2.37 (0.05, 4.79), p=0.07] and ADHD symptoms [4.53 (0.51, 9.57), p=0.08] compared to controls. In a secondary analysis, a distinct trend emerged within the contact group, revealing pronounced elevations in mental health symptoms among individuals with lower socioeconomic status (<$50,000/year) compared to higher income subgroups, and these symptoms decreased as income levels rose [depression: -3.08 (-4.47, -1.7), p<0.001; anxiety: -1.95 (-3.15, -0.76), p=0.002; ADHD: -4.99 (-8.28, -1.69), p=0.004; PTSD: -4.42 (-7.28, -1.57), p=0.003; aggression: -6.19 (-11.02, -1.36), p=0.01]. This trend was absent in the non-contact control group. Discussion: Our data suggest that even individuals at the amateur level of contact sports have an increased likelihood of being diagnosed with mental health disorders or experiencing mental health symptoms compared to non-contact athletes. Our findings indicate that socioeconomic status may have an interactive effect on individuals' mental health, particularly among those with a long history of RHI exposure.

A Pilot Study Investigating the Use of Serum Glial Fibrillary Acidic Protein to Monitor Changes in Brain White Matter Integrity After Repetitive Head Hits During a Single Collegiate Football Game.

Repetitive head hits (RHHs) in sports and military settings are increasingly recognized as a risk factor for adverse neurological outcomes, but they are not currently tracked. Blood-based biomarkers of concussion have recently been shown to increase after nonconcussive RHHs during a single sporting contest, raising the possibility that they could be used in real time to monitor the brain's early response to repeated asymptomatic head hits. To test this hypothesis, we measured GFAP in serum immediately before (T0), immediately after (T1) and 45 min (T2) after a single collegiate football game in 30 athletes. Glial fibrillary acidic protein (GFAP) changes were correlated with three measures of head impact exposure (number of hits, total linear acceleration, and total rotational acceleration captured by helmet impact sensors) and to changes in brain white matter (WM) integrity, estimated by regional changes in fractional anisotropy (FA) and mean diffusivity (MD) on diffusion tensor imaging from 24 h before (T1) to 48 h after (T3) the game. To account for the potentially confounding effects of physical exertion on GFAP, correlations were adjusted for kilocalories of energy expended during the game measured by wearable body sensors. All 30 participants were male with a mean age of 19.5 ± 1.2 years. No participant had a concussion during the index game. We observed a significant increase in GFAP from T0 to T1 (mean 79.69 vs. 91.95 pg/mL, p = 0.008) and from T0 to T2 (mean 79.69 vs. 99.21 pg/mL, p < 0.001). WM integrity decreased in multiple WM regions but was statistically significant in the right fornix (mean % FA change -1.43, 95% confidence interval [CI]: -2.20, -0.66). T0 to T2 increases in GFAP correlated with reduced FA in the left fornix, right fornix, and right medical meniscus and with increased MD in the right fornix (r-values ranged from 0.59 to 0.61). Adjustment for exertion had minimal effect on these correlations. GFAP changes did not correlate to head hit exposure, but after adjustment for exertion, T0 to T2 increases correlated with all three hit metrics (r-values ranged from 0.69 to 0.74). Thus, acute elevations in GFAP after a single collegiate football game of RHHs correlated with in-game head hit exposure and with reduced WM integrity 2 days later. These results suggest that GFAP may be a biologically relevant indicator of the brain's early response to RHHs during a single sporting event. Developing tools to measure the neurological response to RHHs on an individual level has the potential to provide insight into the heterogeneity in adverse outcomes after RHH exposure and for developing effective and personalized countermeasures. Owing to the small sample size, these findings should be considered preliminary; validation in a larger, independent cohort is necessary.

Cerebral Cortical Surface Structure and Neural Activation Pattern Among Adolescent Football Players.

Importance: Recurring exposure to head impacts in American football has garnered public and scientific attention, yet neurobiological associations in adolescent football players remain unclear. Objective: To examine cortical structure and neurophysiological characteristics in adolescent football players. Design, Setting, and Participants: This cohort study included adolescent football players and control athletes (swimming, cross country, and tennis) from 5 high school athletic programs, who were matched with age, sex (male), and school. Neuroimaging assessments were conducted May to July of the 2021 and 2022 seasons. Data were analyzed from February to November 2023. Exposure: Playing tackle football or noncontact sports. Main Outcomes and Measures: Structural magnetic resonance imaging (MRI) data were analyzed for cortical thickness, sulcal depth, and gyrification, and cortical surface-based resting state (RS)-functional MRI analyses examined the amplitude of low-frequency fluctuation (ALFF), regional homogeneity (ReHo), and RS-functional connectivity (RS-FC). Results: Two-hundred seventy-five male participants (205 football players; mean [SD] age, 15.8 [1.2] years; 5 Asian [2.4%], 8 Black or African American [3.9%], and 189 White [92.2%]; 70 control participants; mean [SD] age 15.8 [1.2] years, 4 Asian [5.7], 1 Black or African American [1.4%], and 64 White [91.5%]) were included in this study. Relative to the control group, the football group showed significant cortical thinning, especially in fronto-occipital regions (eg, right precentral gyrus: t = -2.24; P = .01; left superior frontal gyrus: -2.42; P = .002). Elevated cortical thickness in football players was observed in the anterior and posterior cingulate cortex (eg, left posterior cingulate cortex: t = 2.28; P = .01; right caudal anterior cingulate cortex 3.01; P = .001). The football group had greater and deeper sulcal depth than the control groups in the cingulate cortex, precuneus, and precentral gyrus (eg, right inferior parietal lobule: t = 2.20; P = .004; right caudal anterior cingulate cortex: 4.30; P < .001). Significantly lower ALFF was detected in the frontal lobe and cingulate cortex of the football group (t = -3.66 to -4.92; P < .01), whereas elevated ALFF was observed in the occipital regions (calcarine and lingual gyrus, t = 3.20; P < .01). Similar to ALFF, football players exhibited lower ReHo in the precentral gyrus and medial aspects of the brain, such as precuneus, insula, and cingulum, whereas elevated ReHo was clustered in the occipitotemporal regions (t = 3.17; P < .001; to 4.32; P < .01). There was no group difference in RS-FC measures. Conclusions and Relevance: In this study of adolescent athletes, there was evidence of discernible structural and physiological differences in the brains of adolescent football players compared with their noncontact controls. Many of the affected brain regions were associated with mental health well-being.

Association Between Serum Neurofilament Light and Glial Fibrillary Acidic Protein Levels and Head Impact Burden in Women's Collegiate Water Polo.

Recent investigations have identified water polo athletes as at risk for concussions and repetitive subconcussive head impacts. Head impact exposure in collegiate varsity women's water polo, however, has not yet been longitudinally quantified. We aimed to determine the relationship between cumulative and acute head impact exposure across pre-season training and changes in serum biomarkers of brain injury. Twenty-two Division I collegiate women's water polo players were included in this prospective observational study. They wore sensor-installed mouthguards during all practices and scrimmages during eight weeks of pre-season training. Serum samples were collected at six time points (at baseline, before and after scrimmages during weeks 4 and 7, and after the eight-week pre-season training period) and assayed for neurofilament light (NfL) and glial fibrillary acidic protein (GFAP) using Simoa® Human Neurology 2-Plex B assay kits. Serum GFAP increased over time (e.g., an increase of 0.6559 pg/mL per week; p = 0.0087). Neither longitudinal nor acute pre-post scrimmage changes in GFAP, however, were associated with head impact exposure. Contrarily, an increase in serum NfL across the study period was associated with cumulative head impact magnitude (sum of peak linear acceleration: B = 0.015, SE = 0.006, p = 0.016; sum of peak rotational acceleration: B = 0.148, SE = 0.048, p = 0.006). Acute changes in serum NfL were not associated with head impacts recorded during the two selected scrimmages. Hormonal contraceptive use was associated with lower serum NfL and GFAP levels over time, and elevated salivary levels of progesterone were also associated with lower serum NfL levels. These results suggest that detecting increases in serum NfL may be a useful way to monitor cumulative head impact burden in women's contact sports and that female-specific factors, such as hormonal contraceptive use and circulating progesterone levels, may be neuroprotective, warranting further investigations.

Structural brain morphology in young adult women who have been choked/strangled during sex: A whole-brain surface morphometry study.

INTRODUCTION: Being choked/strangled during partnered sex is an emerging sexual behavior, particularly prevalent among young adult women. Using a multiparameter morphometric imaging approach, we aimed to characterize neuroanatomical differences between young adult women (18-30 years old) who were exposed to frequent sexual choking and their choking naïve controls. METHODS: This cross-sectional study consisted of two groups (choking [≥4 times in the past 30 days] vs. choking-naïve group). Participants who reported being choked four or more times during sex in the past 30 days were enrolled in the choking group, whereas those without were assigned to the choking naïve group. High-resolution anatomical magnetic resonance imaging (MRI) data were analyzed using both volumetric features (cortical thickness) and geometric features (fractal dimensionality, gyrification, sulcal depth). RESULTS: Forty-one participants (choking n = 20; choking-naïve n = 21) contributed to the final analysis. The choking group showed significantly increased cortical thickness across multiple regions (e.g., fusiform, lateral occipital, lingual gyri) compared to the choking-naïve group. Widespread reductions of the gyrification were observed in the choking group as opposed to the choking-naïve group. However, there was no group difference in sulcal depth. The fractal dimensionality showed bi-directional results, where the choking group exhibited increased dimensionality in areas including the postcentral gyrus, insula, and fusiform, whereas decreased dimensionality was observed in the bilateral superior frontal gyrus and pericalcarine cortex. CONCLUSION: These data in cortical morphology suggest that sexual choking events may be associated with neuroanatomical alteration. A longitudinal study with multimodal assessment is needed to better understand the temporal ordering of sexual choking and neurological outcomes.

Association of Frequent Sexual Choking/Strangulation With Neurophysiological Responses: A Pilot Resting-State fMRI Study.

Being choked or strangled during partnered sex is an emerging sexual behavior, prevalent among young adult women. The goal of this study was to test whether, and to what extent, frequently being choked or strangled during sex is associated with cortical surface functioning and functional connectivity. This case-control study consisted of two groups (choking vs. choking-naïve). Women who were choked 4 or more times during sex in the past 30 days were enrolled into the choking group, whereas those without were assigned to the choking-naïve group. We collected structural and resting-state functional magnetic resonance imaging (fMRI) data and analyzed the data for amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo) using cortical surface-based resting-state fMRI analysis, followed by static and dynamic resting-state fMRI connectivity analysis. Forty-one participants (choking n = 20; choking-n-aïve n = 21) contributed to the analysis. An inter-hemispheric imbalance in neuronal activation pattern was observed in the choking group. Specifically, we observed significantly lower ALFF and ReHo in the left cortical regions (e.g., angular gyrus, orbitofrontal gyrus) and higher ALFF and ReHo in the right cortical regions (e.g., pre-central/post-central gyri) in the choking group compared with the choking-naïve group. A significant group difference was found in static functional connectivity between the bilateral angular gyrus and the whole brain, in which the choking group's angular gyrus showed hyperconnectivity with, for example, the post-central gyrus, pre-central gyrus, and Rolandic operculum, relative to the choking-naïve group. The dynamic analysis revealed hyperconnectivity between the left angular gyrus and the bilateral postcentral gyrus in the choking group compared with the choking-naïve group. Taken together, our data show that multiple experiences of sexual choking/strangulation are associated with an inter-hemispheric imbalance in neural activation pattern and hyperconnectivity between the angular gyrus and brain regions related to motor control, consciousness, and emotion. A longitudinal study using multi-modal neurological assessments is needed to clarify the acute and chronic consequences of sexual choking/strangulation.

Effects of Physical Exertion on Early Changes in Blood-Based Brain Biomarkers: Implications for the Acute Point of Care Diagnosis of Concussion.

Blood-based brain biomarkers (BBM) such as glial fibrillary acidic protein (GFAP) and ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) have potential to aid in the diagnosis of concussion. Recently developed point-of-care test devices would enable BBMs to be measured in field settings such military and sport environments within minutes of a suspicious head hit. However, head hits in these environments typically occur in the setting of vigorous physical exertion, which can itself increase BBMs levels. Thus, efforts to develop BBMs as acute concussion aids in field settings need to account for the effects of physical exertion. To determine the acute effects of physical exertion on the BBMs, we measured GFAP, UCH-L1, tau, and neurofilament light chain (NF-L) immediately before, immediately after, and 45 min after a single workout session consisting of aerobic and resistance exercises in 30 collegiate football players. Subjects wore body sensors measuring several aspects of exertion and underwent diffusion tensor imaging 24 h before and 48 h after exertion. All subjects were male with a mean age of 19.5 ± 1.2 years. The mean duration of activity during the workout session was 94 ± 31 min. There was a significant decrease in serum GFAP immediately after (median decrease of 27.76%, p < 0.0001) and a significant increase in serum UCH-L1 45 min after (median increase of 37.11%, p = 0.016) exertion, compared with pre-exertion baseline. No significant changes in tau or NF-L were identified. The duration of exertion had a significant independent linear correlation to the increase in serum UCHL1 from pre-exertion to 45 min after exertion (r = 0.68, p = 0.004). There were no significant pre- to post-exertional changes in any of the 39 examined brain white matter regions, and biomarker changes did not correlate to variation in white matter integrity in any of these regions. Thus, exertion appeared to be associated with immediate decreases in serum GFAP and very acute (45 min) increases in UCH-L1. These changes were related to the duration of exertion, but not to changes in brain white matter integrity. Our results have important implications for how these BBMs might be used to aid in the on-scene diagnosis of concussion occurring in the setting of physical exertion.

Blood biomarkers of neuronal injury in paediatric cerebral malaria and severe malarial anaemia.

Persistent neurodisability is a known complication in paediatric survivors of cerebral malaria and severe malarial anaemia. Tau, ubiquitin C-terminal hydrolase-L1, neurofilament-light chain, and glial fibrillary acidic protein have proven utility as biomarkers that predict adverse neurologic outcomes in adult and paediatric disorders. In paediatric severe malaria, elevated tau is associated with mortality and neurocognitive complications. We aimed to investigate whether a multi-analyte panel including ubiquitin C-terminal hydrolase-L1, neurofilament-light chain, and glial fibrillary acidic protein can serve as biomarkers of brain injury associated with mortality and neurodisability in cerebral malaria and severe malarial anaemia. In a prospective cohort study of Ugandan children, 18 months to 12 years of age with cerebral malaria (n = 182), severe malarial anaemia (n = 158), and asymptomatic community children (n = 118), we measured admission blood levels of ubiquitin C-terminal hydrolase-L1, neurofilament-light chain, and glial fibrillary acidic protein. We investigated differences in biomarker levels, associations with mortality, blood-brain barrier integrity, neurodeficits and cognitive Z-scores in survivors up to 24-month follow-up. Admission ubiquitin C-terminal hydrolase-L1 levels were elevated >95th percentile of community children in 71 and 51%, and neurofilament-light chain levels were elevated >95th percentile of community children in 40 and 37% of children with cerebral malaria and severe malarial anaemia, respectively. Glial fibrillary acidic protein was not elevated in disease groups compared with controls. In cerebral malaria, elevated neurofilament-light chain was observed in 16 children who died in hospital compared with 166 survivors (P = 0.01); elevations in ubiquitin C-terminal hydrolase-L1 levels were associated with degree of blood-brain barrier disruption (P = 0.01); and the % predictive value for neurodeficits over follow-up (discharge, 6-, 12-, and 24 months) increased for ubiquitin C-terminal hydrolase-L1 (60, 67, 72, and 83), but not neurofilament-light chain (65, 68, 60, and 67). In cerebral malaria, elevated ubiquitin C-terminal hydrolase-L1 was associated with worse memory scores in children <5 years at malaria episode who crossed to over 5 years old during follow-up cognitive testing [ß -1.13 (95% confidence interval -2.05, -0.21), P = 0.02], and elevated neurofilament-light chain was associated with worse attention in children ≥5 years at malaria episode and cognitive testing [ß -1.08 (95% confidence interval -2.05, -1.05), P = 0.03]. In severe malarial anaemia, elevated ubiquitin C-terminal hydrolase-L1 was associated with worse attention in children <5 years at malaria episode and cognitive testing [ß -0.42 (95% confidence interval -0.76, -0.07), P = 0.02]. Ubiquitin C-terminal hydrolase-L1 and neurofilament-light chain levels are elevated in paediatric cerebral malaria and severe malarial anaemia. In cerebral malaria, elevated neurofilament-light chain is associated with mortality whereas elevated ubiquitin C-terminal hydrolase-L1 is associated with blood-brain barrier dysfunction and neurodeficits over follow-up. In cerebral malaria, both markers are associated with worse cognition, while in severe malarial anaemia, only ubiquitin C-terminal hydrolase-L1 is associated with worse cognition.