Characterizing Intimate Partner Violence-Caused Brain Injury in a Sample of Survivors in the Two Spirit, Lesbian, Gay, Bisexual, Transgender, Queer or Questioning Community.

Research in the field of intimate partner violence-caused brain injury (IPV-BI) has predominantly focused on heterosexual women, ignoring the unique needs of the Two Spirit, Lesbian, Gay, Bisexual, Transgender, Queer or Questioning (2S/LGBTQ) community. The purpose of this exploratory research was to better understand the prevalence of IPV and IPV-BI in 2S/LGBTQ relationships where IPV was defined as physical, psychological, financial, sexual, and/or identity-based abuse from a current of former intimate partner. This study used a cross sectional internet-based survey that ran from September to December of 2022. In addition to descriptive statistics, prevalence rates and their corresponding Wilson Score confidence intervals are reported to estimate the proportion of individuals who experienced IPV and IPV-BI. Finally, for both gender identity and sexual orientation, we tested whether participants with each identity had differing levels of brain injury severity compared to participants who did not hold that identity using Mann-Whitney U tests. In total, 170 2S/LGBTQ+ adults responded to the survey. Among the respondents, 54% identified as Two-Spirit, 24% identified as gay, 17% identified as queer, 14% identified as bisexual, and 8% identified as lesbian or pansexual, respectively. Respondents were predominantly multiracial, post-secondary educated, full-time employed, cisgender women (35%) or cisgender men (19%). The overwhelming majority reported lifetime prevalence of IPV at 98% (n = 166, 95% CI [94.11, 99.08]). Additionally, 68% (n = 115, 95% CI [60.29, 74.22]) of participants reported symptoms consistent with an IPV-BI. These results are consistent with the findings that the 2S/LGBTQ community are at heightened risk of experiencing physical IPV. These findings are the first to our knowledge to report a high rate of symptoms consistent with an IPV-BI in the 2S/LGBTQ population.

Investigating the Efficacy of a Community Support Network Rehabilitation Intervention for Improving Resiliency, Quality of Life, and Neurocognitive Function in Survivors of Intimate Partner Violence-Caused Brain Injury: Protocol for a Feasibility Study.

BACKGROUND: Globally, approximately 1 in 3 women experience intimate partner violence (IPV) in their lifetime. Brain injury (BI) is a common, yet often unrecognized, consequence of IPV. BIs caused by IPV tend to be mild, occur repetitively over the course of months or years, are remote in time, and result in chronic symptoms. Similar to BI from other causes, therapeutic treatment for women with IPV-caused BI (IPV-BI) is crucial to help resolve any physical or cognitive impairments, enhance the quality of life (QoL), and minimize longer-term neurodegeneration. OBJECTIVE: This study aims to investigate the feasibility and efficacy of a community support network (CSN) rehabilitation intervention regarding its impact on resiliency, QoL, and neurocognitive function. METHODS: In this pre- and postexperimental design, women (aged 18 to 50 years) who are survivors of IPV and IPV-BI will be recruited from various community organizations serving survivors of IPV. Exclusion criteria will include current pregnancy and any diagnosed neurological disorder known to affect cerebrovascular, neurocognitive, or sensorimotor function. A CSN rehabilitation intervention that includes aerobic exercise, cognitive training, mindfulness meditation, and counseling will be administered. A trauma-informed approach will be integrated into the design and implementation of the program. Furthermore, the program will include a participant navigator who will provide trauma- and violence-informed advocacy and systems navigation support to participants, in addition to facilitating a monthly peer support group. The intervention will be provided for 2.5 hours a day and 2 days a week for 3 months. Participants will complete psychological assessments and provide clinic-demographic information in the first assessment. In the second (before intervention), third (after intervention), and fourth (at follow-up) sessions, they will complete tests of resiliency, QoL, and neurocognition. The estimated sample size is 100. The objective of this study will be accomplished by quantitatively measuring resiliency, QoL, and neurocognition before and immediately after the intervention. A follow-up assessment will occur 3 months after the completion of the intervention to evaluate the maintenance of any improvements in function. One-way ANOVAs will be used to evaluate the intervention outcome across the testing times. Relationships among various variables will be explored using regression analysis. RESULTS: We anticipate that the CSN rehabilitation intervention will be effective in improving resiliency, QoL, and neurocognitive function in women who have experienced IPV-BI. Furthermore, we anticipate that this intervention will be feasible in terms of study recruitment, adherence, and retention. CONCLUSIONS: The CSN rehabilitation intervention will have a positive impact on resiliency, QoL, and neurocognitive functions in survivors of IPV-BI. Subsequently, a comparative study will be conducted by recruiting a control group receiving usual care. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/54605.

A Four Country Study of Strangulation-related Alterations in Consciousness in Women who have Experienced Intimate Partner Violence: Co-occurrence with Traumatic Brain Injuries and Measures of Psychological Distress.

At least one in three women experience intimate partner violence (IPV) in their lifetime. The most commonly sustained IPV-related brain injuries include strangulation-related alterations in consciousness (S-AICs) and traumatic brain injuries (TBIs). Moreover, survivors of IPV-related S-AICs and/or TBIs often demonstrate psychological distress such as depression, anxiety, and post-traumatic stress. However, the co-occurrence of S-AICs and TBIs, and whether such TBIs may be moderate to severe, has not been systematically examined, and most data have been collected from women in North America. The purpose of this study was to examine the co-occurrence of IPV-related S-AICs and TBIs across a range of geographical locations and to determine the extent to which these S-AICs are related to psychological distress. Women who had experienced physical IPV (N=213) were included in this secondary analysis of retrospectively collected data across four countries (Canada, USA, Spain, and Colombia). The Brain Injury Severity Assessment (BISA) was used to assess IPV-related BI across all sites. Because various questionnaires were employed to assess levels of depression, anxiety, and PTSD at each site, we created a standardized composite score by converting raw scores into Z-scores for analysis. Mann Whitney U tests and Chi square tests were conducted to examine differences between women with- versus without-experience of S-AICs and to discover if there was a relationship between the occurrence of S-AICs and TBIs. Analysis of variance, and analysis of covariance (to control for the potential confounding effects of age, education, and non IPV-related TBI) were used to compare levels of psychological distress in women who had or had not experienced S-AICs. Approximately 67% of women sustained at least one IPV-related BI (i.e., TBI and/or S-AIC). In a sub-sample of women who sustained at least one IPV-related BI, approximately 37% sustained both S-AICs and TBIs, 2% sustained only S-AICs (with no TBIs), and 61% sustained TBIs exclusively (with no S-AICs). Furthermore, women who had sustained S-AICs (with or without a TBI) were more likely to have experienced a moderate to severe BI than those who had not sustained an S-AIC (BISA severity subscale: U=3939, p=0.006). Additionally, women who experienced S-AICs (with or without a TBI) reported higher levels of psychological distress compared to women who never experienced S-AICs, irrespective of whether they occurred once or multiple times. These data underscore the importance of assessing for S-AIC in women who have experienced IPV and when present, to also assess for TBIs and the presence of psychological distress. Unfortunately, there were methodological differences across sites precluding cross-site comparisons. Nonetheless, data were collected across four culturally and geographically diverse countries, and therefore highlight IPV-related BIs as a global issue which needs to be aggressively studied with policies established and then implemented to address find.

Neurovascular coupling is altered in women who have a history of brain injury from intimate partner violence: a preliminary study.

Introduction: Intimate partner violence (IPV) is a global health crisis with 30% of women over the age of 15 experiencing at least one event in their lifetime. Brain injury (BI) due to head impacts and/or strangulation is a common but understudied part of this experience. Previous research has shown BI from other injury mechanisms can disrupt neurovascular coupling (NVC). To gain further insight into whether similar changes occur in this population, we assessed NVC responses in women with a history of IPV-BI. Methods: NVC responses were measured for the middle and posterior cerebral arteries (MCA, PCA) using transcranial Doppler ultrasound while participants performed a complex visual search task. The lifetime history of previous exposure to IPV-BI was captured using the Brain Injury Severity Assessment (BISA) along with measures of post-traumatic stress disorder (PTSD), anxiety, depression, substance use, and demographic information. Initial analyses of NVC metrics were completed comparing participants who scored low vs. high on the BISA or did or did not experience non-fatal strangulation followed by a stepwise multiple regression to examine the impact of PTSD, anxiety, and depression on the relationship between the NVC metrics and IPV-BI. Results: Baseline and peak cerebral blood velocity were higher and the percentage increase was lower in the PCA in the low compared to the high BISA group whereas no differences between the groups were apparent in the MCA. In addition, those participants who had been strangled had a lower initial slope and area under the curve in the PCA than those who had not experienced strangulation. Finally, the stepwise multiple regression demonstrated the percentage increase in the PCA was significantly related to the BISA score and both depression and anxiety significantly contributed to different components of the NVC response. Conclusions: This preliminary study demonstrated that a lifetime history of IPV-BI leads to subtle but significant disruptions to NVC responses which are modulated by comorbid depression and anxiety. Future studies should examine cerebrovascular function at the acute and subacute stages after IPV episodes to shed additional light on this experience and its outcomes.

Intimate Partner Violence-Related Brain Injury: Unmasking and Addressing the Gaps.

Intimate partner violence (IPV) is a significant, global public health concern. Women, individuals with historically underrepresented identities, and disabilities are at high risk for IPV and tend to experience severe injuries. There has been growing concern about the risk of exposure to IPV-related head trauma, resulting in IPV-related brain injury (IPV-BI), and its health consequences. Past work suggests that a significant proportion of women exposed to IPV experience IPV-BI, likely representing a distinct phenotype compared with BI of other etiologies. An IPV-BI often co-occurs with psychological trauma and mental health complaints, leading to unique issues related to identifying, prognosticating, and managing IPV-BI outcomes. The goal of this review is to identify important gaps in research and clinical practice in IPV-BI and suggest potential solutions to address them. We summarize IPV research in five key priority areas: (1) unique considerations for IPV-BI study design; (2) understanding non-fatal strangulation as a form of BI; (3) identifying objective biomarkers of IPV-BI; (4) consideration of the chronicity, cumulative and late effects of IPV-BI; and (5) BI as a risk factor for IPV engagement. Our review concludes with a call to action to help investigators develop ecologically valid research studies addressing the identified clinical-research knowledge gaps and strategies to improve care in individuals exposed to IPV-BI. By reducing the current gaps and answering these calls to action, we will approach IPV-BI in a trauma-informed manner, ultimately improving outcomes and quality of life for those impacted by IPV-BI.

A computational pipeline towards large-scale and multiscale modeling of traumatic axonal injury.

Contemporary biomechanical modeling of traumatic brain injury (TBI) focuses on either the global brain as an organ or a representative tiny section of a single axon. In addition, while it is common for a global brain model to employ real-world impacts as input, axonal injury models have largely been limited to inputs of either tension or compression with assumed peak strain and strain rate. These major gaps between global and microscale modeling preclude a systematic and mechanistic investigation of how tissue strain from impact leads to downstream axonal damage throughout the white matter. In this study, a unique subject-specific multimodality dataset from a male ice-hockey player sustaining a diagnosed concussion is used to establish an efficient and scalable computational pipeline. It is then employed to derive voxelized brain deformation, maximum principal strains and white matter fiber strains, and finally, to produce diverse fiber strain profiles of various shapes in temporal history necessary for the development and application of a deep learning axonal injury model in the future. The pipeline employs a structured, voxelized representation of brain deformation with adjustable spatial resolution independent of model mesh resolution. The method can be easily extended to other head impacts or individuals. The framework established in this work is critical for enabling large-scale (i.e., across the entire white matter region, head impacts, and individuals) and multiscale (i.e., from organ to cell length scales) modeling for the investigation of traumatic axonal injury (TAI) triggering mechanisms. Ultimately, these efforts could enhance the assessment of concussion risks and design of protective headgear. Therefore, this work contributes to improved strategies for concussion detection, mitigation, and prevention.

The Concussion Awareness Training Tool for Women's Support Workers Improves Knowledge of Intimate Partner Violence-Caused Brain Injury.

Women who experience physical intimate partner violence (IPV) are at high risk of suffering a brain injury (BI) due to head impacts and/or strangulation. Currently, most staff at women's shelters tend not to be aware of IPV-caused BIs. The objective of this study was to address this by developing a new online module within the Concussion Awareness Training Tool (cattonline.com) specifically focused on IPV-caused BI, and measuring its effectiveness in increasing BI awareness and knowledge among staff members at women's shelters. A mixed-methods approach was used which included (i) a survey to measure participant knowledge before and after completing the module; (ii) a 1-on-1 interview 6 months post-training to better understand participants' perceptions of what effect the training had on how they worked with women in their job; and (iii) an evaluation of the content of the module using behavior change techniques. About 81 participants recruited from staff at women's shelters completed the pre/post survey. The average BI knowledge score increased significantly from the pre-survey (M = 8.12/12, SD = 1.05) to the post-survey (M = 9.72/12, SD = 1.62), t(80) = 9.12, P < .001, d = 1.01). Analysis of the interviews with 9 participants highlighted 3 main themes arising from the module: knowledge, mindfulness, and advocacy. All participants felt their knowledge of IPV-caused BIs had increased and said they would recommend the training to their co-workers. Analysis of the module content revealed the most frequent behavior change techniques were related to instructions on how to perform screening and accommodation for IPV-caused BI. The results showed the module was effective in increasing knowledge of IPV-caused BIs amongst women's shelter staff as well as improving how they advocate for, and are mindful of, their clients with BIs. This online training may help improve the care women with IPV-caused BIs receive, and ultimately improve their quality of life.

Repetitive bout of controlled soccer heading does not alter heart rate variability metrics: A preliminary investigation.

Objectives: There is elevated unease regarding how repetitive head impacts, such as those associated with soccer heading, contribute to alterations in brain function. This study examined the extent heart rate variability (HRV) and cardiac baroreceptor sensitivity (BRS) metrics are altered immediately following an acute bout of soccer heading. Methods: Seven male elite soccer players (24.1 ± 1.5 years) completed 40 successful soccer headers in 20-min. The headers were performed under controlled circumstances using a soccer ball launcher located 25 meters away and using an initial ball velocity of 77.5 ± 3.7 km/h (heading condition). An accelerometer (xPatch) on the right mastoid process quantified linear/rotational head accelerations. Participants also completed sham (body contact) and control (non-contact) sessions. A three-lead ECG and finger photoplethysmography characterized short-term spontaneous HRV/cardiac BRS, before and after each condition. The SCAT3 indexed symptom scores pre-post exposures to all three conditions. Results: During the heading condition, cumulative linear and rotational accelerations experienced were 1,574 ± 97.9 g and 313,761 ± 23,966 rad/s2, respectively. Heart rate trended toward an increase from pre- to post-heading (p = 0.063), however HRV metrics in the time-domain (ps > 0.260) and frequency-domain (ps > 0.327) as well as cardiac BRS (ps > 0.144) were not significantly changed following all three conditions. Following the heading condition, SCAT3 symptom severity increased (p = 0.030) with a trend for symptom score augmentation (p = 0.078) compared to control and sham. Conclusion: Whereas, symptoms as measured by the SCAT3 were induced following an acute bout of controlled soccer heading, these preliminary findings indicate they were not accompanied by alterations to autonomic function. Ultimately, this demonstrates further research is needed to understand the physiological underpinnings of alterations in brain function occurring immediately after a bout of soccer heading and how these may, over time, contribute to long-term neurological impairments.

Ethicolegal considerations of screening for brain injury in women who have experienced intimate partner violence.

The vast majority of women who experience physical intimate partner violence (IPV) will likely suffer a brain injury (BI) as a result of the abuse. Accurate screening of IPV-BI can ensure survivors have access to appropriate health care and other supports, but screening results may also impact them receiving fair and equitable treatment in the legal system, and the justice they deserve. We used semi-structured interviews, combined with a contrastive vignette that described a realistic but hypothetical scenario involving IPV with or without BI, to explore the impact of BI on parenting disputes. Participants were lawyers (n = 12) whose focus is family law. Results highlight the potential adverse consequences of a positive BI screen that are influenced by the legal responsibility of counsel, the legal aid status of the woman, ongoing family dynamics, and the expectations of society while the focus on the best interests of the child is retained. Taken together, the findings reflect the legal vulnerability of women in decision-making about their capacity to parent after a BI. We conclude with recommendations for the future of IPV-BI screening aimed at mitigating risk and equipping women to navigate a legal system that has disadvantaged them, both historically and in the current context.

The effect of increased cognitive processing on reactive balance control following perturbations to the upper limb.

Reactive balance control following hand perturbations is important for everyday living as humans constantly encounter perturbations to the upper limb while performing functional tasks while standing. When multiple tasks are performed simultaneously, cognitive processing is increased, and performance on at least one of the tasks is often disrupted, owing to attentional resources being divided. The purpose here was to assess the effects of increased cognitive processing on whole-body balance responses to perturbations of the hand during continuous voluntary reaching. Sixteen participants (8 females; 22.9 ± 4.5 years) stood and grasped the handle of a KINARM - a robotic-controlled manipulandum paired with an augmented visual display. Participants completed 10 total trials of 100 mediolateral arm movements at a consistent speed of one reach per second, and an auditory n-back task (cognitive task). Twenty anteroposterior hand perturbations were interspersed randomly throughout the reaching trials. The arm movements with random arm perturbations were either performed simultaneously with the cognitive task (combined task) or in isolation (arm perturbation task). Peak centre of pressure (COP) displacement and velocity, time to COP displacement onset and peak, as well as hand displacement and velocity following the hand perturbation were evaluated. N-back response times were 8% slower and 11% less accurate for the combined than the cognitive task. Peak COP displacement following posterior perturbations increased by 8% during the combined compared to the arm perturbation task alone, with no other differences detected. Hand peak displacement decreased by 5% during the combined compared to the arm perturbation task. The main findings indicate that with increased cognitive processing, attentional resources were allocated from the cognitive task towards upper limb movements, while attentional resources for balance seemed unaltered.

An acute bout of controlled subconcussive impacts can alter dynamic cerebral autoregulation indices: a preliminary investigation.

OBJECTIVES: There is growing concern repetitive head contacts sustained by soccer players may lead to long-term health ramifications. Therefore, this preliminary investigation examined the impact an acute soccer heading bout has on dynamic cerebral autoregulation (dCA) metrics. METHODS: In this preliminary investigation, 40 successful soccer headers were performed in 20 min by 7 male elite soccer players (24.1 ± 1.5 years). Soccer balls were launched at 77.5 ± 3.7 km/h from JUGS soccer machine, located 35 m away from participants. Linear and rotational head accelerations impacts were measured using an accelerometer (xPatch). The SCAT3 indexed concussion symptom score and severity before and after: soccer headers, sham (body contact only), and control conditions. Squat-stand maneuvers were performed at 0.05 Hz and 0.10 Hz to quantity dCA through measures of coherence, phase, and gain. RESULTS: Cumulative linear and rotational accelerations during soccer headers were 1574 ± 97.9 g and 313,761 ± 23,966 rads/s2, respectively. SCAT3 symptom severity was elevated after the soccer heading bout (pre 3.7 ± 3.6, post 9.4 ± 7.6: p = 0.030) and five of the seven participants reported an increase in concussion-like symptoms (pre: 2.6 ± 3.0, post: 6.7 ± 6.2; p = 0.078). Phase at 0.10 Hz was elevated following soccer heading (p = 0.008). No other dCA metric differed following the three conditions. CONCLUSION: These preliminary results indicate an acute bout of soccer heading resulted in alterations to dCA metrics. Therefore, future research with larger sample sizes is warranted to fully comprehend short- and long-term physiological changes related to soccer heading.

Using Behavior Change Theory to Understand How to Support Screening for Traumatic Brain Injuries Among Women Who Have Experienced Intimate Partner Violence.

Background: Women who experience intimate partner violence (IPV) are at a high risk for traumatic brain injuries (TBIs). Women's shelters may be an ideal location for TBI screening. Behavior change theory can help understand factors that influence screening at women's shelters and develop interventions to promote screening. Objective: To use behavior change theory to understand the local context of women's shelters, factors influencing screening for TBIs among staff who work at women's shelters, and co-develop intervention recommendations to promote screening of TBIs at women's shelters. Methods: The research was conducted in three phases in partnership with the Kelowna Women's Shelter. In phase 1, participants (staff at women's shelters across Canada) completed an online survey that assessed their current TBI screening behaviors, knowledge of TBIs, and factors influencing screening. In phase 2, participants (staff at women's shelters in the Okanagan) completed an interview regarding the factors that influence screening for TBIs. In both phases, factors were analyzed using the Theoretical Domains Framework. In phase 3, intervention recommendations were co-developed using the Behavior Change Wheel. Results: In phase 1, findings indicate that participants (n = 150) lack skills (mean = 2.1, standard deviation [SD] = 1.9) and knowledge (mean = 2.9, SD = 2.2) with regard to screening and are nervous to screen (mean = 3.0, SD = 2.4) for TBIs. In phase 2, 194 barriers to screening for TBI were extracted from 10 interviews with staff members. Prominent domains included knowledge (37%), beliefs about capabilities (16%), and environmental context and resources (15%). Finally, in phase 3, five intervention recommendations were co-developed for interventions aiming to promote TBI screening in women's shelters. Conclusions: This thesis was the first theory-based study to develop intervention recommendations for promoting screening of TBIs at women's shelters. The recommendations have the potential to increase TBI screening at women's shelters ultimately improving the quality of life of women who have experienced a TBI from IPV.

Characterization of Cognitive-Motor Function in Women Who Have Experienced Intimate Partner Violence-Related Brain Injury.

Intimate partner violence (IPV) affects at least one in three women worldwide, and up to 92% report symptoms consistent with brain injury (BI). Although a handful of studies have examined different aspects of brain structure and function in this population, none has characterized potential deficits in cognitive-motor function. This knowledge gap was addressed in the current study by having participants who had experienced IPV complete the bimanual Object Hit & Avoid (OHA) task in a Kinesiological Instrument for Normal and Altered Reaching Movement (KINARM) End-Point Laboratory. BI load, post-traumatic stress disorder (PTSD), anxiety, depression, substance use, and history of abuse were also assessed. A stepwise multiple regression was undertaken to explore the relationship between BI load and task performance while accounting for comorbid psychopathologies. Results demonstrated that BI load accounted for a significant amount of variability in the number of targets hit and the average hand speed. PTSD, anxiety, and depression also contributed significantly to the variability in these measures as well as to the number and proportion of distractor hits, and the object processing rate. Taken together, these findings suggest that IPV-related BI, as well as comorbid PTSD, anxiety, and depression, disrupt the processing required to quickly and accurately hit targets while avoiding distractors. This pattern of results reflects the complex interaction between the physical injuries induced by the episodes of IPV and the resulting impacts that these experiences have on mental health.

A global collaboration to study intimate partner violence-related head trauma: The ENIGMA consortium IPV working group.

Intimate partner violence includes psychological aggression, physical violence, sexual violence, and stalking from a current or former intimate partner. Past research suggests that exposure to intimate partner violence can impact cognitive and psychological functioning, as well as neurological outcomes. These seem to be compounded in those who suffer a brain injury as a result of trauma to the head, neck or body due to physical and/or sexual violence. However, our understanding of the neurobehavioral and neurobiological effects of head trauma in this population is limited due to factors including difficulty in accessing/recruiting participants, heterogeneity of samples, and premorbid and comorbid factors that impact outcomes. Thus, the goal of the Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) Consortium Intimate Partner Violence Working Group is to develop a global collaboration that includes researchers, clinicians, and other key community stakeholders. Participation in the working group can include collecting harmonized data, providing data for meta- and mega-analysis across sites, or stakeholder insight on key clinical research questions, promoting safety, participant recruitment and referral to support services. Further, to facilitate the mega-analysis of data across sites within the working group, we provide suggestions for behavioral surveys, cognitive tests, neuroimaging parameters, and genetics that could be used by investigators in the early stages of study design. We anticipate that the harmonization of measures across sites within the working group prior to data collection could increase the statistical power in characterizing how intimate partner violence-related head trauma impacts long-term physical, cognitive, and psychological health.

An Acute Bout of Soccer Heading Subtly Alters Neurovascular Coupling Metrics.

Objective: The current investigation examined how a bout of soccer heading may impact brain function. Design: Semi-randomized crossover cohort. Setting: Controlled soccer heading. Participants: Seven male soccer players (24.1 ± 1.5 years). Intervention: 40 successful soccer headers were performed in 20 min (25 m, launch velocity ~80 km/h). X2 xPatch recorded linear and rotational head accelerations during each impact. A contact control "sham" condition - ball made body contact, but not by the head; and a no activity time "control" condition were also completed. Main Outcome Measures: Posterior and middle cerebral artery (PCA and MCA, respectively), cerebral blood velocity (CBV) was recorded during a visual task (neurovascular coupling: NVC) alongside SCAT3 symptoms scores pre/post a controlled bout of soccer heading. Results: Cumulative linear and rotational accelerations were 1,574 ± 97.9 g and 313,761 ± 23,966 rads/s2, respectively, during heading and changes in SCAT3 symptom number (pre: 2.6 ± 3.0; post: 6.7 ± 6.2, p = 0.13) and severity (pre: 3.7 ± 3.6, post: 9.4 ± 7.6, p = 0.11) were unchanged. In the PCA, no NVC differences were observed, including: relative CBV increase (28.0 ± 7.6%, p = 0.71) and total activation (188.7 ± 68.1 cm, p = 0.93). However, MCA-derived NVC metrics were blunted following heading, demonstrating decreased relative CBV increase (7.8 ± 3.1%, p = 0.03) and decreased total activation (26.7 ± 45.3 cm, p = 0.04). Conclusion: Although an acute bout of soccer heading did not result in an increase of concussion-like symptoms, there were alterations in NVC responses within the MCA during a visual task. This suggests an acute bout of repetitive soccer heading can alter CBV regulation within the region of the brain associated with the header impacts.

A Prospective Transcranial Doppler Ultrasound-Based Evaluation of the Effects of Repetitive Subconcussive Head Trauma on Neurovascular Coupling Dynamics.

OBJECTIVE: To determine the effects of repetitive subconcussive head trauma on neurovascular coupling (NVC) responses. DESIGN: Prospective cohort study collected between September 2013 and December 2016. SETTING: University laboratory. PARTICIPANTS: One hundred seventy-nine elite, junior-level (age, 19.6 ± 1.5 years) contact sport (ice hockey, American football) athletes recruited for preseason testing. Fifty-two nonconcussed athletes returned for postseason testing. Fifteen noncontact sport athletes (age, 20.4 ± 2.2 years) also completed preseason and postseason testing. EXPOSURE(S): Subconcussive sport-related head trauma. MAIN OUTCOME MEASURES: Dynamics of NVC were estimated during cycles of 20 seconds eyes closed and 40 seconds eyes open to a visual stimulus (reading) by measuring cerebral blood flow (CBF) velocity in the posterior (PCA) and middle (MCA) cerebral arteries via transcranial Doppler ultrasound. RESULTS: Both athlete groups demonstrated no significant differences in PCA or MCA NVC dynamics between preseason and postseason, despite exposure to a median of 353.5 (range, 295.0-587.3) head impacts (>2g) over the course of the season for contact sport athletes. CONCLUSIONS: Within the context of growing concern over detrimental effects of repetitive subconcussive trauma, the current results encouragingly suggest that the dynamics of NVC responses are not affected by 1 season of participation in junior-level ice hockey or American football. This is an important finding because it indicates an appropriate postseason CBF response to elevated metabolic demand with increases in neural activity.

Modulation of vestibular-evoked responses prior to simple and complex arm movements.

During destabilizing, voluntary arm movements, the vestibular system provides sensory cues related to head motion that are necessary to preserve upright balance. Although sensorimotor processing increases in accordance with task complexity during the preparation phase of reaching, it is unclear whether vestibular signals are also enhanced when maintaining postural control prior to the execution of a voluntary movement. To probe whether vestibular cues are a component of complexity-related increases in sensorimotor processing during movement preparation, vestibular-evoked responses to stochastic (0-25 Hz; root mean square = 1 mA) binaural, bipolar electrical vestibular stimulation (EVS) were examined. These responses were assessed using cumulant density function estimates in the upper and lower limbs prior to ballistic arm movements of varying complexity in both standing (experiment 1) and seated (experiment 2) conditions. In experiment 1, EVS-electromyography (EMG) cumulant density estimates surpassed 95% confidence intervals for biceps and triceps brachii, as well as the left and right medial gastrocnemius. For the latter two muscles, the responses were enhanced 10-18% with increased movement complexity. In experiment 2, the EVS-EMG cumulant density estimates also surpassed 95% confidence intervals in the upper limb, confirming the presence of vestibular-evoked responses while seated; however, the amplitude was significantly less than standing. This study demonstrates the vestibular system contributes to postural stability during the preparation phase of reaching. As such, vestibular-driven signals may be used to update an internal model for upcoming reaching tasks or to prepare for imminent postural disturbances.

Attention Is Required to Coordinate Reaching and Postural Stability during Upper Limb Movements Generated While Standing.

In the present study we investigated how attention contributes to the interaction between reach planning and execution, and postural control. Reaching movements were generated while standing and were performed either in isolation or in conjunction with a secondary reaction time (RT) task. In addition, to better understand how online movement control is affected by this interaction, the reaching movements could be unexpectedly perturbed medial-laterally. Postural kinetic, arm kinematic and RT, and secondary RT measures were used to characterize the responses. Results indicate task performance worsened when both the reaching and secondary tasks were completed simultaneously. Our results imply the generation of reaching movements while standing requires attentional resources to properly coordinate the interaction between the reaching task and postural control.

Characterizing symptoms of traumatic brain injury in survivors of intimate partner violence.

Objective: This study examined the extent symptoms associated with potential traumatic brain injury (TBI) in intimate partner violence (IPV) survivors overlap with sport-related concussions (SRC). IPV survivor responses on the Brain Injury Severity Assessment (BISA) tool, an IPV-specific questionnaire developed to assess TBI symptoms; and the widely-used Sport Concussion Assessment Tool (SCAT5), were compared. Additionally, psychopathological assessments of post-traumatic stress disorder (PTSD), depression, and anxiety were completed to account for confounding influences. Design: Eighteen women who had experienced IPV were recruited from high-barrier community-based women's shelters. Results: The total number of reported TBI were higher when employing the BISA compared to SCAT5, the strongest symptom-based correlations associated TBI severity was associated with arousal states ("Fatigue", "Anxious", "Drowsiness", "Just Don't Feel Right") or aspects of memory/cognition ("Difficulty Concentrating", "Difficulty Remembering"). Furthermore, TBI severity was also related to the degree of depression and anxiety, but unrelated to PTSD. Conclusions: Taken together, these findings can contribute to the development of enhanced screening tools and supports to help front-line staff identify TBI as a possible contributor to challenges faced by IPV survivors. By this means, women who have experienced IPV will be more likely to break the cycle of abuse and have more positive long-term health outcomes.

The Time Course of Motoneuronal Excitability during the Preparation of Complex Movements.

For a simple RT task, movement complexity increases RT and also corticospinal excitability, as measured by the motor evoked potential (MEP) elicited by TMS of the motor cortex. However, it is unknown if complexity-related increases in corticospinal excitability during the preparation of movement are mediated at the cortical or spinal level. The purposes of this study were to establish a time course of motoneuronal excitability before prime mover activation and to assess task-dependent effects of complex movements on motoneuronal and cortical excitability in a simple RT paradigm. It was hypothesized that motoneuronal and cortical excitability would increase before prime mover activation and in response to movement complexity. In a seated position, participants completed ballistic elbow extension/flexion movements with their dominant arm to one, two, or three targets. TMS and transmastoid stimulation (TS) were delivered at 0%, 70%, 80% or 90% of mean premotor RT for each complexity level. Stimulus intensities were set to elicit MEPs and cervicomedullary MEPs (CMEPs) of ∼10% of the maximal M-wave in the triceps brachii. Compared with 0% RT, motoneuronal excitability (CMEP amplitude) was already 10% greater at 70% RT. CMEP amplitude also increased with movement complexity as both the two- and three-movement conditions had greater motoneuronal excitability than the one-movement condition (p < .038). Importantly, when normalized to the CMEP, there was no increase in MEP amplitude. This suggests that complexity-related increases in corticospinal excitability are likely to be mediated more by increased excitability at a motoneuronal than cortical level.