Faculty Bibliography

The discriminability of motion direction is asymmetric, with some motion directions that are better discriminated than others. For example, discrimination of directions near the cardinal axes (upward/downward/leftward/rightward) tends to be better than oblique directions. Here, we tested discriminability for multiple motion directions at multiple polar angle locations. We found three systematic asymmetries. First, we found a large cardinal advantage in a cartesian reference frame - better discriminability for motion near cardinal reference directions than oblique directions. Second, we found a moderate cardinal advantage in a polar reference frame - better discriminability for motion near radial (inward/outward) and tangential (clockwise/counterclockwise) reference directions than other directions. Third, we found a small advantage for discriminating motion near radial compared to tangential reference directions. The three advantages combine in an approximately linear manner, and together predict variation in motion discrimination as a function of both motion direction and location around the visual field. For example, best performance is found for radial motion on the horizontal and vertical meridians, as these directions encompass all three advantages, whereas poorest performance is found for oblique motion stimuli located on the horizontal and vertical meridians, as these directions encompass all three disadvantages. Our results constrain models of motion perception and suggest that reference frames at multiple stages of the visual processing hierarchy limit performance.

ADEM is an inflammatory disease, with new onset polyfocal neurologic symptoms, encephalopathy and multifocal demyelination, typically in childhood. Initial diagnosis of ADEM is challenging and up to 20 % of children with MS or NMOSD are initially diagnosed with ADEM. We describe characteristics of patients with monophasic ADEM vs. recurrent demyelinating syndromes at onset and identify features consistent with monophasic course. This is a multicenter observational study of children with demyelinating disease, followed at 12 regional pediatric MS centers. Descriptive statistics were used to report patient characteristics, clinical/imaging features and outcomes. Logistic regression was used to predict features associated with monophasic course. As of July 2019, 837 children with final diagnosis of ADEM (n = 79), MS (n = 646) or NMOSD (n = 112) were identified. The mean follow-up was 5·7 +/- 3·2 years. ADEM patients were youngest with mean age at first event 5·2 +/- 3·8 years (p < 0.001) and male predominant (66 %) (p < 0·001). After 2 years of follow-up, 83 % of patients initially diagnosed with monophasic ADEM retained this diagnosis. In multivariable analysis, older age (OR 1·16 [95 % CI 1·02 - 1·33] for 1-year increase, p = 0·02), presenting with optic neuritis (OR 8.18 [95 % CI 1.88 - 35.64], p = 0·005) and presence of gadolinium enhancement (OR 4.08 [95 % CI 1.38 - 12.08], p = 0·011) were associated with reclassification of ADEM to MS, NMOSD or DDNOS within 2 years. Children with monophasic ADEM vs. those reclassified as other demyelinating disorders are younger at onset, and less likely to have optic neuritis or gadolinium-enhancing lesions at onset.

OBJECTIVES/OBJECTIVE:Thrombectomy improves outcomes in patients with basilar artery (BA) occlusion. We hypothesized that the anatomic configuration of the BA bifurcation, classified as T- or Y-shaped, may impact the outcome as a T-shaped BA would involve more deep penetrating arteries of the midbrain and thalamus. MATERIALS AND METHODS/METHODS:In this 2-center retrospective cohort study, we included patients with stroke due to distal BA occlusion and performed blinded classification of their BA distal bifurcation as either T- or Y-shaped. The primary outcomes were favorable outcome at 90-days (modified Rankin Scale 0 - 2) and successful recanalization (TICI scores 2B or 3). RESULTS:70 patients (mean age 66 years, 36% women) were included. 38 had T- and 32 had Y-shaped bifurcations. Baseline characteristics were similar for both groups, including demographics, onset to arterial puncture time, baseline NIHSS, THRIVE score, posterior circulation collateral score, and presence of tandem occlusion. Comparing the T- to the Y- shape, there was no difference in the likelihood of successful recanalization (RR: 1.02, CI: [0.86-1.21], p=1.00) nor 90-day favorable mRS (0-2) score (RR: 0.58, CI: [0.25-1.32]; p=0.18). Similarly, mortality at 30 and 90-days were not significantly affected by the type of bifurcation. CONCLUSIONS:The configuration of the basilar artery does not significantly impact on recanalization success or stroke outcome in our study. Further studies are needed to confirm our observations.

BACKGROUND:Trials of the efficacy and safety of endovascular thrombectomy in patients with large ischemic strokes have been carried out in limited populations. METHODS:We performed a prospective, randomized, open-label, adaptive, international trial involving patients with stroke due to occlusion of the internal carotid artery or the first segment of the middle cerebral artery to assess endovascular thrombectomy within 24 hours after onset. Patients had a large ischemic-core volume, defined as an Alberta Stroke Program Early Computed Tomography Score of 3 to 5 (range, 0 to 10, with lower scores indicating larger infarction) or a core volume of at least 50 ml on computed tomography perfusion or diffusion-weighted magnetic resonance imaging. Patients were assigned in a 1:1 ratio to endovascular thrombectomy plus medical care or to medical care alone. The primary outcome was the modified Rankin scale score at 90 days (range, 0 to 6, with higher scores indicating greater disability). Functional independence was a secondary outcome. RESULTS:The trial was stopped early for efficacy; 178 patients had been assigned to the thrombectomy group and 174 to the medical-care group. The generalized odds ratio for a shift in the distribution of modified Rankin scale scores toward better outcomes in favor of thrombectomy was 1.51 (95% confidence interval [CI], 1.20 to 1.89; P<0.001). A total of 20% of the patients in the thrombectomy group and 7% in the medical-care group had functional independence (relative risk, 2.97; 95% CI, 1.60 to 5.51). Mortality was similar in the two groups. In the thrombectomy group, arterial access-site complications occurred in 5 patients, dissection in 10, cerebral-vessel perforation in 7, and transient vasospasm in 11. Symptomatic intracranial hemorrhage occurred in 1 patient in the thrombectomy group and in 2 in the medical-care group. CONCLUSIONS:Among patients with large ischemic strokes, endovascular thrombectomy resulted in better functional outcomes than medical care but was associated with vascular complications. Cerebral hemorrhages were infrequent in both groups. (Funded by Stryker Neurovascular; SELECT2 ClinicalTrials.gov number, NCT03876457.).

Background Cardiovascular complications after acute ischemic stroke (AIS) can be related to chronic/comorbid cardiac conditions or acute disruption of the brain-heart autonomic axis (stroke-heart syndrome). Women are known to be more vulnerable to certain stress-induced cardiac complications, such as Takotsubo cardiomyopathy. We investigated sex differences in cardiac troponin (cTn) elevation, cardiac events, and outcomes after AIS. Methods and Results We retrospectively analyzed consecutive patients with AIS from 5 stroke centers. Patients with AIS with elevated baseline cTn and at least 2 cTn measurements were included, while patients with acute comorbid conditions that could impact cTn levels were excluded. Poststroke acute myocardial injury was defined as the presence of a dynamic cTn pattern (rise/fall >20% in serial measurements) in the absence of acute atherosclerotic coronary disease (type 1 myocardial infarction) or cardiac death (type 3 myocardial infarction). From a total cohort of 3789 patients with AIS, 300 patients were included in the study: 160 were women (53%). Women were older, had a lower burden of cardiovascular risk factors, and more frequently had cardioembolic stroke and right insula involvement (P values all <0.05). In multivariate analysis, women were more likely to have a dynamic cTn pattern (adjusted odds ratio, 2.1 [95% CI, 1.2-3.6]) and develop poststroke acute myocardial injury (adjusted odds ratio, 2.1 [95% CI, 1.1-3.8]). Patients with poststroke acute myocardial injury had higher 7-day mortality (adjusted odds ratio, 5.5 [95% CI, 1.2-24.4]). Conclusions In patients with AIS with elevated cTn at baseline, women are twice as likely to develop poststroke acute myocardial injury, and this is associated with higher risk of short-term mortality. Translational studies are needed to clarify mechanisms underlying sex differences in cardiac events and mortality in AIS.

In 2019, the International Olympic Committee (IOC) published a consensus statement outlining the principles for recording and reporting injury and illness in elite sport. The authors encouraged sport federations to adapt the framework to their sport-specific context. Since this publication, several sports have published extensions to the IOC consensus statement.In response to a paucity of epidemiological data on athlete mental health, the IOC mental health working group adapted the IOC consensus statement on injury and illness surveillance to improve the capturing of athlete mental health data. In addition to the members of the working group, other experts and athlete representatives joined the project team to address gaps in expertise, and to add stakeholder perspective, respectively. Following an in-person meeting, the authors worked remotely, applying the scientific literature on athlete mental health to the IOC injury and illness surveillance framework. A virtual meeting was held to reach consensus on final recommendations.Practical outcomes based on the analysis of the scientific literature are provided with respect to surveillance design, data collection and storage, data analysis and reporting of athlete mental health data. Mental health-specific report forms for athlete and health professional utilisation are included for both longitudinal and event-specific surveillance.Ultimately, this publication should encourage the standardisation of surveillance methodology for mental health symptoms and disorders among athletes, which will improve consistency in study designs, thus facilitating the pooling of data and comparison across studies. The goal is to encourage systematic surveillance of athlete mental health.

OBJECTIVES/OBJECTIVE:To characterise psychological distress during the COVID-19 pandemic among collegiate athletes and assess whether racial and ethnic differences in psychological distress are attenuated when accounting for inequitable exposure to structural and social determinants of health. METHODS:Participants were collegiate athletes on teams competing in the National Collegiate Athletic Association (n=24 246). An electronic questionnaire was distributed by email, open for completion 6 October to 2 November 2020. Multivariable linear regression models were used to assess the cross-sectional associations between meeting basic needs, death or hospitalisation due to COVID-19 of a close contact, race and ethnicity, and psychological distress. RESULTS:Athletes racialised as Black had higher levels of psychological distress than their white peers (B=0.36, 95% CI 0.08 to 0.64). Psychological distress was higher among athletes who had more difficulties meeting basic needs, and who had a close contact die or be hospitalised with COVID-19. After adjusting for these structural and social factors, Black athletes experienced less psychological distress than white peers (B=-0.27, 95% CI -0.54 to -0.01). CONCLUSIONS:The present findings provide further evidence of how inequitable structural and social exposures are associated with racial and ethnic differences in mental health outcomes. Sports organisations should ensure the mental health services available for their athletes are appropriate for meeting the needs of individuals experiencing complex and traumatic stressors. Sports organisations should also consider whether there are opportunities to screen for social needs (eg, related to food or housing insecurity), and to connect athletes with resources to help meet those needs.

For over two decades, the Concussion in Sport Group has held meetings and developed five international statements on concussion in sport. This 6th statement summarises the processes and outcomes of the 6th International Conference on Concussion in Sport held in Amsterdam on 27-30 October 2022 and should be read in conjunction with the (1) methodology paper that outlines the consensus process in detail and (2) 10 systematic reviews that informed the conference outcomes. Over 3½ years, author groups conducted systematic reviews of predetermined priority topics relevant to concussion in sport. The format of the conference, expert panel meetings and workshops to revise or develop new clinical assessment tools, as described in the methodology paper, evolved from previous consensus meetings with several new components. Apart from this consensus statement, the conference process yielded revised tools including the Concussion Recognition Tool-6 (CRT6) and Sport Concussion Assessment Tool-6 (SCAT6, Child SCAT6), as well as a new tool, the Sport Concussion Office Assessment Tool-6 (SCOAT6, Child SCOAT6). This consensus process also integrated new features including a focus on the para athlete, the athlete's perspective, concussion-specific medical ethics and matters related to both athlete retirement and the potential long-term effects of SRC, including neurodegenerative disease. This statement summarises evidence-informed principles of concussion prevention, assessment and management, and emphasises those areas requiring more research.

We sought to identify concepts that may facilitate National Collegiate Athletic Association efforts to assist member institutions in addressing the mental health needs of student-athletes of colour. A two-step process was followed to generate and refine concepts, guided by Delphi methodology. First, a scoping review was conducted, including original peer-reviewed research articles that quantified or qualitatively described determinant(s) of racial or ethnic differences in athlete mental health or mental healthcare. Next, a multiday virtual meeting was facilitated to review the results of the scoping review, discuss lived experiences and generate potential concepts. Participants included a racially and ethnically diverse group of student-athletes, medical and mental health professionals, athletics administrators, diversity, equity and inclusion experts, health educators and representatives from leading organisations involved in athlete mental health. Through the consensus process, participants identified 42 concepts that member institutions might consider implementing on their campuses. Concepts were largely focused on organisational policies and practices such as staffing diversity and inclusion, expanded options for clinical support (ie, identity-relevant support groups) and within-organisation accountability. Concepts related to specific areas for stakeholder education were also identified. Institutions have the potential to play an important role in supporting the mental well being of student-athletes of colour, and the present concepts can help inform institutional action. While concepts proposed are believed to be broadly relevant across athletics settings, they would need to be further considered and tailored to reflect setting-specific organisational structures, resources and needs.