The effects of obstacle proximity on aperture crossing behaviours.

Affordance theory and behavioural dynamics have been used as theoretical constructs to explain how individuals interact with the environment in order to avoid obstacles. Features of obstacle distance and multiple obstacle avoidance have been discussed in unique studies, yet the interactions of these environmental features have yet to be explored. The purpose of this study was to asses the effects of obstacle distance, relative to the goal, on aperture crossing strategies. Kinematics and gaze behaviours were assessed in a cohort of female young adults (N = 24, 21.3 ± 1.4 years). Results identified that participants chose to navigate through gaps of 1.3× shoulder width or greater, regardless of obstacle distance. However, safety margin in the anterior-posterior direction was found to increase with increased obstacle distance, suggesting unique environmental affordances for each obstacle distance. Therefore, although decision making on whether to navigate through, or around, the aperture appears to be unaffected by obstacle location, specific environmental features result in unique kinematic behaviours. Such behaviours fit within, and add merit to, the tenets of both affordance theory and behavioural dynamics.

Acute Hemorrhagic Encephalitis Related to COVID-19.

PURPOSE OF REVIEW: The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the most critical public health challenge in recent history. In this report, we present a case of suspected acute hemorrhagic encephalitis with bilateral intracranial hemorrhages associated with coronavirus disease 2019 (COVID-19) infection. RECENT FINDINGS: A 48-year-old female COVID-19-positive patient developed acute changes in her neurologic status. A head CT with CT angiography demonstrated extensive bilateral parietal and occipital intraparenchymal hemorrhage with intraventricular extension and acute hydrocephalus. The patient was treated with an external ventricular drain, and a CSF sample was tested for SARS-CoV-2 but was found to be negative. SUMMARY: The underlying mechanism for developing acute hemorrhagic encephalitis in viral illnesses may be autoimmune in nature and warrants further investigation. The initial neurologic presentation of COVID-19-related hemorrhagic encephalitis is altered level of consciousness, which may prompt further neurologic examination and imaging to exclude this feature.

Visuomotor deficits during locomotion in previously concussed athletes 30 or more days following return to play.

Current protocols for returning athletes to play (RTP) center around resolution of physical symptoms of concussion. However, recent research has identified that balance and cognitive deficits persist beyond physical symptom recovery. Protocols that involve testing dynamic balance and visuomotor integration have been recommended as potential tools for better understanding of length of impairment following concussion. A dynamic, visuomotor paradigm was undertaken in the current study to assess decision making in athletes who had sustained a concussion >30 days before study participation and had been cleared to RTP (N = 10). Two obstacles created a gap that varied between 0.6 and 1.8× participants' individual shoulder width in open space. Participants made decisions to navigate through or deviate around the gap created by the two obstacles. The results revealed that previously concussed athletes were highly variable in their decision making and demonstrated variable Medial-Lateral (ML) center of mass (COM) control when approaching the obstacles, when compared with nonconcussed, age-matched controls. As such, they showed poor visuomotor control and decision making, as well as poor dynamic stability compared to controls. Visuomotor deficits were persistent in the sample of previously concussed individuals, well beyond deficits identified by current RTP standards. This study suggests that dynamic, visuomotor integration tasks may be of benefit to increase rigor in RTP protocols and increase safety of athletes returning to sport.