Abstract-Imperceptible visual distortion, in the form of a disguised progression of performance goals, may be a helpful addition to rehabilitation after stroke and other brain injuries. This paper describes work that has been done to lay the groundwork for testing this hypothesis. We have constructed and validated an experimental environment that provides controllable visual distortion and allows precise force and position measurements. To estimate the amount of visual distortion that should be imperceptible, we measured the limits for force and distance/position perception in our rehabilitation environment for young and elderly unimpaired subjects and for a single traumatic brain injury (TBI) patient. We found the Just Noticeable Difference (JND) for produced force to be 19.7% (0.296 N) and the JND for movement distance/finger position to be 13.0% (3.99 mm) for young subjects (ages 18-35). For elderly subjects (ages 61-80), the JND for force was measured to be 31.0% (0.619 N) and the JND for distance/position was 16.1% (5.01 mm). JNDs of 46.0% (0.920 N) and 45.0% (14.8 mm) were found for the motor-impaired individual. In addition, a subject's rating of effort was found to be profoundly influenced by visual feedback concerning the force magnitude. Even when this feedback was distorted, it accounted for 99% of the variance of the effort rating. These results indicate that substantial visual distortions should be imperceptible to the subject, and that visual feedback can be used to influence the subject's perceived experience in our robotic environment. This means that we should be able to use imperceptible visual distortion to alter a patient's perception of therapeutic exercise in a robotic environment.

Objective: The aim of this observational study was to determine the optimal timing of interleukin-6 receptor inhibitor (IL6ri) administration for coronavirus disease 2019 (COVID-19). Methods: Patients with COVID-19 were given an IL6ri (sarilumab or tocilizumab) based on iteratively reviewed guidelines. IL6ri were initially reserved for critically ill patients, but after review, treatment was liberalized to patients with lower oxygen requirements. Patients were divided into two groups: those requiring ≤45% fraction of inspired oxygen (FiO 2 ) (termed stage IIB) and those requiring >45% FiO 2 (termed stage III) at the time of IL6ri administration. The main outcomes were all-cause mortality, discharge alive from hospital, and extubation. Results: A total of 255 COVID-19 patients were treated with IL6ri (149 stage IIB and 106 stage III). Patients treated in stage IIB had lower mortality than those treated in stage III (adjusted hazard ratio (aHR) 0.24, 95% confidence interval (CI) 0.08–0.74). Overall, 218 (85.5%) patients were discharged alive. Patients treated in stage IIB were more likely to be discharged (aHR 1.43, 95% CI 1.06–1.93) and were less likely to be intubated (aHR 0.43, 95% CI 0.24–0.79). Conclusions: IL6ri administration prior to >45% FiO 2 requirement was associated with improved COVID-19 outcomes. This can guide clinical management pending results from randomized controlled trials

Infective endocarditis (IE) is a systemic disease with many potential neurologic manifestations including ischemic and hemorrhagic strokes, cerebral microbleeding, infectious intracranial aneurysms, meningitis, brain abscesses, and encephalopathy. The majority of left-sided (heart) IE patients have brain lesions that may alter management decisions, warranting the systematic use of magnetic resonance imaging. Many patients require surgical treatment of valvular disease, and central nervous system lesions weigh into decision making. Data regarding the timing of surgery are conflicting, but earlier surgery appears to be safe in most ischemic strokes, while ideally surgery should be delayed for 3 to 4 weeks in patients with hemorrhagic strokes. IE requires a multidisciplinary team to collaboratively care for the patient. In this article, we review the current understanding and management of the neurological complications of IE and their impact on the performance and timing of cardiac surgery.