Clinical Reasoning: A 23-Year-Old Man With Progressive Asymmetric Weakness and Numbness.

We report a case of a 23-year-old man who presented with progressive asymmetric weakness and numbness in his distal extremities over 4 months, with initial symptoms starting days after a coronavirus 2019 (COVID-19) vaccine booster. Initial neurologic examination was notable for distal weakness of both upper and lower extremities that was more pronounced on the left, complete areflexia, and decreased distal sensation to pinprick and vibration without loss of proprioception. Nerve conduction studies demonstrated a generalized, non-length-dependent, sensorimotor, demyelinating polyneuropathy, with conduction block seen in multiple compound muscle action potentials. Sensory nerve action potentials were normal in absolute terms but had asymmetric amplitudes.Based on the patient's nerve conduction studies, he was diagnosed with a specific immune-mediated neuromuscular disorder. He was started on intravenous immunoglobulin, but within days of the first infusions experienced a rare and potentially life-threatening complication. He received appropriate treatment and was started on alternative immunotherapy, after which his symptoms improved.Our case exemplifies the features of a specific subtype of a more common immune-mediated neuromuscular diagnosis with unique elements of history, examination, and nerve conduction studies that required interpretation in the clinical context. We also discuss a rare side effect of a commonly used immunotherapy and its risk factors and comment on the likelihood that this diagnosis may be related to a preceding COVID-19 vaccine booster.

Inertial Measurement Units and Application for Remote Health Care in Hip and Knee Osteoarthritis: Narrative Review.

BACKGROUND: Measuring and modifying movement-related joint loading is integral to the management of lower extremity osteoarthritis (OA). Although traditional approaches rely on measurements made within the laboratory or clinical environments, inertial sensors provide an opportunity to quantify these outcomes in patients' natural environments, providing greater ecological validity and opportunities to develop large data sets of movement data for the development of OA interventions. OBJECTIVE: This narrative review aimed to discuss and summarize recent developments in the use of inertial sensors for assessing movement during daily activities in individuals with hip and knee OA and to identify how this may translate to improved remote health care for this population. METHODS: A literature search was performed in November 2018 and repeated in July 2019 and March 2021 using the PubMed and Embase databases for publications on inertial sensors in hip and knee OA published in English within the previous 5 years. The search terms encompassed both OA and wearable sensors. Duplicate studies, systematic reviews, conference abstracts, and study protocols were also excluded. One reviewer screened the search result titles by removing irrelevant studies, and 2 reviewers screened study abstracts to identify studies using inertial sensors as the main sensing technology and a primary outcome related to movement quality. In addition, after the March 2021 search, 2 reviewers rescreened all previously included studies to confirm their relevance to this review. RESULTS: From the search process, 43 studies were determined to be relevant and subsequently included in this review. Inertial sensors have been successfully implemented for assessing the presence and severity of OA (n=11), assessing disease progression risk and providing feedback for gait retraining (n=7), and remotely monitoring intervention outcomes and identifying potential responders and nonresponders to interventions (n=14). In addition, studies have validated the use of inertial sensors for these applications (n=8) and analyzed the optimal sensor placement combinations and data input analysis for measuring different metrics of interest (n=3). These studies show promise for remote health care monitoring and intervention delivery in hip and knee OA, but many studies have focused on walking rather than a range of activities of daily living and have been performed in small samples (<100 participants) and in a laboratory rather than in a real-world environment. CONCLUSIONS: Inertial sensors show promise for remote monitoring, risk assessment, and intervention delivery in individuals with hip and knee OA. Future opportunities remain to validate these sensors in real-world settings across a range of activities of daily living and to optimize sensor placement and data analysis approaches.