Autonomic and neuropathic complaints of long-COVID objectified: an investigation from electrophysiological perspective

Purpose Here , we aimed to assess the frequency and phenomenology of autonomic and neuropathic complaints of long-COVID and to evaluate them by means of electrophysiology. Methods Step 1. Patients with prior COVID-19 infection were screened by COMPASS-31 and mTORONTO to create the target population for further evaluation. Step 2. Patients with high scores were invited for a detailed history of their complaints and electrophysiological analysis, which included nerve conduction studies, cutaneous silent period (CSP), and sympathetic skin response (SSR). We also constituted a control group composed of healthy subjects of similar age and sex for electrophysiological analysis. Results There were 106 patients, who matched the study criteria. Among them, thirty-eight patients (%35.8) had neuropathic or autonomic complaints or both. Fatigue and headache were significantly more frequent in patients with autonomic and neuropathic complaints. Detailed examination and electrophysiological evaluation were performed in 14 of 38 patients. Neuropathic complaints were patchy and proximally located in the majority. The entire CSP suppression index was higher in the patients (p = 0.002). There was no difference in palmar and plantar SSR between patients and healthy subjects. mTORONTO scores were negatively correlated with palmar and plantar SSR amplitudes, and the correlation was moderate. Conclusion Neuropathic or autonomic complaints were seen in more than one-third of patients with long-COVID. Neuropathic complaints were generally patchy, proximally predominant, asymmetric, or diffuse. The CSP suppression index was abnormal whereas SSRs were normal

Increased prevalence of mild myopathic changes in the post-COVID-19 duration

There are reports of peripheral nerve and muscle involvement during or after coronavirus disease 2019 (COVID-19), even following a mild infection. Here, we aimed to analyze the objective findings regarding peripheral nerve, neuromuscular junction, and muscle function using electrophysiology in patients with a previous COVID-19 infection. All consecutive patients with a history of COVID-19 were questioned for post-COVID-19 duration-related neurological complaints via Composite Autonomic Symptom Score-31 (COMPASS-31), modified Toronto Neuropathy score (mTORONTO), and Fatigue Severity Scale (FSS). Patients were dichotomized into two groups based on their scores in the questionnaire. Group 1 (patients with high scores in any area of the questionnaire) and Group 2 (patients with normal scores in all sections of the questionnaire). In the second step, Group 1 was invited to a preplanned hospital visit for electrophysiological analysis, including nerve conduction studies, repetitive nerve stimulation, needle electromyography (EMG), quantitative motor unit potential analysis (qMUP), and single fiber EMG. We included 106 patients in the study. According to the questionnaire, 38 patients constituted Group 1, and 68 formed Group 2. Of the 38 patients, 14 accepted and underwent preplanned electrophysiological examinations. Needle EMG revealed small, short, polyphasic MUPs with early recruitment, and qMUP analysis demonstrated an increased percentage of polyphasic potentials in three patients. The examinations in other patients were unremarkable. The high prevalence of complaints and objective myopathic findings in our cohort implicated the role of muscle involvement in the post-COVID-19 duration. Considering the socioeconomic and psychological burden of the post-COVID-19 duration among individuals and societies, a better understanding of the symptoms and myopathy is warranted.</p