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.

Pre-pandemic electrodermal activity predicts current COVID-related fears: household size during lockdown as a moderating factor.

Background: Despite the immense impact of COVID-19 on mental health, there is a lack of prospective studies examining physiological predictors of current risk factors. Moreover, although physiological processes evidently interact with socio-demographic factors to modulate individuals' response to a crisis, it remains largely unknown how these complex interactions shape people's mental responses to COVID-19. To fill these gaps of knowledge, we chose a potent physiological marker of distress - heightened baseline electrodermal activity (EDA) measured before the pandemic began - and hypothesized it would be related to greater COVID-related fears and worries as a function of individuals' household size.Method: 185 individuals (71% women), who had participated in our lab studies 2-3 years ago, in which we assessed their baseline EDA, completed several questionnaires online, including assessments of their current fears regarding COVID. Participants also reported the number of people in their household, with whom they had been together during a lockdown which was taking place at the time. We used pre-pandemic EDA measures in combination with their household size to predict participants' current fears.Results: Pre-pandemic EDA measures predicted current COVID-related fears and worries. Specifically for the EDA measure "number of skin conductance responses", we further found that the number of people in the household during the lockdown, moderated the abovementioned relationship, such that it occurred in individuals with average and larger households and not in those with small households.Conclusions: We provide a highly relevant and unique combination of physiological, socio-demographic, and psychological measures, which augments the potential to optimally target populations vulnerable to COVID-related distress, and subsequently offer them early mental health interventions.

Pre-pandemic autonomic nervous system activity predicts mood regulation expectancies during COVID-19 in Israel.

Despite the unfolding impact of the COVID-19 pandemic on psychological well-being, there is a lack of prospective studies that target physiological markers of distress. There is a need to examine physiological predictors from the pre-pandemic period to identify and treat individuals at-risk. In this study, our aim was to use pre-pandemic markers of autonomic nervous system (ANS) parasympathetic and sympathetic regulation to predict individuals' psychological well-being during the crisis. We also assessed the role of mood regulation expectancies as a mediator of the association between pre-pandemic physiological measures and COVID-related well-being. In May to June 2020, 185 Israeli adults completed online questionnaires assessing their mood regulation expectancies since COVID-19 began, and their current well-being. These individuals had participated in lab studies 1.5-3 years prior to this assessment, where their physiological measures were taken, including respiratory sinus arrhythmia (RSA) and skin conductance level (SCL). RSA was positively related to mood regulation expectancies during COVID-19 (b = 3.46, 95% CI [0.84, 6.05]). Mood regulation expectancies, in turn, positively predicted well-being during the crisis (b = 0.021, 95% CI [0.016, 0.027]). The mediation was significant and moderated by SCL (index = -0.09, 95% CI [-0.02, -0.0001]), such that it was strongest for individuals with low SCL. We point to pre-pandemic physiological mechanisms underlying individuals' mental well-being during the COVID-19 pandemic. These findings have theoretical, diagnostic, and clinical implications that may refine our understanding of the physiological basis of resilience to the COVID-19 pandemic and thus may be implemented to identify and assist individuals in these times.

Wearable Sensors for Assessing the Role of Olfactory Training on the Autonomic Response to Olfactory Stimulation.

Wearable sensors are nowadays largely employed to assess physiological signals derived from the human body without representing a burden in terms of obtrusiveness. One of the most intriguing fields of application for such systems include the assessment of physiological responses to sensory stimuli. In this specific regard, it is not yet known which are the main psychophysiological drivers of olfactory-related pleasantness, as the current literature has demonstrated the relationship between odor familiarity and odor valence, but has not clarified the consequentiality between the two domains. Here, we enrolled a group of university students to whom olfactory training lasting 3 months was administered. Thanks to the analysis of electrocardiogram (ECG) and galvanic skin response (GSR) signals at the beginning and at the end of the training period, we observed different autonomic responses, with higher parasympathetically-mediated response at the end of the period with respect to the first evaluation. This possibly suggests that an increased familiarity to the proposed stimuli would lead to a higher tendency towards relaxation. Such results could suggest potential applications to other domains, including personalized treatments based on odors and foods in neuropsychiatric and eating disorders.

Sudomotor dysfunction in patients recovered from COVID-19.

Dysautonomia has been reported in COVID-19. Sweat function testing has been proposed to assess autonomic neuropathy. Fifty Indian patients consulting for neurological symptoms participated in this observational study. The NHS questionnaire for neurological symptoms was completed and electrochemical skin conductance was measured using Sudoscan. The 26% of patients with sweat dysfunction i) were older (p = 0.001), ii) were more frequently treated at home (p = 0.008), iii) were more likely to have received antiviral treatment (p = 0.0006), and iv) more frequently reported at least one motor, sensory or autonomic symptom (p = 0.04). This preliminary study suggests that patients with COVID-19 should be screened for dysautonomia.