Deficient GABABergic and glutamatergic excitability in the motor cortex of patients with long-COVID and cognitive impairment.

OBJECTIVE: Attention, working memory and executive processing have been reported to be consistently impaired in Neuro-Long coronavirus disease (COVID). On the hypothesis of abnormal cortical excitability, we investigated the functional state of inhibitory and excitatory cortical regulatory circuits by single "paired-pulse" transcranial magnetic stimulation (ppTMS) and Short-latency Afferent Inhibition (SAI). METHODS: We compared clinical and neurophysiological data of 18 Long COVID patients complaining of persistent cognitive impairment with 16 Healthy control (HC) subjects. Cognitive status was evaluated by means of the Montreal Cognitive Assessment (MoCA) and a neuropsychological evaluation of the executive function domain; fatigue was scored by the Fatigue Severity Scale (FSS). Resting motor threshold (RMT), the amplitude of the motor evoked potential (MEP), Short Intra-cortical Inhibition (SICI), Intra-cortical Facilitation (ICF), Long-interval Intracortical Inhibition (LICI) and Short-afferent inhibition (SAI) were investigated over the motor (M1) cortex. RESULTS: MoCA corrected scores were significantly different between the two groups (p = 0.023). The majority of the patients' performed sub-optimally in the neuropsychological assessment of the executive functions. The majority (77.80%) of the patients reported high levels of perceived fatigue in the FSS. RMT, MEPs, SICI and SAI were not significantly different between the two groups. On the other hand, Long COVID patients showed a reduced amount of inhibition in LICI (p = 0.003) and a significant reduction in ICF (p < 0.001). CONCLUSIONS: Neuro-Long COVID patients performing sub-optimally in the executive functions showed a reduction of LICI related to GABAb inhibition and a reduction of ICF related to glutamatergic regulation. No alteration in cholinergic circuits was found. SIGNIFICANCE: These findings can help to better understand the neurophysiological characteristics of Neuro-Long COVID, and in particular, motor cortex regulation in people with "brain fog".

Impaired Neuromuscular Efficiency and Symptom-Limited Aerobic Exercise Capacity 4 Weeks After Recovery From COVID-19 Appear to Be Associated With Disease Severity at Onset.

OBJECTIVE: The objectives of this study were to evaluate neuromuscular recruitment and efficiency in participants who recovered from COVID-19 and assess the association between neuromuscular efficiency and symptom-limited aerobic exercise capacity. METHODS: Participants who recovered from mild (n = 31) and severe (n = 17) COVID-19 were evaluated and compared with a reference group (n = 15). Participants underwent symptom-limited ergometer exercise testing with simultaneous electromyography evaluation after a 4-week recovery period. Activation of muscle fiber types IIa and IIb and neuromuscular efficiency (watts/percentage of root-mean-square obtained at the maximum effort) were determined from electromyography of the right vastus lateralis. RESULTS: Participants who had recovered from severe COVID-19 had lower power output and higher neuromuscular activity than the reference group and those who had recovered from mild COVID-19. Type IIa and IIb fibers were activated at a lower power output in participants who had recovered from severe COVID-19 than in the reference group and those who had recovered from mild COVID-19, with large effect sizes (0.40 for type IIa and 0.48 for type IIb). Neuromuscular efficiency was lower in participants who had recovered from severe COVID-19 than in the reference group and those who had recovered from mild COVID-19, with a large effect size (0.45). Neuromuscular efficiency showed a correlation with symptom-limited aerobic exercise capacity (r = 0.83). No differences were observed between participants who had recovered from mild COVID-19 and the reference group for any variables. CONCLUSION: This physiological observational study supports the notion that more severe COVID-19 symptoms at disease onset appear to correspondingly impair neuromuscular efficiency in survivors over a short time frame of 4 weeks after recovery, potentially contributing to reduced cardiorespiratory capacity. Further studies are needed to replicate and extend these findings with respect to their clinical implications for assessment/evaluation and interventions. IMPACT: After 4 weeks of recovery, neuromuscular impairment is particularly evident in severe cases; this problem may contribute to reduced cardiopulmonary exercise capacity.

Chronic cough in post-COVID syndrome: Laryngeal electromyography findings in vagus nerve neuropathy.

BACKGROUND: Despite being a new entity, there is a large amount of information on the characteristics of SARS-CoV-2 infection and the symptoms of the acute phase; however, there are still many unknowns about the clinical features and pathophysiology of post-COVID syndrome. Refractory chronic cough is one of the most prevalent symptoms and carries both a medical problem and a social stigma. Many recent studies have highlighted the role of SARS-CoV-2 neurotropism, but no studies have demonstrated vagus nerve neuropathy as a cause of persistent chronic cough or other COVID-19 long-term effects. OBJECTIVE: The main objective was to assess the involvement of the vagus nerve neuropathy as a cause of chronic cough and other post-COVID syndrome symptoms. MATERIAL AND METHODS: This was a single-center observational study with prospective clinical data collected from 38 patients with chronic cough and post-COVID-19 syndrome. Clinical characteristics and laryngeal electromyographic findings were analyzed. RESULTS: Clinical data from 38 patients with chronic cough after 12 weeks of the acute phase of COVID-19 infection were analyzed. Of these patients, 81.6% suffered from other post-COVID conditions and, 73.6% reported fluctuating evolution of symptoms. Laryngeal electromyography (LEMG) of the thyroarytenoid (TA) muscles and cricothyroid (CT) muscles was pathological in 76.3% of the patients. Of the patients with abnormal LEMG, chronic denervation was the most frequent finding (82.8%), 10.3% presented acute denervation signs, and 6.9% presented myopathic pattern in LEMG. CONCLUSIONS: LEMG studies suggest the existence of postviral vagus nerve neuropathy after SARS-CoV-2 infection that could explain chronic cough in post-COVID syndrome.

Laryngeal sensory neuropathy caused by COVID-19: findings using laryngeal electromyography.

PURPOSE: Laryngeal sensory neuropathy (LSN) is caused by a disorder of the superior laryngeal nerve or the recurrent laryngeal nerve. A diagnosis of LSN should include laryngeal electromyography (LEMG) and laryngovideostroboscopy (LVS). The aim of this study was to characterize the physical and subjective symptoms of neuropathy in patients diagnosed with LSN following COVID-19. MATERIAL AND METHODS: Since the beginning of the COVID-19 pandemic, 6 patients who had recovered from the disease presented to us with LSN symptoms. All patients underwent laryngological and phoniatric examination, objective and subjective voice assessment, and LEMG. RESULTS: The most common LSN symptom reported by patients was periodic hoarseness of varying severity. Other common symptoms were the sensation of a foreign body in the throat and voice fatigue. Endoscopy often showed functional abnormalities. The LSN patients could be characterized by LEMG recordings, and all showed abnormal activity of the cricothyroid (CT) muscle. The degree of EMG changes in the CT correlated moderately with the severity of dysphonia. CONCLUSIONS: Sensory neuropathy of the larynx may be a long-lasting complication of SARS-COV-2 infection. The severity of EMG neuropathic changes in the CT muscle broadly corresponds to the severity of dysphonia.

Human Arm Workout Classification by Arm Sleeve Device Based on Machine Learning Algorithms.

Wearables have been applied in the field of fitness in recent years to monitor human muscles by recording electromyographic (EMG) signals. Understanding muscle activation during exercise routines allows strength athletes to achieve the best results. Hydrogels, which are widely used as wet electrodes in the fitness field, are not an option for wearable devices due to their characteristics of being disposable and skin-adhesion. Therefore, a lot of research has been conducted on the development of dry electrodes that can replace hydrogels. In this study, to make it wearable, neoprene was impregnated with high-purity SWCNTs to develop a dry electrode with less noise than hydrogel. Due to the impact of COVID-19, the demand for workouts to improve muscle strength, such as home gyms and personal trainers (PT), has increased. Although there are many studies related to aerobic exercise, there is a lack of wearable devices that can assist in improving muscle strength. This pilot study proposed the development of a wearable device in the form of an arm sleeve that can monitor muscle activity by recording EMG signals of the arm using nine textile-based sensors. In addition, some machine learning models were used to classify three arm target movements such as wrist curl, biceps curl, and dumbbell kickback from the EMG signals recorded by fiber-based sensors. The results obtained show that the EMG signal recorded by the proposed electrode contains less noise compared to that collected by the wet electrode. This was also evidenced by the high accuracy of the classification model used to classify the three arms workouts. This work classification device is an essential step towards wearable devices that can replace next-generation PT.

Not myopathic, but autonomic changes in patients with long-COVID syndrome: a case series.

INTRODUCTION: Neurological sequelae following SARS-CoV-2 infection still represent a serious concern both for neurologists and neuroscientists. In our paper, we investigated pain, myalgia, and fatigue as symptoms in long-COVID patients with an electrophysiological approach, comprising the evaluation of sympathetic skin responses (SSRs) and quantitative electromyography (qEMG). MATERIALS AND METHODS: Twelve patients were enrolled (mean age, 47.7 ± 11.6 years), referred to our attention because of myalgia, pain, or muscle cramps, which persisted about 6 months after the diagnosis of SARS-CoV-2 infection. They underwent conventional electroneurography (ENG), needle electromyography (EMG), and SSRs; moreover, qEMG was performed by sampling at least 20 motor unit potentials (20-30 MUPs) during weak voluntary contraction in deltoid and tibialis anterior muscles. The mean duration, amplitude, and percentage of polyphasic potentials were assessed and compared with healthy and age-matched volunteers. RESULTS: ENG did not disclose significant changes compared to healthy subjects; needle EMG did not reveal denervation activity. In addition, qEMG showed MUPs similar to those recorded in healthy volunteers in terms of polyphasia (deltoid: p = 0.24; TA: p = 0.35), MUP area (deltoid: p = 0.45; TA: p = 0.44), mean duration (deltoid: p = 0.06; TA: p = 0.45), and amplitude (deltoid: p = 0.27; TA: p = 0.63). SSRs were not recordable from lower limbs in seven patients (58%) and from the upper ones in three of them (25%). CONCLUSION: Our data suggest an involvement of the autonomic system, with a focus on cholinergic efferent sympathetic activity, without any evidence of myopathic changes.

Myopathy as a cause of Long COVID fatigue: Evidence from quantitative and single fiber EMG and muscle histopathology.

OBJECTIVE: To describe neurophysiological abnormalities in Long COVID and correlate quantitative electromyography (qEMG) and single fiber EMG (sfEMG) results to clinical scores and histopathology. METHODS: 84 patients with non-improving musculoskeletal Long COVID symptoms were examined with qEMG and sfEMG. Muscle biopsies were taken in a subgroup. RESULTS: Mean motor unit potential (MUP) duration was decreased in ≥ 1 muscles in 52 % of the patients. Mean jitter was increased in 17 % of the patients in tibialis anterior and 25 % in extensor digitorum communis. Increased jitter was seen with or without myopathic qEMG. Low quality of life score correlated with higher jitter values but not with qEMG measures. In addition to our previously published mitochondrial changes, inflammation, and capillary injury, we show now in muscle biopsies damage of terminal nerves and motor endplate with abundant basal lamina material. At the endplate, axons were present but no vesicle containing terminals. The post-synaptic cleft in areas appeared atrophic with short clefts and coarse crests. CONCLUSIONS: Myopathic changes are common in Long COVID. sfEMG abnormality is less common but may correlate with clinical scores. sfEMG changes may be due to motor endplate pathology. SIGNIFICANCE: These findings may indicate a muscle pathophysiology behind fatigue in Long COVID.

Electrophysiological assessment in patients with COVID-19-related peripheral neuropathies and myopathies: a systematic review.

Neurological manifestations associated with Coronavirus Disease-2019 (COVID-19) are commonly reported, but patients were not referred to perform the electrophysiological assessment. We aimed to review the existing literature on clinical studies on COVID-19 peripheral neuropathy to correlate patients' symptoms and characteristics with nerve conduction studies/electromyography (NCS/EMG) outcomes. This protocol is registered in the Open Science Framework (https://www.doi.org/10.17605/OSF.IO/ZF4PK). The systematic search included PubMed, ScienceDirect, and Google Scholar, for articles published from December 2019 to March 2022. A total of 727 articles were collected, and according to our inclusion and exclusion criteria, only 6 articles were included. Of 195 participants, only 175 underwent NCS/EMG assessment. Of these, 44 participants (25.1%) had abnormal EMG, 54 participants (30.8%) had abnormal motor NCS, and only 7 participants (4%) had abnormal sensory NCS. All cases presented with myopathy, while a limited number of cases presented with polyneuropathy. According to motor NCS and EMG, the most affected nerves were the tibial and peroneal in the lower extremities and the ulnar nerve in the upper extremities. Interestingly, the median nerve was reported to be associated with the severity and the rate of motor recovery of patients with COVID-19. COVID-19 generates a demyelinating motor neuropathy and myopathy. Clinicians are encouraged to refer patients with COVID-19 presenting with neurological symptoms to be assessed by electrophysiological methods to objectively determine the nature of their symptoms, follow their prognosis, and plan their rehabilitation.

Electromyography-biofeedback for chronic low back pain: A qualitative cohort study.

BACKGROUND AND AIMS: Surface electromyography-biofeedback (sEMG-BF) may reduce the burden of CLBP by improving physical functioning, sleep, pain catastrophizing, anxiety, and depression. This qualitative study investigated the impact of weekly EMG-BF sessions on adults with CLBP. METHODS: Twenty-six individuals with CLBP participated in telephone interviews after completing an 8-week virtual sEMG-BF intervention. Trained interviewers conducted the 10-to-15-minute semi-structured interviews to understand participants' experience with the intervention. Common themes and subthemes were identified and analyzed using MAXQDA 2022 software. RESULTS: Participants were predominantly middle-aged females (M = 45, range of 19 - 66) who have had exposure to utilizing conventional therapies such as physical therapy, chiropractor, and massage for the treatment of CLBP. This study focused on participants who reported their experience of the main outcome study which included perceived reductions in CLBP symptoms, including pain and stress, and positive effects on self-awareness and sleep. Three overarching themes emerged and were further divided into subthemes: participants' involvement (virtual experience, accessibility of device, and future recommendations) perceived benefits (participants gained awareness, recommendations for future treatment, met expectations, and implementation), and desire for flexibility (obstacles and COVID-19 Impact). No adverse effects were reported by any of the participants within the study. CONCLUSIONS: Both physical and psychological improvements were reported by participants following an sEMG-BF intervention. Specific implementation procedures and critical barriers were identified. In particular, the ability to receive care for CLBP during the COVID-19 pandemic was important to participants.

The Difference in Electromyographic Activity While Wearing a Medical Mask in Women with and without Temporomandibular Disorders.

Wearing a medical mask influences resting activity of the temporalis anterior and masseter muscles in healthy young women. However, no studies link medical mask-wearing with masticatory muscle activity in patients with temporomandibular disorders (TMDs). Therefore, this study aims to compare electromyographic patterns while wearing a medical mask between women with and without temporomandibular disorders. Based on the Research Diagnostic Criteria for Temporomandibular Disorders, 115 adult women qualified for the study. Participants were divided into the following two groups: diagnosed TMDs (n = 55; mean age: 23.5 ± 2.3 years) and healthy women (n = 60; mean age: 23.7 ± 2.6 years). Examinations of the resting and functional electromyographic activity of the temporalis anterior (TA), superficial masseter (MM), anterior bellies of the digastric muscle (DA), and the middle part of the sternocleidomastoid muscle (SCM) were carried out using the BioEMG III™. Both groups showed statistically significant decreases in resting masticatory muscle activity during medical mask examination compared to no mask measurement. The significant differences in no mask measurement between both groups were noted regarding resting masticatory activity, clenching in the intercuspal position, and clenching on dental cotton rollers. During medical mask examination, women with TMDs showed differences in resting masticatory activity and clenching on dental cotton rollers compared to the healthy group. In all analyzed variables, both groups showed similar electromyographic patterns in the maximum mouth opening measurement during medical mask and no mask examination. A medical mask influences the resting bioelectric activity of the masticatory muscles in women with temporomandibular disorders and healthy women. We observed differences and some similarities in resting and functional electromyographic patterns within masticatory and neck muscles in both groups during medical mask and no mask examination.

Electroneurological changes in peripheral nerves in patients post-COVID.

Various neurological manifestations are observed in about 36.4% of patients infected with SARS-CoV-2 and post-COVID neuropathy is one of them. There is lack of studies describing neurophysiological abnormalities in peripheral nerves in case of patients who had SARS-CoV-2 infection. The aim of this study was to analyze the changes in peripheral nervous system in case of COVID-19 survivors. In the presented study, 45 COVID-19 survivors who had nerve conduction study (NCS) were involved. Results were compared with control group consisting of healthy patients who had nerve conduction study before the COVID-19 pandemic. In our study group, neurophysiological abnormalities were present in the case of both sensory and motor nerve fibers. The most significant reduction of NCS parameters was observed in the case of sensory action potential amplitude of sural nerve. Moreover, that correlation was the most significant in the case of amplitude and conduction velocity in sensory and motor neuron fibers both in arms and legs. Those abnormalities were observed even 6 mo after COVID-19. Further investigation needs to be done regarding the polyneuropathies associated with human coronaviruses, and we should answer the question whether the virus directly damages peripheral nerves or factors mediating inflammatory response are responsible for the neural damage.NEW & NOTEWORTHY Various neurological manifestations are observed in about 36.4% of patients infected with SARS-CoV-2 and post-COVID neuropathy is one of them. There is lack of studies describing neurophysiological abnormalities in peripheral nerves in case of patients who had SARS-CoV-2 infection. The aim of this study was to analyze changes in peripheral nervous system in case of COVID-19 survivors.

Neurophysiological Findings in Critical COVID-19 Patients With Peripheral Nervous System Manifestations.

INTRODUCTION: Coronavirus disease 2019 patients hospitalized in intensive care units develop neuromuscular manifestations. However, to our knowledge, a study describing the neurophysiological findings in these patients has not been reported. The objective of this study was to diagnose the cause of neuromuscular deficit in severe coronavirus disease 2019 patients, through neurophysiological examination. METHODS: This is a retrospective, observational case series. Data were collected from April 13, 2020, to May 31, 2020. Twenty-two coronavirus disease 2019 patients with generalized neuromuscular deficit during intensive care unit hospitalization were studied. Neurophysiological examinations included motor and sensory peripheral nerve conductions, needle electromyography, F waves, and repetitive nerve stimulation. RESULTS: The subjects were 14 men (63.6%) and eight women, ranged from 35 to 74 years old (58.0, interquartile ranges 50.7-66.2). Intensive care unit hospitalization time ranged from 14 to 82 days (median 37.5, interquartile ranges 22.7-55.0). Through neurophysiological examination, myopathy was diagnosed in 17 patients (77.3%) and polyneuropathy in four (18.2%). Focal neuropathies were diagnosed in 12 patients (54.6%), with a total of 19 affected nerves. Common peroneal nerve lesions at the fibular head (68.4%) and ulnar nerve lesions at the elbow level (21.1%) were the most frequent locations. No significant differences were established between neurophysiological findings and clinical or analytical data. CONCLUSIONS: In critical coronavirus disease 2019 patients with neuromuscular complaints, neurophysiological examination provides an accurate diagnosis-useful to select treatment measures and establish the prognosis of recovery. Neurophysiological findings are similar to those described for critical illness neuromuscular disease, with myopathy being the most frequent diagnosis.

Muscle fatigability and post-acute COVID-19 syndrome: A case study.

The acute phase of COVID-19 has been well studied, however with increasing post-acute COVID-19 syndrome, much is unknown about its long-term effects. A common symptom in both the acute and post-acute phases has been fatigue, assessed predominantly qualitatively. Here we present a case study objectively assessing neuromuscular fatiguability in a young male (27 year, 1.85 m, 78 kg) who continues to experience COVID-19 related fatigue and cognitive dysfunction, including other symptoms, 12+ months post-infection. Prior to infection, he was part of a neuromuscular study forming the basis of our pre-COVID-19 results. The study was repeated 12 months post-COVID-19 infection. Muscle strength, endurance, torque steadiness, voluntary activation, twitch properties, electromyography, and compound muscle action potential were obtained and compared pre- and post-COVID-19. All measurements were done using a dorsiflexion dynamometer in which the participant also was asked to produce a one-minute fatiguing maximal voluntary contraction. Muscle strength, voluntary activation, and fatigability (slope of torque) showed no meaningful differences, suggesting intrinsic neuromuscular properties are not affected. However, torque steadiness was impaired three-fold in the post- compared with pre-COVID-19 test. The participant also reported a higher level of perceived exertion subjectively and a continued complaint of fatigue. These findings indicate that muscle fatiguability in post-acute COVID-19 syndrome may not be a limitation of the muscle and its activation, but a perceptual disconnect caused by cognitive impairments relating to physical efforts. This case report suggests the potential value of larger studies designed to assess these features in post-acute COVID-19 syndrome.

The influence of idiopathic chronic neck pain on upper trapezius and sternocleidomastoid muscle activity and elasticity during functional reaching: A cross-sectional study.

It remains unclear whether idiopathic chronic neck pain is associated with changes in muscle stiffness alongside alterations in neuromuscular control. Therefore, the purpose of this study was to determine the influence of idiopathic chronic neck pain on the muscle stiffness and muscle activity of the upper trapezius and sternocleidomastoid muscles during the maintenance of unilateral and bilateral functional reaching tasks. Surface electromyography (EMG) and ultrasound shear wave elastography were collected from the sternocleidomastoid and upper trapezius muscles in 18 individuals with idiopathic chronic neck pain and 18 matched healthy controls. Participants completed three functional reaching tasks; 1) unilateral forward reach, 2) bilateral forward reach, and 3) unilateral upward reach, and held at the top of each reaching movement for data to be collected bilaterally. A univariate ANOVA was utilized for each outcome measure (mean EMG amplitude and shear wave velocity) and each reaching task. Individuals with idiopathic chronic neck pain exhibited significantly lower upper trapezius activation during bilateral reaches without corresponding changes to stiffness during similar trials. Similarly, this cohort exhibited decreased sternocleidomastoid stiffness during forward reaching, without corresponding activation changes. Lastly, women demonstrated consistently higher sternocleidomastoid activation and stiffness when compared to men. These findings indicate individuals with idiopathic chronic neck pain may adapt their movement strategies, possibly for pain avoidance. The demonstrated changes in muscle stiffness independent of changes in muscle activity highlight the importance of evaluating both muscle stiffness and activation in individuals with idiopathic chronic neck pain prior to designing rehabilitation programs.

Early-Onset Myasthenia Gravis Following COVID-19 Vaccination.

As coronavirus disease 2019 (COVID-19) has spread worldwide, the rate of COVID-19 vaccination uptake is encouraging. Neurological complications associated with COVID-19 vaccines such as stroke, Guillain-Barré syndrome, and Bell's palsy have been reported. Recently, late-onset myasthenia gravis (MG) following COVID-19 vaccination has been reported. To date, however, there has been no evidence of increased risk of early-onset MG following COVID-19. Here, we report a case of a patient with new-onset MG that arose after receiving a COVID-19 vaccine. A 33-year-old woman suddenly experienced generalized weakness and diplopia on the evening she had received the second dose of the Pfizer-BioNTech COVID-19 vaccine. The temporal relationship suggests that this new-onset MG is related to the vaccination. It also implies that COVID-19 vaccination could trigger early-onset MG symptoms in patients at risk of MG.

Guillain-Barre Syndrome After Two COVID-19 Vaccinations: Two Case Reports With Follow-up Electrodiagnostic Study.

Guillain-Barre syndrome (GBS) is an immune-mediated acute polyradiculoneuropathy and commonly occurs after a preceding infection or immunization sequalae. Following the severe acute respiratory syndrome-coronavirus-2 virus pandemic with co-introduction of massive vaccinations, several GBS cases associated with coronavirus disease 2019 (COVID-19) infection per se or after vaccination for COVID-19 were reported internationally. Herein, we report two cases of Korean GBS presenting with tetraplegia after two different COVID-19 vaccinations (42-year old man by AstraZeneca and 48-year woman by Pfizer vaccines) within four weeks after vaccination. The patients were diagnosed with clinical examination, serial electromyography, and compatible laboratory results and improved after comprehensive rehabilitative treatment and intravenous immunoglobulin therapy. Furthermore, we performed an electrodiagnostic follow-up study of each case to examine their unique characteristics.

Dermatomyositis Following BNT162b2 mRNA COVID-19 Vaccination.

Dermatomyositis (DM) is one of the uncommon multi-organ idiopathic inflammatory myopathies that has been reported following the hepatitis B, Influenza, tetanus toxoid, H1N1, and BCG vaccines. However, an association with the coronavirus disease 2019 (COVID-19) vaccine is yet to be reported. In this case, we present the case of a 43-year-old Asian Indian female who was diagnosed with DM 10 days after receiving the second dosage of BNT162b2 mRNA COVID-19 vaccination, in the absence of any additional triggering factors. The diagnosis was established based on physical examination, serological antibodies, magnetic resonance imaging of the muscles, skin biopsy, and electromyography. She received standard treatment for DM, including oral high doses of prednisolone, hydroxychloroquine, mycophenolate, and physiotherapy. The treatment successfully reversed skin changes and muscle weakness. This is the first reported case of classic DM complicated by interstitial lung disease following COVID-19 vaccination. More clinical and functional studies are needed to elucidate this association. Clinicians should be aware of this unexpected adverse event following COVID-19 vaccination and arrange for appropriate management.

Biopotential Signal Monitoring Systems in Rehabilitation: A Review.

Monitoring physical activity in medical and clinical rehabilitation, in sports environments or as a wellness indicator is helpful to measure, analyze and evaluate physiological parameters involving the correct subject's movements. Thanks to integrated circuit (IC) technologies, wearable sensors and portable devices have expanded rapidly in monitoring physical activities in sports and tele-rehabilitation. Therefore, sensors and signal acquisition devices became essential in the tele-rehabilitation path to obtain accurate and reliable information by analyzing the acquired physiological signals. In this context, this paper provides a state-of-the-art review of the recent advances in electroencephalogram (EEG), electrocardiogram (ECG) and electromyogram (EMG) signal monitoring systems and sensors that are relevant to the field of tele-rehabilitation and health monitoring. Mostly, we focused our contribution in EMG signals to highlight its importance in rehabilitation context applications. This review focuses on analyzing the implementation of sensors and biomedical applications both in literature than in commerce. Moreover, a final review discussion about the analyzed solutions is also reported at the end of this paper to highlight the advantages of physiological monitoring systems in rehabilitation and individuate future advancements in this direction. The main contributions of this paper are (i) the presentation of interesting works in the biomedical area, mainly focusing on sensors and systems for physical rehabilitation and health monitoring between 2016 and up-to-date, and (ii) the indication of the main types of commercial sensors currently being used for biomedical applications.

Impact of Lockdown during COVID-19 Pandemic on Central Activation, Muscle Activity, Contractile Function, and Spasticity in People with Multiple Sclerosis.

BACKGROUND: People with multiple sclerosis (MS) suffer from symptoms related to neural control, such as reduced central activation, lower muscle activity, and accentuated spasticity. A forced 9-week home confinement related to COVID-19 in Spain may have worsened these symptoms. However, no study has demonstrated the impact of home confinement on neuromuscular mechanisms in the MS population. This study was aimed at analyzing the effects of a 9-week home confinement on central activation, muscle activity, contractile function, and spasticity in MS patients. METHODS: Eighteen participants were enrolled in the study. Left and right knee extensor maximum voluntary isometric contraction (MVIC), maximal neural drive via peak surface electromyography (EMG) of the vastus lateralis, central activation ratio (CAR), and muscle contractile function via electrical stimulation of the knee extensor muscles, as well as spasticity using the pendulum test, were measured immediately before and after home confinement. RESULTS: Seventeen participants completed the study. CAR significantly decreased after lockdown (ES = 1.271, p < 0.001). Regarding spasticity, there was a trend to decrease in the number of oscillations (ES = 0.511, p = 0.059) and a significant decrease in the duration of oscillations (ES = 0.568, p = 0.038). Furthermore, in the left leg, there was a significant decrease in the first swing excursion (ES = 0.612, p = 0.027) and in the relaxation index (ES = 0.992, p = 0.001). Muscle contractile properties, MVIC, and EMG variables were not modified after confinement. CONCLUSIONS: The results suggest that a home confinement period of 9 weeks may lead to an increase in lower limb spasticity and a greater deficit in voluntary activation of the knee extensors.