Peripheral Neuropathies Derived from COVID-19: New Perspectives for Treatment

Transdermal electrophysiological recordings of diet-induced small fiber peripheral neuropathy using a needle electrode array in mice and man

Background

Diabetic peripheral neuropathy (DPN) is a common complication of diabetes. Proactive treatment options remain limited, which is exacerbated by a lack of sensitive and convenient diagnostics, especially early in disease progression or specifically to assess small fiber neuropathy (SFN), the loss of distal small diameter axons that innervate tissues and organs.

Methods

We designed, fabricated, tested, and validated a first-of-its-kind medical diagnostic device for the functional assessment of transdermal small fiber nerve activity. This device, the Detecting Early Neuropathy (DEN), is an electrically conductive needle array designed to record nerve electrical activity in the skin and subdermal tissues, as a feature of a broader theragnostic platform.

Results

DEN recordings were validated across a time course of diet-induced PN in mice, using statistical and computational analyses and compared to other SFN measures. Based on these preclinical mouse data, the device design was adapted to obtain recordings in human with a flexible printed circuit board to mold to the leg or other skin regions. The DEN successfully recorded various types of neural activity in mouse and human, with or without stimulation, including validated action potentials and electromyography signals.

Conclusion

New functional diagnostic tools like DEN offer a promising outlook for patients needing an earlier or more sensitive diagnosis of DPN/SFN, to allow for earlier and more effective treatment options, especially as more become available in the clinic in future years.

Unilateral Compressive Peroneal Neuropathy in Intensive Care Settings During the COVID-19 Pandemic: A Series of Three Cases

Peroneal nerve entrapment, typically associated with behaviors like cross-legged sitting or squatting, can also occur from extended periods of lying down where the lower limbs usually assume a position of hip external rotation and knee flexion. In such positions, the fibular head's prominence can exert sustained pressure on the peroneal nerve. We report three cases of unilateral peroneal neuropathy in intensive care unit (ICU) patients during the coronavirus disease (COVID-19) pandemic, highlighting the possible role of prolonged supine or lateral decubitus positions in the development of this condition. Electrophysiological studies confirmed peroneal nerve palsy in all cases, with two patients achieving full recovery, while the third required a permanent ankle foot orthosis for mobility due to a lack of neurological recovery. The COVID-19 pandemic has challenged ideal nursing care, including in ICU settings, leading to suboptimal nursing care standards and compromised frequent positioning regimes.

A new perspective on vitamin B12 deficiency in rheumatology: a case-based review

Vitamin B12 (cobalamin) deficiency is common in patients with rheumatic diseases. Pernicious anemia is a well-known cause, but recent reports suggest that autoimmune-derived deficiency may not be limited to this cause alone. Symptoms of low vitamin B12 concentration are often deceptive, mimicking and overlapping with symptoms of other conditions. Neuropsychiatric manifestations, anemia, and fatigue are frequently attributed to a rheumatic disease without further evaluation. In this study, we present three cases of patients with neuropathic pain, depression, fatigue, and muscle weakness, initially attributed to a rheumatic disease, which almost completely resolved after implementing vitamin B12 supplementation. Furthermore, we provide an overview of current scientific reports regarding the potential use of cobalamin in rheumatology. Treatment of pain and neuropathy, often very challenging in long-lasting rheumatic diseases, can be more effective after a course of vitamin B12, even when no apparent deficiency is detected in laboratory tests. Considering recent research demonstrating vitamin B12's nerve-protecting properties, we recommend that physicians should assess vitamin B12 levels early in the diagnostic process of rheumatic diseases. In specific cases, physicians should consider cobalamin supplementation regardless of vitamin B12 serum concentration.

Precision management of post-COVID pain: An evidence and clinical-based approach

Background Pain after a SARS-CoV-2 acute infection (post-COVID pain) is becoming a new healthcare emergency but remains underestimated and most likely undertreated due to a lack of recognition of the phenomenon and knowledge of the underlying pain mechanisms. Evidence supporting any particular treatment approach for the management of post-COVID pain is lacking. Large variability in the patient response to any standard pain treatments is clinically observed, which has led to calls for a personalized, tailored approach to treating patients with chronic post-COVID pain (i.e. 'precision pain medicine'). Applying the global concerted action towards precision medicine to post-COVID pain could help guide clinical decision-making and aid in more effective treatments. Methods The current position paper discusses factors to be considered by clinicians for managing post-COVID pain ranging from identification of the pain phenotype to genetic consideration. Results The ability of clinicians to phenotype post-COVID pain into nociceptive, neuropathic, nociplastic or mixed type is suggested as the first step to better planification of a treatment programme. Further, the consideration of other factors, such as gender, comorbidities, treatments received at the acute phase of infection for onset-associated COVID-19 symptoms, factors during hospitalization or the presence of emotional disturbances should be implemented into a treatment programme. Conclusions Accordingly, considering these factors, management of post-COVID pain should include multimodal pharmacological and non-pharmacological modalities targeting emotional/cognitive aspects (i.e. psychological and/or coping strategies), central sensitization-associated mechanisms (i.e. pain neuroscience education), exercise programmes as well as lifestyle interventions (e.g. nutritional support and sleep management). SIGNIFICANCE: This position paper presents an evidence-based clinical reasoning approach for precision management of post-COVID pain.

Unveiling the Mysteries of Long COVID Syndrome: Exploring the Distinct Tissue and Organ Pathologies Linked to Prolonged COVID-19 Symptoms

The ongoing battle against the coronavirus disease 2019 (COVID-19) pandemic has encountered a complex aspect with the emergence of long COVID syndrome. There has been a growing prevalence of COVID-19-affected individuals experiencing persistent and diverse symptoms that extend beyond the initial infection phase. The phenomenon known as long COVID syndrome raises significant questions about the underlying mechanisms driving these enduring symptoms. This comprehensive analysis explores the complex domain of long COVID syndrome with a view to shed light on the specific tissue and organ pathologies contributing to its intricate nature. This review aims to analyze the various clinical manifestations of this condition across different bodily systems and explore potential mechanisms such as viral persistence, immune dysregulation, autoimmunity, and molecular mimicry. The goal is to gain a better understanding of the intricate network of pathologies contributing to long COVID syndrome. Understanding these distinct pathological indicators provides valuable insights into comprehending the complexities of long COVID and presents opportunities for developing more accurate diagnostic and therapeutic strategies, thereby improving the quality of patient care by effectively addressing the ever-changing medical challenge in a more focused manner.

Delayed Surgical Treatment in Patients with Chronic Carpal Tunnel Syndrome Is Still Effective in the Improvement of Hand Function

Background and Objectives: Severe carpal tunnel syndrome (CTS) is the most common compression neuropathy in the upper extremities treated conservatively; later, when advanced, CTS is treated mostly surgically. The most prevalent symptoms comprise numbness, as well as sensation loss in the thumb, index, and middle finger, and thenar muscle strength loss, resulting in impaired daily functioning for patients. Data on the results of CTS treatment in patients with delayed surgical intervention are scarce. The aim of this study was to determine the postoperative results of chronic carpal tunnel syndrome treatment in patients with symptoms lasting for at least 5 years. Materials and Methods: A total of 86 patients (69 females, 17 males) with a mean age of 58 years reporting symptoms of CTS for at least 5 years (mean: 8.5 years) were prospectively studied. The average follow-up time was 33 months. All patients underwent the surgical open decompression of the median nerve at the wrist. A preoperative observation was composed of an interview and a clinical examination. The subjects completed the DASH (the Disabilities of the Arm, Shoulder, and Hand), PRWE (Patient-Rated Wrist Evaluation), and self-report questionnaires. Global grip strength, sensory discrimination, characteristic symptoms of CTS, and thenar muscle atrophy were examined. Postoperatively, clinical and functional examinations were repeated, and patients expressed their opinions by completing a BCTQ (Boston Carpal Tunnel Syndrome Questionnaire). Results: We found improvements in daily activities and hand function postoperatively. Overall, 88% of patients were satisfied with the outcome of surgery. DASH scores decreased after surgery from 44.82 to 14.12 at p < 0.001. PRWE questionnaire scores decreased from 53.34 to 15.19 at p < 0.001. The mean score of the BCTQ on the scale regarding the severity of symptoms was 1.48 and 1.62 on the scale regarding function after surgery. No significant differences were found in the scores between the male and female groups or between age groups (p > 0.05). A significant increase in global grip strength from 16.61 kg to 21.91 kg was observed postoperatively at p < 0.001. No significant difference was detected in the measurement of sensory discrimination (6.02 vs. 5.44). In most of the examined patients, night numbness and wrist pain subsided after surgery at p < 0.001. Thenar muscle atrophy diminished after surgery at p < 0.001. Conclusions: Most patients were satisfied with the results of CTS surgery regarding the open decompression of the median nerve even after 5 years of ineffective conservative treatment. Significant improvement of the hand function was confirmed in the functional studies.

Long COVID, the Brain, Nerves, and Cognitive Function

SARS-CoV-2, a single-stranded RNA coronavirus, causes an illness known as coronavirus disease 2019 (COVID-19). Long-term complications are an increasing issue in patients who have been infected with COVID-19 and may be a result of viral-associated systemic and central nervous system inflammation or may arise from a virus-induced hypercoagulable state. COVID-19 may incite changes in brain function with a wide range of lingering symptoms. Patients often experience fatigue and may note brain fog, sensorimotor symptoms, and sleep disturbances. Prolonged neurological and neuropsychiatric symptoms are prevalent and can interfere substantially in everyday life, leading to a massive public health concern. The mechanistic pathways by which SARS-CoV-2 infection causes neurological sequelae are an important subject of ongoing research. Inflammation- induced blood-brain barrier permeability or viral neuro-invasion and direct nerve damage may be involved. Though the mechanisms are uncertain, the resulting symptoms have been documented from numerous patient reports and studies. This review examines the constellation and spectrum of nervous system symptoms seen in long COVID and incorporates information on the prevalence of these symptoms, contributing factors, and typical course. Although treatment options are generally lacking, potential therapeutic approaches for alleviating symptoms and improving quality of life are explored.

Novel Approach to the Treatment of Neuropathic Pain Using a Combination with Palmitoylethanolamide and Equisetum arvense L. in an In Vitro Study

Neuropathic pain is a typical patient disorder resulting from damage and dysfunction of the peripheral neuraxis. Injury to peripheral nerves in the upper extremities can result in a lifelong reduction in quality of life and a devastating loss of sensory and motor function. Since some standard pharmaceutical therapies can cause dependence or intolerance, nonpharmacological treatments have gained great interest in recent years. In this context, the beneficial effects of a new combination of palmitoylethanolamide and Equisetum arvense L. are evaluated in the present study. The bioavailability of the combination was initially analyzed in a 3D intestinal barrier simulating oral intake to analyze its absorption/biodistribution and exclude cytotoxicity. In a further step, a 3D nerve tissue model was performed to study the biological effects of the combination during the key mechanisms leading to peripheral neuropathy. Our results demonstrate that the combination successfully crossed the intestinal barrier and reached the target site, modulating the nerve recovery mechanism after Schwann cell injury and offering the initial response of relieving pain. This work supported the efficacy of palmitoylethanolamide and Equisetum arvense L. in reducing neuropathy and modifying the major pain mechanisms, outlining a possible alternative nutraceutical approach.