Evolving role of VIADISC for chronic low back and discogenic pain: a narrative review.

INTRODUCTION: Chronic lower back pain is a leading cause of disability and healthcare spending worldwide. Discogenic pain, pain originating from the intervertebral disk, is a common etiology of chronic lower back pain. Currently, accepted treatments for chronic discogenic pain focus only on the management of symptoms, such as pain. There are no approved treatments that stop or reverse degenerating intervertebral discs. Biologic therapies promoting disc regeneration have been developed to expand treatment options. VIADISC™ NP, is a viable disc allograft supplementation that, in a recent trial, demonstrated a significant reduction in pain and increased function in patients suffering from symptomatic degenerative disc disease. AREAS COVERED: This manuscript summarizes the epidemiology and etiology of low back pain, the pathophysiology of degenerative disc disease, current treatments, and a need for newer therapies. The rationale behind intradiscal biologics for the treatment of symptomatic degenerative disc disease is also discussed. EXPERT OPINION: Characterization of the biology leading to disc degeneration has allowed for the development of intradiscal biologics. They may soon be capable of preventing and reversing disc degeneration. Clinical trials have shown promise, but further research into efficacy and safety is needed before these therapies are widely employed.

Recent Advances in Management of Neuropathic, Nociceptive, and Chronic Pain: A Narrative Review with Focus on Nanomedicine, Gene Therapy, Stem Cell Therapy, and Newer Therapeutic Options.

PURPOSE OF REVIEW: This manuscript summarizes novel clinical and interventional approaches in the management of chronic, nociceptive, and neuropathic pain. RECENT FINDINGS: Pain can be defined as a feeling of physical or emotional distress caused by an external stimulus. Pain can be grouped into distinct types according to characteristics including neuropathic pain, which is a pain caused by disease or lesion in the sensory nervous system; nociceptive pain, which is pain that can be sharp, aching, or throbbing and is caused by injury to bodily tissues; and chronic pain, which is long lasting or persisting beyond 6 months. With improved understanding of different signaling systems for pain in recent years, there has been an upscale of methods of analgesia to counteract these pathological processes. Novel treatment methods such as use of cannabinoids, stem cells, gene therapy, nanoparticles, monoclonal antibodies, and platelet-rich plasma have played a significant role in improved strategies for therapeutic interventions. Although many management options appear to be promising, extensive additional clinical research is warranted to determine best practice strategies in the future for clinicians.

The Role of Platelet Rich Plasma in Vertebrogenic and Discogenic Pain: A Systematic Review and Meta-Analysis.

PURPOSE OF REVIEW: The present investigation evaluates clinical uses and roles of platelet rich plasma in the management of vetrebrogenic and discogenic mediated pain states. RECENT FINDINGS: Back pain is a common and significant condition that affects millions of people around the world. The cause of back pain is often complex and multifactorial, with discogenic and vertebrogenic pain being two subtypes of back pain. Currently, there are numerous methods and modalities in which back pain is managed and treated such as physical therapy, electrical nerve stimulation, pharmacotherapies, and platelet-rich plasma. To conduct this systematic review, the authors used the keywords "platelet-rich plasma", "vertebrogenic pain", and "discogenic pain", on PubMed, EuroPMC, Who ICTRP, and clinicaltrials.gov to better elucidate the role of this treatment method for combating vertebrogenic and discogenic back pain. In recent decades, there has been a rise in popularity of the use of platelet-rich plasma for the treatment of numerous musculoskeletal conditions. Related to high concentration of platelets, growth factors, cytokines, and chemokines, platelet-rich plasma is effective in reducing pain related symptoms and in the treatment of back pain. Platelet-rich plasma use has evolved and gained popularity for pain related conditions, including vertebrogenic and discogenic back pain. Additional well-designed studies are warranted in the future to better determine best practice strategies to provide future clinicians with a solid foundation of evidence to make advancements with regenerative medical therapies such as platelet-rich plasma.

Peripheral Nerve Stimulation in Postoperative Analgesia: A Narrative Review.

PURPOSE OF REVIEW: Recent research has shown the effectiveness of peripheral nerve stimulators (PNS) in managing chronic pain conditions. Ongoing studies aim to explore its potential application in treating acute postoperative pain states. The purpose of this systematic review is to assess the role of PNS in providing relief for postoperative pain. RECENT FINDINGS: Clinical studies investigating the use of peripheral nerve stimulators (PNS) for analgesia following various surgeries, such as total knee arthroplasty, anterior cruciate ligament repair, ankle arthroplasty, rotator cuff repair, hallux valgus correction, and extremity amputation, have shown promising results. Lead placement locations include the brachial plexus, sciatic, femoral, tibial, genicular, perineal, sural, radial, median, and ulnar nerves. These studies consistently report clinically significant reductions in pain scores, and some even indicate a decrease in opioid consumption following PNS for postoperative pain. PNS involves the subcutaneous placement of electrode leads to target peripheral nerve(s) followed by delivery of an electric current via an external pulse generator. While the precise mechanism is not fully understood, the theory posits that PNS modulates electrical stimulation, hindering the signaling of nociceptive pain. PNS presents itself as an alternative to opioid therapy, holding promise to address the opioid epidemic by offering a nonpharmacologic approach for both acute and chronic pain states.

Liquid biopsy in the setting of leptomeningeal metastases: a systematic review and meta-analysis.

PURPOSE: The blood-brain barrier can prevent circulating tumor DNA (ctDNA) derived from the central nervous system from entering the blood making it challenging to evaluate molecular features of leptomeningeal metastasis (LM). Accordingly, we sought to systematically compare the diagnostic power or significance of ctDNA derived from cerebrospinal fluid (CSF) compared to plasma ctDNA in patients with LM. METHODS: A systematic review and meta-analysis was performed under the PRISMA guideline. We used PubMed, EMBASE, and the EuroPMC to search the literature using combinations of the following terms: circulating tumor DNA, ctDNA, circulating tumor cell, brain metastasis, leptomeningeal metastasis, outcome(s), and prognosis. We included all available English language studies that compared the diagnostic significance of CSF derived and serum ctDNA. All eligible studies level of bias was assessed using the New Castle Ottawa Scale (NOS). RESULTS: Our meta-analysis from 6 included studies (n = 226) that confirmed the diagnostic power of liquid biopsies in detecting genomic alteration is better when taking a CSF-derived samples than from the plasma (RR 1.46 [0.93; 2.29]; I2 = 92%; p-value < 0.01). CONCLUSION: CSF ctDNA is better at describing molecular landscape for LM; such an understanding may ultimately help inform patient treatment and responses to therapy.

Cebranopadol for the Treatment of Chronic Pain.

PURPOSE OF REVIEW: Regardless of the etiology, if pain persists chronically, it can detrimentally impact multiple aspects of a patient's well-being. Both physical and psychological effects are significant in many chronic pain patients. In this regard, psychological consequences can alter a patient's quality of life, functionality, and social functioning. Opioids have been the long-established gold standard for acute pain treatment in settings such as the postoperative period. An alternative to opioids in pain management has been highly sought after. Through a non-selective mechanism, cebranopadol is a first-in-class oral drug which combines agonism of the mu and nociceptin opioid peptide (NOP) receptors to provide improved analgesia, while reducing the occurrence of many typically opioid side effects. This manuscript is a narrative review of the possible use of cebranopadol in pain management. RECENT FINDINGS: In pre-clinical studies, cebranopadol was similar to morphine in its pain control efficacy. In a phase IIa trial, cebranopadol was superior to placebo in reducing pain. In a randomized clinical trial, cebranopadol was superior to morphine. Another study concluded that cebranopadol had a lower misuse potential when compared to hydromorphone. In summary, cebranopadol offers new opportunities in treating chronic moderate to severe pain, while also countering risks of addiction. Additional studies are warranted to further evaluate the safety and efficacy of cebranopadol. In this regard, cebranopadol could prove to be a promising alternative to current pain treatment options.

The Use of Oxytocin for the Treatment of Opioid Use Disorder.

Nearly 27 million people have an opioid use disorder (OUD) according to the 2016 Global Burden of Disease study, most of which occur in the US where opioids are a common class of medication used to treat acute and chronic pain. In 2016 alone, more than 60 million patients had at least one prescription for opioids filled or refilled. Over the past decade, prescription rates have risen astronomically and have created an epidemic in the US dubbed the "opioid crisis." In this regard, there has been an increase in overdoses and OUD diagnoses. Several studies have found dysregulation of balance between several neurotransmitters involved in the neural circuitry that subserves several behavioral domains, such as reward recognition, motivation, learning, and memory, affect, stress, and executive function, that contribute to the manifestation of craving. On the horizon is a new treatment approach consisting of the neuropeptide oxytocin, which may be involved in the overlapping mechanisms of stable attachment formation and coping with stress. Through this mechanism, it can shift processing from novelty and reward-seeking to an appreciation of familiarity and thus reduce stress and increase resilience in the face of addiction. It has been hypothesized that there is a connection between the glutaminergic and oxytocinergic systems, making oxytocin a possible therapeutic agent in reducing drug-induced actions seen in OUD patients. This manuscript will review the potential and feasible use of oxytocin in treating OUD.

Concomitant Occurrence of Peripheral Neuropathy and Vision Loss Due to Multivitamin Deficiency After Bariatric Surgery.

Vitamin deficiencies, especially after Bariatric surgery, are common and, when not properly addressed, can lead to debilitating complications. Bariatric procedures, to variable degrees, alter the anatomy and physiology of the gastrointestinal; this alteration makes these patients more susceptible to developing nutritional deficiencies. Peripheral neuropathy is one of the complications that can arise from nutritional deficiencies, and it can cause severe functional impairment. Vision loss is a relatively uncommon complication after weight loss procedure. Changes in the retinal nerve fiber layer, choroidal thickness, and visual fields due to hypovitaminosis result in nutritional optic neuropathy and retinopathy. The main retinal complication is nyctalopia (night blindness), which is caused by vitamin A deficiency. We present a case of concomitant peripheral neuropathy and vision loss secondary to reduced levels of multiple vitamins following gastric bypass surgery. This case highlights the need for regular vitamin level monitoring and appropriate replenishment in patients after bariatric surgery to prevent significant morbidities.

Immune Thrombocytopenia and Cerebral Venous Sinus Thrombosis Following COVID-19 Vaccination: A Case Report.

Mass vaccination against coronavirus disease 2019 (COVID-19) has been safe and effective. The ongoing emergence of vaccine-induced complications has challenged the public trust in vaccination programs and, though uncommon, can lead to significant morbidity and mortality. Vaccine-induced immune thrombocytopenia and thrombosis (VITT) is a rare and fatal complication of the COVID-19 vaccine. We present a rare case of VITT in a young female who presented with worsening headache, body rash with deteriorating neurological deficit after 12 days of the second dose of the ChAdOx1 COVID-19 vaccine. Initial blood tests showed thrombocytopenia with deranged clotting time and D-dimer levels. Her computed tomography venogram showed thrombosis in the left transverse sinus, and she was diagnosed with a provisional diagnosis of VITT. She initially managed with dexamethasone, intravenous immunoglobulins, and apixaban to reverse the autoimmune process. Our case highlights the clinical course, diagnosis, and management of VITT, which will assist physicians in the timely recognition and adequate management of VITT.

Literature Review: Pericranial Nerve Blocks for Chronic Migraines.

Purpose of Review: Headaches, especially migraines, are one of the most pervasive neurological disorders affecting up to 15.9% of the population. Current methods of migraine treatment include lifestyle changes, pharmacologic, and minimally invasive techniques such as peripheral nerve stimulation (PNS) and pericranial nerve blocks (PNB). Recent Findings: PNBs are used to treat and prevent migraines and involves injection of local anesthetics with or without corticosteroids. PNBs include the greater occipital, supraorbital, supratrochlear, lesser occipital, auriculotemporal, sphenopalantine ganglion, and cervical root nerve blocks. Of the PNBs, the most extensively studied is the greater occipital nerve block (GONB) which has been shown to be an efficacious treatment for migraines, trigeminal neuralgia, hemi-crania continua, and post-lumbar puncture, post-concussive, cluster, and cervicogenic headaches but not medication overuse and chronic tension type headaches. Summary: In this review, we aim to summarize the recent literature on PNBs and their efficacy in the treatment of migraines including a brief discussion of peripheral nerve stimulation.

Multiple Sclerosis Relapse Following COVID-19 Vaccination: A Case Report and Literature Review.

Mass vaccination against coronavirus disease 19 (COVID-19) has effectively controlled the pandemic and has been remarkably effective and safe. Reports of a few adverse events have been reported after post-marketing surveillance. We present a rare case of multiple sclerosis (MS) relapse in a female who presented with fatigue, involuntary eye movements, and numbness; autoimmunity following the COVID-19 vaccine has also been described. She was diagnosed with MS six years back and was in remission. She received her COVID-19 vaccine 18 days ago. Her clinical and radiological features confirmed the MS relapse. Her serology for COVID-19 immunoglobulin G (IgG) and IgM was positive, and she was managed with intravenous methylprednisolone and symptomatic management. Our case provides a possible association of vaccine-associated MS relapse; however, more evidence is warranted from future studies.

Antineutrophil Cytoplasmic Antibody (ANCA)-Associated Renal Vasculitis After COVID-19 Infection: A Case Report.

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis is a class of autoimmune diseases that can cause kidney failure because of mononuclear cell infiltration and the destruction of small and medium-sized blood vessels. Coronavirus disease 2019 (COVID-19) may trigger or exacerbate autoimmune diseases. We present a case of ANCA-associated vasculitis in a patient with rheumatoid arthritis after a COVID-19 infection, who presented with intermittent hemoptysis and dyspnea and was diagnosed with COVID-19 pneumonia three weeks ago. Her clinical, radiological, and serological picture was concerned with pulmonary-renal syndrome. Her serum was positive for antinuclear antibody and ANCAs, and renal biopsy showed pauci-immune crescentic glomerulonephritis. She was diagnosed clinicopathologically with pauci-immune glomerulonephritis in the setting of rheumatoid arthritis (RA) after a COVID-19 infection. Her condition improved after she was treated with rituximab and pulse dose methylprednisolone.

Viloxazine for the Treatment of Attention Deficit Hyperactivity Disorder.

Purpose of Review: Attention deficit hyperactivity disorder (ADHD) is a widely diagnosed neurodevelopmental disorder giving rise to symptoms of hyperactivity, impulsivity, and inattentiveness that can impair daily functioning. Stimulants, such as methylphenidate and amphetamines, are the mainstay of treatment for ADHD. However, nonstimulant drugs such as viloxazine, atomoxetine, guanfacine, and clonidine are becoming more popular due to minimal adverse effects when compared to stimulants. Recent Findings: Viloxazine is a selective norepinephrine reuptake inhibitor (NRI) originally used to treat depression in adults with activity in both the noradrenergic as well as serotonergic pathways. Studies have demonstrated its efficacy for its use in the treatment of ADHD. Unlike stimulants, viloxazine has a decreased chance of substance abuse, drug dependance, and withdrawal symptoms upon the cessation of therapy. Additionally, dopamine levels in the nucleus accumbens after treatment with viloxazine are elevated considerably less in comparison with traditional stimulant ADHD treatments. Viloxazine provides an alternative, nonstimulant approach to treating ADHD. Summary: Viloxazine is a recently approved, non-stimulant medication functions by inhibiting the uptake of norepinephrine which has been seen to be decreased in patients with ADHD. When patients do not respond to first-line stimulants, cannot tolerate the side effects, or have contraindications to stimulants, viloxazine may be a nonstimulant option offering patients an increasing arsenal of medications to treat ADHD.

Daridorexant for the Treatment of Insomnia.

Purpose of Review: Insomnia is a complex sleeping disorder that affects the lives of many individuals worldwide. Insomnia often occurs in the presence of coexisting comorbidities making it a complex disorder that requires a multifactorial approach to therapy. First-line therapy is cognitive-behavioral therapy for insomnia (CBT-I). Pharmacotherapy for insomnia falls into four classes based on mechanism of action: benzodiazepine receptor agonists (BZRAs), histamine receptor antagonists, melatonin receptor agonists, and dual orexin receptor antagonists (DORAs). Recent Findings: Daridorexant is a dual orexin type 1 and types 2 (OX1 and OX2) receptor antagonist that was recently approved by the US FDA for the treatment of adults suffering from insomnia. It was shown to be effective in reducing insomnia symptoms, increasing daytime functioning, and improving the overall quality of sleep. Daridorexant offers patients relief from insomnia while avoiding the severe side effects and dependency issues of traditional treatments like benzodiazepines and sedatives. Summary: In this article, we review the most recent data on insomnia treatments and summarize the safety and efficacy of daridorexant in treating insomnia.

COVID-19-Induced Seizures: A Meta-Analysis of Case Series and Retrospective Cohorts.

The adverse events and complications of coronavirus disease 2019 (COVID-19) continue to challenge the medical profession despite the worldwide vaccination against the severe acute respiratory coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19. Other than typical respiratory manifestations, COVID-19 also presents a wide range of neurological manifestations. This article underlines the pooled incidence of COVID-19-induced seizures in patients with epilepsy and without epilepsy. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocols, we conducted a bibliographical search, and an initial search revealed 1,375 articles. In total, 21 articles were included in the final analysis by following the inclusion criteria. A total of 11,526 patients from 21 published articles that met the predetermined search criteria were included. The median age of the patients was 61.9 years, of whom 51.5% were males. A total of 255 patients presented with seizures as the first manifestation of COVID-19 with a prevalence of 2.2% (95% confidence interval = 0.05-0.24, p < 0.01) (I 2 = 97%), of which 71 patients had previously been diagnosed with epilepsy. Among patients with epilepsy, 49 patients had seizures as an initial presentation of SARA-CoV-2 with an incidence of 72% (0.54-0.85, p = 0.1) (I 2 = 34). Although the incidence of COVID-19-induced seizures is not high compared to other neurological manifestations, seizure incidence in epileptic patients with COVID-19 is remarkably high. New-onset seizures in any patient should be considered a presentation of COVID-19 in the absence of other causative factors.

New onset of ocular myasthenia gravis in a patient with COVID-19: a novel case report and literature review.

The novel coronavirus outbreak of SARS-CoV-2 first began in Wuhan, China, in December 2019. The most striking manifestation of SARS-CoV-2 is atypical pneumonia and respiratory complications; however, various neurological manifestations are now well recognized. Currently, there have been very few case reports regarding COVID-19 in patients with a known history of myasthenia gravis. Myasthenia gravis (MG) causes muscle weakness, especially respiratory muscles, in high-risk COVID-19 patients, which can lead to severe respiratory compromise. There are few reported cases of severe myasthenia crisis following COVID-19, likely due to the involvement of the respiratory apparatus and the use of immunosuppressive medication. We report the first case of ocular MG developing secondary to COVID-19 infection in a 65-year-old woman. Two weeks prior to hospitalization, the patient suffered from cough, fever, and diarrhea and was found to be positive for COVID-19 via a nasopharyngeal RT-PCR swab test. The electrodiagnostic test showed decremental response over more than 10% on repetitive nerve stimulation test of orbicularis oculi. She tested positive for antibodies against acetylcholine receptor. COVID-19 is known to cause the release of inflammatory cytokines, leading to immune-mediated damage. MG is an immune-mediated disorder caused by molecular mimicry and autoantibodies against the neuromuscular junction.

Multiple embolic stroke on magnetic resonance imaging of the brain in a COVID-19 case with persistent encephalopathy.

The pulmonary manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or coronavirus disease 2019 (COVID-19) are well known. The literature on neurological manifestations and complications in patients with COVID-19 has been increasing but is still sparse. At present, there are only a few reported case reports and clinical studies on neurological manifestations of COVID-19, of which ischemic stroke is one of the most common ones. Coagulopathy and vascular endothelial dysfunction have been proposed as the complications of COVID-19 which can ultimately lead to ischemic stroke. In this case report, we present a case of multifocal ischemic stroke in a patient with COVID-19. This patient had persistent encephalopathy and dysarthria after recovering from hypoxic respiratory failure and subsequently developed ischemic stroke in multiple vascular territories during hospital admission.

Guillain Barré Syndrome and its variants as a manifestation of COVID-19: A systematic review of case reports and case series.

BACKGROUND: The COVID-19 pandemic caused by SARS-COV-2 began in Wuhan, China in December 2019. Reports of COVID-19 with central (CNS) and peripheral nervous (PNS) system manifestations are emerging. In this systematic review, we compared and summarized the demographics, clinical features, Brighton criteria, immunological and laboratory findings with a focus on modified Erasmus GBS Outcome Score (mEGOS) in SARS-CoV-2 patients with GBS and its variants. METHODS: Based on PRISMA guidelines, we searched three databases (PubMed, Scopus, and Google Scholar) for studies on COVID-19 and GBS between December 1, 2019 to July 15, 2020. For descriptive analysis, we studied two groups with: 1) acute inflammatory demyelinating polyradiculoneuropathy (AIDP) variant, and 2) Non-AIDP/Other variants. We compared mEGOS scores for patients in both groups along with other key clinical features. RESULTS: Of the 50 GBS cases identified from 37 studies, 33 (66%) had acute inflammatory demyelinating polyradiculopolyneuropathy (AIDP) while 17 (34%) were of other (non-AIDP) variants. There mEGOS scores did not differ between AIDP patients and AMAN/AMSAN patients. Majority of the AIDP (66.7%) and AMAN/AMSAN (57.2%) patients belonged to Brighton level 1 indicating maximum diagnostic certainty. CONCLUSION: To our knowledge, this is among the first reviews that includes GBS variants and the clinical prediction tool mEGOS for prognostication in COVID-19 patients. Further research is needed to assess whether IVIG is preferable over plasmapheresis in this population of GBS patients. It would also be crucial to follow these patients over time to identify the long-term disability as well as treatment outcomes.

A Comprehensive Systematic Review of CSF analysis that defines Neurological Manifestations of COVID-19.

BACKGROUND: Limited literature exists on Cerebrospinal fluid (CSF) findings in COVID-19 patients with neurological symptoms. In this review, we conducted a descriptive analysis of CSF findings in patients with COVID-19 to understand prognosis and explore therapeutic options. METHODS: We searched PubMed, Google Scholar, and Scopus databases using the keywords "SARS-CoV-2 in cerebrospinal fluid" and "SARS-CoV-2 and CNS Complications"" for reports of CSF findings in COVID-19 related neurological manifestations. Descriptive analyses were conducted to observe the CSF protein and cell counts based on age, gender, severity, fatality of COVID-19, and whether central (CNS) or peripheral nervous system (PNS) was associated. RESULTS: A total of 113 patients were identified from 67 studies. Of these, 7 patients (6.2%) were fatal COVID-19 cases and 35 patients (31%) were considered severe COVID-19 cases. CSF protein was elevated in 100% (7/7) of the fatal cases with an average of 61.28 mg/dl and in 65.0% (52/80) in non-fatal cases with an average 56.73 mg/dl. CSF protein levels were elevated in 74.5% (38/51) patients with non-severe COVID-19 and 68.6% (24/35) in those with a severe COVID-19 infection. CSF cell count was increased in 43% of fatal cases, 25.7% severe cases, and 29.4% of non-severe cases. CONCLUSION: Our analysis showed that the most common CSF findings situation in COVID-19 infection is elevated protein with, very occasionally, mild lymphocyte predominant pleocytosis. Further studies to elucidate the pathophysiology of neurological complications in COVID-19 are recommended.

Acute transverse myelitis with Dysautonomia following SARS-CoV-2 infection: A case report and review of literature.

OBJECTIVE: To report a unique case and literature review of post COVID-19 associated transverse myelitis and dysautonomia with abnormal MRI and CSF findings. BACKGROUND: Coronavirus disease have been reported to be associated with several neurological manifestations such as stroke, Guillain-Barré syndrome, meningoencephalitis amongst others. There are only few reported cases of transverse myelitis with the novel coronavirus (n-CoV-2) and only one reported case identifying dysautonomia in COVID-19 patient. Here, we identify a COVID-19 patient diagnosed with acute transverse myelitis in addition to dysautonomia following with complete resolution of symptoms. METHOD: A retrospective chart review of a patient diagnosed with post SARS-CoV-2 infection acute transverse myelitis and dysautonomia, and a review of literature of all the reported cases of transverse myelitis and COVID-19, from December 1st, 2019 till December 25th, 2020, was performed. CONCLUSION: To our knowledge, this is the first reported case of transverse myelitis and dysautonomia in a patient with SARS-CoV-2 infection, who responded to intravenous methyl prednisone and bromocriptine. Follow-up imaging of the spine showed complete resolution of the lesion. Further studies would be recommended to identify the underlying correlation between COVID-19 and transverse myelitis.