Post-infectious focal encephalitis due to COVID-19

Post-COVID-19 Neurological Sequelae of Polyneuropathy and Encephalitis: A Comprehensive Case Report

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, commonly known as COVID-19, has been associated with various neurological complications. However, the mechanisms underlying these neurological manifestations remain incompletely understood. We present a case of a 63-year-old male who was admitted to the intensive care unit with severe COVID-19 pneumonia. Following recovery from respiratory symptoms, he was found to have weakness in the limbs. Months later, he also developed altered mental status, hallucinations, and behavioral changes. Neurological examination revealed signs consistent with polyneuropathy and autoimmune encephalitis. Further investigations, including nerve conduction studies, cerebrospinal fluid analysis, and response to steroids, supported the diagnosis of COVID-19-related polyneuropathy and autoimmune encephalitis. This is a rare presentation of COVID-19 and has only been described in a few case reports. Further research is warranted to elucidate the pathophysiological mechanisms underlying neurological sequelae of COVID-19 and to develop targeted therapeutic strategies.

Headache in COVID-19 and Long COVID: to Know Facts for Clinical Practice

PURPOSE OF REVIEW

Headache is one of the most frequent symptoms of the acute and post-acute phase of COVID-19. Specific epidemiology, clinical features, risk factors, pathophysiology, and treatment have been reported in these two scenarios. With this narrative review of the literature, we aim to provide updated knowledge on headache in the COVID-19 setting and give clinicians a practical approach on this topic to guide them in their clinical practice.

RECENT FINDINGS

Headache mechanisms in COVID-19 are still poorly understood. Strong evidence is also lacking on how to best treat and manage these patients, especially those with persistent and disabling headache after COVID-19. Data are also scarce on the characteristics of headache in COVID-19 caused by the new SARS-CoV-2 (Omicron) variants and how these may influence the acute and persistent symptoms of COVID-19. Patients with pre-existing primary headache disorders remain a particularly concerning population due to their biological predisposition in suffering from headaches and the potential risk of worsening in the setting of SARS-CoV-2 infection. Although there is an exponential growth of scientific evidence, studies are often controversial and focused on the first wave of the pandemic, making COVID-19 headache still a challenging matter for clinicians. New research is therefore needed.

Secondary Central Nervous System Demyelinating Disorders in the Elderly: A Narrative Review

Secondary demyelinating diseases comprise a wide spectrum group of pathological conditions and may either be attributed to a disorder primarily affecting the neurons or axons, followed by demyelination, or to an underlying condition leading to secondary damage of the myelin sheath. In the elderly, primary demyelinating diseases of the central nervous system (CNS), such as multiple sclerosis, are relatively uncommon. However, secondary causes of CNS demyelination may often occur and in this case, extensive diagnostic workup is usually needed. Infectious, postinfectious, or postvaccinal demyelination may be observed, attributed to age-related alterations of the immune system in this population. Osmotic disturbances and nutritional deficiencies, more commonly observed in the elderly, may lead to conditions such as pontine/extrapontine myelinolysis, Wernicke encephalopathy, and demyelination of the posterior columns of the spinal cord. The prevalence of malignancies is higher in the elderly, sometimes leading to radiation-induced, immunotherapy-related, or paraneoplastic CNS demyelination. This review intends to aid clinical neurologists in broadening their diagnostic approach to secondary CNS demyelinating diseases in the elderly. Common clinical conditions leading to secondary demyelination and their clinical manifestations are summarized here, while the current knowledge of the underlying pathophysiological mechanisms is additionally presented.

Efficacy of intravenous immunoglobulin (IVIg) on COVID-19-related neurological disorders over the last 2 years: an up-to-date narrative review

Introduction

Among the clinical manifestations of SARS-CoV-2 infection, neurological features have been commonly reported and the state-of-the-art technique suggests several mechanisms of action providing a pathophysiological rationale for central and peripheral neurological system involvement. However, during the 1st months of the pandemic, clinicians were challenged to find the best therapeutic options to treat COVID-19-related neurological conditions.

Methods

We explored the indexed medical literature in order to answer the question of whether IVIg could be included as a valid weapon in the therapeutic arsenal against COVID-19-induced neurological disorders.

Results

Virtually, all reviewed studies were in agreement of detecting an acceptable to great efficacy upon IVIg employment in neurological diseases, with no or mild adverse effects. In the first part of this narrative review, the interaction of SARS-CoV-2 with the nervous system has been discussed and the IVIg mechanisms of action were reviewed. In the second part, we collected scientific literature data over the last 2 years to discuss the use of IVIg therapy in different neuro-COVID conditions, thus providing a summary of the treatment strategies and key findings.

Discussion

Intravenous immunoglobulin (IVIg) therapy is a versatile tool with multiple molecular targets and mechanisms of action that might respond to some of the suggested effects of infection through inflammatory and autoimmune responses. As such, IVIg therapy has been used in several COVID-19-related neurological diseases, including polyneuropathies, encephalitis, and status epilepticus, and results have often shown improvement of symptoms, thus suggesting IVIg treatment to be safe and effective.

A Review on Headaches Due to COVID-19 Infection

Since December 2019, the time when the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was spotted, numerous review studies have been published on COVID-19 and its neuro invasion. A growing number of studies have reported headaches as a common neurological manifestation of COVID-19. Although several hypotheses have been proposed regarding the association between headache and the coronavirus, no solid evidence has been presented for the mechanism and features of headache in COVID-19. Headache also is a common complaint with the omicron variant of the virus. COVID-19 vaccination also is a cause of new-onset headaches or aggravation of the previous headache in migraine or tension headache sufferers. In this review study, the types of headaches reported in previous studies and their possible pathogenic mechanisms are outlined. To accomplish this objective, various types of headaches are classified and their patterns are discussed according to ICHD-3 diagnostic criteria, including, headaches attributed to systemic viral infection, viral meningitis or encephalitis, non-infectious inflammatory intracranial disease, hypoxia and/or hypercapnia, cranial or cervical vascular disorder, increased cerebrospinal fluid (CSF) pressure, refractive error, external-compression headache, and cough headache. Then, their pathogeneses are categorized into three main categories, direct trigeminal involvement, vascular invasion, and inflammatory mediators. Furthermore, persistent headache after recovery and the predictors of intensity is further investigated. Post-vaccination headache is also discussed in this review.

Post COVID-19 neurological complications; a meta-analysis

Introduction

Despite numerous studies regarding neurological manifestations and complications of COVID-19, only a few cases of neurological consequences following complete recovery from SARS-CoV-2 infection have been described.

Objectives

The current study aims to present a quantitative meta-analysis of published studies regarding the post-infectious neurological complications of COVID-19.

Data sources

The Web of Science, PubMed, MEDLINE on OVID, and Google scholar were searched for English-language researches published after January 1, 2020.

Result

The review of the literature revealed 60 cases - of which 40 (66.7%) cases were male, and 18 (30%) were female. The average age was 44.95 years. Overall, 17 (28.3%) patients had comorbid conditions. Twenty-four (40%) patients were hospitalized during an active COVID-19 infection. The average interval from the COVID-19 infection to the onset of neurological sequelae was 33.2 days. Guillain-Barre syndrome was the most commonly reported neurological condition (15, 25%).

Conclusion

Despite recovery from acute infection, the pandemic highlights the significance of ongoing, comprehensive follow-up of all COVID-19 patients - even those initially were believed to be asymptomatic.

Cerebrospinal fluid analysis in patients with COVID-19-associated central nervous system manifestations: a systematic review

ABSTRACT Background: Central nervous system (CNS) symptoms may occur in patients with acute COVID-19. The role of CSF examination in these patients remains to be established. Objective: A systematic review of CSF findings relating to COVID-19 was carried out. Methods: CSF parameters, including cytological and biochemical analyses, SARS-CoV-2 RT-PCR and other CSF markers, were recorded and analyzed among patients with acute COVID-19 and one of the following CNS syndromes: stroke, encephalopathy, encephalitis, inflammatory syndromes, seizure, headache and meningitis. Results: Increased white blood cells and/or increased protein concentration were found in 52.7% of the patients with encephalitis, 29.4% of the patients with encephalopathy and 46.7% of the patients with inflammatory syndromes (P < 0.05). CSF RT-PCR for SARS-CoV-2 was positive in 17.35% of the patients with encephalitis and less than 3.5% of the patients with encephalopathy or inflammatory syndromes (P < 0.05). Intrathecal production of immunoglobulins was found in only 8% of the cases. More than 85% of the patients had increased CSF cytokines and chemokines. Increased CSF neurofilament light chain (NfL) and CSF Tau were found in 71% and 36% of the cases, respectively. Conclusion: Non-specific inflammatory CSF abnormalities were frequently found in patients with COVID-19 CNS syndromes. The increase in neurodegeneration biomarkers suggests that neuronal damage occurs, with long-term consequences that are still unknown.

COVID-19-Associated Encephalopathy—Case Series and Clinical Considerations

Neurological manifestations of the SARS-CoV-2 infection are present in up to 80% of the affected patients. While the majority of them is benign, in certain patients, viral replication in the central nervous system results in a severe disruption in cognitive function as well as basic life functions. In this case series, the authors present a detailed description of the three SARS-CoV-2 infection cases, which were all complicated by severe encephalopathy. Consecutive neurological status changes were described for each patient with detailed imaging and clinical sequelae. In the discussion, the authors highlight similarities in the course of the disease in presented patients, as well as common features in test results. An effective causal treatment could not be introduced in any of the patients, nor could the progression of the central nervous system (CNS) damage be stopped. The authors hope that the experiences they gathered will help to accelerate the diagnostic and therapeutic process in other patients with COVID-19-associated encephalopathy and can result in introducing an effective treatment.

[Manifestations of the central nervous system after COVID-19]

Numerous diseases of the central nervous system (CNS), especially in the postacute phase after an infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been described. These include neuroimmunologically mediated diseases, such as encephalopathy, encephalitis, myelitis, acute disseminated encephalomyelitis (ADEM), acute necrotizing hemorrhagic leukoencephalitis (ANHLE) and neuromyelitis optica spectrum disorder (NMOSD) as well as others, such as posterior reversible encephalopathy syndrome (PRES), opsoclonus myoclonus ataxia (OMA) and cerebrovascular diseases. A parainfectious or postinfectious association is discussed but the pathophysiological mechanisms are so far unknown. Underlying mechanisms could be a virus-triggered overactivation of the immune system with hyperinflammation and cytokine storm but possibly also the development of specific autoantibodies against CNS tissue. Direct damage due to the invasion of SARS-CoV‑2 into the brain or spinal cord does not seem to play a relevant role. An exact clinical phenotyping and initiation of additional diagnostics are recommended, also to rule out other causes. To date no medicinal treatment options for CNS manifestations of long COVID exist; however, first results regarding inflammation and autoimmunity are promising and could lead to new treatment approaches.

Delayed presentation of postinfectious encephalitis associated with SARS-CoV-2 infection: a case report

Neurological manifestations of SARS-CoV-2 are increasingly being recognised and can arise as a result of direct viral invasion, para-infectious or postinfectious immune mechanisms. We report a delayed presentation of COVID-19 postinfectious immune-mediated encephalitis and status epilepticus occurring in a 47-year-old woman 4 weeks after SARS-CoV-2 pulmonary disease. SARS-CoV-2-specific IgG and IgM antibodies were detected in her cerebrospinal fluid with features of encephalitis evident in both magnetic resonance imaging of the brain and electroencephalogram. She made a complete recovery following treatment with high-dose intravenous corticosteroids and intravenous immunoglobulins. Diagnosis of COVID-19 postinfectious encephalitis may prove challenging in patients presenting many weeks following the initial infection. A high index of clinical suspicion and testing intrathecal SARS-CoV-2-specific antibodies are key to its diagnosis. Early immunotherapy is likely to result in a good outcome.