Acute Disseminated Encephalomyelitis and Acute Hemorrhagic Leukoencephalitis Following COVID-19: Systematic Review and Meta-synthesis

Recovery from acute haemorrhagic leucoencephalitis secondary to COVID-19

A man in his 50s presented with sudden onset expressive aphasia and right-sided facial droop after experiencing coryzal symptoms and malaise for 7 days prior to admission. A brain MRI showed a rapidly progressive mass effect across both hemispheres and cerebrospinal fluid analysis revealed neutrophil predominance with raised protein levels. Acute disseminated encephalomyelitis was provisionally diagnosed, and high-dose methylprednisone was initiated.On admission to the high dependency unit, the patient tested positive for COVID-19 and was treated with appropriate therapeutic agents for severe COVID-19. A subsequent brain biopsy confirmed a demyelinating process, strongly indicating a diagnosis of acute haemorrhagic leucoencephalitis when correlated with the presence of severe oedema on imaging. Nine sessions of plasma exchange were provided over 18 days.At the time of writing, the patient has made an excellent recovery. We urge clinicians to consider this diagnosis and these treatment options for an otherwise devastating condition.

COVID-19 Neuroimaging Update: Pathophysiology, Acute Findings, and Post-Acute Developments

COVID-19 has prominent effects on the nervous system with important manifestations on neuroimaging. In this review, we discuss the neuroimaging appearance of acute COVID-19 that became evident during the early stages of the pandemic. We highlight the underlying pathophysiology mediating nervous system effects and neuroimaging appearances including systemic inflammatory response such as cytokine storm, coagulopathy, and para/post-infections immune mediated phenomena. We also discuss the nervous system manifestations of COVID-19 and the role of imaging as the pandemic has evolved over time, including related to the development of vaccines and the emergence of post-acute sequalae such as long COVID.

Bilateral Cerebellar Hemorrhages: An Atypical Presentation of Acute Hemorrhagic Encephalomyelitis

Hurst disease, or Weston-Hurst syndrome, or acute hemorrhagic encephalomyelitis (AHEM), is an infrequent condition that usually gets provoked after a viral infection (respiratory tract infection) or, as reported in many case reports, post-vaccination. Hurst disease is a difficult-to-diagnose condition because it mimics common presentations such as stroke, decreased or loss of consciousness, brain abscess, and seizures, making clinical diagnosis challenging. Radiological imaging, such as magnetic resonance imaging (MRI) of the brain with diffusion-weighted imaging, now serves as the primary modality to identify such conditions, despite its lack of specificity. The treating doctor needs to do an in-depth analysis of the patient's history, as this carries a very high mortality rate. We hereby discuss a case that presented with seizures and deteriorating Glasgow Coma Scale (GCS) score, on imaging revealed posterior circulation acute hemorrhagic leukoencephalitis (AHLE)/AHEM, therein treated with steroids, plasmapheresis resulted in a good outcome implicating, early detection and timely management can reduce the mortality due to this condition.

Long COVID in Brain Health Research: A Call to Action

The COVID-19 pandemic has brought attention to the long-term consequences of the virus, particularly the persistent symptoms that characterize long COVID. This syndrome, which can last for months after the initial infection, includes a range of neurological and neuropsychiatric manifestations that have significant implications for brain health and dementia research. This review explores the current understanding of long COVID's cognitive, neurological, and psychiatric symptoms and their potential impact on brain stimulation and neuroimaging studies. It argues that researchers must adapt their study designs and screening processes to account for the confounding effects of long COVID and ensure the accuracy and reliability of their findings. To advance the understanding of this condition and its long-term effects on brain health, the review proposes a series of strategies, including the development of standardized screening tools, the investigation of underlying mechanisms, and the identification of risk factors and protective factors. It also emphasizes the importance of collaborative research efforts and international data sharing platforms in accelerating the pace of discovery and developing targeted interventions for individuals with long COVID. As the prevalence of this condition continues to grow, it is imperative that the neuroscience community comes together to address this challenge and support those affected by long COVID.

CASE REPORT: Fulminant acute hemorrhagic Leukoencephalitis (AHLE): A rare and ruinous outcome with cerebral herniation (COVID-19)

Background

Acute hemorrhagic leukoencephalitis (AHLE) is a very rare demyelinating disease with rapid fulminant inflammation of the white matter. Although the exact etiology is unknown, AHLE usually manifests post a viral or bacterial infection and less often seen post vaccination for measles or rabies. AHLE has a very poor prognosis and a high mortality rate. Owing to the rarity of this entity there is not clear consensus on the proper line of management. In this report, we present a case of AHLE as a para-infectious sequel to COVID-19 in a young patient.

Clinical presentation

We report a 30-year-old turkish patient with an initial presentation of upper respiratory tract infection due to COVID-19. Initially, she was admitted to the hospital with generalized tonic-clonic seizure (GTCS) and deterioration in her level of consciousness lapsing into a coma. An initial CT scan showed diffuse brain edema and an MRI head confirmed the suspicion of Acute hemorrhagic leukoencephalitis (AHLE). Despite prompt and diligent osmotic therapy and pulsed intravenous (IV) methylprednisolone, her condition rapidly depreciated and progressed into cerebral edema with gravid sequela of brainstem herniation.

Conclusions

AHLE is a very rare entity and perhaps its fulminant debilitating course and high mortality should warrant further studies on disease pathophysiology and its optimal treatment parameters. Life-saving decompressive hemicraniectomy should be considered in the multidisciplinary approach of the management with tailored osmotic and immunotherapy.

Uncommon Causes of Nontraumatic Intracerebral Hemorrhage

Nontraumatic intracerebral hemorrhage is an important health issue. Although common causes such as hypertension and cerebral amyloid angiopathy predominantly affect the elderly, there exists a spectrum of uncommon etiologies that contribute to the overall incidence of intracerebral hemorrhage. The identification of these rare causes is essential for targeted clinical management, informed prognostication, and strategic secondary prevention where relevant. This topical review explores the uncommon intracerebral hemorrhage causes and provides practical clues for their clinical and imaging identification. By expanding the clinician's differential diagnosis, this review aims to bridge the gap between standard intracerebral hemorrhage classification systems and the nuanced reality of clinical practice.

Bilateral optic neuritis and encephalopathy as the atypical presentations of multiple sclerosis following severe acute respiratory syndrome coronavirus 2 infection

Numerous evidence suggests coronavirus disease 2019 (COVID-19) potentially triggers demyelinating diseases, inclusive of multiple sclerosis (MS), and acute disseminated encephalomyelitis (ADEM), and various mechanisms have been proposed. We report a 42-year-old male presented with bilateral optic neuritis and encephalopathy, 2 weeks following COVID-19 infection. He denied any history or family history of neurological and ocular diseases. Severe bilateral visual impairment (only light perception) and pain with eye movement were reported. Fundoscopy revealed bilateral optic disc swelling. Magnetic resonance imaging showed tortuous bilateral optic nerves with optic nerve and nerve sheath enhancement. Multiple hyperintense nodules in bilateral cerebral white matter were noted on fluid-attenuated inversion recovery T2-weighted imaging without diffusion restriction or gadolinium contrast enhancement. Hypointense nodules in cerebral white matter were also noted on T1-weighted imaging, which implied some old lesions. Dissemination in space and time and cerebrospinal fluid-specific oligoclonal bands confirmed the diagnosis of MS. Both serum aquaporin-4 and myelin oligodendrocyte glycoprotein antibodies were negative. He received pulse steroid therapy for 5 days, followed by slowly tapering oral prednisolone. His vision, ocular motion pain, and encephalopathy improved gradually. However, the visual outcome was still poor (bilateral 20/400), and optic atrophy was noticed during 1-year follow-up. To our knowledge, this is the first case of MS following severe acute respiratory syndrome coronavirus 2 infection presented with bilateral optic neuritis and encephalopathy. Since these manifestations are exceedingly rare in MS, we suspect acute immune reactions induced by COVID-19 could bring about the atypical ADEM-like presentations of MS.

Predicting factors for acute encephalopathy in febrile seizure children with SARS-CoV-2 omicron variant: a retrospective study

BACKGROUND

SARS-CoV-2 posed a threat to children during the early phase of Omicron wave because many patients presented with febrile seizures. The study aimed to investigate predicting factors for acute encephalopathy of children infected by SARS-CoV-2 Omicron variant presenting with febrile seizures.

METHODS

The retrospective study analyzed data from pediatric patients who visited the emergency department of Chang Gung Memorial Hospital in Taiwan between April and July 2022. We specifically focused on children with COVID-19 who presented with febrile seizures, collecting demographic, clinical, and laboratory data at the pediatric emergency department, as well as final discharge diagnoses. Subsequently, we conducted a comparative analysis of the clinical and laboratory characteristics between patients diagnosed with acute encephalopathy and those with other causes of febrile seizures.

RESULTS

Overall, 10,878 children were included, of which 260 patients presented with febrile seizures. Among them, 116 individuals tested positive for SARS-CoV-2 and of them, 14 subsequently developed acute encephalopathy (12%). Those with acute encephalopathy displayed distinctive features, including older age (5.1 vs. 2.6 years old), longer fever duration preceding the first seizure (1.6 vs. 0.9 days), cluster seizure (50% vs. 16.7%), status epilepticus (50% vs. 13.7%) and occurrences of bradycardia (26.8% vs. 0%) and hypotension (14.3% vs. 0%) in the encephalopathy group. Besides, the laboratory findings in the encephalopathy group are characterized by hyperglycemia (mean (95% CI) 146 mg/dL (95% CI 109-157) vs. 108 mg/dL (95% CI 103-114) and metabolic acidosis (mean (95% CI) pH 7.29(95% CI 7.22-7.36) vs. 7.39 (95%CI 7.37-7.41)).

CONCLUSIONS

In pediatric patients with COVID-19-related febrile seizures, the occurrence of seizures beyond the first day of fever, bradycardia, clustered seizures, status epilepticus, hyperglycemia, and metabolic acidosis should raise concerns about acute encephalitis/encephalopathy. However, the highest body temperature and the severity of leukocytosis or C-reactive protein levels were not associated with poor outcomes.

Is there an immunological cross-reactivity of antibodies to the myelin oligodendrocyte glycoprotein and coronaviruses?

Recent reports indicated that myelin oligodendrocyte glycoprotein antibody-associated disease might be a rare complication after severe acute respiratory syndrome coronavirus 2 infection or vaccination. It is unclear whether this is an unspecific sequel of infection or vaccination or caused by possible immunological cross-reactivity of severe acute respiratory syndrome coronavirus 2 proteins and myelin oligodendrocyte glycoprotein. The aim of this study was therefore to elucidate whether there is an immunological cross-reactivity between severe acute respiratory syndrome coronavirus 2 spike or nucleocapsid proteins and myelin oligodendrocyte glycoprotein and to explore the relation of antibody responses against myelin oligodendrocyte glycoprotein and severe acute respiratory syndrome coronavirus 2 and other coronaviruses. We analysed serum samples from patients with severe acute respiratory syndrome coronavirus 2 infection and neurological symptoms with (myelin oligodendrocyte glycoprotein antibody-associated disease, n = 12) or without myelin oligodendrocyte glycoprotein-antibodies (n = 10); severe acute respiratory syndrome coronavirus 2 infection without neurological symptoms (n = 32); vaccinated patients with no history of severe acute respiratory syndrome coronavirus 2 infection and neurological symptoms with (myelin oligodendrocyte glycoprotein antibody-associated disease, n = 10) or without myelin oligodendrocyte glycoprotein-antibodies (n = 9); and severe acute respiratory syndrome coronavirus 2 negative/naïve unvaccinated patients with neurological symptoms with (myelin oligodendrocyte glycoprotein antibody-associated disease, n = 47) or without myelin oligodendrocyte glycoprotein-antibodies (n = 20). All samples were analysed for serum antibody responses to myelin oligodendrocyte glycoprotein, severe acute respiratory syndrome coronavirus 2, and other common coronaviruses (CoV-229E, CoV-HKU1, CoV-NL63 and CoV-OC43). Based on sample amount and antibody titres, 21 samples were selected for analysis of antibody cross-reactivity between myelin oligodendrocyte glycoprotein and severe acute respiratory syndrome coronavirus 2 spike and nucleocapsid proteins using affinity purification and pre-absorption. Whereas we found no association of immunoglobulin G and A myelin oligodendrocyte glycoprotein antibodies with coronavirus antibodies, infections with severe acute respiratory syndrome coronavirus 2 correlated with an increased immunoglobulin M myelin oligodendrocyte glycoprotein antibody response. Purified antibodies showed no cross-reactivity between severe acute respiratory syndrome coronavirus 2 spike protein and myelin oligodendrocyte glycoprotein. However, one sample of a patient with myelin oligodendrocyte glycoprotein antibody-associated disease following severe acute respiratory syndrome coronavirus 2 infection showed a clear immunoglobulin G antibody cross-reactivity to severe acute respiratory syndrome coronavirus 2 nucleocapsid protein and myelin oligodendrocyte glycoprotein. This patient was also seropositive for other coronaviruses and showed immunological cross-reactivity of severe acute respiratory syndrome coronavirus 2 and CoV-229E nucleocapsid proteins. Overall, our results indicate that an immunoglobulin G antibody cross-reactivity between myelin oligodendrocyte glycoprotein and severe acute respiratory syndrome coronavirus 2 proteins is rare. The presence of increased myelin oligodendrocyte glycoprotein-immunoglobulin M antibodies after severe acute respiratory syndrome coronavirus 2 infection may either be a consequence of a previous infection with other coronaviruses or arise as an unspecific sequel after viral infection. Furthermore, our data indicate that myelin oligodendrocyte glycoprotein-immunoglobulin A and particularly myelin oligodendrocyte glycoprotein-immunoglobulin M antibodies are a rather unspecific sequel of viral infections. Finally, our findings do not support a causative role of coronavirus infections for the presence of myelin oligodendrocyte glycoprotein-immunoglobulin G antibodies.

Acute hemorrhagic leukoencephalitis following the first dose of BNT162b2 vaccine against SARS-CoV-2: A case report

Acute hemorrhagic leukoencephalitis (AHLE), is a rare inflammatory demyelinating disorder, variant of acute disseminated encephalomyelitis. The diagnosis of AHLE remains challenging due to the rarity of the disease and the lack of a reliable biomarker. We report here a case of a 73-year-old male patient with a progressive, low-grade febrile confusional syndrome 20 days after receiving the first dose of BNT162b2 vaccine against SARS-CoV-2. Evidence indicative of the underlying condition by an extensive panel of imaging (brain magnetic resonance imaging, computed tomography and digital subtraction angiography), laboratory (complete blood count, biochemistry, coagulation, tests for autoimmune or infectious disorders, tumor markers, hormonal levels, cerebrospinal fluid analysis) and electrodiagnostic tests were scarce, and mainly non-specific. Sequential neuroimaging revealed the appearance of extensive T2 lesions (signs of gliosis) along with multiple hemorrhagic lesions at various cortical sites. The patient was treated with corticosteroids, discontinued due to severe adverse effects, and subsequently with sessions of plasmapheresis and monthly intravenous administration of cyclophosphamide. Considering the rapid aggravation of the patient's neurological status, the MRI findings of cortical lesions and the lack of response to any treatment, a biopsy of a frontal lobe lesion was conducted, confirming the presence of confluent, inflammatory-edematous lesions with scattered areas of necrosis and hemorrhage, and ultimately areas of demyelination, thus confirming the diagnosis of AHLE. After more than 5 months of hospitalization the patient was transferred in a primary care facility and remained in a permanent vegetative state until his death, more than 2 years later.

HIV and COVID-19: two pandemics with significant (but different) central nervous system complications

Human immunodeficiency virus (HIV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cause significant neurologic disease. Central nervous system (CNS) involvement of HIV has been extensively studied, with well-documented invasion of HIV into the brain in the initial stage of infection, while the acute effects of SARS-CoV-2 in the brain are unclear. Neuropathologic features of active HIV infection in the brain are well characterized whereas neuropathologic findings in acute COVID-19 are largely non-specific. On the other hand, neuropathologic substrates of chronic dysfunction in both infections, as HIV-associated neurocognitive disorders (HAND) and post-COVID conditions (PCC)/long COVID are unknown. Thus far, neuropathologic studies on patients with HAND in the era of combined antiretroviral therapy have been inconclusive, and autopsy studies on patients diagnosed with PCC have yet to be published. Further longitudinal, multidisciplinary studies on patients with HAND and PCC and neuropathologic studies in comparison to controls are warranted to help elucidate the mechanisms of CNS dysfunction in both conditions.

General features, pathogenesis, and laboratory diagnostics of autoimmune encephalitis

Autoimmune encephalitis (AE) is a group of inflammatory conditions that can associate with the presence of antibodies directed to neuronal intracellular, or cell surface antigens. These disorders are increasingly recognized as an important differential diagnosis of infectious encephalitis and of other common neuropsychiatric conditions. Autoantibody diagnostics plays a pivotal role for accurate diagnosis of AE, which is of utmost importance for the prompt recognition and early treatment. Several AE subgroups can be identified, either according to the prominent clinical phenotype, presence of a concomitant tumor, or type of neuronal autoantibody, and recent diagnostic criteria have provided important insights into AE classification. Antibodies to neuronal intracellular antigens typically associate with paraneoplastic neurological syndromes and poor prognosis, whereas antibodies to synaptic/neuronal cell surface antigens characterize many AE subtypes that associate with tumors less frequently, and that are often immunotherapy-responsive. In addition to the general features of AE, we review current knowledge on the pathogenic mechanisms underlying these disorders, focusing mainly on the potential role of neuronal antibodies in the most frequent conditions, and highlight current theories and controversies. Then, we dissect the crucial aspects of the laboratory diagnostics of neuronal antibodies, which represents an actual challenge for both pathologists and neurologists. Indeed, this diagnostics entails technical difficulties, along with particularly interesting novel features and pitfalls. The novelties especially apply to the wide range of assays used, including specific tissue-based and cell-based assays. These assays can be developed in-house, usually in specialized laboratories, or are commercially available. They are widely used in clinical immunology and in clinical chemistry laboratories, with relevant differences in analytic performance. Indeed, several data indicate that in-house assays could perform better than commercial kits, notwithstanding that the former are based on non-standardized protocols. Moreover, they need expertise and laboratory facilities usually unavailable in clinical chemistry laboratories. Together with the data of the literature, we critically evaluate the analytical performance of the in-house vs commercial kit-based approach. Finally, we propose an algorithm aimed at integrating the present strategies of the laboratory diagnostics in AE for the best clinical management of patients with these disorders.

A Quality Assessment of Aquaporin-4 & Myelin Oligodendrocyte Glycoprotein Antibody Testing

BACKGROUND

Accurate anti-aquaporin-4 (AQP4) and anti-myelin oligodendrocyte glycoprotein (MOG) autoantibody assays are needed to effectively diagnose neuromyelitis optica spectrum disorder and MOG antibody-associated disease. A proportion of patients at our centre have been tested for anti-AQP4 and anti-MOG autoantibodies locally, followed by an outsourced test as part of real-world practice. Outsourced testing is costly and of unproven utility. We conducted a quality improvement project to determine the value of outsourced testing for anti-AQP4 and anti-MOG autoantibodies.

METHODS

All patients seen by Calgary neurological services who underwent cell-based testing for anti-AQP4 and/or anti-MOG autoantibodies at both MitogenDx (Calgary, AB) and Mayo Clinic Laboratories (Rochester, MN, USA) between 2016 and 2020 were identified from a provincial database. The interlaboratory concordance was calculated by pairing within-subject results collected no more than 365 days apart. Retrospective chart review was done for subjects with discordant results to determine features associated with discordance and use of outsourced testing.

RESULTS

Fifty-seven anti-AQP4 and 46 anti-MOG test pairs from January 2016 to July 2020 were analyzed. Concordant tests pairs comprised 54/57 (94.7%, 95%CI 88.9-100.0%) anti-AQP4 and 41/46 (89.1%, 95%CI 80.1-98.1%) anti-MOG results. Discordant anti-AQP4 pairs included two local weak positives (negative when outsourced) and one local negative (positive when outsourced). Discordant anti-MOG pairs were all due to local weak positives (negative when outsourced).

CONCLUSION

Interlaboratory discordant results for cell-based testing of anti-AQP4 autoantibodies were rare. Local anti-MOG weak positive results were associated with discordance, highlighting the need for cautious interpretation based on the clinical context. Our findings may reduce redundant outsourced testing.

Effects of COVID-19 on cognition and brain health

COVID-19 is associated with a range of neurological, cognitive, and mental health symptoms both acutely and chronically that can persist for many months after infection in people with long-COVID syndrome. Investigations of cognitive function and neuroimaging have begun to elucidate the nature of some of these symptoms. They reveal that, although cognitive deficits may be related to brain imaging abnormalities in some people, symptoms can also occur in the absence of objective cognitive deficits or neuroimaging changes. Furthermore, cognitive impairment may be detected even in asymptomatic individuals. We consider the evidence regarding symptoms, cognitive deficits, and neuroimaging, as well as their possible underlying mechanisms.

Chorea following SARS-CoV-2 infection and vaccination: a systematic review of reported cases

OBJECTIVES

Chorea following SARS-CoV-2 infection and vaccination, has been increasingly recognized. We aimed to synthesize clinical and paraclinical characteristics, treatment responses, and outcomes of this neurologic complication.

METHODS

We systematically reviewed LitCOVID, the World Health Organization database on COVID-19, and MedRxiv up to March 2023, following a published protocol.

RESULTS

We included 14 chorea cases in patients with SARS-CoV-2 infection and eight following COVID-19 vaccination. Acute or subacute chorea preceded COVID-19 symptoms within 1-3 days or developed up to 3 months after infection. Frequently it was generalized (85.7%), with associated neurological manifestations (encephalopathy 35.7%; other movement disorders 7.1%). After vaccination, chorea had a sudden onset (87.5%) within 2 weeks (75%); 87.5% of cases presented hemichorea, with hemiballismus (37.5%) or other movement disorders; 12.5% presented additional neurological findings. Cerebrospinal fluid was normal in 50% of infected individuals but abnormal in all vaccinated cases. Brain magnetic resonance imaging detected normal basal ganglia in 51.7% of infection cases and 87.5% following vaccination.

CONCLUSION

In SARS-CoV-2 infection, chorea may present several pathogenic mechanisms: autoimmune response to infection, direct infection-related injury, or an infection-related complication (i.e., acute disseminated encephalomyelitis, cerebral venous sinus thrombosis, hyperglycemia); also, previous Sydenham chorea may relapse. After COVID-19 vaccination, chorea could be due to an autoimmune reaction or other mechanisms (vaccine-induced hyperglycemia, stroke).

Pathophysiology, diagnosis, and management of neuroinflammation in covid-19

Although neurological complications of SARS-CoV-2 infection are relatively rare, their potential long term morbidity and mortality have a significant impact, given the large numbers of infected patients. Covid-19 is now in the differential diagnosis of a number of common neurological syndromes including encephalopathy, encephalitis, acute demyelinating encephalomyelitis, stroke, and Guillain-Barré syndrome. Physicians should be aware of the pathophysiology underlying these presentations to diagnose and treat patients rapidly and appropriately. Although good evidence has been found for neurovirulence, the neuroinvasive and neurotropic potential of SARS-CoV-2 is limited. The pathophysiology of most complications is immune mediated and vascular, or both. A significant proportion of patients have developed long covid, which can include neuropsychiatric presentations. The mechanisms of long covid remain unclear. The longer term consequences of infection with covid-19 on the brain, particularly in terms of neurodegeneration, will only become apparent with time and long term follow-up.

The Influence of COVID-19 in Endocrine Research: Critical Overview, Methodological Implications and a Guideline for Future Designs

The COVID-19 pandemic has changed many aspects of people's lives, including not only individual social behavior, healthcare procedures, and altered physiological and pathophysiological responses. As a result, some medical studies may be influenced by one or more hidden factors brought about by the COVID-19 pandemic. Using the literature review method, we are briefly discussing the studies that are confounded by COVID-19 and facemask-induced partiality and how these factors can be further complicated with other confounding variables. Facemask wearing has been reported to produce partiality in studies of ophthalmology (particularly dry eye and related ocular diseases), sleep studies, cognitive studies (such as emotion-recognition accuracy research, etc.), and gender-influenced studies, to mention a few. There is a possibility that some other COVID-19 related influences remain unrecognized in medical research. To account for heterogeneity, current and future studies need to consider the severity of the initial illness (such as diabetes, other endocrine disorders), and COVID-19 infection, the timing of analysis, or the presence of a control group. Face mask-induced influences may confound the results of diabetes studies in many ways.

Encephalitis: diagnosis, management and recent advances in the field of encephalitides

Encephalitis describes inflammation of the brain parenchyma, typically caused by either an infectious agent or through an autoimmune process which may be postinfectious, paraneoplastic or idiopathic. Patients can present with a combination of fever, alterations in behaviour, personality, cognition and consciousness. They may also exhibit focal neurological deficits, seizures, movement disorders and/or autonomic instability. However, it can sometimes present non-specifically, and this combined with its many causes make it a difficult to manage neurological syndrome. Despite improved treatments in some forms of encephalitides, encephalitis remains a global concern due to its high mortality and morbidity. Prompt diagnosis and administration of specific and supportive management options can lead to better outcomes. Over the last decade, research in encephalitis has led to marked developments in the understanding, diagnosis and management of encephalitis. In parallel, the number of autoimmune encephalitis syndromes has rapidly expanded and clinically characteristic syndromes in association with pathogenic autoantibodies have been defined. By focusing on findings presented at the Encephalitis Society's conference in December 2021, this article reviews the causes, clinical manifestations and management of encephalitis and integrate recent advances and challenges of research into encephalitis.

Frequency and Referral Patterns of Neural Antibody Studies During the COVID-19 Pandemic: Experience From an Autoimmune Neurology Center

OBJECTIVE

To determine whether the frequency of paraneoplastic or autoimmune encephalitis antibodies examined in a referral center changed during the COVID-19 pandemic.

METHODS

The number of patients who tested positive for neuronal or glial (neural) antibodies during pre-COVID-19 (2017-2019) and COVID-19 (2020-2021) periods was compared. The techniques used for antibody testing did not change during these periods and included a comprehensive evaluation of cell-surface and intracellular neural antibodies. The chi-square test, Spearman correlation, and Python programming language v3 were used for statistical analysis.

RESULTS

Serum or CSF from 15,390 patients with suspected autoimmune or paraneoplastic encephalitis was examined. The overall positivity rate for antibodies against neural-surface antigens was similar in the prepandemic and pandemic periods (neuronal 3.2% vs 3.5%; glial 6.1 vs 5.2) with a mild single-disease increase in the pandemic period (anti-NMDAR encephalitis). By contrast, the positivity rate for antibodies against intracellular antigens was significantly increased during the pandemic period (2.8% vs 3.9%, p = 0.01), particularly Hu and GFAP.

DISCUSSION

Our findings do not support that the COVID-19 pandemic led to a substantial increase of known or novel encephalitis mediated by antibodies against neural-surface antigens. The increase in Hu and GFAP antibodies likely reflects the progressive increased recognition of the corresponding disorders.

Post-COVID-19 acute disseminated encephalomyelitis in a 51-year-old female from Nepal: A case report with literature review

There have been a growing number of acute disseminated encephalomyelitis cases following coronavirus disease-19 (COVID-19) infection. Given the rare occurrence, studies eliciting the clinical features, treatment response, and outcomes are still limited. In patients recovering from COVID-19, multifocal neurologic symptoms in the presence or absence of encephalopathy must be closely evaluated by neurologists and physicians. Early radiographic evaluation using magnetic resonance imaging and timely administration of glucocorticoid-based treatment reduces mortality and leads to satisfactory outcomes.

Incidence of Pediatric Acute Disseminated Encephalomyelitis During the Coronavirus Disease 2019 Pandemic in South Korea

BACKGROUND

Acute disseminated encephalomyelitis (ADEM) is an immune-mediated demyelinating disorder of the central nervous system that is usually triggered by infections. We aimed to determine the temporal trends in the incidence of ADEM before and during the pandemic and their correlation with viral epidemiology.

METHODS

We conducted a nationwide, population-based, retrospective, ADEM cohort study by using the Health Insurance Review and Assessment Service database. New-onset ADEM was defined as a patient (age <19 years) who was hospitalized with a diagnostic code of G04.0, G36.8, and G36.9 and a prescription of intravenous methylprednisolone. The National Infectious Disease Surveillance System was used to collect the nationwide viral epidemics.

RESULTS

A total of 185 new-onset pediatric ADEM cases were included. The mean patient age was 7.0 ± 4.9 years. The incidence of ADEM was 0.34 to 0.48 of 100,000 persons per year before the pandemic, which dropped to 0.22 of 100,000 persons per year during the first pandemic year. The risk of ADEM occurrence was approximately 1.74% higher during the prepandemic years compared with the first pandemic year (odds ratio = 1.017, P = 0.009). There was a weak positive correlation between acute respiratory viral infection and ADEM incidence (r = 0.28, P = 0.03).

CONCLUSION

This study demonstrates how infection control during the early coronavirus disease 2019 (COVID-19) pandemic influenced the incidence of ADEM. The low incidence of ADEM in the early COVID-19 pandemic may be related to the decline in acute respiratory viral infections, which are potential triggers of ADEM.

Coronavirus Disease 2019-Associated Neurological Manifestations in Children: A Large Single-Center Experience With Rare Cases

BACKGROUND

We aimed to analyze pediatric patients with coronavirus disease 2019 (COVID-19) with a diverse spectrum of neurological manifestations in a single center since neurological involvement in children is still poorly understood.

METHODS

We performed a retrospective study on 912 children aged between zero and 18 years who had a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test result and symptoms of COVID-19 from March 2020 to March 2021 in a single center.

RESULTS

Among 912 patients, 37.5% (n = 342) had neurological symptoms and 62.5% (n = 570) had no neurological symptoms. The mean age of patients with neurological symptoms was significantly higher (14.2 ± 3.7 vs 9.9 ± 5.7; P < 0.001). Three hundred and twenty-two patients had nonspecific symptoms (ageusia, anosmia, parosmia, headache, vertigo, myalgia), whereas 20 patients had specific involvement (seizures/febrile infection-related epilepsy syndrome, cranial nerve palsy, Guillain-Barré syndrome and variants, acute disseminated encephalomyelitis, central nervous system vasculitis). The mean age of the patients with nonspecific neurological symptoms was significantly higher (14.6 ± 3.1 vs 7.7 ± 5.7; P < 0.001).

CONCLUSION

This study presents a large number of patients with a diverse spectrum of neurological manifestations. The rare neurological manifestations reported in our study will contribute to better understanding the neurological involvement of SARS-CoV-2 in children. The study also points out the differences of SARS-CoV-2-related neurological manifestations between patients at different ages. Physicians should be alert about recognizing the early neurological manifestations of the SARS-CoV-2 in children.

Acute disseminated encephalomyelitis (ADEM) following COVID-19 vaccination: A systematic review

BACKGROUND

Although global vaccination against COVID-19 infection has its excellence, potential side effects are yet of concern. Several lines of evidence have proposed ADEM occurrence after SARS-CoV-2 infection. Moreover, a large number of case reports and case series have also suggested the casual association between ADEM and COVID-19 vaccination. To better understand the development of ADEM following COVID-19 vaccination and its potential association, we aimed to systematically review ADEM cases reported after COVID-19 vaccination.

METHODS

We conducted a comprehensive systematic search using three databases including PubMed, Scopus, and Web of Science. Studies that reported ADEM after COVID-19 vaccination were eligible to include in our study. Observational studies, case reports, and case series which reported cases of ADEM with sufficient detail to confirm clinical diagnosis following COVID-19 vaccination were eligible to enter our study.

RESULTS

Twenty studies were included in our systematic review after the abstract and full-text screening with a total of 54 cases. Among included patients, 45 (85.1 %) developed ADEM after the first dose of the COVID-19 vaccine, and seven (12.9 %) cases experienced ADEM after the second dose. The median time interval between vaccination and neurological symptoms was 14 days which ranged from 12 h to 63 days. Twelve (22.2 %) patients experienced symptoms of muscle weakness, ten (18.5 %) presented unconsciousness, nine (16.6 %) patients had urinary complaints, nine (16.6 %) had visual impairments, and five (9.2 %) experienced a seizure. After treatments, four (13.8 %) patients died. Forty-six patients had clinical improvement (85.1 %), also improvement in brain MRI was observed among 44 (81.4 %) patients.

CONCLUSION

In conclusion, it is not clear that ADEM could be a potential complication of COVID-19 vaccination based on the current evidence and further studies are needed. However, this rare condition should not trigger stopping the mass vaccination programs since the only way to eradicate the current pandemic of COVID-19 is to extend the number of immunized people.

Central Nervous System Neuroimmunologic Complications of COVID-19

Autoimmune disorders of the central nervous system following COVID-19 infection include multiple sclerosis (MS), neuromyelitis optica spectrum disorder, myelin oligodendrocyte glycoprotein antibody-associated disease, autoimmune encephalitis, acute disseminated encephalomyelitis, and other less common neuroimmunologic disorders. In general, these disorders are rare and likely represent postinfectious phenomena rather than direct consequences of the SARS-CoV-2 virus itself. The impact of COVID-19 infection on patients with preexisting neuroinflammatory disorders depends on both the disorder and disease-modifying therapy use. Patients with MS do not have an increased risk for severe COVID-19, though patients on anti-CD20 therapies may have worse clinical outcomes and attenuated humoral response to vaccination. Data are limited for other neuroinflammatory disorders, but known risk factors such as older age and medical comorbidities likely play a role. Prophylaxis and treatment for COVID-19 should be considered in patients with preexisting neuroinflammatory disorders at high risk for developing severe COVID-19.

What Can We Still Learn from Brain Autopsies in COVID-19?

Neuropathological findings have been published from ∼900 patients who died with or from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, representing less than 0.01% of the close to 6.4 million deaths reported to the World Health Organization 2 years into the coronavirus disease 2019 (COVID-19) pandemic. In this review, we extend our prior work summarizing COVID-19 neuropathology by including information on published autopsies up to June 2022, and neuropathological studies in children, COVID-19 variants, secondary brain infections, ex vivo brain imaging, and autopsies performed in countries outside of the United States or Europe. We also summarize research studies that investigate mechanisms of neuropathogenesis in nonhuman primates and other models. While a pattern of cerebrovascular pathology and microglial-predominant inflammation remains the primary COVID-19-associated neuropathological finding, there is no singular understanding of the mechanisms that underlie neurological symptoms in acute COVID-19 or the post-acute COVID-19 condition. Thus, it is paramount that we incorporate microscopic and molecular findings from brain tissue into what we know about the clinical disease so that we attain best practice guidance and direct research priorities for the study of the neurological morbidity of COVID-19.

Neuroimaging of COVID-19

We review the wide variety of common neuroimaging manifestations related to coronavirus disease 2019 (COVID-19) and COVID therapies, grouping the entities by likely pathophysiology, recognizing that the etiology of many entities remains uncertain. Direct viral invasion likely contributes to olfactory bulb abnormalities. COVID meningoencephalitis may represent direct viral infection and/or autoimmune inflammation. Para-infectious inflammation and inflammatory demyelination at the time of infection are likely primary contributors to acute necrotizing encephalopathy, cytotoxic lesion of the corpus callosum, and diffuse white matter abnormality. Later postinfectious inflammation and demyelination may manifest as acute demyelinating encephalomyelitis, Guillain-Barré syndrome, or transverse myelitis. The hallmark vascular inflammation and coagulopathy of COVID-19 may produce acute ischemic infarction, microinfarction contributing to white matter abnormality, space-occupying hemorrhage or microhemorrhage, venous thrombosis, and posterior reversible encephalopathy syndrome. Adverse effects of therapies including zinc, chloroquine/hydroxychloroquine, antivirals, and vaccines, and current evidence regarding "long COVID" is briefly reviewed. Finally, we present a case of bacterial and fungal superinfection related to immune dysregulation from COVID.

Neuropathological features of SARS-CoV-2 delta and omicron variants

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is continually evolving resulting in variants with increased transmissibility, more severe disease, reduced effectiveness of treatments or vaccines, or diagnostic detection failure. The SARS-CoV-2 Delta variant (B.1.617.2 and AY lineages) was the dominant circulating strain in the United States from July to mid-December 2021, followed by the Omicron variant (B.1.1.529 and BA lineages). Coronavirus disease 2019 (COVID-19) has been associated with neurological sequelae including loss of taste/smell, headache, encephalopathy, and stroke, yet little is known about the impact of viral strain on neuropathogenesis. Detailed postmortem brain evaluations were performed for 22 patients from Massachusetts, including 12 who died following infection with Delta variant and 5 with Omicron variant, compared to 5 patients who died earlier in the pandemic. Diffuse hypoxic injury, occasional microinfarcts and hemorrhage, perivascular fibrinogen, and rare lymphocytes were observed across the 3 groups. SARS-CoV-2 protein and RNA were not detected in any brain samples by immunohistochemistry, in situ hybridization, or real-time quantitative PCR. These results, although preliminary, demonstrate that, among a subset of severely ill patients, similar neuropathological features are present in Delta, Omicron, and non-Delta/non-Omicron variant patients, suggesting that SARS-CoV-2 variants are likely to affect the brain by common neuropathogenic mechanisms.

Acute Disseminated Encephalomyelitis and Acute Encephalitis Following Vaccination Against SARS-CoV-2: Two Case Reports and Review of Literature

The spectrum of severe neurological complications following COVID-19 vaccination includes cerebrovascular events, inflammatory diseases of the CNS, cranial and peripheral nerve involvement and muscle affections. Post-vaccinal acute disseminated encephalomyelitis (ADEM) and acute encephalitis are rare. We report on a patient suffering from acute encephalitis and another with post-vaccinal monophasic ADEM. Beside imaging features typical for acute autoimmune associated inflammation, cranial MRI disclosed also transient haemorrhagic signal alterations in some cerebral lesions. To our best knowledge, this has not been mentioned before in literature. Competing causes were excluded by extensive laboratory investigations including serial CSF analysis. In line with the literature, repeated iv high-dosage corticosteroid therapy resulted in impressive improvement of neurological symptoms in both patients.

Acute disseminated encephalomyelitis (ADEM)-like illness in a pediatric patient following COVID-19 vaccination

Since the inception of the COVID-19 pandemic, over 60 cases of ADEM or ADEM-like clinically isolated syndromes have been linked to COVID-19 infection. However, cases linked to COVID-19 vaccination remain exceptionally rare. To the author’s knowledge, eight published cases of ADEM or ADEM-like clinically isolated syndrome have been described after patients received COVID-19 vaccinations, all of which occurred in adults.

This report details the first documented case of an acute disseminated encephalomyelitis (ADEM)-like illness in a pediatric patient, which developed shortly after receiving the Pfizer (Pfizer-BioNTech, Germany) COVID-19 vaccination. The patient made a near complete clinical recovery over 10 days after receiving a 5 day course of intravenous immunoglobulin (IVIG) therapy.

Coronavirus Disease: Subacute to Chronic Neuroimaging Findings

Several neurologic disorders are associated with coronavirus disease 2019 (COVID-19). In this article, clinical syndromes typically occurring in the subacute to chronic phase of illness and their neuroimaging findings are described with discussion of their COVID-19 specific features and prognosis. Proposed pathogenic mechanisms of these neuroimaging findings and challenges in determining etiology are reviewed.

Acute Disseminated Encephalomyelitis Post COVID-19 Pneumonia

Acute disseminated encephalomyelitis (ADEM) is a monophasic condition characterized by inflammation of the central nervous system. Besides multiple sclerosis, optic neuropathy, acute transverse myelitis, and neuromyelitis optica spectrum disorder, ADEM is a primary inflammatory demyelinating disorder of the central nervous system. It is estimated that approximately three-quarters of cases of encephalomyelitis occur after an infection or immunization, where the onset of neurological disease is coincident with a febrile event. Here, we report an 80-year-old woman with coronavirus disease pneumonia who developed sudden onset of decreased level of consciousness, focal seizure, and right-side weakness. Magnetic resonance imaging (MRI) of the brain showed a multifocal hemorrhagic lesion with surrounding edema, suggesting ADEM. An electroencephalogram (EEG) revealed moderate generalized encephalopathy. The patient received alternating pulse steroids with plasma exchange for five days. Subsequently, her Glasgow coma scale score continued to decrease, and thus, she required inotropic support until she expired.

Neuropsychiatric aspects of long COVID: A comprehensive review

Although some patients have persistent symptoms or develop new symptoms following coronavirus disease 2019 (COVID-19) infection, neuropsychiatric aspects of long COVID are not well known. This review summarizes and provides an update on the neuropsychiatric dimensions of long COVID. Its neuropsychiatric manifestations commonly include fatigue, cognitive impairment, sleep disorders, depression, anxiety, and post-traumatic stress disorder. There are no specific tests for long COVID, but some characteristic findings such as hypometabolism on positron emission tomography have been reported. The possible mechanisms of long COVID include inflammation, ischemic effects, direct viral invasion, and social and environmental changes. Some patient characteristics and the severity and complications of acute COVID-19 infection may be associated with an increased risk of neuropsychiatric symptoms. Long COVID may resolve spontaneously or persist, depending on the type of neuropsychiatric symptoms. Although established treatments are lacking, various psychological and pharmacological treatments have been attempted. Vaccination against COVID-19 infection plays a key role in the prevention of long coronavirus disease. With differences among the SARS-CoV-2 variants, including the omicron variant, the aspects of long COVID are likely to change in the future. Further studies clarifying the aspects of long COVID to develop effective treatments are warranted.

Infection and inflammation: radiological insights into patterns of pediatric immune-mediated CNS injury

The central nervous system (CNS) undergoes constant immune surveillance enabled via regionally specialized mechanisms. These include selectively permissive barriers and modifications to interlinked innate and adaptive immune systems that detect and remove an inciting trigger. The end-points of brain injury and edema from these triggers are varied but often follow recognizable patterns due to shared underlying immune drivers. Imaging provides insights to understanding these patterns that often arise from unique interplays of infection, inflammation and genetics. We review the current updates in our understanding of these intersections and through examples of cases from our practice, highlight that infection and inflammation follow diverse yet convergent mechanisms that can challenge the CNS in children.

Acute Disseminated Encephalomyelitis Following COVID-19 Infection

Acute disseminated encephalomyelitis (ADEM) is a relatively rare, post-inflammatory, immune-mediated demyelinating central nervous system disease that is predominantly reported in pediatric populations. Following the emergence of severe acute respiratory syndrome coronavirus 2, cases of ADEM are being reported following infection with this virus. Our case report describes a male patient in his early 40s who developed severe coronavirus disease 2019 (COVID-19) that rapidly progressed to a critical disease requiring invasive mechanical ventilation and high positive end-expiratory pressure, which was complicated by extensive neurological involvement and quadriplegia. MRI of the brain showed characteristic demyelinating lesions, suggestive of ADEM. As other entities were ruled out, our patient was treated using pulse steroids and intravenous immunoglobulins. The patient showed a good response to treatment and had an overall good prognosis, despite the severity of his condition. ADEM following COVID-19 is a rare entity worldwide.

A review of the potential neurological adverse events of COVID-19 vaccines

Despite the advantages of getting access to the coronavirus disease 2019 (COVID-19) vaccines, their potential ability to induce severe adverse events (AEs) has been a significant concern. Neurological complications are significant among the various adverse events following immunization (AEFI) due to their likely durability and debilitating sequelae. Neurological AEs following COVID-19 vaccination can either exacerbate or induce new-onset neuro-immunologic diseases, such as myasthenia gravis (MG) and Guillain-Barre syndrome (GBS). The more severe spectrum of AEs post-COVID19 vaccines has included seizures, reactivation of the varicella-zoster virus, strokes, GBS, Bell's palsy, transverse myelitis (TM), and acute disseminated encephalomyelitis (ADEM). Here, we discuss each of these neurological adverse effects separately.

Fluoxetine plus lithium for treatment of mental health impairment in Long Covid

Purposes

(1) To summarize the mental conditions that may accompany persistent symptoms following acute infection by SARS-CoV-2, often termed Long Covid; (2) to formulate treatment based upon the brain cells that are dominantly affected.

Methods

(1) Review the reports relating to the mental symptoms occurring in Long Covid. (2) Review the drugs that address the brain cells affected in Long Covid, and suggest pharmacotherapy for those patients whose response to psychotherapy is suboptimal.

Results

Long Covid affects ~ 10% of patients infected by SARS-CoV-2, and mental symptoms affect ~ 20% of persons with Long Covid. The brain cell-types that have been demonstrated as dominantly affected in Long Covid are astrocytes, oligodendrocytes, neurons, endothelial cells/pericytes, and microglia. Lithium and fluoxetine each address all of those four cell-types. Low dosage of each is likely to be well-tolerated and to cause neither clinically important adverse events (AE) nor serious adverse events (SAE).

Conclusion

For those patients whose response to psychotherapy is suboptimal, lithium and fluoxetine should be administered in combination for both depth of benefit and reduction of dosages.

Two-year follow-up of a young male with possible acute hemorrhagic leukoencephalitis: A case report

RATIONALE

Acute hemorrhagic leukoencephalitis (AHLE) is a rare but fetal fulminant demyelinating disease of unknown etiology. It is commonly regarded as a severe variant of acute demyelinating encephalomyelitis (ADEM). Its rapid clinical deterioration and high mortality appeal to clinicians to attach importance to early diagnosis. Immunosuppressive therapy is the main management to attenuate the autoimmune process, but with varied response and prognosis.

PATIENT CONCERNS

A young male presented with moderate fever, headache and seizures after extraction of impacted teeth, and then deteriorated rapidly to deep coma. Initial magnetic resonance imaging (MRI) revealed multiple plaque-like lesions in bilateral cerebra, right thalamus and pontobulbar region with massive edematous swelling and multifocal small hemorrhagic foci. Inflammatory parameters in the peripheral blood were only mild higher with a pleocytosis in CSF.

DIAGNOSIS

His clinical presentation, laboratory evaluation and radiological features were consistent with a suspected diagnosis of AHLE.

INTERVENTIONS

He underwent pulse corticosteroids initially but failed to respond to it. However, his consciousness improved obviously when he was treated with multiple courses of intravenous injection of immunoglobulin (IVIG) combined with mycophenolate mofetil (MMF).

OUTCOMES

The patient regained consciousness gradually on day 180 and was in minimally conscious state (MCS) during the two-year follow-up.

LESSONS

AHLE presents distinctly from classical ADEM, and the situation may pose a diagnostic challenge. Clinicians should be vigilant in recognizing AHLE because of its rapid clinical deterioration and high mortality. We highlight the critical role of multimodal MRI, particularly susceptibility-weighted imaging (SWI) in the diagnosis of AHLE if cerebral biopsies are unavailable. Multiple courses of IVIG with MMF may be effective when early single pulse of corticosteroids fails. Individual who survives the initial insult may carry relatively good prognosis.

Acute Hemorrhagic Leukoencephalitis (AHLE): A Comprehensive Review on Causes, Symptoms, Link with COVID-19, Diagnosis, and Treatment

Acute hemorrhagic leukoencephalitis (AHLE), also called Hurst disease, is a rare demyelinating disease of the central nervous system (CNS) marked by rapid progression and acute inflammation of the white matter. Due to the correlation in their suspected postinfectious autoimmune pathogenesis, it is regarded as the most severe form of acute disseminated encephalomyelitis (ADEM). Because this clinical scenario has a high mortality rate, aggressive and immediate treatment is required. Although the exact cause of AHLE is unknown, it usually occurs after a bacterial or viral infection, or, less frequently, after a measles or rabies vaccination. AHLE has been reported in patients with coronavirus disease 2019 (COVID-19) as a rare but serious neurological complication. However, due to the lack of evidence-based diagnostic criteria, diagnosis is difficult. The small number of cases described in the literature, which most likely reflects underreporting and/or low incidence, necessitates greater public awareness. Increased clinical suspicion and early imaging identification of this entity may allow clinicians to pursue more aggressive treatment options, potentially reducing fatal outcomes. This study focuses on symptoms and causes of AHLE, difference between AHLE and ADME, diagnosis and treatment of AHLE, and its link with COVID-19.

Acute Disseminated Encephalomyelitis Following Thoracic Endovascular Aortic Repair

Acute disseminated encephalomyelitis (ADEM) is a central nervous system demyelinating condition. The postulated etiology is an autoimmune reaction, however, the mechanistic details are yet unknown. While infection and immunization are the most prevalent precipitating causes of ADEM, we postulate that radiopaque contrast material might have played a role as an immunological trigger. This presentation is unusual and has not been recorded so far. This case also emphasizes the challenges involved in evaluating emerging neurological problems following a period of intubation/sedation among these patients. We present a patient who passed away due to the manifestations of ADEM following admission to the intensive care unit after thoracic endovascular aortic repair for type B aortic dissection. Magnetic resonance imaging (MRI) performed following multiple attempts at sedation weaning demonstrated typical features of this condition. Clinicians and radiologists should be diligent and consider ADEM as a differential diagnosis when treating patients who present with neurological symptoms following radiological interventional procedures and have a high index suspicion to reduce mortality and achieve satisfactory clinical outcomes.

Therapeutic Approaches to the Neurologic Manifestations of COVID-19

As of May 2022, there have been more than 527 million infections with severe acute respiratory disease coronavirus type 2 (SARS-CoV-2) and over 6.2 million deaths from Coronavirus Disease 2019 (COVID-19) worldwide. COVID-19 is a multisystem illness with important neurologic consequences that impact long-term morbidity and mortality. In the acutely ill, the neurologic manifestations of COVID-19 can include distressing but relatively benign symptoms such as headache, myalgias, and anosmia; however, entities such as encephalopathy, stroke, seizures, encephalitis, and Guillain-Barre Syndrome can cause neurologic injury and resulting disability that persists long after the acute pulmonary illness. Furthermore, as many as one-third of patients may experience persistent neurologic symptoms as part of a Post-Acute Sequelae of SARS-CoV-2 infection (Neuro-PASC) syndrome. This Neuro-PASC syndrome can affect patients who required hospitalization for COVID-19 or patients who did not require hospitalization and who may have had minor or no pulmonary symptoms. Given the large number of individuals affected and the ability of neurologic complications to impair quality of life and productivity, the neurologic manifestations of COVID-19 are likely to have major and long-lasting personal, public health, and economic consequences. While knowledge of disease mechanisms and therapies acquired prior to the pandemic can inform us on how to manage patients with the neurologic manifestations of COVID-19, there is a critical need for improved understanding of specific COVID-19 disease mechanisms and development of therapies that target the neurologic morbidities of COVID-19. This current perspective reviews evidence for proposed disease mechanisms as they inform the neurologic management of COVID-19 in adult patients while also identifying areas in need of further research.

Cerebral microvascular injuries in severe COVID-19 infection: progression of white matter hyperintensities post-infection

A range of neuroradiological findings has been reported in patients with COVID-19, some mimicking cerebral small vessel disease (CSVD). We present a case of a man in his 50s with severe COVID-19, who was Glasgow Coma Scale 3 and tetraparetic after sedation was ceased in the intensive care unit. Return of consciousness and motor activity was slow. An MRI 1 month after debut of symptoms demonstrated white matter hyperintensities on T2-weighted Fluid Attenuated Inversion Recovery (T2-FLAIR) and many small areas with impaired diffusion in primarily supratentorial and infratentorial white matter on Diffusion-Weighted Imaging (DWI). In the following months, the patient made a remarkable clinical recovery. Despite clinical improvement, an MRI after 7 months showed that white matter hyperintensities had progressed and become confluent. Both MRIs demonstrated findings resembling CSVD, which could relate to a COVID-19-specific process affecting cerebral microvasculature.

Safety of COVID-19 Vaccines: Spotlight on Neurological Complications

The COVID-19 pandemic has led to unprecedented demand on the global healthcare system. Remarkably, at the end of 2021, COVID-19 vaccines received approvals for human use in several countries worldwide. Since then, a solid base for response in the fight against the virus has been placed. COVID-19 vaccines have been shown to be safe and effective drugs. Nevertheless, all kinds of vaccines may be associated with the possible appearance of neurological complications, and COVID-19 vaccines are not free from neurological side effects. Neurological complications of COVID-19 vaccination are usually mild, short-duration, and self-limiting. However, severe and unexpected post-vaccination complications are rare but possible events. They include the Guillain-Barré syndrome, facial palsy, other neuropathies, encephalitis, meningitis, myelitis, autoimmune disorders, and cerebrovascular events. The fear of severe or fatal neurological complications fed the "vaccine hesitancy" phenomenon, posing a vital communication challenge between the scientific community and public opinion. This review aims to collect and discuss the frequency, management, and outcome of reported neurological complications of COVID-19 vaccines after eighteen months of the World Health Organization's approval of COVID-19 vaccination, providing an overview of safety and concerns related to the most potent weapon against the SARS-CoV-2.

Nonvascular Nervous System Complications in Pediatric Patients with COVID-19 Infection

Coronavirus disease (COVID-19) is caused by a novel severe acute respiratory syndrome coronavirus 2 virus which primarily targets the lungs. However, the central nervous system (CNS) and peripheral nervous system involvement due to COVID-19, however, has been reported as early as the cases of respiratory system involvement. In addition, there have been many reports describing neuroimaging features of COVID-19, but data beyond case studies in the pediatric population are still limited, indicating limited CNS involvement. The CNS involvement and complications include, but are not limited to, encephalopathy, meningoencephalitis, ischemic stroke, venous sinus thrombosis, acute necrotizing encephalopathy, acute disseminated encephalomyelitis, posterior reversible encephalopathy syndrome, acute cerebellitis, acute hemorrhagic myelitis, and Guillain–Barré syndrome. In this manuscript, we will discuss the imaging characteristics of some of these entities with a known diagnosis of COVID-19.

Neuroinflammatory Disease following Severe Acute Respiratory Syndrome Coronavirus 2 Infection in Children

OBJECTIVE

To describe neurologic, radiologic and laboratory features in children with central nervous system (CNS) inflammatory disease complicating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

STUDY DESIGN

We focused on CNS inflammatory diseases in children referred from 12 hospitals in the Paris area to Necker-Sick Children Reference Centre.

RESULTS

We identified 19 children who had a history of SARS-CoV-2 infection and manifest a variety of CNS inflammatory diseases: encephalopathy, cerebellar ataxia, acute disseminated encephalomyelitis, neuromyelitis optica spectrum disorder, or optic neuritis. All patients had a history of SARS-CoV-2 exposure, and all tested positive for circulating antibodies against SARS-CoV-2. At the onset of the neurologic disease, SARS-CoV-2 PCR results (nasopharyngeal swabs) were positive in 8 children. Cerebrospinal fluid was abnormal in 58% (11/19) and magnetic resonance imaging was abnormal in 74% (14/19). We identified an autoantibody co-trigger in 4 children (myelin-oligodendrocyte and aquaporin 4 antibodies), representing 21% of the cases. No autoantibody was found in the 6 children whose CNS inflammation was accompanied by a multisystem inflammatory syndrome in children. Overall, 89% of patients (17/19) received anti-inflammatory treatment, primarily high-pulse methylprednisolone. All patients had a complete long-term recovery and, to date, no patient with autoantibodies presented with a relapse.

CONCLUSIONS

SARS2-CoV-2 represents a new trigger of postinfectious CNS inflammatory diseases in children.

SARS-COV-2 a trigger of myelin oligodendrocyte glycoprotein-associated disorder

SARS-COV-2 frequently cause neurological disorders and is sometimes associated with onset of autoimmune diseases affecting the nervous system. Over recent years, a rare but distinct diagnosis designated myelin oligodendrocyte glycoprotein-associated disorder (MOGAD) has been recognized in patients with attacks of optic neuritis, myelitis, or encephalomyelitis and increased levels of anti-MOG antibodies. The cause of MOGAD is unknown. However, there have been reports of single cases of MOGAD in patients with Covid-19 infection. We report a series of SARS-CoV-2 positive patients that developed MOGAD, but a homology search did not support a cross-reactive immune response to SARS-CoV-2 spike-protein and MOG.

Neurological Manifestations of SARS-CoV-2 Infection: Protocol for a Sub-analysis of the COVID-19 Critical Care Consortium Observational Study

Introduction

Neurological manifestations and complications in coronavirus disease-2019 (COVID-19) patients are frequent. Prior studies suggested a possible association between neurological complications and fatal outcome, as well as the existence of potential modifiable risk factors associated to their occurrence. Therefore, more information is needed regarding the incidence and type of neurological complications, risk factors, and associated outcomes in COVID-19.

Methods

This is a pre-planned secondary analysis of the international multicenter observational study of the COVID-19 Critical Care Consortium (which collected data both retrospectively and prospectively from the beginning of COVID-19 pandemic) with the aim to describe neurological complications in critically ill COVID-19 patients and to assess the associated risk factors, and outcomes. Adult patients with confirmed COVID-19, admitted to Intensive Care Unit (ICU) will be considered for this analysis. Data collected in the COVID-19 Critical Care Consortium study includes patients' pre-admission characteristics, comorbidities, severity status, and type and severity of neurological complications. In-hospital mortality and neurological outcome were collected at discharge from ICU, and at 28-days.

Ethics and Dissemination

The COVID-19 Critical Care Consortium main study and its amendments have been approved by the Regional Ethics Committee of participating sites. No further approval is required for this secondary analysis.

Trial Registration Number

ACTRN12620000421932.

[Acute disseminated encephalomyelitis associated with SARS-CoV-2 infection without respiratory compromise]

INTRODUCTION

COVID-19, the disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), continues to grow all over the world since december of 2019. Although the main clinical manifestation is pulmonary disease, neurological manifestations are a prominent and increasingly recognized feature of the disease. The Acute Disseminated Encephalomyelitis (ADEM) is a rare autoimmune disorder, most commonly triggered by a viral infection. There are a few case reports of ADEM associated with COVID-19, almost all of them associated pulmonary disease. We report the case of a young patient with diagnosis of ADEM with SARS-CoV-2 infection without clinical respiratory symptoms.

CASE REPORT

A 20-year-old woman with no relevant medical history was brought to the emergency department with a progressive confusional state lasted for 7 days. Family reported the development of smell and taste deficit since two weeks before the onset of neurological symptoms. There were no complaints of pulmonary symptoms. At admission, she was drowsy and disoriented. Left homonymous hemianopsia and an ipsilateral Babinski sign was identified. A brain magnetic resonance image was done showing multiple hyperintense bilateral, asymmetric patchy and poorly marginated lesions with gadolinium enhancement. She was SARS-CoV-2 PCR positive on nasopharyngeal swab. Intravenous high-dose glucocorticoids were administered with marked clinical improvement.

CONCLUSION

ADEM is an extremely uncommon complication of SARS-CoV-2infection. Acute disseminated encephalomyelitis should be considered a potentially treatable cause of encephalopathy or multifocal neurological deficits in COVID-19 patients, even in the absence of respiratory symptoms.

Acute Disseminated Encephalomyelitis with Prefrontal Cortex Involvement in a 9-Year-Old Child after COVID-19 Infection: A Case Report

The aim of the study was to present the rare co-occurring radiological findings of a child presenting with acute disseminated encephalomyelitis (ADEM) with a spinal cord and prefrontal cortex involvement after coronavirus disease 2019 (COVID-19) illness. The patient, who had COVID-19 a few weeks earlier, presented with progressive weakness in the right upper and lower extremities. Neurological examination of the patient was performed, and cranial magnetic resonance imaging (MRI) was taken on the same day. Serum severe acute respiratory syndrome coronavirus immunoglobulin M antibody testing was positive. MRI of the brain parenchyma and thoracic spine revealed fluid-attenuated inversion recovery and T2-weighted hyperintense lesions. Additionally, mild contrast enhancement was observed in both the prefrontal cortexes. The patient was discharged 10 days later with complete clinical recovery. Unlike other post-COVID-19 ADEM cases presenting in the literature, prefrontal cortex involvement makes our case rare.

Clinical Presentation and Outcomes of Acute Disseminated Encephalomyelitis in Adults Worldwide: Systematic Review and Meta-Analysis

Background

Acute disseminated encephalomyelitis (ADEM) is a rare demyelinating disorder that is often misdiagnosed. To improve early diagnosis, we performed a systematic review and meta-analysis of clinical features, outcomes for ADEM in adults.

Methods

The PubMed, Embase, Web of Science and Cochrane Library databases were searched for studies reporting the clinical features of adults with ADEM between January 1990 and May 2021. A random-effects meta-analysis model was used to pool data on clinical features and functional outcomes.

Results

Twelve studies examining 437 adults with ADEM met the inclusion criteria. Overall, the clinical features and diagnostic findings observed in more than two-thirds of the patients were white matter lesions [87.1%, 95% confidence interval (CI)=75-95.6], polyfocal onset (80.5%, 95% CI=50.5-98.9) and pyramidal signs (68.7%, 95% CI =40.0-91.9). The mortality rate was 7.8% (95% CI = 3.3–13.5), and the risk of residual deficits was 47.5% (95% CI = 31.8–63.4).

Conclusions

Adults with ADEM had worse outcomes than children. Clinicians should maintain high clinical suspicion for patients presenting with certain clinical features and diagnostic findings.