Acute disseminated encephalomyelitis with bilateral optic neuritis following ChAdOx1 COVID-19 vaccination

Serious adverse events following immunization with COVID-19 vaccines in Lebanon: a retrospective analysis of the National Pharmacovigilance Database

Continuous surveillance and risk assessment of inactivated Coronavirus Disease 2019 (COVID-19)) vaccines provide an understanding of their safety profiles, guide vaccination strategy and public health policy. This study aims to analyze the characteristics and prevalence of officially reported serious adverse events following immunization (AEFIs) with inactivated COVID-19 vaccines by System Organ Class (SOC), age, and sex.To achieve this aim, a retrospective observational study was conducted between February 14th, 2021, and June 30th, 2022. Reported AEFIs were evaluated for data completeness. Causality assessment adhered to the World Health Organization guidelines.Findings revealed that the AEFIs occurrence did not significantly differ between vaccines used (ChAdOx1 vs. BNT162b2), sex, or SOC. The most prevalent AEFIs were vascular disorders (37%), followed by cardiac (25%) and nervous system disorders (14%). The adverse events were predominantly reported post-vaccination with the BNT162b2 vaccine, mainly after the first dose. The mean age was highest for miscellaneous disorders (70 ± 21.7 years) and the lowest for nervous system (46 ± 22 years) and immune system disorders (45 ± 19 years). Age differences were statistically different for vascular disorders (p = 0.003) and immune system disorders (p = 0.012).In conclusion, ongoing surveillance and risk assessment of the vaccine's safety profile is crucial for detecting potential safety signals. Active surveillance of the reported serious AEFIs is highly needed to support evidence-based vaccination strategies and maintain public confidence in immunization programs.

Optic neuritis following COVID-19 vaccination: Case series and review of the literature

OBJECTIVE

To review cases of optic neuritis after COVID-19 vaccination and add similar cases to the literature.

METHODS

Thorough PubMed and Scopus searches were conducted, and data from studies describing optic neuritis after COVID-19 vaccination were extracted, tabulated, pooled, and reviewed.

RESULTS

We present 6 cases of optic neuritis following COVID-19 vaccination. Our literature search yielded 48 similar cases. All 54 cases were divided into 3 groups with respect to their serostatus: (1) double-seronegative or unknown serostatus optic neuritis cases, (2) myelin oligodendrocyte glycoprotein (MOG)-associated optic neuritis cases, and (3) aquaporin-4-associated optic neuritis cases. Data from each group were separately pooled and reviewed. While the most frequent vaccine among the anti-AQP4+ subgroup was BNT162b2 (Pfizer-BioNTech) (2/3), recombinant vaccines, e.g., AZD122 and Ad26.Cov2.s were mostly injected in the other subgroups (23/51). No significant gender inclination was seen among different subgroups. The mean interval from vaccination to symptom onset was less than one month in all subgroups; symptom manifestations mainly occurred after the first dose (28/54). Almost all cases showed improvement after steroid therapy±plasma exchange (52/54).

CONCLUSION

Despite having rare side effects such as optic neuritis, vaccination remains our most helpful protection against SARS-CoV-2. Nevertheless, larger studies are needed to ascertain the pathophysiology of such adverse effects. Likewise, the association between COVID-19 vaccination and optic neuritis warrants further investigation.

Cardiac and Neurological Complications Post COVID-19 Vaccination: A Systematic Review of Case Reports and Case Series

Following mass vaccinations for the control of the COVID-19 epidemic, a spectrum of cardiac and neurological disorders was reported among vaccinated individuals. This study examined the range of complications documented and factors related to their occurrence. Three electronic databases were searched for case reports and case series with descriptions of cardiac and/or neurological complications in COVID-19 vaccine recipients. A total of 698 vaccinees were included in this review, of which 259 (37.1%) had cardiac and 439 (62.9%) had neurological complications. Inflammatory conditions were the commonest among the cardiac complications; while polyneuropathy, demyelinating diseases and cerebrovascular disorders were the more common neurological complications. The mean age of those with cardiac complications (33.8 years) was much younger than those with neurological complications (49.7 years). There was no notable difference in the gender distribution between these two groups of vaccine recipients. mRNA vaccines (all brands) were associated with almost 90.0% of the cardiac complications, whereas viral vector vaccines were associated with slightly over half (52.6%) of the neurological complications. With regard to the dose, cardiac complications were more common after the second (69.1%), whereas neurological complications were more common after the first dose (63.6%). The majority of the cases had an uncomplicated clinical course. Nevertheless, 5.9% of cases with neurological complications and 2.5% of those with cardiac complications were fatal, underscoring the significance of the consistent surveillance and vigilant monitoring of vaccinated individuals to mitigate these occurrences.

A review of neuro-ophthalmic sequelae following COVID-19 infection and vaccination

Background

It has become increasingly clear that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can affect most organs in the human body, including the neurologic and ophthalmic systems. Vaccination campaigns have been developed at rapid pace around the world to protect the population from the fast-mutating virus. This review seeks to summarise current knowledge of the neuro-ophthalmic manifestations of both COVID-19 infection and vaccination.

Evidence acquisition

Electronic searches for published literature were conducted using EMBASE and MEDLINE on the 30th of July 2023. The search strategy comprised of controlled vocabulary and free-text synonyms for the following terms in various combinations: "coronavirus, COVID-19, SARS-CoV-2, 2019-nCoV, vaccination, vaccine, immunisation and neuro-ophthalmology". No time range limits were set for the literature search. Published English abstracts for articles written in a different language were screened if available.

Results

A total of 54 case reports and case series were selected for use in the final report. 34 articles documenting neuro-ophthalmic manifestations following COVID-19 infection and 20 articles with neuro-ophthalmic complications following COVID-19 vaccination were included, comprising of 79 patients in total. The most commonly occurring condition was optic neuritis, with 25 cases following COVID-19 infection and 27 cases following vaccination against COVID-19.

Conclusions

The various COVID-19 vaccines that are currently available are part of the global effort to protect the most vulnerable of the human population. The incidence of neuro-ophthalmic consequences following infection with COVID-19 is hundred-folds higher and associated with more harrowing systemic effects than vaccination against the virus.

Systematic review exploring the clinical features of optic neuritis after SARS-CoV infection and vaccination

BACKGROUND

This study aims to characterise the symptoms and clinical features of optic neuritis (ON) following SARS-CoV-2 infection and vaccination.

METHOD

A literature search was conducted in four databases (PubMed, Medline, Embase and Google Scholar) to identify relevant case reports and case series. The records were screened and articles adhering to the inclusion criteria were critically appraised.

RESULTS

Sixty-eight studies were found to be eligible for inclusion, including 34 reporting ON following SARS-CoV-2 infection and an equal number reporting cases postvaccination. In total 93 patients and 125 eyes were included. The infection cohort included 42 patients and 56 eyes, 51.2% were female and 33.3% experienced bilateral ON. The mean visual acuity was 1.64 log of minimum angle of resolution (LogMAR), while pain was present in 77.8%. Oligoclonal bands were present in 3 patients, myelin oligodendrocyte glycoprotein (MOG) antibodies in 18 patients and AQP-4 antibodies in 4 patients. The vaccination cohort included 51 patients and 69 eyes. 60.8% were female and 35.3% had a bilateral ON. The mean visual acuity was 0.93 LogMAR. Oligoclonal bands were present in 46.7%, MOG antibodies in nine patients and AQP-4 antibodies in three patients.

CONCLUSION

Patients with ON post-SARS-CoV infection were more likely to experience severe visual impairment than in cases following vaccination. Further research is required to outline the clinical features of ON after COVID-19 infection and vaccination, and establish causality.

The Occurrence of Acute Disseminated Encephalomyelitis in SARS-CoV-2 Infection/Vaccination: Our Experience and a Systematic Review of the Literature

BACKGROUND

The neurological complications of coronavirus disease 2019 (COVID-19) infection and the side effects of vaccination include immune-mediated diseases of the central nervous system (CNS) such as acute disseminated encephalomyelitis (ADEM). It is an acute-onset demyelinating disease that involves a rapid evolution and multifocal neurological deficits that develops following a viral or bacterial infection or, less frequently, following vaccination. Acute hemorrhagic leukoencephalitis (AHLE) is the hemorrhagic variant of ADEM that presents a more severe evolution which can be followed by coma and death. The objectives of this study consist in evaluating the diagnosis, clinical characteristics, imaging and laboratory features, evolution, and treatment of ADEM and AHLE following COVID-19 infection or vaccination.

METHODS

We performed a systematic review of the medical literature according to PRISMA guidelines that included ADEM cases published between 1 January 2020 and 30 November 2022 following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and vaccination and also included our own clinical experience regarding this pathology.

RESULTS

A total number of 74 patients were diagnosed with ADEM, 45 following COVID-19 infection and 29 after a SARS-CoV-2 vaccine. A total of 13 patients (17.33%) presented AHLE. The moderate form of COVID-19 presented a positive correlation with AHLE (r = 0.691, p < 0.001). The existence of coma and AHLE was correlated with poor outcomes. The following more aggressive immunomodulatory therapies applied in severe cases were correlated with poor outcomes (major sequelae and death): therapeutic plasma exchange (TPE) treatment (r = 382, p = 0.01) and combined therapy with corticosteroids and TPE (r = 0.337, p = 0.03).

CONCLUSIONS

Vaccinations are essential to reduce the spread of the COVID-19 pandemic, and the monitoring of adverse events is an important part of the strategic fight against SARS-CoV-2. The general benefits and the overall good evolution outweigh the risks, and prompt diagnosis is associated with a better prognosis in these patients.

Post-COVID-19 Vaccination CNS Magnetic Resonance Imaging Findings: A Systematic Review

OBJECTIVE

This systematic review aims to synthesize and analyze the available literature on central nervous system (CNS) magnetic resonance imaging (MRI) findings in individuals who have received COVID-19 vaccinations. Our objective is to enhance understanding of potential neurological side effects, inform clinical practice, and guide future research on the neurological implications of COVID-19 vaccination.

METHODS

In this systematic review, we conducted a comprehensive search in PubMed, Scopus, and Web of Science from January 2020 to April 2023, using terms related to COVID-19 vaccination and CNS MRI findings. We evaluated the quality of the study, extracted relevant data, and included 89 eligible studies that covered various vaccines, demographics of patients, symptoms, and MRI findings to provide a thorough understanding of SARS-CoV-2 vaccination-related CNS problems.

RESULTS

We investigated CNS MRI findings following COVID-19 vaccination across various vaccine types. Common diseases associated with post-vaccination CNS MRI findings included cerebral venous sinus thrombosis (CVST), vaccine-induced immune thrombotic thrombocytopenia (VITT), acute disseminated encephalomyelitis (ADEM), acute myelitis, autoimmune encephalitis (AE), and others. Patients presented with diverse onset symptoms and neurological manifestations. Abnormalities identified in CNS MRI findings included white matter (WM) hyperintensity. Our analysis offers a comprehensive overview of the current literature on post-vaccination CNS MRI findings. Discussion. We highlight a range of post-COVID-19 vaccination CNS MRI findings, including CVST, with a higher incidence in individuals receiving the ChAdOx1 (AstraZeneca) vaccine. Other notable observations include cases of ADEM, myelitis or transverse myelitis (TM), Guillain-Barré syndrome (GBS), and acute encephalopathy following COVID-19 vaccination. The incidence of these neurological complications is extremely rare, and the benefits of vaccination outweigh the risks. The reviewed studies were primarily case reports or case series, and thus large-scale epidemiological studies and controlled clinical trials are needed to better understand the underlying mechanisms and risk factors associated with these neurological complications following COVID-19 vaccination.

Neurological Adverse Reactions to SARS-CoV-2 Vaccines

SARS-CoV-2 vaccines are not free of side effects and most commonly affect the central or peripheral nervous system (CNS, PNS). This narrative review aims to summarise recent advances in the nature, frequency, management, and outcome of neurological side effects from SARS-CoV-2 vaccines. CNS disorders triggered by SARS-CoV-2 vaccines include headache, cerebro-vascular disorders (venous sinus thrombosis [VST], ischemic stroke, intracerebral hemorrhage, subarachnoid bleeding, reversible, cerebral vasoconstriction syndrome, vasculitis, pituitary apoplexy, Susac syndrome), inflammatory diseases (encephalitis, meningitis, demyelinating disorders, transverse myelitis), epilepsy, and a number of other rarely reported CNS conditions. PNS disorders related to SARS-CoV-2 vaccines include neuropathy of cranial nerves, mono-/polyradiculitis (Guillain-Barre syndrome [GBS]), Parsonage-Turner syndrome (plexitis), small fiber neuropathy, myasthenia, myositis/dermatomyositis, rhabdomyolysis, and a number of other conditions. The most common neurological side effects are facial palsy, intracerebral hemorrhage, VST, and GBS. The underlying pathophysiology is poorly understood, but several speculations have been generated to explain the development of CNS/PNS disease after SARS-CoV-2 vaccination. In conclusion, neurological side effects develop with any type of SARS-CoV-2 vaccine and are diverse, can be serious and even fatal, and should be taken seriously to initiate early treatment and improve outcome and avoid fatalities.

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.

Relapsing Encephalomyelitis After COVID-19 Infection and Vaccination: From the National MS Society Case Conference Proceedings

Prior case studies suggest that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its vaccines may unmask CNS neuroinflammatory conditions. We present a case of relapsing steroid-responsive encephalomyelitis after SARS-CoV-2 infection and subsequent COVID-19 vaccination. We also characterize the frequency of CNS neuroinflammatory events reported in the literature after both SARS-CoV-2 infection and COVID-19 vaccination.

Encephalitis following COVID-19 Vaccination: A Systematic Review

Background: Since the advent of global COVID-19 vaccination, several studies reported cases of encephalitis with its various subtypes following COVID-19 vaccinations. In this regard, we conducted a systematic review to investigate and characterize the clinical settings of these reported cases to aid in physician awareness and proper care provision. Methods: We systematically searched PubMed, Web of Science, and Scopus and manually searched Google Scholar. Studies published until October 2022 were included. Demographic data, clinical features, vaccine data, treatment lines, and outcomes were extracted. Results: A total of 65 patients from 52 studies were included. The mean age of patients was 46.82 ± 19.25 years, 36 cases (55.4%) were males. AstraZeneca was the most-reported vaccine associated with encephalitis (38.5%) followed by Pfizer (33.8%), Moderna (16.9%), and others. Moat encephalitis cases occurred after the first dose of vaccination in 41/65 (66.1%). The mean time between vaccination and symptom onset was 9.97 ± 7.16 days. Corticosteroids (86.2 %) and immunosuppressants (81.5 %) were the most used lines of treatment. The majority of affected individuals experienced a full recovery. Conclusion: Our study summarizes the current evidence of reported post-vaccination encephalitis, regarding clinical presentation, symptoms onset, management, outcomes, and comorbid conditions; however, it fails to either acknowledge the incidence of occurrence or establish a causal relationship between various COVID-19 vaccines and encephalitis.

Sequential orbital apex syndrome following the COVID-19 vaccination: A case report

Background

Many kinds of vaccines have been developed worldwide to bring the coronavirus disease 2019 (COVID-19) to an end. We report a case of recurrent orbital apex syndrome following the first and third doses of SARS-CoV-2 vaccination.

Case presentation

A 71-year-old woman presented with acute painless diplopia and visual disturbance for two days. She had received the first dose of the COVID-19 vaccine two weeks before. She showed decreased visual acuity and ophthalmoplegia in the right eye. An orbital magnetic resonance image (MRI) revealed a hyperintense lesion with enhanced bulging in the right cavernous sinus. Following the steroid pulse therapy, she fully recovered. However, six months after the first attack, painful ophthalmoplegia with decreased visual acuity recurred in her left eye after the booster vaccination for COVID-19. MRI also showed a well-enhanced hyperintense lesion in the left orbital apex. Fortunately, her visual acuity and ocular motility returned to normal after the steroid therapy.

Conclusions

Immunologic reactions from COVID-19 vaccines may cause multiple cranial neuropathies. Diverse individual immunologic states should be considered before any kind of vaccine.

Acute central nervous system inflammation following COVID-19 vaccination: An observational cohort study

BACKGROUND

Reports suggest a potential association between coronavirus disease 2019 (COVID-19) vaccines and acute central nervous system (CNS) inflammation.

OBJECTIVE

The main objective of this study is to describe features of acute CNS inflammation following COVID-19 vaccination.

METHODS

A retrospective observational cohort study was performed at the BARLO MS Centre in Toronto, Canada. Clinicians reported acute CNS inflammatory events within 60 days after a COVID-19 vaccine from March 2021 to August 2022. Clinical characteristics were evaluated.

RESULTS

Thirty-eight patients (median age 39 (range: 20-82) years; 60.5% female) presented within 0-55 (median 15) days of a receiving a COVID-19 vaccine and were diagnosed with relapsing remitting multiple sclerosis (MS) (n = 16), post-vaccine transverse myelitis (n = 7), clinically isolated syndrome (n = 5), MS relapse (n = 4), tumefactive demyelination (n = 2), myelin oligodendrocyte glycoprotein antibody disease (n = 1), neuromyelitis optica spectrum disorder (n = 1), chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (n = 1) and primary autoimmune cerebellar ataxia (n = 1). Twenty-two received acute treatment and 21 started disease-modifying therapy. Sixteen received subsequent COVID-19 vaccination, of which 87.5% had no new or worsening neurological symptoms.

CONCLUSION

To our knowledge, this is the largest study describing acute CNS inflammation after COVID-19 vaccination. We could not determine whether the number of inflammatory events was higher than expected.

Acute disseminated encephalomyelitis following the COVID-19 vaccine Ad26.COV2.S, a case report

BACKGROUND

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic has been leading to dramatic health, social and economic problems around the world. It was necessary to introduce worldwide vaccination program against SARS-CoV-2 virus. Vaccination of billions of people around the world leads to many questions about risk of vaccines and possible side effects. It is well known that acute disseminated encephalomyelitis (ADEM) is a rare, but possible complication of vaccines. Previously, cases of ADEM following various COVID-19 vaccines, including the vaccines from AstraZenica, Pfizer, Sputnik V, SinoVac, Moderna, Sinopharm, have been described. In this case report, we present the first documented case of ADEM following the COVID-19 vaccine Ad26.COV2.S from Johnson & Johnson.

CASE PRESENTATION

We present the case of a 31-year-old female with gradually progression of right-sided weakness and numbness during a three-week period. Four weeks prior to symptom onset, the patient received the single-dose SARS-CoV-2 vaccine Ad26.COV2.S. Neuroimaging revealed five large juxtacortical T2 FLAIR hyperintense lesions with incomplete contrast enhancement on post-contrast T1 images located supratentorial: one in the right cerebral hemisphere and four in left cerebral hemisphere. The patient was followed up for four months. Symptom debut, clinical picture and MRI were typical for ADEM and the patient completely recovered after high dose intravenous methylprednisolone treatment.

CONCLUSIONS

This is, to the best of our knowledge, the first case report of ADEM following the COVID-19 vaccine Ad26.COV2.S. This case illustrates, although ADEM is a rare complication following SARS-CoV-2 vaccines, the necessity of maintaining a vaccine safety monitoring system to identify patients at high risk from developing severe complications from the vaccines.

Bilateral Optic Neuritis after COVID-19 Vaccination: A Case Report

BACKGROUND

Neuro-ophthalmic manifestations after vaccines are rare, with optic neuritis (ON) being the most common presentation. Patients with vaccine-related ON are similar to those with idiopathic ON. The temporal relationship between vaccination against and the occurrence of ON is vital. Here, we report a case of bilateral ON after the administration of the ChAdOx1-S nCoV-19 SARS-CoV-2 vaccine.

CASE

A 49-year-old healthy Asian female presented with sudden onset of bilateral blurred vision within 2 days. She complained of photophobia and extraocular pain upon movement over 3 days. Upon examination, her best corrected visual acuity (BCVA) was 20/30 in the right eye and 20/200 in the left eye. Anterior segment findings were unremarkable, with normal intraocular pressure. Fundoscopic examination revealed bilateral disc edema with vessel engorgement. Visual field examination revealed profound visual field defect in both eyes. She denied any trauma, use of new medication or medical history. She had received the ChAdOx1 nCoV-19 SARS-CoV-2 vaccine 14 days prior. Under suspicion of vaccine-related optic neuritis, she was given intravenous methylprednisolone 1 gm/day for 3 days, shifting to oral prednisolone under gradual tapering for 2 weeks.

CONCLUSIONS

Typically presenting with sudden-onset visual decline and extraocular pain during movement, acute ON is generally idiopathic. Bilateral ON is rare, but quick identification is important because it can potentially lead to permanent loss of vision if left untreated. Vaccination-induced ON is even rarer but not difficult to treat. However, such patients require further evaluation and long-term follow-up because they may be prone to other neurological disorders in the future.

COVID-19 Vaccine-Associated Optic Neuropathy: A Systematic Review of 45 Patients

We provide a systematic review of published cases of optic neuropathy following COVID-19 vaccination. We used Ovid MEDLINE, PubMed, and Google Scholar. Search terms included: “COVID-19 vaccination”, “optic neuropathy”, “optic neuritis”, and “ischemic optic neuropathy”. The titles and abstracts were screened, then the full texts were reviewed. Sixty eyes from forty-five patients (28 females) were included. Eighteen eyes from fourteen patients (31.1%) were diagnosed with anterior ischemic optic neuropathy (AION), while 34 eyes from 26 patients (57.8%) were diagnosed with optic neuritis (ON). Other conditions included autoimmune optic neuropathy and Leber hereditary optic neuropathy. Fifteen patients (33.3%) had bilateral involvement. The mean age of all patients was 47.4 ± 17.1 years. The mean age of AION patients was 62.9 ± 12.2 years and of ON patients was 39.7 ± 12.8 years (p < 0.001). The mean time from vaccination to ophthalmic symptoms was 9.6 ± 8.7 days. The mean presenting visual acuity (VA) was logMAR 0.990 ± 0.924. For 41 eyes with available follow-up, the mean presenting VA was logMAR 0.842 ± 0.885, which improved to logMAR 0.523 ± 0.860 at final follow-up (p < 0.001). COVID-19 vaccination may be associated with different forms of optic neuropathy. Patients diagnosed with ON were more likely to be younger and to experience visual improvement. More studies are needed to further characterize optic neuropathies associated with COVID-19 vaccination.

The Clinical Neurophysiology of COVID-19- Direct Infection, Long-Term Sequelae and Para-Immunization responses: A literature review

The COVID-19 pandemic resulting from the SARS-CoV-2 virus is in its third year. There is continuously evolving information regarding its pathophysiology and its effects on the nervous system. Clinical neurophysiology techniques are commonly employed to assess for neuroanatomical localization and/or defining the spectrum of neurological illness. There is an evolving body of literature delineating the effects of the SARS-CoV-2 virus on the nervous system as well as para-immunization responses to vaccination against this virus. This review focuses on the use of neurophysiological diagnostic modalities in the evaluation of potential acute and long-term neurological complications in patients that experience direct infection with SARS-CoV-2 and analyzes those reports of para-immunization responses to vaccination against the SARS-CoV-2 virus. The neurophysiological modalities to be discussed include electroencephalography (EEG), evoked potentials (EPs), nerve conduction studies and electromyography (EMG/NCV), autonomic function tests, transcranial magnetic stimulation (TMS) and Transcranial Doppler ultrasound (TCD).

A Case of Atypical Unilateral Optic Neuritis Following BNT162b2 mRNA COVID-19 Vaccination

Background: We report a case of atypical unilateral optic neuritis after receiving the BNT162b2 mRNA-based COVID-19 vaccine. Case Presentation: An 86-year-old man complained of blurred vision and decreased visual acuity in his right eye 8 days after receiving the second BNT162b2 mRNA-based COVID-19 vaccine and was referred to our hospital. He also had pain with eye movement. Best corrected visual acuity (BCVA) in the right eye was 20/200 and critical flicker frequency dropped to 16 Hz. Relative afferent pupillary defect was positive and central scotomas were observed on visual field analysis. Fundus examination and SD-OCT revealed optic disc swelling and apparent thickening of the retinal nerve fiber layer around the optic disc in the right eye. Although either an increase in CRP or ESR on laboratory tests, demyelinating lesion on MRI, or positive of anti-MOG antibodies or anti-AQP4 antibodies were not observed, fluorescein angiography presented only hyperfluorescence of the optic disc in the right eye, but there were no findings such as papillary deficiency and choroidal delay that would suggest ischemic optic neuropathy. We diagnosed atypical optic neuritis developed after the SARS-CoV-2 mRNA-based vaccination and initiated oral corticosteroid therapy. One month later, the optic disc swelling disappeared and BCVA improved to 20/100; however, the central scotoma remained and no further improvement in visual function OD was obtained. Conclusions: An atypical acute idiopathic optic neuritis can occur after receiving the second vaccination with BNT162b2, which may present a limited response to corticosteroid therapy.

Atypical acute disseminated encephalomyelitis with systemic inflammation after a first dose of AztraZaneca COVID-19 vaccine. A case report

Background

Only a few cases of acute disseminated encephalomyelitis (ADEM) following coronavirus disease 19 (COVID-19) vaccination have been described since the beginning of the vaccination campaign.

Results

Here we report the first case of central nervous system (CNS) demyelination with systemic inflammatory findings on whole body 19-fluorodeoxyglucose positron emission tomography with computed tomography (FDG-PET/CT) following the ChAdOx1 nCoV-19 vaccine.

Conclusions

Clinicians should stay aware of potential new adverse events after immunization.

Incidence of Guillain-Barré syndrome following SARS-CoV-2 immunization: Analysis of a nationwide registry of recipients of 81 million doses of seven vaccines

Background and purpose

Information on Guillain–Barré syndrome (GBS) as an adverse event following immunization (AEFI) against SARS‐CoV‐2 remains scarce. We aimed to report GBS incidence as an AEFI among adult (≥18 years) recipients of 81,842,426 doses of seven anti‐SARS‐CoV‐2 vaccines between December 24, 2020, and October 29, 2021, in Mexico.

Methods

Cases were retrospectively collected through passive epidemiological surveillance. The overall observed incidence was calculated according to the total number of administered doses. Vaccines were analyzed individually and by vector as mRNA‐based (mRNA‐1273 and BNT162b2), adenovirus‐vectored (ChAdOx1 nCov‐19, rAd26‐rAd5, Ad5‐nCoV, and Ad26.COV2‐S), and inactivated whole‐virion‐vectored (CoronaVac) vaccines.

Results

We identified 97 patients (52 males [53.6%]; median [interquartile range] age 44 [33–60] years), for an overall observed incidence of 1.19/1,000,000 doses (95% confidence interval [CI] 0.97–1.45), with incidence higher among Ad26.COV2‐S (3.86/1,000,000 doses, 95% CI 1.50–9.93) and BNT162b2 recipients (1.92/1,00,000 doses, 95% CI 1.36–2.71). The interval (interquartile range) from vaccination to GBS symptom onset was 10 (3–17) days. Preceding diarrhea was reported in 21 patients (21.6%) and mild COVID‐19 in four more (4.1%). Only 18 patients were tested for Campylobacter jejuni (positive in 16 [88.9%]). Electrophysiological examinations were performed in 76 patients (78.4%; axonal in 46 [60.5%] and demyelinating in 25 [32.8%]); variants were similar across the platforms. On admission, 91.8% had a GBS disability score ≥3. Seventy‐five patients (77.3%) received intravenous immunoglobulin, received seven plasma exchange (7.2%), and 15 (15.5%) were treated conservatively. Ten patients (10.3%) died, and 79.1% of survivors were unable to walk independently.

Conclusions

Guillain–Barré syndrome was an extremely infrequent AEFI against SARS‐CoV‐2. The protection provided by these vaccines outweighs the risk of developing GBS.

Case report of acute encephalitis following the AstraZeneca COVID-19 vaccine

Coronavirus disease 2019 (COVID-19) vaccines have proven to be safe, effective and life-saving. However, little information is available on the neurological complications of COVID-19 vaccine. Here, we report a case who developed acute encephalomyelitis 1 week after being vaccinated with AstraZeneca COVID-19 vaccine (AZ vaccine). Autoimmune/inflammatory syndrome induced by adjuvants (ASIA) was also suspected. After intravenous dexamethasone and subcutaneous fondaparinux therapy, he returned to normal life without neurological sequelae. Four months later, he received Moderna COVID-19 vaccine without any sequelae.