Case report: The histopathological analyses of two myelin oligodendrocyte glycoprotein antibody-associated diseases with a distinctive linear radiating gadolinium enhancement on MRI.

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) has highly heterogeneous clinical presentations, in which encephalitis is an important phenotype. Moreover, MOGAD has been reported to exhibit diverse imaging findings. However, there have been no previous reports of cases with perivascular radial gadolinium enhancement in periventricular regions, commonly reported in autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy. In this paper, we present two cases of MOGAD with this MRI feature, both of which underwent brain biopsy for the lesions. Brain biopsies revealed perivenous demyelination and inflammation consistent with acute disseminated encephalomyelitis (ADEM), with pronounced axonal damage in Case 1 and minimal axonal involvement in Case 2. Case 1 exhibited more severe cerebral atrophy than Case 2, correlating with the extent of axonal damage. Through these cases, we highlight the heterogeneity of radiological manifestations of MOGAD, expanding the spectrum beyond previously defined MRI patterns. Furthermore, histopathological analysis revealed distinct axonal involvement as a potential prognostic marker of brain atrophy. These observations emphasize the importance of considering MOGAD in the differential diagnosis, even in cases with atypical imaging findings, and highlight the significance of brain biopsy in guiding both diagnosis and prognosis.

Thunderclap headache as a first manifestation of acute disseminated encephalomyelitis: case report and literature review.

BACKGROUND: Acute Disseminated Encephalomyelitis (ADEM) is an acute demyelinating disorder of the central nervous system, characterize by multiple white matter hyperintensities on T2 MRI. Patients usually present with subacute progressive encephalopathy and polyfocal neurological deficits. Possible treatments are corticosteroids, immunoglobulins and plasma exchange. Full clinical recovery is seen in more than half of the cases. CASE: We describe a case of a 62-year-old patient presenting with thunderclap headache as the first symptom, two weeks after an upper respiratory tract infection. The clinical course was complicated by progressive coma and intracranial hypertension mandating external ventricular drainage and sedation. Initial treatment with methylprednisolone was unsuccessful but clinical resolution and radiological regression was achieved after plasma exchanges and cyclophosphamide. CONCLUSION: To our knowledge, this is the first reported case of ADEM presenting with thunderclap headache. Intracranial hypertension with the need for invasive neuromonitoring and pressure management is also a very rare complication of ADEM. In this report, we describe the findings of the literature review concerning ADEM, thunderclap headache and intracranial hypertension.

Long-term outcomes of ADEM-like and tumefactive presentations of CNS demyelination: a case-comparison analysis.

A minority of initial multiple sclerosis (MS) presentations clinically or radiologically resemble other central nervous system (CNS) pathologies, acute disseminated encephalomyelitis (ADEM) or tumefactive demyelination (atypical demyelination presentations). With the aim of better defining the long-term outcomes of this group we have performed a retrospective cohort comparison of atypical demyelination versus 'typical' MS presentations. Twenty-seven cases with atypical presentations (both first and subsequent demyelinating events) were identified and compared with typical MS cases. Disease features analysed included relapse rates, disability severity, whole brain and lesion volumes, lesion number and distribution. Atypical cases represented 3.9% of all MS cases. There was considerable overlap in the magnetic resonance imaging (MRI) features of ADEM-like and tumefactive demyelination cases. ADEM-like cases tended to be younger but not significantly so. Atypical cases showed a trend towards higher peak expanded disability severity score (EDSS) score at the time of their atypical presentation. Motor, cranial nerve, cerebellar, cerebral and multifocal presentations were all more common in atypical cases, and less likely to present with optic neuritis. Cerebrospinal fluid (CSF) white cell counts were higher in atypical cases (p = 0.002). One atypical case was associated with peripheral blood myelin oligodendrocyte glycoprotein (MOG) antibodies, but subsequent clinical and radiological course was in keeping with MS. There was no difference in long-term clinical outcomes including annualised relapse rates (ARR), brain volume, lesion numbers or lesion distributions. Atypical demyelination cases were more likely to receive high potency disease modifying therapy early in the course of their illness. Despite the severity of initial illness, our cohort analysis suggests that atypical demyelination presentations do not confer a higher risk of long-term adverse outcomes.

Catastrophic tumefactive acute disseminated encephalomyelitis in patient with dengue virus: a case report.

Tumefactive demyelinating lesions (TDL) are a rare occurrence among inflammatory demyelinating diseases of the central nervous system, distinguished by tumor-like lesions exceeding 2 cm in diameter. While various etiologies have been associated with TDL, only a limited number of case reports document the coexistence of acute disseminated encephalomyelitis (ADEM) and TDL. Here, we present the case of a female diagnosed with dengue fever two weeks prior, who subsequently developed left hemiparesis and encephalopathy. Both her brain magnetic resonance imaging (MRI) and clinical course align with the characteristics of tumefactive ADEM.

Clinico-radiologic Spectrum and Outcome of Pediatric Acquired Demyelinating Disorders of Central Nervous System: A Retrospective Indian Tertiary Care Hospital Cohort.

BACKGROUND: Pediatric acquired demyelinating syndrome (ADS) constitutes a group of treatable disorders with acute neurologic dysfunction. Neuroimaging has played a significant role in diagnosis of ADS. We describe clinico-radiologic spectrum, outcomes, and comparison of the groups: acute disseminated encephalomyelitis (ADEM), neuromyelitis optica spectrum disorder (NMOSD), clinically isolated syndrome (CIS), multiple sclerosis (MS), and myelin oligodendrocyte glycoprotein antibody-associated disorders (MOGAD). METHODS: Retrospective review of 70 children with ADS at a tertiary care hospital over 15 years (2008-2023) was performed. Diagnosis was assigned as per International Pediatric Multiple Sclerosis Study Group criteria 2016. Fisher's exact and chi-square tests were applied. RESULTS: Thirty-nine boys and 31 girls aged 8.2 ± 4.0 years with CIS (n = 27), ADEM (n = 16), NMOSD (n = 13), MS (n = 1), and MOGAD (n = 13) were included. Clinical syndromes with positive significant association included polyfocal symptoms, encephalopathy in ADEM, optic neuritis (ON) in MOGAD, brainstem, area postrema syndrome in NMOSD. MOGAD presented with atypical presentations like prolonged fever (PF; 76.9%) and aseptic meningitis (23%). Seropositivity for myelin oligodendrocyte glycoprotein immunoglobulin-G was 62% and for NMO-IgG 2.6%. Neuroimaging of MOGAD showed lesions predominantly in basal ganglia/thalami (69.2%), optic nerve (46.2%), and cerebellum (46.2%). Imaging patterns between ADEM and MOGAD were comparable except for more ON (p = 0.004), spinal cord (p = 0.01), and cerebellar lesions (p = 0.03) in MOGAD. Area postrema lesion was unique to NMOSD. All patients received immunotherapy, of whom 91.4% (n = 64) had good recovery, 8.6% (n = 6) had functional limitation on modified Rankin scale at discharge, and 12 (17.1%) relapsed. CONCLUSION: The largest group was CIS. Seropositivity of MOG was high with atypical presentations like PF and aseptic meningitis. Specific neuroimaging patterns correlated with ADS categories. Short-term outcome with immunotherapy was favorable in spite of relapses.

Acute disseminated encephalomyelitis following Saint Louis encephalitis virus infection.

Saint Louis encephalitis virus (SLEV) infection is an arbovirosis associated with a broad spectrum of neurological complications. We present a case of a 55-year-old man hailing from Manaus, a city situated in the heart of the Amazon Rainforest, who exhibited symptoms of vertigo, tremors, urinary and fecal retention, compromised gait, and encephalopathy 3 weeks following SLEV infection. Neuroaxis MRI revealed diffuse, asymmetric, and poorly defined margins hyperintense lesions with peripheral and ring enhancement in subcortical white matter, as well as severe spinal cord involvement. Serology for SLEV was positive both on serum and cerebrospinal fluid. To the best of our knowledge, the present report is the first to show brain lesions along with myelitis as a post-infectious complication of SLEV infection.

Influenza B-induced longitudinally extensive transverse myelitis and bithalamic acute disseminated encephalomyelitis.

In the COVID-era, other viral pathogens, like influenza B, gain less attention in scientific reporting. However, influenza still is endemic, and rarely affects central nervous system (CNS). Here, we report the case of a 35-year-old male who presented with fever since 1 week, and developed acute ascending flaccid paralysis and urinary retention. The clinical presentation of paraparesis in combination with the inflammation proven by the lumbar puncture, and the MRI full spine, fulfilled the diagnostic criteria of longitudinally extensive transverse myelitis (LETM). In this case, it is most likely based on a post-viral Influenza type B. Additionally, the brain MRI showed a necrotizing encephalopathy bilaterally in the thalamus. Both locations of inflammatory disease were part of one auto-immune-mediated, monophasic CNS disorder: influenza-induced ADEM which is very unique, fortunately with favorable outcome.

Acquired Demyelinating Syndromes of the Central Nervous System in Children: The Importance of Regular Follow-up in the First Year After Onset.

AIM: We reviewed the clinical features of a sample of pediatric acquired demyelinating syndromes with the purpose of determining the appropriate protocol for follow-up after the first episode. METHODS: A multicenter retrospective observational study was conducted on a cohort of 40 children diagnosed with a first episode of acquired demyelinating syndrome over the period 2012-2021. Patients were evaluated with clinical and neuroradiologic assessment after 3, 6, and 12 months, with a median follow-up of 4.0 years. RESULTS: At the first acquired demyelinating syndrome episode, 18 patients (45%) were diagnosed with acute disseminated encephalomyelitis, 18 (45%) with clinical isolated syndrome, and 4 (10%) with multiple sclerosis. By month 12, 12 patients (30%) had progressed from an initial diagnosis of acute disseminated encephalomyelitis (2) or clinical isolated syndrome (10) to multiple sclerosis. Of these, 6 had clinical relapse and 6 radiologic relapse only. The first relapse occurred after a median of 3 months. Among the patients who had evolved toward multiple sclerosis, there was a prevalence of females (P = .014), higher oligoclonal bands positivity (P = .009), and older median age (P < .001) as compared with those who had remained stable. INTERPRETATION: Both clinical and radiologic follow-up of children with acquired demyelinating syndromes is crucial, especially during the first year after acute onset, for early identification of multiple sclerosis and prompt initiation of disease-modifying treatment to delay axonal damage and to limit disability.

Clinical course, imaging, and pathological features of 45 adult and pediatric cases of myelin oligodendrocyte glycoprotein antibody-associated disease.

BACKGROUND: Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a recently described neuroinflammatory demyelinating disease. OBJECTIVE: To better understand the clinical spectrum, risk factors and outcomes in MOGAD. METHODS: Retrospective cohort study including all subjects harboring anti-MOG antibodies identified in major academic hospitals across the province of Quebec. RESULTS: We identified 45 MOGAD cases. The minimal estimated point-prevalence was 0.52/100 000 in Quebec. Median age at presentation was 32 years (range 1-71) with equal sex ratio. Most frequent ethnic groups were Caucasians and Asians. The most frequent clinical manifestations at onset were optic neuritis (ON), affecting 56% of adults, and acute disseminated encephalomyelitis (ADEM), affecting 33% of children. First MRI was abnormal in 84% of cases. Most CSF samples showed pleocytosis without oligoclonal bands. Two brain biopsies revealed lipid-laden macrophages and reactive astrocytes. Despite steroids, only 38% had fully recovered at 4 weeks after onset. Half of pediatric and two thirds of adult-onset MOGAD subjects experienced relapses. At last follow-up, 69% showed residual deficits, which were moderate to severe in 17% of adults. CONCLUSION: MOGAD has heterogeneous disease course, and it is not a benign disease for a substantial proportion of adults. Best disease-modifying therapies remain to be determined.

Can't pee, can't climb a tree: Seropositive myelin oligodendrocyte glycoprotein (MOG) antibodies in acute disseminated encephalomyelitis (ADEM).

When weighing the costs and benefits of "choosing wisely," in a healthcare climate that continues to stress cost-saving practices, it is difficult to argue with approaching low-risk patients with conservative approaches and treatments. In defense of liberal and broad approaches to patient workups, however, one must also weigh the bounce-back emergency department (ED) visit, which may represent either a failure of initial evaluation or a success of appropriate return precautions. An 18-year-old male presented to the ED with two days of urinary retention, abdominal pain, and subjective fever, was discharged with urology follow-up and doxycycline, and subsequently returned to the ED in <24 h with inability to stand and loss of reflexes in bilateral lower extremities. Magnetic Resonance Imaging (MRI) of the brain and spine demonstrated extensive and multifocal areas of signal abnormalities consistent with active demyelination concerning for acute disseminated encephalomyelitis (ADEM). Additional lab workup demonstrated seropositive myelin oligodendrocyte glycoprotein (MOG) antibodies, further supporting the diagnosis of ADEM, an immune-mediated disorder which can lead to rapid multifocal neurologic dysfunction.

Encephalomyelitis in a patient with monkeypox: an unusual complication.

A new outbreak of monkeypox has been reported worldwide with CNS complications like encephalitis or myelitis being extremely rare. We present a case of a 30-year-old man with PCR-confirmed diagnosis of monkeypox who developed rapid neurological deterioration with extensive inflammatory involvement of the brain and spinal cord on MRI. Because of the clinical and radiological resemblance to acute disseminated encephalomyelitis (ADEM), it was decided to indicate treatment with high-dose corticosteroids for 5 days (without concomitant antiviral management due to lack of availability in our country). Given the poor clinical and radiological response, 5 days of immunoglobulin G were administered. During follow-up the patient's clinical condition improved, physiotherapy was started and all associated medical complications were controlled. To our knowledge, this is the first reported monkeypox case with severe CNS complications treated with steroids and immunoglobulin in the absence of specific antiviral treatment.

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.

Impaired Brain Growth in Myelin Oligodendrocyte Glycoprotein Antibody-Associated Acute Disseminated Encephalomyelitis.

BACKGROUND AND OBJECTIVES: Acute disseminated encephalomyelitis (ADEM) is the most common phenotype in pediatric myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease. A previous study demonstrated impaired brain growth in ADEM. However, the effect of MOG antibodies on brain growth remains unknown. Here, we performed brain volume analyses in MOG-positive and MOG-negative ADEM at onset and over time. METHODS: In this observational cohort study, we included a total of 62 MRI scans from 24 patients with ADEM (54.2% female; median age 5 years), of which 16 (66.7%) were MOG positive. Patients were compared with healthy controls from the NIH pediatric MRI data repository and a matched local cohort. Mixed-effect models were applied to assess group differences and other relevant factors, including relapses. RESULTS: At baseline and before any steroid treatment, patients with ADEM, irrespective of MOG antibody status, showed reduced brain volume compared with matched controls (median [interquartile range] 1,741.9 cm3 [1,645.1-1,805.2] vs 1,810.4 cm3 [1,786.5-1,836.2]). Longitudinal analysis revealed reduced brain growth for both MOG-positive and MOG-negative patients with ADEM. However, MOG-negative patients showed a stronger reduction (-138.3 cm3 [95% CI -193.6 to -82.9]) than MOG-positive patients (-50.0 cm3 [-126.5 to -5.2]), independent of age, sex, and treatment. Relapsing patients (all MOG positive) showed additional brain volume loss (-15.8 cm3 [-68.9 to 37.3]). DISCUSSION: Patients with ADEM exhibit brain volume loss and failure of age-expected brain growth. Importantly, MOG-negative status was associated with a more pronounced brain volume loss compared with MOG-positive patients.

Eight-and-a-half syndrome as manifestation of acute disseminated adenovirus encephalomyelitis.

Acute disseminated encephalomyelitis is an immune mediated inflammatory-demyelinizing disease that usually manifests after infection or vaccination in school-age children. It typically presents a prodromal phase with flu-like symptoms, followed by a phase with varied clinical symptoms, neuro-ophthalmological alterations such as ophthalmoplegia or optic neuritis may occur. The differential diagnosis includes tumor, vascular, infectious, inflammatory and demyelinating diseases. Diagnosis is based on the clinical history and the characteristics of brain magnetic resonance imaging, the gold standard test. The study of the cerebrospinal fluid can help to guide the clinical picture. The prognosis is favorable, with an excellent response to corticosteroids and immunoglobulins, with minimal long-term sequelae in most cases. We report the case of an 8-year-old male with acute demyelinating disease due to adenovirus whose manifestation was an eight-and-a-half syndrome.

Prognostic factors for functional recovery in children with moderate to severe acute disseminated encephalomyelitis.

BACKGROUND: Acute disseminated encephalomyelitis (ADEM) is an immune-mediated encephalopathy with heterogeneous disease courses. However, clinical characteristics for a prognostication of functional recovery from acute episodes of ADEM remain limited. The study aims to characterize the clinical presentations and neuroimaging findings of children with poor functional recoveries from acute episodes of moderate to severe ADEM. METHODS: The multicenter retrospective cohort study included children under 18 years of age who presented with moderate to severe ADEM (modified Rankin Scale [mRS] ≥ 3 at nadir) from 2002 to 2019. Children were assigned to a good recovery group (mRS ≤ 2) and a poor recovery group (mRS ≥ 3) after mean 4.3 months of follow-up. The clinical presentations and the distribution of brain lesions on magnetic resonance imaging were compared between the two groups by the t-test for numerical variables and Fisher's exact test for categorical variables. Analyses of logistic regression were conducted and significant variables in the multivariate model were examined by the receiver operating characteristic curve for the prediction of functional recovery. RESULTS: Among the 73 children with moderate to severe ADEM, 56 (77%) had good functional recoveries and 17 (23%) showed poor functional recoveries. Children with poor recoveries had a lower rate of prodromal headache (12% vs. 39%, p = 0.04), and presented with higher proportions of dystonia (29% vs. 9%, p = 0.046), myoclonus (24% vs. 2%, p = 0.009), and cerebellar lesions on neuroimages (59% vs. 23%, p = 0.01). The multivariate analyses identified that a lack of prodromal headache (OR 0.1, 95% CI 0.005 - 0.7, p = 0.06) and the presentations of myoclonus (OR 21.6, 95% CI 1.7 - 874, p = 0.04) and cerebellar lesions (OR 4.8, 95% CI 1.3 - 19.9, p = 0.02) were associated with poor functional recoveries. These three factors could prognosticate poor outcomes in children with moderate to severe ADEM (area under the receiver operating characteristic curve 0.80, 95% CI 0.68 - 0.93, p = 0.0002). CONCLUSION: Nearly one-fourth of children with moderate to severe ADEM had a poor functional recovery from acute episodes, who were characterized by a lack of prodromal headache, the presentation of myoclonus, and the neuroimaging finding of cerebellar lesions. The clinical variables associated with poor functional recoveries could assist in the planning of immunotherapies during hospitalization for a better outcome in moderate to severe ADEM.

Oligoclonal bands, age 11-17 years, occipital lesion, and female sex differentiate pediatric multiple sclerosis from acute disseminated encephalomyelitis: A nationwide cohort study.

BACKGROUND: Our aim was to propose criteria to distinguish multiple sclerosis (MS) from acute disseminated encephalomyelitis (ADEM) at onset based on age at onset, sex, cerebrospinl fluid (CSF)-specific oligoclonal bands, and MRI. METHODS: A neuroradiologist undertook retrospective evaluation of the baseline magnetic resonance imaging (MRI) in a nationwide cohort of children with medical record-validated MS (n = 67) and monophasic ADEM (n = 46). Children with ADEM had at least 5 years of follow-up for relapse. We used forward stepwise conditional logistic regression to develop our criteria based on age at onset, sex, CSF-specific oligoclonal bands, and MRI. We undertook sensitivity analyses using children with ADEM including encephalopathy and polyfocal neurological deficits and in those with onset between 11 and 17 years of age. We estimated accuracy statistics from our criteria and all previously proposed MRI criteria to distinguish MS and ADEM. RESULTS: The best performing criteria to differentiate MS from ADEM were scoring at least three points in the following categories: presence of CSF-specific oligoclonal bands (2 points), occipital lesion (1 point), age 11-17 years (1 point), female sex (1 point). These criteria gave highly reliable discrimination with sensitivity of 95% (95% CI=89%-100%), specificity of 100% (95% CI=100%-100%), and area under the curve of 98% (95% CI=95%-100%). The best performing MRI criteria had area under the curve of 84% (95% CI=78%-91%). Previously proposed MRI criteria had the following areas under the curve: Callen (75%), KIDMUS (82%), and McDonald 2017 criteria (68%). CONCLUSION: Combining sex, age at onset, CSF-specific oligoclonal bands, and MRI gives highly reliable differentiation between pediatric MS and monophasic ADEM at onset.