RARE DISEASE
Acute disseminated encephalomyelitis
Acute disseminated encephalomyelitis
Acute disseminated encephalomyelitis
Synonyms: ADEM, Acute disseminated encephalitis
Synonyms: ADEM, Acute disseminated encephalitis
Synonyms: ADEM, Acute disseminated encephalitis
Drug discovery
1
drug
With orphan designation
Overview
Acute Disseminated Encephalomyelitis (ADEM) is an immune-mediated demyelinating disorder of the CNS, typically triggered by infections (50-75% of cases) or vaccinations. It presents with acute encephalopathy, multifocal neurologic deficits, and MRI findings of large, bilateral white matter lesions. Diagnosis requires excluding mimics like multiple sclerosis and infectious encephalitis. First-line treatment involves high-dose corticosteroids, with plasma exchange or IVIG for refractory cases. Most patients recover fully, though 5-25% experience relapses [1][4][7][16].
Therapies
Categories: rare neurological diseases, rare ophthalmic disorders
Research Papers
463 drug discovery papers about Acute disseminated encephalomyelitis, with 3 first-in-class emerging drug candidates forecasted to outperform the average preclinical success rate. Recent publications:
463 drug discovery papers about Acute disseminated encephalomyelitis, with 3 first-in-class emerging drug candidates forecasted to outperform the average preclinical success rate. Recent publications:
2026-08-04 | Treatment of acute demyelinating encephalomyelitis associated with recent rickettsial infection.
Acute disseminated encephalomyelitis (ADEM) is a rare, immune-mediated demyelinating disorder of the central nervous system that typically follows viral or bacterial infections. There are only two known case reports that describe an association with ADEM post rickettsial infection. A female in her 80s presented with progressive neurological decline, including dysarthria, dysphagia and hemiparesis, following recent treatment in Hong Kong for rickettsial infection. Initial CT brain imaging showed a right subcortical infarct. She deteriorated with encephalopathy and respiratory failure, requiring intubation. MRI revealed extensive brain and spinal demyelination. Infectious, autoimmune and paraneoplastic investigations were negative, while serology revealed markedly elevated spotted fever group antibodies. Treatment with high-dose corticosteroids and plasma exchange therapy resulted in significant neurological recovery. She was discharged after rehabilitation with a good recovery at 70%-80% of pre-morbid function. This case supports a possible post-infectious immune-mediated mechanism linking rickettsia and ADEM and underscores the importance of early recognition and treatment of ADEM.
2026-07-07 | Myelin oligodendrocyte glycoprotein antibody-related autoimmune encephalitis misdiagnosed as acute cerebral infarction: A case report.
Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is an inflammatory demyelinating autoimmune disorder of the central nervous system that exhibits a broad spectrum of known clinical phenotypes, including optic neuritis, myelitis, acute disseminated encephalomyelitis, encephalitis, meningoencephalitis, and brainstem encephalitis. However, new evidence indicates that a small subset of patients may present with cortical cerebral encephalitis (CCE). When CCE manifests as acute unilateral limb weakness, it may closely mimic acute cerebral infarction (ACI), resulting in misdiagnosis and delayed initiation of immunotherapy. Here, we report a case initially diagnosed as ACI and highlight key diagnostic clues and therapeutic considerations that may help to facilitate earlier recognition and appropriate management. A young woman was admitted with left-sided limb weakness and was initially diagnosed with ACI. The final diagnosis was myelin oligodendrocyte glycoprotein (MOG) antibody-related autoimmune encephalitis, which was established by integrating the clinical presentation, contrast-enhanced brain magnetic resonance imaging (MRI) findings, cerebrospinal fluid (CSF) antibody testing, and systematic exclusion of alternative etiologies. After an initial misdiagnosis, the patient received neuroprotective agents without meaningful improvement. Subsequent lumbar puncture and CSF testing supported the diagnosis of MOG antibody-related autoimmune encephalitis. Treatment was then adjusted to include both high-dose intravenous corticosteroid pulse therapy and immunotherapy, which resulted in marked clinical improvement. The patient's condition remained stable at 2-month follow-up, with no disease progression. Contrast-enhanced MRI showed no abnormalities in the unilateral cerebral cortex. CCE associated with MOGAD may be misdiagnosed as ACI, particularly when focal motor deficits are the predominant presenting feature. Early recognition, prompt diagnostic evaluation, and timely initiation of immunotherapy are crucial for improving clinical outcomes. Greater clinician awareness and improved neuroimaging-based differentiation between ACI and CCE are therefore needed. In patients with stroke-mimicking presentations but atypical imaging findings, contrast-enhanced MRI and cerebrospinal fluid testing for MOG immunoglobulin G should be prioritized. High-dose steroid pulse therapy combined with immunotherapy remains the recommended first-line treatment for suspected MOG antibody-related autoimmune encephalitis.
2026-07-01 | Delayed Myelin Oligodendrocyte Glycoprotein Antibody-Associated Demyelination Five Years After an Acute Disseminated Encephalomyelitis-Like Episode in an Adolescent: A Case Report
Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is an immune-mediated inflammatory demyelinating disorder of the central nervous system with a broad pediatric clinical spectrum. Acute disseminated encephalomyelitis (ADEM)-like presentations are more frequent in younger children, whereas older children and adolescents may present with optic neuritis, transverse myelitis, or multifocal central nervous system involvement. We report the case of a 14-year-old male adolescent who developed a severe MOG-IgG-positive demyelinating event five years after an initial ADEM-like episode. At nine years of age, he presented with back pain, gait disturbance, urinary incontinence, mild drowsiness, fever, cerebrospinal fluid pleocytosis, subcortical and medullary brain lesions, and longitudinally extensive myelitis. MOG-IgG testing was not available at that time, and the episode was diagnosed as ADEM based on the overall clinico-radiological presentation, with complete recovery after corticosteroid therapy. Five years later, he presented with fever, acute quadriparesis predominating in the lower limbs, pyramidal signs, and sphincter dysfunction. Brain MRI showed multiple ill-defined subcortical T2-weighted/fluid-attenuated inversion recovery (T2/FLAIR) hyperintense lesions, and spinal MRI demonstrated longitudinally extensive cervical myelitis from the cervicomedullary junction to C6. Cerebrospinal fluid analysis showed marked pleocytosis, elevated protein, absence of oligoclonal bands, and negative infectious studies. Serum MOG-IgG was positive at a titer of 1:100 using a fixed cell-based assay, while AQP4-IgG was negative. He received intravenous methylprednisolone followed by intravenous immunoglobulin because of insufficient initial improvement, with complete clinical recovery at one month and marked radiological regression at six months. This case emphasizes that a confirmed MOG-IgG-positive demyelinating event may occur after a prolonged relapse-free interval following an earlier ADEM-like demyelinating episode, while also underscoring that the first episode should be interpreted cautiously because MOG-IgG testing was unavailable. Long-term follow-up remains essential because short-term clinical and radiological improvement does not establish durable disease control.
2026-06-20 | Suspected Acute Disseminated Encephalomyelitis Presenting With Persistent Vegetative State and Full Neurological Recovery in an Adult: A Case Study
Acute disseminated encephalomyelitis (ADEM) is an autoimmune inflammatory disease of the central nervous system that typically presents with headache, fever, altered consciousness, and seizures. Diagnosis is made clinically and radiologically, supported by the exclusion of mimics. Delayed treatment can lead to severe neurological impairment, including a persistent vegetative state. A 69-year-old Asian female with rheumatic heart disease and prior transverse myelitis presented with hypoxic respiratory failure. On hospital day (HD) 4, she developed a rapid decline in mental status, progressing to a vegetative state with electroclinical seizures. Brain MRI showed diffuse, symmetric T2/fluid-attenuated inversion recovery (FLAIR) hyperintensities involving subcortical white matter, which is an atypical finding for classic ADEM. Extensive infectious and autoimmune testing was unrevealing. Lumbar puncture on HD 11 (prior to steroids) showed no pleocytosis. She remained vegetative for 39 days without response to high-dose corticosteroids. Following a five-day course of intravenous immunoglobulin (IVIG), she showed marked neurological recovery. At discharge, she returned to her baseline functional status. This case illustrates the diagnostic challenges of suspected ADEM in an older adult with atypical symmetric imaging, prolonged vegetative state, and delayed response to immunotherapy. The case adds to the limited literature on extended encephalopathy in suspected ADEM and underscores the role of IVIG when steroid response is unclear.
2026-05-26 | Recurrent Myelin Oligodendrocyte Glycoprotein Antibody-Positive Aseptic Meningitis at the Identical Site in a Child: Leptomeningeal Enhancement Detected by Contrast-Enhanced FLAIR Imaging.
Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is an acquired demyelinating syndrome of the central nervous system mediated by MOG antibodies. Clinical phenotypes include optic neuritis, transverse myelitis, and acute disseminated encephalomyelitis. MOG antibody-associated meningitis (MOGAM) is a form of aseptic meningitis characterized by the presence of serum MOG antibodies. Parenchymal lesions are typically absent in MOGAM; however, some cases may progress to MOGAD. Leptomeningeal lesions are rarely detected on contrast-enhanced T1-weighted magnetic resonance imaging (MRI) but may be conspicuous on contrast-enhanced fluid-attenuated inversion recovery (FLAIR) imaging. We report a case of a 5-year-old boy who initially presented with a prolonged headache and fever. Contrast-enhanced FLAIR imaging revealed localized leptomeningeal enhancement (LME), and the patient was treated for suspected aseptic meningitis. Subsequently, additional parenchymal lesions developed, and serum MOG antibodies were detected, leading to a diagnosis of MOGAD. He achieved remission with corticosteroid therapy but experienced a relapse a year later, with LME localized to the same site on MRI. At recurrence, the contrast-enhanced T1-weighted image showed faint leptomeningeal enhancement, whereas contrast-enhanced FLAIR imaging clearly depicted LME. Intravenous methylprednisolone pulse therapy was promptly initiated, which resulted in resolution without progression to MOGAD. This is the first pediatric report of recurrent MOGAM with LME recurring at the identical site. Contrast-enhanced FLAIR imaging enabled early detection of LME at recurrence and facilitated timely corticosteroid therapy, which may have prevented progression to MOGAD.
2026-08-04 | Treatment of acute demyelinating encephalomyelitis associated with recent rickettsial infection.
Acute disseminated encephalomyelitis (ADEM) is a rare, immune-mediated demyelinating disorder of the central nervous system that typically follows viral or bacterial infections. There are only two known case reports that describe an association with ADEM post rickettsial infection. A female in her 80s presented with progressive neurological decline, including dysarthria, dysphagia and hemiparesis, following recent treatment in Hong Kong for rickettsial infection. Initial CT brain imaging showed a right subcortical infarct. She deteriorated with encephalopathy and respiratory failure, requiring intubation. MRI revealed extensive brain and spinal demyelination. Infectious, autoimmune and paraneoplastic investigations were negative, while serology revealed markedly elevated spotted fever group antibodies. Treatment with high-dose corticosteroids and plasma exchange therapy resulted in significant neurological recovery. She was discharged after rehabilitation with a good recovery at 70%-80% of pre-morbid function. This case supports a possible post-infectious immune-mediated mechanism linking rickettsia and ADEM and underscores the importance of early recognition and treatment of ADEM.
2026-07-07 | Myelin oligodendrocyte glycoprotein antibody-related autoimmune encephalitis misdiagnosed as acute cerebral infarction: A case report.
Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is an inflammatory demyelinating autoimmune disorder of the central nervous system that exhibits a broad spectrum of known clinical phenotypes, including optic neuritis, myelitis, acute disseminated encephalomyelitis, encephalitis, meningoencephalitis, and brainstem encephalitis. However, new evidence indicates that a small subset of patients may present with cortical cerebral encephalitis (CCE). When CCE manifests as acute unilateral limb weakness, it may closely mimic acute cerebral infarction (ACI), resulting in misdiagnosis and delayed initiation of immunotherapy. Here, we report a case initially diagnosed as ACI and highlight key diagnostic clues and therapeutic considerations that may help to facilitate earlier recognition and appropriate management. A young woman was admitted with left-sided limb weakness and was initially diagnosed with ACI. The final diagnosis was myelin oligodendrocyte glycoprotein (MOG) antibody-related autoimmune encephalitis, which was established by integrating the clinical presentation, contrast-enhanced brain magnetic resonance imaging (MRI) findings, cerebrospinal fluid (CSF) antibody testing, and systematic exclusion of alternative etiologies. After an initial misdiagnosis, the patient received neuroprotective agents without meaningful improvement. Subsequent lumbar puncture and CSF testing supported the diagnosis of MOG antibody-related autoimmune encephalitis. Treatment was then adjusted to include both high-dose intravenous corticosteroid pulse therapy and immunotherapy, which resulted in marked clinical improvement. The patient's condition remained stable at 2-month follow-up, with no disease progression. Contrast-enhanced MRI showed no abnormalities in the unilateral cerebral cortex. CCE associated with MOGAD may be misdiagnosed as ACI, particularly when focal motor deficits are the predominant presenting feature. Early recognition, prompt diagnostic evaluation, and timely initiation of immunotherapy are crucial for improving clinical outcomes. Greater clinician awareness and improved neuroimaging-based differentiation between ACI and CCE are therefore needed. In patients with stroke-mimicking presentations but atypical imaging findings, contrast-enhanced MRI and cerebrospinal fluid testing for MOG immunoglobulin G should be prioritized. High-dose steroid pulse therapy combined with immunotherapy remains the recommended first-line treatment for suspected MOG antibody-related autoimmune encephalitis.
2026-07-01 | Delayed Myelin Oligodendrocyte Glycoprotein Antibody-Associated Demyelination Five Years After an Acute Disseminated Encephalomyelitis-Like Episode in an Adolescent: A Case Report
Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is an immune-mediated inflammatory demyelinating disorder of the central nervous system with a broad pediatric clinical spectrum. Acute disseminated encephalomyelitis (ADEM)-like presentations are more frequent in younger children, whereas older children and adolescents may present with optic neuritis, transverse myelitis, or multifocal central nervous system involvement. We report the case of a 14-year-old male adolescent who developed a severe MOG-IgG-positive demyelinating event five years after an initial ADEM-like episode. At nine years of age, he presented with back pain, gait disturbance, urinary incontinence, mild drowsiness, fever, cerebrospinal fluid pleocytosis, subcortical and medullary brain lesions, and longitudinally extensive myelitis. MOG-IgG testing was not available at that time, and the episode was diagnosed as ADEM based on the overall clinico-radiological presentation, with complete recovery after corticosteroid therapy. Five years later, he presented with fever, acute quadriparesis predominating in the lower limbs, pyramidal signs, and sphincter dysfunction. Brain MRI showed multiple ill-defined subcortical T2-weighted/fluid-attenuated inversion recovery (T2/FLAIR) hyperintense lesions, and spinal MRI demonstrated longitudinally extensive cervical myelitis from the cervicomedullary junction to C6. Cerebrospinal fluid analysis showed marked pleocytosis, elevated protein, absence of oligoclonal bands, and negative infectious studies. Serum MOG-IgG was positive at a titer of 1:100 using a fixed cell-based assay, while AQP4-IgG was negative. He received intravenous methylprednisolone followed by intravenous immunoglobulin because of insufficient initial improvement, with complete clinical recovery at one month and marked radiological regression at six months. This case emphasizes that a confirmed MOG-IgG-positive demyelinating event may occur after a prolonged relapse-free interval following an earlier ADEM-like demyelinating episode, while also underscoring that the first episode should be interpreted cautiously because MOG-IgG testing was unavailable. Long-term follow-up remains essential because short-term clinical and radiological improvement does not establish durable disease control.
2026-06-20 | Suspected Acute Disseminated Encephalomyelitis Presenting With Persistent Vegetative State and Full Neurological Recovery in an Adult: A Case Study
Acute disseminated encephalomyelitis (ADEM) is an autoimmune inflammatory disease of the central nervous system that typically presents with headache, fever, altered consciousness, and seizures. Diagnosis is made clinically and radiologically, supported by the exclusion of mimics. Delayed treatment can lead to severe neurological impairment, including a persistent vegetative state. A 69-year-old Asian female with rheumatic heart disease and prior transverse myelitis presented with hypoxic respiratory failure. On hospital day (HD) 4, she developed a rapid decline in mental status, progressing to a vegetative state with electroclinical seizures. Brain MRI showed diffuse, symmetric T2/fluid-attenuated inversion recovery (FLAIR) hyperintensities involving subcortical white matter, which is an atypical finding for classic ADEM. Extensive infectious and autoimmune testing was unrevealing. Lumbar puncture on HD 11 (prior to steroids) showed no pleocytosis. She remained vegetative for 39 days without response to high-dose corticosteroids. Following a five-day course of intravenous immunoglobulin (IVIG), she showed marked neurological recovery. At discharge, she returned to her baseline functional status. This case illustrates the diagnostic challenges of suspected ADEM in an older adult with atypical symmetric imaging, prolonged vegetative state, and delayed response to immunotherapy. The case adds to the limited literature on extended encephalopathy in suspected ADEM and underscores the role of IVIG when steroid response is unclear.
2026-05-26 | Recurrent Myelin Oligodendrocyte Glycoprotein Antibody-Positive Aseptic Meningitis at the Identical Site in a Child: Leptomeningeal Enhancement Detected by Contrast-Enhanced FLAIR Imaging.
Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is an acquired demyelinating syndrome of the central nervous system mediated by MOG antibodies. Clinical phenotypes include optic neuritis, transverse myelitis, and acute disseminated encephalomyelitis. MOG antibody-associated meningitis (MOGAM) is a form of aseptic meningitis characterized by the presence of serum MOG antibodies. Parenchymal lesions are typically absent in MOGAM; however, some cases may progress to MOGAD. Leptomeningeal lesions are rarely detected on contrast-enhanced T1-weighted magnetic resonance imaging (MRI) but may be conspicuous on contrast-enhanced fluid-attenuated inversion recovery (FLAIR) imaging. We report a case of a 5-year-old boy who initially presented with a prolonged headache and fever. Contrast-enhanced FLAIR imaging revealed localized leptomeningeal enhancement (LME), and the patient was treated for suspected aseptic meningitis. Subsequently, additional parenchymal lesions developed, and serum MOG antibodies were detected, leading to a diagnosis of MOGAD. He achieved remission with corticosteroid therapy but experienced a relapse a year later, with LME localized to the same site on MRI. At recurrence, the contrast-enhanced T1-weighted image showed faint leptomeningeal enhancement, whereas contrast-enhanced FLAIR imaging clearly depicted LME. Intravenous methylprednisolone pulse therapy was promptly initiated, which resulted in resolution without progression to MOGAD. This is the first pediatric report of recurrent MOGAM with LME recurring at the identical site. Contrast-enhanced FLAIR imaging enabled early detection of LME at recurrence and facilitated timely corticosteroid therapy, which may have prevented progression to MOGAD.
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Drug Discovery Landscape
1 orphan drug designation for Acute disseminated encephalomyelitis.
1 orphan drug designation for Acute disseminated encephalomyelitis.
Drug | Therapy type | Regulator | Orphan designation | Approval | Sponsor |
|---|---|---|---|---|---|
(R)-2-((1-(2-(4-methoxy-3-(2-morpholinoethoxy) phenyl)-5-methylthiazol-4-yl)ethyl)thio)pyrimidine-4,6-diamine | small molecules | FDA | 2021-01-07 | — | Trethera Corporation |
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