Acute disseminated encephalomyelitis in 228 patients

Advances in Diagnosis and Management of Atypical Demyelinating Diseases

The last two decades have seen tremendous progress in understanding central nervous system (CNS) demyelinating diseases, heralding an exciting new era for the diagnosis and treatment of patients with a variety of non-multiple sclerosis neuroinflammatory diseases. This article comprehensively reviews atypical CNS demyelinating diseases, beginning with the general approach to CNS demyelination, continuing with suggestions to facilitate the initial evaluation, and followed by a discussion about specific diseases (neuromyelitis optica, myelin oligodendrocyte glycoprotein antibody disease, acute disseminated encephalomyelitis, iatrogenic CNS demyelination, and transverse myelitis). MRI examples of these disorders are provided to illustrate key radiographic findings. The article concludes with recommendations for treatment.

Adult Onset Acute Disseminated Encephalomyelitis: A Case Report

Acute disseminated encephalomyelitis (ADEM) is a rare autoimmune demyelinating disorder of the central nervous system that can mimic other neurological diseases, such as multiple sclerosis. ADEM is thought to manifest in the presence of environmental triggers, namely viral or bacterial infections, with multiple simultaneous neurological deficits, frequently accompanied by encephalopathy. Here, we report the case of a 49-year-old female patient who presented in the emergency department with encephalopathy, right-side muscle weakness, dizziness, vertigo, ataxia, and postural imbalance, preceded by symptoms suggesting recent pharyngitis/sialadenitis three weeks prior. Cerebrospinal fluid analysis revealed lymphocytic pleocytosis, elevated protein levels, normal glucose levels, no oligoclonal bands, and culture and viral studies were negative. After a normal cerebral computed tomography, brain and cervical spine magnetic resonance imaging (MRI) revealed multiple, T2-weighted hyperintense supratentorial and infratentorial white matter lesions, including the right cerebellar peduncle and posterior limb of the left internal capsule. The diagnosis of ADEM was made, and the patient was treated with high-dose intravenous glucocorticoids followed by oral tapering with clinical improvement. During follow-up, the control MRI was compatible with the diagnosis. This case illustrates the diagnostic approach of a patient presenting with subacute neurological deficits and the importance of contemplating possible differential diagnoses and swiftly initiating treatment.

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.

Emergent Management of Central Nervous System Demyelinating Disorders

OBJECTIVE

This article reviews the various conditions that can present with acute and severe central nervous system demyelination, the broad differential diagnosis of these conditions, the most appropriate diagnostic workup, and the acute treatment regimens to be administered to help achieve the best possible patient outcomes.

LATEST DEVELOPMENTS

The discovery of anti-aquaporin 4 (AQP4) antibodies and anti-myelin oligodendrocyte glycoprotein (MOG) antibodies in the past two decades has revolutionized our understanding of acute demyelinating disorders, their evaluation, and their management.

ESSENTIAL POINTS

Demyelinating disorders comprise a large category of neurologic disorders seen by practicing neurologists. In the majority of cases, patients with these conditions do not require care in an intensive care unit. However, certain disorders may cause severe demyelination that necessitates intensive care unit admission because of numerous simultaneous multifocal lesions, tumefactive lesions, or lesions in certain brain locations that lead to acute severe neurologic dysfunction. Intensive care may be necessary for the management and prevention of complications for patients who have severely altered mental status, rapidly progressive neurologic worsening, elevated intracranial pressure, severe cerebral edema, status epilepticus, or respiratory failure.

Neuromyelitis optica spectrum disorder co-existing with antiphospholipid syndrome: A case report

Key clinical message

Neuromyelitis optica spectrum disorder is an autoimmune disease, rarely presents with antiphospholipid syndrome. Diagnosis and management of NMOSD are challenging in the background of diverse presentations, especially in resource-limited settings.

Abstract

Neuromyelitis optica spectrum disorder (NMOSD) is a progressive demyelinating autoimmune condition resulting from the autoantibodies produced against aquaporin-4 (AQP-4) proteins which are widely distributed in astrocytes in the nervous system. In the setting of NMOSD, it is very crucial to consider other autoimmune diseases as differential diagnoses or co-occurrences due to the diversity of symptoms. NMOSD co-exists with other autoimmune diseases such as myasthenia gravis, thyroid disease, ankylosing spondylitis, pernicious anemia, thrombotic thrombocytopenic purpura, ulcerative colitis, and systemic lupus erythematosus. Few cases of antiphospholipid syndrome co-existing with NMOSD have been reported. In resource-limited settings, the published data are scarce, and therefore, autoimmune diseases are poorly studied. Therefore, late diagnosis and delayed treatment initiation pose long-term sequelae and hence poor prognosis. Here, we present a case of an African woman in her early 40s presenting with bilateral progressive loss of vision, transverse myelitis, extensive longitudinal hyperintense T2 cervical lesion, and AQP-4 autoantibody keeping with NMOSD. The co-existence of antiphospholipid syndrome, in this case, was supported by a history of recurrent pregnancy loss and positive antiphospholipid antibodies. This case underscores the importance of individualized-based medicine, especially in resource-limited settings.

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.

Multimodal evoked potentials are useful for the diagnosis of pediatric acute disseminated encephalomyelitis

BACKGROUND

The application of evoked potentials (EPs) to the diagnosis of acute disseminated encephalomyelitis (ADEM ) has not been investigated in detail. The aim of this study, therefore, was to analyze the value of multimodal EPs in the early diagnosis of pediatric ADEM.

METHODS

This was a retrospective study in which we enrolled pediatric ADEM patients and controls (Cs) from neurology units between 2017 and 2021. We measured indices in patients using brainstem auditory evoked potentials (BAEPs), visual evoked potentials (VEPs) and somatosensory evoked potentials (SEPs), and then we analyzed their early diagnostic value in ADEM patients.

RESULTS

The mean age of the ADEM group was 6.15 ± 3.28 years (range,1-12 years) and the male/female ratio was 2.1:1 The mean age of the Cs was 5.97 ± 3.40 years (range,1-12 years) and the male/female ratio was 1.3:1. As we used magnetic resonance imaging (MRI) as the diagnostic criterion, the sensitivity, specificity, and accuracy (κ was 0.88) of multimodal EPs were highly consistent with those of MRI; and the validity could be ranked in the following order with respect to the diagnosis of ADEM: multimodal Eps > single SEP > single VEP > single BAEP. Of 34 patients with ADEM, abnormalities in multimodal EPs were 94.12%, while abnormalities in single VEPs, BAEPs and SEPs were 70.59%,64.71%and 85.3%, respectively. We noted significant differences between single VEP/BAEPs and multimodal EPs (χ2 = 6.476/8.995,P = 0.011/0.003).

CONCLUSIONS

The combined application of multimodal EPs was superior to BAEPs, VEPs, or SEPs alone in detecting the existence of central nerve demyelination, and we hypothesize that these modalities will be applicable in the early diagnosis of ADEM.

Recurrent Acute Disseminated Encephalomyelitis Presenting as Conus Medullaris Syndrome: A Case Report

Acute disseminated encephalomyelitis (ADEM) is an inflammatory demyelinating disorder that typically follows an infection or recent vaccination. Symptoms such as encephalopathy and focal neurological deficits appear weeks after the initial illness, leading to swift and progressive neurological decline. While ADEM in the brain has been well documented, reports of ADEM, specifically in the spinal cord, are relatively limited. A 58-year-old male presented with rapidly progressive bilateral lower extremity tingling, numbness, and mild gait disturbance approximately two days prior to visiting the emergency room. Spinal magnetic resonance imaging revealed a diffuse, longitudinal, high-signal lesion with mild enlargement of the conus and proximal cauda equina. The lesions were predominantly localized in the distal conus and cauda equina, and serial electrodiagnostic studies showed that the lesions progressed toward the proximal conus in tandem with symptom evolution and lacked clear lateralization. The patient was subsequently treated with high-dose steroids for seven days (intravenous methylprednisolone, 1 mg/kg). The patient's lower extremity weakness gradually improved and he was able to walk independently under supervision three weeks after symptom onset. In this case of spinal ADEM in a middle-aged adult, high-dose steroid treatment led to outstanding neurological recovery from both the initial occurrence and subsequent attacks.

Characteristics and predictors of disease course in children initially presenting with ADEM

ADEM is an inflammatory disease, with new onset polyfocal neurologic symptoms, encephalopathy and multifocal demyelination, typically in childhood. Initial diagnosis of ADEM is challenging and up to 20 % of children with MS or NMOSD are initially diagnosed with ADEM. We describe characteristics of patients with monophasic ADEM vs. recurrent demyelinating syndromes at onset and identify features consistent with monophasic course. This is a multicenter observational study of children with demyelinating disease, followed at 12 regional pediatric MS centers. Descriptive statistics were used to report patient characteristics, clinical/imaging features and outcomes. Logistic regression was used to predict features associated with monophasic course. As of July 2019, 837 children with final diagnosis of ADEM (n = 79), MS (n = 646) or NMOSD (n = 112) were identified. The mean follow-up was 5·7 +/- 3·2 years. ADEM patients were youngest with mean age at first event 5·2 +/- 3·8 years (p < 0.001) and male predominant (66 %) (p < 0·001). After 2 years of follow-up, 83 % of patients initially diagnosed with monophasic ADEM retained this diagnosis. In multivariable analysis, older age (OR 1·16 [95 % CI 1·02 - 1·33] for 1-year increase, p = 0·02), presenting with optic neuritis (OR 8.18 [95 % CI 1.88 - 35.64], p = 0·005) and presence of gadolinium enhancement (OR 4.08 [95 % CI 1.38 - 12.08], p = 0·011) were associated with reclassification of ADEM to MS, NMOSD or DDNOS within 2 years. Children with monophasic ADEM vs. those reclassified as other demyelinating disorders are younger at onset, and less likely to have optic neuritis or gadolinium-enhancing lesions at onset.

Multiple sclerosis imaging in clinical practice: a European-wide survey of 428 centers and conclusions by the ESNR Working Group

OBJECTIVES

To evaluate compliance with the available recommendations, we assessed the current clinical practice of imaging in the evaluation of multiple sclerosis (MS).

METHODS

An online questionnaire was emailed to all members and affiliates. Information was gathered on applied MR imaging protocols, gadolinium-based contrast agents (GBCA) use and image analysis. We compared the survey results with the Magnetic Resonance Imaging in MS (MAGNIMS) recommendations considered as the reference standard.

RESULTS

A total of 428 entries were received from 44 countries. Of these, 82% of responders were neuroradiologists. 55% performed more than ten scans per week for MS imaging. The systematic use of 3 T is rare (18%). Over 90% follow specific protocol recommendations with 3D FLAIR, T2-weighted and DWI being the most frequently used sequences. Over 50% use SWI at initial diagnosis and 3D gradient-echo T1-weighted imaging is the most used MRI sequence for pre- and post-contrast imaging. Mismatches with recommendations were identified including the use of only one sagittal T2-weighted sequence for spinal cord imaging, the systematic use of GBCA at follow-up (over 30% of institutions), a delay time shorter than 5 min after GBCA administration (25%) and an inadequate follow-up duration in pediatric acute disseminated encephalomyelitis (80%). There is scarce use of automated software to compare images or to assess atrophy (13% and 7%). The proportions do not differ significantly between academic and non-academic institutions.

CONCLUSIONS

While current practice in MS imaging is rather homogeneous across Europe, our survey suggests that recommendations are only partially followed.

CLINICAL RELEVANCE STATEMENT

Hurdles were identified, mainly in the areas of GBCA use, spinal cord imaging, underuse of specific MRI sequences and monitoring strategies. This work will help radiologists to identify the mismatches between their own practices and the recommendations and act upon them.

KEY POINTS

• While current practice in MS imaging is rather homogeneous across Europe, our survey suggests that available recommendations are only partially followed. • Several hurdles have been identified through the survey that mainly lies in the areas of GBCA use, spinal cord imaging, underuse of specific MRI sequences and monitoring strategies.

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.

Rapid Progressive Fatal Acute Hemorrhagic Encephalomyelitis

Acute hemorrhagic encephalomyelitis (AHEM) is the most severe form of acute disseminated encephalomyelitis (ADEM). Patients with AHEM usually have unfavorable outcomes with high mortality rate. We reported a middle-aged male, who was diagnosed with AHEM and died 35 days after admission even under intensive immune therapy. Clinical courses were recorded and serial MR images were demonstrated to illustrate the rapidly changes in brain parenchyma. By highlighting these aspects, we hope to provide valuable insights for future studies and potential advancements in the management of AHEM.

An Adult Case of Adenovirus-Associated Acute Disseminated Encephalomyelitis

Acute disseminated encephalomyelitis (ADEM) is an autoimmune neurological disease that predominately affects pediatric population. Only a single fatal adult case of adenovirus-associated ADEM has previously been published by Qamar et al. in 2021. Here, we present an adult case of adenovirus-associated ADEM, which was diagnosed early in her clinical course. The patient was treated with the prompt initiation of steroids, intravenous immune globulin (IVIG), and plasmapheresis (PLEX), and the patient recovered fully. This case highlights the importance of early accurate diagnosis for other clinicians to treat adenovirus-associated ADEM in a timely fashion to prevent a potentially fatal outcome.

Clinical, radiological, therapeutic and prognostic differences between MOG-seropositive and MOG-seronegative pediatric acute disseminated encephalomyelitis patients: a retrospective cohort study

Objective

This study aimed to compare the clinical, radiological, therapeutic, and prognostic differences between pediatric patients showing acute disseminated encephalomyelitis (ADEM) with and without myelin oligodendrocyte glycoprotein (MOG) antibodies.

Methods

We retrospectively collected all available data of children diagnosed with ADEM and tested for serum MOG antibodies at the Children's Hospital of Chongqing Medical University from January 2017 to May 2021.

Results

A total of 62 patients were included in our cohort, of which 35 were MOG-seropositive and 27 were MOG-seronegative. MOG-seropositive ADEM children presented with significantly lower rates of seizures (P = 0.038) and cranial nerve (III-XII) palsy (P = 0.003). Isolated leukocytosis in the blood was more common in ADEM children with MOG antibodies (P < 0.001). The two groups showed no significant differences in the distributions and extent of the MRI lesions as well as the appearance of typical/atypical magnetic resonance imaging (MRI) features. MOG-seropositive children were more likely to relapse (P = 0.017) despite having slower oral prednisolone tapering after acute treatments (P = 0.028). In scoring performed on the basis of two neurological function scoring systems, MOG-seropositive children showed milder neurological disability status at onset (P = 0.017 and 0.025, respectively) but showed no difference during follow-up.

Conclusion

In summary, the differences in the clinical manifestations and auxiliary examination findings for MOG-seropositive and MOG-seronegative ADEM children lacked significance and specificity, making early identification difficult. MOG-seropositive children were more likely to relapse and showed slower steroid tapering. Moreover, MOG-seronegative children tended to have more severe neurological impairments at onset with no difference during follow-up.

[Viral diseases of the nervous system-Selected new and old viruses]

Viral diseases of the nervous system are ancient and poliomyelitis was described in Egypt as early as 2000 BC. They can cause a wide range of neurological symptoms, such as meningitis, encephalitis, meningoencephalitis, Guillain-Barré-like syndrome and stroke, often leaving mild to severe residuals. Depending on the pathogen, the symptoms appear quickly within hours, or lead to increasing chronic symptoms within 1 week or months. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which was newly identified in January 2020 and occurs worldwide, illustrates the sequelae of a phenomenon that has been known for centuries, the possible rapid spread of pathogen-related infectious diseases. Due to vaccination programs some pathogens are becoming rarer or are considered to be eradicated. Nevertheless, vaccination programs, especially in the poorer regions, are repeatedly interrupted, for example by wars. The most recent example is the interruption of vaccination against poliomyelitis in Ukraine. As life expectancy continues to rise and years of life lost to infectious diseases decrease, the new infectious disease threat is likely to come from emerging and re-emerging infections; however, according to a recent analysis of population data from 29 countries, life expectancy during the corona pandemic has decreased, e.g., by 28 months in the USA and by 6 months in Germany. Climate change, rapid urbanization and changing land-use patterns could increase the risk in the coming decades. In particular, the climate change can alter the spectrum of global pathogens and especially vector-borne infections can spread to new areas. A sustained increase in travel, trade and mobility enables the pathogens to spread quickly.

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.

Levamisole-associated multifocal inflammatory encephalopathy: clinical and MRI characteristics, and diagnostic algorithm

Levamisole-associated multifocal inflammatory encephalopathy (LAMIE) is a devastating adverse effect of levamisole (LEV) treatment. In Russia, people often use LEV without a doctor's prescription for anthelmintic prophylaxis. LAMIE often misdiagnosed as the first episode of MS or acute disseminated encephalomyelitis (ADEM). The aim of our study was to describe clinical, laboratory and morphological characteristics of LAMIE, magnetic resonance imaging (MRI) patterns and create an algorithm for the differential diagnosis. This study was a prospective observational study with retrospective analysis of cases. It was performed at two hospitals with ambulatory service for MS. We included 43 patients with LAMIE with follow-up was from 1 year to 5 years. Age was 19-68 y.o. with female predominance. The most typical manifestations of LAMIE were cerebellar, pyramidal and cognitive symptoms, and majority of patients had biphasic course of the disease. Three main types of MRI patterns were described: ADEM-like, MS-like, atypical demyelination. About 40% of patients had CSF specific oligoclonal bands synthesis, but only 20 % of them converted to MS during the period from 1 month until 2 years. The CSF albumin levels and immunoglobulin G index were elevated in LAMIE patients compared to reference values. We described results of brain biopsy in two cases. Therefore LAMIE should be considered in patients with demyelinating or inflammatory conditions with biphasic onset of the disease and variable MRI presentation.

Motor symptoms in nonparaneoplastic CNS disorders associated with neural antibodies

Motor symptoms are common, and sometimes predominant, in almost all nonparaneoplastic CNS disorders associated with neural antibodies. These CNS disorders can be classified into five groups: (1) Autoimmune encephalitis with antibodies against synaptic receptors, (2) cerebellar ataxias associated with neuronal antibodies that mostly target intracellular antigens. (3) Stiff-person syndrome and progressive encephalomyelitis with rigidity and myoclonus which have antibodies against glutamic acid decarboxylase and glycine receptor, respectively. Both diseases have in common the presence of predominant muscle stiffness and rigidity. (4) Three diseases associated with glial antibodies. Two present motor symptoms mainly due to the involvement of the spinal cord: neuromyelitis optica spectrum disorders with aquaporin-4 antibodies and myelin oligodendrocyte glycoprotein antibody-associated disease. The third disorder is the meningoencephalitis associated with glial fibrillar acidic protein antibodies which frequently also presents a myelopathy. (5) Two antibody-related diseases which are characterized by prominent sleep dysfunction: anti-IgLON5 disease, a disorder that frequently presents a variety of movement disorders, and Morvan syndrome associated with contactin-associated protein-like 2 antibodies and clinical manifestations of peripheral nerve hyperexcitability. In this chapter, we describe the main clinical features of these five groups with particular emphasis on the presence, frequency, and types of motor symptoms.

Pediatric Acquired Demyelinating Disorders

PURPOSE OF REVIEW

This article reviews the clinical presentation, diagnostic evaluation, treatment, and prognosis of the most common monophasic and relapsing acquired demyelinating disorders presenting in childhood.

RECENT FINDINGS

Our understanding of neuroimmune disorders of the central nervous system is rapidly expanding. Several clinical and paraclinical factors help to inform the diagnosis and ultimately the suspicion for a monophasic versus relapsing course, including the age of the patient (prepubertal versus postpubertal), presence or absence of clinical encephalopathy, identification of serum autoantibodies (eg, myelin oligodendrocyte glycoprotein [MOG] and aquaporin-4), presence of intrathecally unique oligoclonal bands, and location/extent of radiologic abnormalities. Collaborative international research efforts have facilitated understanding of the safety and efficacy of currently available immunotherapies in children with acquired demyelinating disorders, particularly multiple sclerosis.

SUMMARY

Although many of the demyelinating disorders presented in this article can affect children and adults across the age spectrum, the clinical and radiologic phenotypes, treatment considerations, and long-term prognoses are often distinct in children.

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.

Magnetic Resonance Imaging of Autoimmune Demyelinating Diseases as a Diagnostic Challenge for Radiologists: Report of Two Cases and Literature Review

The magnetic resonance characteristics of autoimmune demyelinating diseases are complex and represent a challenge for the radiologist. In this study we presented two different cases of detected autoimmune demyelinating diseases: one case of acute disseminated encephalomyelitis and one case of neuromyelitis optica, respectively. Expected and unexpected findings of magnetic resonance imaging examination for autoimmune demyelinating diseases were reported in order to provide a valuable approach for diagnosis. In particular, we highlight, review and discuss the presence of several uncommon imaging findings which could lead to a misinterpretation. The integration of magnetic resonance imaging findings with clinical and laboratory data is necessary to provide a valuable diagnosis.

Rapidly progressive dementia in a nonagenarian with acute disseminated encephalomyelitis

We describe a case of rapidly progressive dementia (RPD) in a nonagenarian. Dementia was caused by an acute disseminated encephalomyelitis (ADEM). Although not frequently diagnosed in the very elderly acute disseminated encephalomyelitis should not be overlooked for it is a treatable condition. A recent infection followed by rapid cognitive deterioration and multifocal neurologic signs should raise the attention to curable autoimmune diseases. Although the cause of ADEM is still unclear, immune suppression is the mainstay of treatment. Most patients improve on high-dose glucocorticoids and eventually immune globulin treatment or plasma exchange if steroid-unresponsive.

Acute Disseminated Encephalomyelitis in FET PET/MR

ABSTRACT

After 3 weeks of daily headache, a 28-year-old, otherwise healthy woman was admitted to the emergency department with a first-time generalized seizure. CT showed a left frontal mass with perifocal edema. Brain MRI raised the suspicion of cerebral lymphoma. Cerebrospinal fluid analysis revealed mononuclear pleocytosis of 14 cells/μL without malignant cells, normal protein levels, and absence of oligoclonal bands. FET PET/MRI of the lesion showed FET characteristics of inflammatory disease, and acute disseminated encephalomyelitis was suggested as diagnosis. Final histopathological results from brain biopsy confirmed acute disseminated encephalomyelitis.

Encephalopathy as a prognostic factor in adults with acute disseminated encephalomyelitis following COVID-19

Numerous reports support the possible occurrence of acute disseminated encephalomyelitis (ADEM) following COVID-19. Herein, we report a case of ADEM in a 53-year-old man 2 weeks after SARS-CoV-2 infection. We reviewed the reports of adult cases of ADEM and its variant acute necrotizing hemorrhagic leukoencephalitis (ANHLE) to check for possible prognostic factors and clinical/epidemiological peculiarities. We performed a descriptive analysis of clinical and cerebrospinal fluid data. Ordinal logistic regressions were performed to check the effect of clinical variables and treatments on ADEM/ANHLE outcomes. We also compared ADEM and ANHLE patients. We identified a total of 20 ADEM (9 females, median age 53.5 years) and 23 ANHLE (11 females, median age 55 years). Encephalopathy was present in 80% of ADEM and 91.3% of ANHLE patients. We found that the absence of encephalopathy predicts a better clinical outcome in ADEM (OR 0.027, 95% CI 0.001–0.611, p = 0.023), also when correcting for the other variables (OR 0.032, 95% CI 0.001–0.995, p = 0.05). Conversely, we identified no significant prognostic factor in ANHLE patients. ANHLE patients showed a trend towards a worse clinical outcome (lower proportion of good/complete recovery, 4.5% vs 16.7%) and higher mortality (36.4% vs 11.1%) as compared to ADEM. Compared to pre-pandemic ADEM, we observed a higher median age of people with post-COVID-19 ADEM and ANHLE, a shorter interval between infection and neurological symptoms, and a worse prognosis both in terms of high morbidity and mortality. Despite being affected by the retrospective nature of the study, these observations provide new insights into ADEM/ANHLE following SARS-CoV-2 infection.

Diagnosis and Management of Central Nervous System Demyelinating Disorders

The spectrum of demyelinating diseases affecting the central nervous system is broad. Although many have a chronic course, neuroinflammatory conditions often present with acute to subacute onset symptoms requiring hospitalization when severe. This article reviews the acute phase assessment and management of these disorders, with a particular focus on multiple sclerosis, neuromyelitis optica spectrum disorder, myelin oligodendrocyte glycoprotein antibody disorder, and several atypical demyelinating diseases.

Acute disseminated encephalomyelitis and myelitis associated with new coronavirus infection COVID-19. Case report

Acute disseminated encephalomyelitis (AEM) and acute transverse myelitis (OPM) are autoimmune demyelinating diseases of the central nervous system. Two clinical observations of AEM and OPM developed after suffering acute coronavirus infection (SARS-CoV-2) are presented. Differential diagnosis was carried out with multiple sclerosis, encephalitis of an infectious nature, compressive myelopathy, and opticomyelitis. Both observations show an almost complete recovery of lost functions. The pathogenetic mechanisms of the development of AEM and OPM in patients with coronavirus infection are discussed. The onset of central nervous system dysimmune lesion in the context of coronavirus infection makes it necessary to monitor the clinical situation with the involvement of a neurologist for timely diagnosis and determination of therapeutic tactics that can reduce the degree of disability of patients.

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

BACKGROUND AND OBJECTIVES

Since the onset of the COVID-19 pandemic, a growing number of reports have described cases of acute disseminated encephalomyelitis (ADEM) and acute hemorrhagic leukoencephalitis (AHLE) following infection with COVID-19. Given their relatively rare occurrence, the primary objective of this systematic review was to synthesize their clinical features, response to treatments, and clinical outcomes to better understand the nature of this neurologic consequence of COVID-19 infection.

METHODS

Patients with a history of COVID-19 infection were included if their reports provided adequate detail to confirm a diagnosis of ADEM or AHLE by virtue of clinical features, radiographic abnormalities, and histopathologic findings. Cases purported to be secondary to vaccination against COVID-19 or occurring in the context of a preexisting relapsing CNS demyelinating disease were excluded. Case reports and series were identified via PubMed on May 17, 2021, and 4 additional cases from the authors' hospital files supplemented the systematic review of the literature. Summary statistics were used to describe variables using a complete case analysis approach.

RESULTS

Forty-six patients (28 men, median age 49.5 years, 1/3 >50 years old) were analyzed, derived from 26 case reports or series originating from 8 countries alongside 4 patient cases from the authors' hospital files. COVID-19 infection was laboratory confirmed in 91% of cases, and infection severity necessitated intensive care in 67%. ADEM occurred in 31 cases, whereas AHLE occurred in 15, with a median presenting nadir modified Rankin Scale score of 5 (bedridden). Anti-MOG seropositivity was rare (1/15 patients tested). Noninflammatory CSF was present in 30%. Hemorrhage on brain MRI was identified in 42%. Seventy percent received immunomodulatory treatments, most commonly steroids, IV immunoglobulins, or plasmapheresis. The final mRS score was ≥4 in 64% of patients with adequate follow-up information, including 32% who died.

DISCUSSION

In contrast to ADEM cases from the prepandemic era, reported post-COVID-19 ADEM and AHLE cases were often advanced in age at onset, experienced severe antecedent infection, displayed an unusually high rate of hemorrhage on neuroimaging, and routinely had poor neurologic outcomes, including a high mortality rate. Findings are limited by nonstandardized reporting of cases, truncated follow-up information, and presumed publication bias.

Differential diagnosis of multiple sclerosis

BACKGROUND AND OBJECTIVES

Despite immense progress of imaging and updates in the MacDonald criteria, the diagnosis of multiple sclerosis remains difficult as it must integrate history, clinical presentation, biological markers, and imaging. There is a multitude of syndromes resembling multiple sclerosis both clinically or on imaging. The goal of this review is to help clinicians orient themselves in these various diagnoses. We organized our review in two categories: inflammatory and autoimmune diseases that are close or can be confused with multiple sclerosis, and non-inflammatory syndromes that can present with symptoms or imaging mimicking those of multiple sclerosis.

METHOD

Review of literature CONCLUSION: Progress of imaging and biological sciences have drastically changed the approach and management of multiple sclerosis. But these developments have also shined a light on a variety of diseases previously unknown or poorly known, therefore greatly expanding the differential diagnosis of multiple sclerosis. While autoimmune, many of these diseases have underlying biological mechanisms that are very different from those of multiple sclerosis, rendering MS therapies usually inefficient. It is crucial to approach these diseases with utmost thoroughness, integrating history, clinical exam, and evolving ancillary tests.

Acute Disseminated Encephalomyelitis: A rare form of COVID-19's neurotropism

Introduction

the COVID-19 pandemic still accounts for thousands of cases every day. It's neurological involvement has been well documented most likely due to auto-immune mechanisms than the virus itself.

Case report

we report the case of a 38 years old women who developed an Acute Disseminated Encephalomyelitis following a COVID-19 infection, with a favorable outcome after immunosuppressive therapy.

Discussion

In this chapter, we discuss ADEM's pathogenesis as well as its clinical and radiological features before detailing its relationship with infectious and vaccination episodes. We also discuss how our patient disease evolved.

Conclusion

Acute Disseminated Encephalomyelitis is an immune-mediated disorder in which the widespread inflammation of the brain and spinal cord is responsible for a variety of symptoms. The novel COVID-19 virus and its vaccine are both a newly incriminated etiologies of this demyelinating disorder.

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COVID-19 neurotropism has been well established and its neurological manifestations are varied.

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Demyelinating disorders are immune-induced disease most likely due to an antigenic analogy between the virus and myelin constituents.

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COVID-19 induced ADEM is extremely rare, only a dozen cases have been reported worldwide, and ours is the only case reported in our country.

COVID-19-Associated Acute Disseminated Encephalomyelitis: A Systematic Review

Objective:

The objective of this study was to provide an overview of acute disseminating encephalomyelitis, a potential and serious complication of COVID-19.

Methods:

Three primary databases were used, PubMed, LitCovid, and WHO. The final review articles reported acute disseminated encephalomyelitis (ADEM) in COVID-19-positive patients and were full-text, peer-reviewed articles. Articles which did not have patient data such as in vitro studies and articles with unclear inference were excluded.

Results:

Out of 21 cases of ADEM, the diagnosis of severe acute respiratory syndrome-coronavirus 2 was confirmed in 18 and suspected in 3. Among the neurological symptoms, altered consciousness was most common (7/21), followed by anosmia (3), paraplegia (3/21), brain stem involvement (3/21), sphincter involvement (2/21), and quadriplegia (1/21). Raised inflammatory markers were most commonly seen in 9/17. Central nervous system imaging was abnormal in 19 cases and unavailable in 2 cases. Fifteen patients were treated with corticosteroids, 11 patients received intravenous immunoglobulin, while 3 patients received convalescent plasma. Two patients needed surgical intervention. Complications included seizures (1), acute kidney injury and septicemic shock (1), raised intracranial pressure (1), and supraventricular tachycardia secondary to hydroxychloroquine (1). One patient recovered completely and one had good recovery with mild deficits. Thirteen patients had incomplete recovery with residual neurological deficit while three patients died as the consequence of the disease.

Conclusion:

The physicians and neurosurgeons should be diligent while treating the COVID-19 patients with neurological manifestations and include ADEM as a differential diagnosis and stress on early diagnosis and treatment to reduce mortality and achieve satisfactory clinical outcome.

Acute disseminated encephalomyelitis following endonasal resection of a craniopharyngioma: illustrative case

BACKGROUND

Acute disseminated encephalomyelitis (ADEM) is a rare, acquired demyelination syndrome that causes cognitive impairment and focal neurological deficits and may be fatal. The potentially reversible disease mainly affects children, often after vaccination or viral infection, but may be seen rarely in adults.

OBSERVATIONS

A 50-year-old woman presented with loss of visual acuity of the left eye. Magnetic resonance imaging (MRI) revealed an intra- and suprasellar mass, which was removed successfully. On postoperative day 1, MRI showed gross total resection of the lesion and no surgery-related complications. On postoperative day 2, the patient presented with a progressive left-sided hemiparesis, hemineglect, and decline of cognitive performance. MRI showed white matter edema in both hemispheres. Cerebrospinal fluid analysis revealed mixed pleocytosis (355/µL) without further evidence of infection. In synopsis of the findings, ADEM was diagnosed and treated with intravenous immunoglobulins. Shortly thereafter, the patient recovered, and no sensorimotor deficits were detected in the follow-up examination.

LESSONS

Pituitary gland pathologies are commonly treated by transsphenoidal surgery, with only minor risks for complications. A case of ADEM after craniopharyngioma resection has not been published before and should be considered in case of progressive neurological deterioration with multiple white matter lesions.

Non-traumatic pediatric intracranial hypertension: key points for different etiologies, diagnosis, and treatment

Intracranial hypertension can be an acute life-threatening event or slowly deteriorating condition, leading to a gradual loss of neurological function. The diagnosis should be taken in a timely fashioned process, which mandates expedite measures to save brain function and sometimes life. An optimal management strategy is selected according to the causative etiology with a core treatment paradigm that can be utilized in various etiologies. Distinct etiologies are intracranial bleeds caused by traumatic brain injury, spontaneous intracranial hemorrhage (e.g., neonatal intraventricular hemorrhage), or the rare pediatric hemorrhagic stroke. The other primary pediatric etiologies for elevated intracranial pressure are intracranial mass (e.g., brain tumor) and hydrocephalus related. Other unique etiologies in the pediatric population are related to congenital diseases, infectious diseases, metabolic or endocrine crisis, and idiopathic intracranial pressure. One of the main goals of treatment is to alleviate the growing pressure and prevent the secondary injury to brain parenchyma due to inadequate blood perfusion and eventually inadequate parenchymal oxygenation and metabolic state. Previous literature discussed essential characteristics of the treatment paradigm derived mainly from pediatric brain traumatic injuries' treatment methodology. Yet, many of these etiologies are not related to trauma; thus, the general treatment methodology must be tailored carefully for each patient. This review focuses on the different possible non-traumatic etiologies that can lead to intracranial hypertension with the relevant modification of each etiology's treatment paradigm based on the current literature.

Acute disseminated encephalomyelitis and COVID-19: A systematic synthesis of worldwide cases

Acute disseminated encephalomyelitis (ADEM) has been reported after coronavirus disease 2019 (COVID-19). In this review, we systematically included worldwide reported cases on this association. We included 30 case reports (pediatric and adults) and explored epidemiological and clinical evidence. We described time to diagnosis, clinical, imaging, and laboratory features, response to treatment regimens, and differences regarding severity. Also, an original case report was presented. Neurologists must be alert to the occurrence of multifocal neurological symptoms with or without encephalopathy in patients recovered from COVID-19. Timely MRI studies should be performed to establish the diagnosis and to consider early corticosteroid-based treatment.

Immune-Mediated Myelopathies: A Review of Etiologies, Diagnostic Approach, and Therapeutic Management

Myelopathy is a broad term used to describe a heterogeneous group of disorders that affects the spinal cord; the focus of this article will be a subgroup of these disorders with an autoimmune and inflammatory-based pathology. Symptoms typically develop over hours or days and then worsen over a matter of days to weeks, but sometimes can have a more insidious or subacute presentation, which can make the diagnosis more puzzling. Despite relatively low incidence rates, almost a third of affected patients are left with severely disabling symptoms. Prompt recognition of the underlying etiology is essential so that a specific targeted therapy can be implemented for optimal outcomes. The authors discuss a systematic approach to immune-mediated myelopathies, with a focus on the unique characteristics of each that may aid in diagnosis.

Rare and Atypical Presentations of Acute Disseminated Encephalomyelitis in Children: A Case Series

Acute disseminated encephalomyelitis (ADEM) is a monophasic demyelinating disorder of central nervous system occurring in children with a wide range of clinical manifestations after infection or vaccination. There are few case reports in literature, describing atypical presentations of ADEM with fever of unknown origin, autonomic dysfunction, complex movement disorders such as myoclonus, dystonia and chorea, acute psychosis and myocarditis. Here, we report four cases of ADEM with atypical features like uniocular blindness, myelin oligodendrocyte glycoprotein antibodies negative multiphasic disseminated encephalomyelitis, ADEM mimicking Guillain-Barre syndrome at presentation and isolated spinal ADEM. Treatment with high-dose steroids elicited an excellent neurological outcome in all patients. A high index of clinical suspicion along-with awareness of atypical features, magnetic resonance imaging and cerebrospinal fluid studies are of paramount importance in establishing ADEM diagnosis and initiation of early treatment for better outcome.

Therapeutic Plasma Exchange in the Critically Ill Patient: Technology and Indications

Therapeutic plasma exchange (TPE) is frequently the most common Apheresis Medicine technique used for extracorporeal therapy of a wide variety of renal, neurological, hematological, and other clinical indications. Many of these clinical indications require intensive care during critical illness. Conventional TPE uses one of two main technical methods to achieve the goal of removing known disease mediators from the plasma: using centrifugal forces to separate and remove components of blood, or a membrane filtration method that separates plasma from the cellular components of blood. The following review discusses the basic principles of TPE, the technological aspects, and relevant clinical scenarios encountered in the intensive care unit, including relevant guidelines and recommendations from the American Society for Apheresis.

Acute disseminated encephalomyelitis (ADEM) associated with COVID-19

A 53-year-old man admitted to the critical care secondary to respiratory failure due to COVID-19 developed agitation and global hypotonia. Brain MRI revealed bilateral hyperintense lesions throughout the brain and cerebrospinal fluid identified oligoclonal bands. Intravenous high-dose glucocorticoids were administered followed by an oral tapering dose and the patient clinically improved. Acute disseminated encephalomyelitis should be considered in patients with COVID-19 who present with altered mentation and polyfocal neurological deficits.

Hepatic epithelioid hemangioendothelioma associated with acute disseminated encephalomyelitis by a possible paraneoplastic process

Epithelioid hemangioendothelioma (EHE) is a low-grade, malignant vascular neoplasm that frequently involves the liver, lungs, bone, and soft tissue. Although not commonly associated with a paraneoplastic syndrome, paraneoplastic syndromes in the setting of EHE have been reported. Acute disseminated encephalomyelitis (ADEM) is an acute, autoimmune, demyelinating disorder of the central nervous system that most commonly occurs after an infection or vaccination. We present the case of a 23 year old female who developed the acute onset of fevers, tremors, right sided hemiplegia, global aphasia, and incontinence of urine and stool. MRI demonstrated findings consistent with a demyelinating disorder and brain biopsy confirmed the diagnosis of ADEM. The patient's work up revealed multiple liver lesions which were biopsy proven EHE. This case report discusses the diagnosis and treatment of two concurrent rare disease processes and the possible association of the processes via a paraneoplastic syndrome.

Acute Disseminated Encephalomyelitis: Current Perspectives

Acute disseminated encephalomyelitis (ADEM) is an immune-mediated central nervous system (CNS) disorder, characterized by polyfocal symptoms, encephalopathy and typical magnetic resonance imaging (MRI) findings, that especially affects young children. Advances in understanding CNS neuroimmune disorders as well as the association of myelin oligodendrocyte glycoprotein antibody (MOG-Ab) with both monophasic and recurrent forms of ADEM have led to new insights into its definition, management and outcome. In this review, we aim to provide an update based on current epidemiologic, clinical, radiological and immunopathological aspects and clinical outcome of ADEM.

Acute disseminated encephalomyelitis following Tdap vaccination and bacterial meningoencephalitis

INTRODUCTION

Association of Acute Disseminated Encephalomyelitis (ADEM) with both recent vaccination and viral infections is well described in current literature. However, the coincidence of ADEM and bacterial infections has been rarely documented. In this report, we present a case of ADEM which occurred after bacterial meningoencephalitis and prior vaccination against tetanus, diphtheria, and pertussis (Tdap).

CASE PRESENTATION

A 62-year old woman was hospitalized with an upper respiratory tract infection three weeks after Tdap triple vaccination. A few days after admission, she became somnolent and developed meningism. Cerebrospinal fluid (CSF) analysis revealed pleocytosis and increased protein/lactate levels compatible with bacterial meningoencephalitis. The patient was treated with intravenous antibacterial triple therapy in combination with dexamethasone leading to a significant improvement of clinical symptoms and improvement of CSF parameters. Five days later, the patient's condition worsened again, and she developed aphasia and right-sided hemiparesis. A magnetic resonance imaging (MRI) scan revealed distinct fluid-attenuated inversion recovery sequence (FLAIR)-hyperintense lesions in both hemispheres. Following brain biopsy, the diagnosis of ADEM was made and methylprednisolone pulse therapy was initiated for five days leading to a nearly complete remission of symptoms.

CONCLUSION

ADEM is a neurological syndrome which may be associated with bacterial infection of the central nervous system (CNS). We hypothesize that the preceding Tdap triple vaccination may have contributed to the development of ADEM.

Immune-mediated encephalitis for the infectious disease specialist

PURPOSE OF REVIEW

Autoimmune encephalitis is increasingly recognized and must be distinguished from infectious forms of encephalitis. Moreover, physicians should be aware of infectious triggers of autoimmune encephalitis and of infectious complications associated with treatment.

RECENT FINDINGS

Recent epidemiological studies suggest that the incidence of autoimmune encephalitis may rival that of infectious encephalitis. Although distinguishing autoimmune from infectious forms of encephalitis on clinical grounds can be challenging, recently proposed diagnostic criteria can provide some assistance. There has been an explosion in our knowledge of autoimmune encephalitis associated with antibodies to neuronal cell surface antigens, and two of the most common forms, anti-NMDA receptor encephalitis and anti-LGI1 encephalitis, are typically associated with distinctive clinical features. Although tumors have long been known to trigger autoimmune encephalitis, it has been recently recognized that herpes simplex encephalitis may trigger the generation of antineuronal autoantibodies resulting in an autoimmune neurologic relapse. Both first and second-line therapies for autoimmune encephalitis are associated with infectious complications, whereas emerging treatments, including anakinra and tocilizumab, may also result in increased susceptibility to certain infections.

SUMMARY

The diagnosis and management of autoimmune encephalitis is complex, and awareness of diagnostic criteria and modalities, typical clinical syndromes, infectious triggers of disease, and infectious complications of therapies is critical in optimizing care for affected patients.

Impact of multiple sclerosis risk loci in postinfectious neurological syndromes

BACKGROUND

The genetic component of multiple sclerosis (MS) is now set to 200 autosomal common variants. However, it is unclear how genetic knowledge be clinically used in the differential diagnosis between MS and other inflammatory conditions like adult-onset postinfectious neurological syndromes (PINS). The aim of this study was to investigate whether PINS and MS have a shared genetic background using an updated polygenic risk scores.

METHODS

Eighty-eight PINS patients have been consecutively recruited between 1996 and 2016 at Mondino Foundation of Pavia, diagnosed according to clinical, MRI and CSF findings and followed-up for several years. Patients were typed using Illumina array, and genotypes imputed using the 1000 Genomes Project reference panel. A weighted genetic risk score (wGRS) has been calculated based on autosomal MS risk loci derived from large-scale studies, and an HLA genetic burden (HLAGB) was also calculated on loci associated to MS.

RESULTS

PINS occurred as an episode of myelitis in 44% of patients, encephalomyelitis in 44%, and encephalitis in remaining cases, with an involvement of peripheral nervous system in 41% of patients. Mean age of onset was 50.1 years, and female:male ratio was 1.4. Patients were followed-up for a mean of 7.2 years, and at last visit 55% had a low disability grade (mRS 0-1). Disease was monophasic in 67% of patients, relapsing in 18% and chronic-progressive in 15%. The wGRS of PINS cases was comparable to 370 healthy controls, while significantly lower compared to 907 bout-onset MS (BOMS) cases (wGRS= 20.9 vs 21.2; p<0.0001). The difference was even larger for PINS with peripheral nervous system involvement (wGRS=20.6) vs BOMS.

CONCLUSION

The distinction between MS and PINS is not easy to make in clinical practice. However, our study shows that the new set of MS risk alleles does not confer increased susceptibility to PINS. These data support the importance to discriminate these cases from MS with pathophysiological and therapeutic implications.