Acute disseminated encephalomyelitis: a 10-year cohort study in Thai children

Distinguishing Transient From Persistent Brain Structural Changes in Pediatric Patients With Acute Disseminated Encephalomyelitis

BACKGROUND AND OBJECTIVES

Pediatric patients with acute disseminated encephalomyelitis (ADEM) are at risk of impaired brain growth, with long-term neuropsychiatric consequences. We previously reported transient expansions of cerebral ventricle volume (VV) in experimental autoimmune encephalomyelitis, which subsequently normalized. In this study, we investigated changes in VV in ADEM in relation to other brain structures and clinical outcomes.

METHODS

We investigated brain MRI scans acquired in routine clinical practice from a multicenter cohort of 61 pediatric patients with ADEM, of whom 39 were myelin oligodendrocyte glycoprotein (MOG) antibody-positive. Patients were compared with 1,219 pediatric healthy controls (HCs). Volumes of multiple brain structures were computed using a contrast-agnostic machine learning-based tool and analyzed with mixed-effect models regarding other clinical parameters.

RESULTS

Patients with ADEM had larger VV than HCs at initial clinical presentation, before immune therapy. Most of the patients showed further VV increases within 2 months after disease onset. Patients had smaller brain volumes than HCs, with specific reductions in deep gray matter structures. These changes were more pronounced in MOG antibody-negative patients.Of the patients with more than 2 MRI scans, 12 of 22 resolved their VV expansion back to within 15% of baseline values while 10 of 22 had persistently increased VV at the last available MRI within 1 year from onset. Patients with persistent VV expansion had greater reductions in volumes of other brain structures at the last MRI than patients whose VV resolved and were more likely to have residual neurologic signs. The VV resolving and nonresolving patients did not differ regarding age, sex, elevated CSF cell counts at baseline, or occurrence of relapses. However, patients with a larger magnitude of VV expansion-≥90% of baseline volume-were more likely to be in the nonresolving group.

DISCUSSION

We could distinguish between 2 outcomes of VV changes in ADEM: one in which the VV expanded but ultimately returned to normal and one in which the expansions continued after disease onset and treatment but failed to resolve. The latter was associated with reduced brain volume, particularly in deep gray matter structures. This highlights the necessity for patients with ADEM to undergo regular MRI scans to assess whether developing VV expansions indicate a greater risk of permanent brain atrophy.

An Insight into Disseminated Acute Encephalomyelitis Pathogenesis and Treatment-A Review

BACKGROUND

Acute disseminated encephalomyelitis (ADEM) is a neural and immunerelated disorder that occurs when the cerebrospinal system is damaged by extensive swelling. Although manifestation is possible regardless of age, adolescents have a greater probability. The purpose of the present manuscript is to provide recent advancements and enhance knowledge of the disease.

METHOD

The literature search on etiology, pathophysiology, diagnosis and treatment was carried out using the online databases of SciFinder, Medline, Pubmed, GoogleScholar, Scopus, etc. Result: Although the cause of ADEM remains unclear, it is believed to be caused by inflammation in those with a genetic sensitivity to environmental stimulation. When people have altered levels of awareness or multifocal neurological abnormalities, ADEM is a possibility as a diagnosis. The diagnosis of ADEM is dependent on a combination of clinical and radiologic symptoms, whereas the exclusion of illnesses mimics ADEM; there is no one test that can establish the diagnosis. The inflammation in a child's brain and spinal cord is treated with medication. Prednisone is occasionally given to youngsters for a brief amount of time.

CONCLUSION

Most children with ADEM improve with high doses of methylprednisolone. Cyclophosphamide is needed by individuals with hypothermia. Most investigations show that 50%- 75% of individuals completely recover between the first and sixth month of their condition.

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.

A nationwide survey of pediatric acquired demyelinating syndromes in Japan

OBJECTIVE

To investigate the clinical and epidemiologic features of pediatric acquired demyelinating syndromes (ADS) of the CNS in Japan.

METHODS

We conducted a nationwide survey and collected clinical data on children with ADS aged 15 years or younger, who visited hospitals between 2005 and 2007.

RESULTS

Among 977 hospitals enrolled, 723 (74.0%) responded to our inquiries and reported a total of 439 patients as follows: 244 with acute disseminated encephalomyelitis (ADEM), 117 with multiple sclerosis (MS), 14 with neuromyelitis optica (NMO), and 64 with other ADS. We collected and analyzed detailed data from 204 cases, including those with ADEM (66), MS (58), and NMO (10). We observed the following: (1) the estimated annual incidence rate of pediatric ADEM in Japan was 0.40 per 100,000 children (95% confidence interval [CI], 0.34-0.46), with the lowest prevalence in the north; (2) the estimated prevalence rate of MS was 0.69 per 100,000 children (95% CI, 0.58-0.80), with the lowest prevalence in the south; (3) NMO in Japan was rare, with an estimated prevalence of 0.06 per 100,000 children (95% CI, 0.04-0.08); and (4) the sex ratio and mean age at onset varied by ADS type, and (5) male/female ratios correlated with ages at onset in each ADS group.

CONCLUSIONS

Our results clarify the characteristic clinical features of pediatric ADS in the Japanese population.

Incidence of acute disseminated encephalomyelitis in the Jiangsu province of China, 2008-2011

Background

It is important to have an estimate of the incidence of acute disseminated encephalomyelitis (ADEM) because the incidence of ADEM is unknown and the outcomes undefined in China.

Objectives

This study attempts to describe ADEM incidence in large Chinese populations located in four geographically different and moderately distant areas of the same province.

Methods

A retrospective investigation was conducted with ADEM patients in Nanjing, Nantong, Yancheng and Xuzhou. The survey was carried out in regions that might have received patients meeting the case definition of ADEM provided by the International Pediatric MS Study Group from 2008 to 2011. A total of 125 hospitals were included and 412 patients were identified through the hospital information systems (HIS).

Results

The incidence of ADEM was 0.32/100,000/year. There are two peaks on the age-specific ADEM rates curve. One is 0.77/100,000/year among 0- to 9-year-olds, the other is 0.45/100,000/year in those aged 50–59 years. The incidence rate found for ADEM in males was 0.34/100,000/year, and in females was 0.29/100,000/year. The highest incidence rate was in Nanjing (0.40/100,000/year).

Conclusions

The average annual incidence of ADEM was 0.32/100,000/year. The peak age of onset was 50–59 years old and 0–9 years old. The incidence among males was insignificantly higher than that among females. There was no significant difference in incidence by seasonal variation.

Epidemiological characteristics of acute disseminated encephalomyelitis in Nanchang, China: a retrospective study

Background

Acute disseminated encephalomyelitis (ADEM) is an autoimmune disease that typically follows a monophasic course and may affect any age group. The precise population-based incidence of ADEM is still unknown in most countries. In China, there is no ADEM surveillance system. The exact incidence of ADEM is difficult to estimate, and other epidemiological characteristics of ADEM are unknown. The purpose of this study is to investigate the epidemiological characteristics of ADEM in Nanchang, China.

Methods

A retrospective investigation was conducted with ADEM patients admitted to second-level and third-level hospitals in Nanchang from 2008 to 2010, aiming to analyse the epidemiologic characteristics of ADEM in the population in Nanchang. ADEM patients, defined as patients who were diagnosed according to the consensus definition of ADEM provided by the International Pediatric MS Study Group, were enrolled in the study. The data were extracted from the ADEM patients’ medical records.

Results

Forty-seven ADEM patients were investigated. The average annual incidence was 0.31/100,000; the incidence among males (0.31/100,000) was nearly equal to that among females (0.31/100,000). The median age of onset was 25.97 years old, and the peak incidence was observed in the 5- to 9-year-old age group (0.75/100,000), followed by the over-60 age group (0.55/100,000). ADEM occurs throughout the year, but it occurs most frequently in March (n = 7) and least frequently in April and July (both n = 2). The patient numbers are roughly even in the other months. In the 2 months before the onset of ADEM, 15 patients presented with a preceding infection, but none of the patients received a vaccination. An increased number of vaccination was not accompanied by a corresponding increased number of cases of ADEM.

Conclusions

The average annual incidence of ADEM was 0.31/100,000 in Nanchang. The incidence among males was nearly equal to that among females. The peak age of onset was 5–9 years old. The peak season of onset was not apparent. There was no evidence of an association between increased number of vaccines administered and number of cases of ADEM in Nanchang, China.

Acute disseminated encephalomyelitis following infectious mononucleosis in a toddler

Symptomatic Epstein-Barr virus (EBV) infection complicated by acute disseminated encephalomyelitis (ADEM) in a toddler is rare. Our patient is a 14 month-old boy who presented with listlessness and reduced eye movements nearly 10 days after a prodromal upper respiratory illness that was accompanied by an amoxicillin rash. On examination, the boy appeared drowsy, had a congested throat and a resolving lower extremity rash, but otherwise had a normal neurological examination. Investigation revealed lymphocytosis, mildly elevated liver enzyme and a positive EBV IgM serology. Cerebrospinal fluid analysis showed pleocytosis. Subsequent brain and spine MRI showed demyelinating disease extending from the cerebral peduncles, across the brain stem and down to the mid-thoracic spinal cord. The patient was treated as a case of ADEM and given intravenous methylprednisolone. On outpatient follow-up his symptoms resolved completely in 6 weeks.

Treatment of acute disseminated encephalomyelitis

Acute disseminated encephalomyelitis (ADEM) is an inflammatory demyelinating disease, characterized by an acute onset of polyfocal central nervous system (CNS) deficits, including encephalopathy, demonstrating multifocal lesions on MRI. ADEM is typically a monophasic disorder, but recurrent and multiphasic courses have been described. Furthermore, an ADEM presentation has been reported in neuromyelitis optica (NMO) and multiple sclerosis (MS), particularly in younger children. CNS infections, other autoimmune diseases, and neurometabolic disorders may mimic ADEM at manifestation. There is no single test confirming the diagnosis of ADEM, and diagnosis is based upon a combination of clinical and radiologic features and exclusion of diseases that resemble ADEM. Therefore, a broad workup including infectious, immunologic, and metabolic tests, as well as a systematic follow-up including MRI, is indicated to establish an accurate diagnosis as a prerequisite for an optimized treatment approach. There is a lack of evidence-based, prospective clinical trial data for the management of ADEM. Empiric antibacterial and antiviral treatment is standard of care until an infectious disease process is ruled out. Based on the presumed autoimmune etiology of ADEM, the common treatment approach consists of intravenous methylprednisolone at a dosage of 20 to 30 mg/kg per day (maximum 1 g/day) for 3 to 5 days, followed by an oral corticosteroid taper of 4 to 6 weeks. In case of insufficient response or contraindications to corticosteroids, intravenous immunoglobulin G (IVIG) at a dosage of 2 g/kg divided over 2 to 5 days is a therapeutic option. For severe or life-threatening cases of ADEM, plasmapheresis should be considered early in the disease course. Decompressive craniectomy has been reported as a life-saving measure for ADEM patients with intracranial hypertension. There is a lack of specific recommendations for the long-term management of recurrent and multiphasic ADEM. In children with relapsing demyelinating events, the diagnosis of a chronic autoimmune CNS disease like MS or NMO should be considered.