Acute disseminated encephalomyelitis: the importance of early magnetic resonance imaging

The diagnosis of acute disseminated encephalomyelitis (ADEM) is frequently missed or delayed with consequent delay in instituting therapy in the crucial phase of the illness. The role of MRI in the diagnosis of ADEM is well established, however, the value of its early utilization of treatment on the outcome of patients has not been adequately stressed. Three patients with ADEM are described. Delay in the diagnosis of the first was associated with severe sequelae, while in the other two early diagnosis and institution of corticosteroid therapy which was facilitated by MRI, was associated with a better outcome. MRI should be carried out early once the diagosis of ADEM is entertained.     

Extensive subpial cortical demyelination is specific to multiple sclerosis

Cortical demyelinated lesions are frequent and widespread in chronic multiple sclerosis (MS) patients, and may contribute to disease progression. Inflammation and related oxidative stress have been proposed as central mediators of cortical damage, yet meningeal and cortical inflammation is not specific to MS, but also occurs in other diseases. The first aim of this study was to test whether cortical demyelination was specific for demyelinating CNS diseases compared to other CNS disorders with prominent meningeal and cortical inflammation. The second aim was to assess whether oxidative tissue damage was associated with the extent of neuroaxonal damage. We studied a large cohort of patients diagnosed with demyelinating CNS diseases and non‐demyelinating diseases of autoimmune, infectious, neoplastic or metabolic origin affecting the meninges and the cortex. Included were patients with MS, acute disseminated encephalomyelitis (ADEM), neuromyelitis optica (NMO), viral and bacterial meningoencephalitis, progressive multifocal leukoencephalopathy (PML), subacute sclerosing panencephalitis (SSPE), carcinomatous and lymphomatous meningitis and metabolic disorders such as extrapontine myelinolysis, thus encompassing a wide range of adaptive and innate cytokine signatures. Using myelin protein immunohistochemistry, we found cortical demyelination in MS, ADEM, PML and extrapontine myelinolysis, whereby each condition showed a disease‐specific histopathological pattern. Remarkably, extensive ribbon‐like subpial demyelination was only observed in MS, thus providing an important pathogenetic and diagnostic cue. Cortical oxidative injury was detected in both demyelinating and non‐demyelinating CNS disorders. Our data demonstrate that meningeal and cortical inflammation alone accompanied by oxidative stress are not sufficient to generate the extensive subpial cortical demyelination found in MS, but require other MS‐specific factors.     

Acute disseminated encephalomyelitis associated with hepatitis B virus reinfection – Consequence or coincidence?

Acute disseminated encephalomyelitis (ADEM) is an idiopathic inflammatory demyelinating disease of the CNS that is particularly difficult to differentiate from the first episode of multiple sclerosis. ADEM typically occurs as a post-infectious phenomenon, and usually presents a monophasic episode, but also includes recurrent and multiphasic forms. We report a case of ADEM associated with hepatitis B virus (HBV) reinfection. After steroid and IV immunoglobulin treatment, neurologic symptoms were improved. We suppose that the HBV reinfection was the cause of ADEM, but possible pathogenetic mechanism is still obscure.     

Acute disseminated encephalomyelitis following nephropathia epidemica

Acute disseminated encephalomyelitis (ADEM) is an acute monophasic inflammatory and demyelinating disease of the central nervous system (CNS) occurring days to weeks after a virus infection or vaccination. Nephropathia epidemica (NE) is a haemorrhagic fever with renal syndrome caused by Puumala virus, with endemic regions in Europe, especially Scandinavia and Western Russia. We describe a case of severe nephropathia epidemica requiring dialysis, followed by severe CNS symptoms caused by ADEM. To our best knowledge this is the first case in the literature in which NE caused ADEM.     

Neuropathologische und neuroradiologische Aspekte akuter disseminierter Enzephalomyelitiden (ADEM)

Among non-neoplastic lesions of the central nervous system, demyelinating pseudotumors of the group of acute disseminated encephalomyelitis (ADEM) most frequently occasion neurosurgical intervention for purposes of definitive diagnosis and thus enter the domain of the surgical pathologist. Typically, ADEM presents with multifocal, bilateral lesions in an asymmetrical distribution. Especially monolocular manifestations may be diagnostically challenging. Due to the acuteness of clinical symptoms and the expansive, space-occupying character of the lesions a diffuse glioma, a metastatic disease, a primary cerebral Non-Hodgkin's lymphoma, brain abscess, a parasitosis or an ischemic brain tissue necrosis may be suspected. This impression is supported by uptake of contrast-medium most pronounced at the periphery of the lesion and the subcortical location. The histomorphologic feature of relative axonal preservation in areas with acute myelin breakdown and lymphocytic infiltrates make the diagnosis of an acute primary demyelinating disease probable. A diagnosis of glioma may be prompted by the florid, cytologically atypical astrogliosis especially in intraoperative request. Based on a series of 14 cases of radiologically and bioptically documented cases of ADEM typical examples will be demonstrated and discussed.     

Acute disseminated encephalomyelitis associated with Mycoplasma pneumoniae infection

An 8 year old girl with acute disseminated encephalomyelitis (ADEM) is described. Elevated serum antibody titers suggested recent Mycoplasma pneumoniae infection. T2-weighted image of magnetic resonance imaging (MRI) disclosed multiple lesions of high signal intensity in bilateral basal ganglia and thalami as well as in the white matter. Postcontrast T1-weighted image revealed an enhanced lesion in the deep white matter. She showed rapid clinical improvement in response to corticosteroid therapy. The lesions had disappeared completely on MRI performed 10 weeks after the onset. ADEM is believed to be a demyelinating disorder of probable autoimmune etiology. MRI findings in this case may support the hypothesis that the primary pathological event is vascular injury and demyelination occurs only as a secondary phenomenon.     

Diffusion- and perfusion-weighted MR imaging in a patient with acute demyelinating encephalomyelitis (ADEM).

To monitor changes of brain tissue metabolism in acute demyelinating encephalitis (ADEM), we examined a patient with suspected ADEM by serial MRI including diffusion- and perfusion-weighted imaging (DWI, PWI). Within the inflammatory tissue, the apparent diffusion coefficients were reduced, normal, and increased. Perfusion varied between reduced and normal values, except for small hyperperfused regions. Combining standard MRI with DWI and PWI may elucidate different overlapping phases in cerebral inflammation.     

Severe steroid-resistant post-infectious encephalomyelitis

Based on their presumed immuno-mediated etiology, post-infectious CNS disorders are commonly treated with high-dose steroids. Factors influencing treatment effectiveness, possible alternative options for steroid-resistant cases, and their outcome profiles, remain unclear. We here describe the clinical features, the prognosis and the efficacy of i. v. immunoglobulins (IVIg) in a series of severe ADEM refractory to steroids. We performed an inception cohort study on inpatients of the Neurologic and Infectious Disease Clinics, consecutively admitted over eight years, with a minimum two-year follow-up. Nineteen patients affected by classic and site-restricted ADEM were treated with IVIg after steroid failure. Five other patients received IVIg as first-line treatment due to steroids contraindications: although not included in the analysis, they were monitored for anecdotal comparison. Steroids were administered as IV 6-methylprednisolone (6-MP) 500/1000 mg daily until a maximum dose of 6-8 g; IVIg were administered at 0.4 g/kg/day for 5 days. The outcome was assessed by the Scripps Neurological Rating Scale (SNRS) score with determined periodicity. We observed that steroid-resistant patients showed high prevalence of PNS damage (89%) and myelitis (95 %). Other features were old age, severe disability at onset, and moderate to severe blood-brain-barrier (BBB) damage on CSF. In 10/19 patients (53 %) IVIg were effective, the clinical improvement beginning within the end of the five-day cycle,without relapses. Prominent effects of IVIg were detectable on motor dysfunction. Milder onset disability (p = 0.013) and lower CSF albumin (p = 0.006) were the predictors of IVIg response. Among steroid-free patients, 3/5 were responsive to IVIg. We conclude that IVIg can be useful in a portion of patients with severe steroid-resistant ADEM and prominent motor dysfunction. Unsolved issues regard the usefulness of IVIg in less selected groups, and the spectrum of their clinical effects.     

Successful Recovery of a Fulminant Form of Acute Disseminated Encephalomyelitis (ADEM) with Intravenous Steroids

Abstract Acute disseminated encephalomyelitis (ADEM) is a rare inflammatory demyelinating disease of the central nervous system mostly associated with a preceding infection or vaccination. It is characterized by multifocal white matter lesions on neuroimaging. A patient is described who developed a fulminant form of ADEM after a bacterial skin infection. Despite poor prognostic factors and extensive white matter lesions, the patient recovered dramatically under high-dose administration of steroids.     

Antibody biomarkers in CNS demyelinating diseases – a long and winding road

Over several decades, studies sought potential markers to diagnose and to predict the clinical course of central nervous system (CNS) demyelinating disorders, especially in multiple sclerosis, acute disseminated encephalomyelitis and neuromyelitis optica spectrum disorders. Reliable biomarkers would ensure correct diagnoses, determine future disease evolvements, stratify patients for appropriate treatments and monitor disease activity and treatment effects – in summary, meet the longing for personalized medicine in these diseases. Out of a plethora of potential biomarker candidates antibodies have turned (again) into the scientific focus, due to pivotal immunological and neuropathological findings in the past 20 years. A major breakthrough and stimulus for further research was the identification of anti‐aquaporin‐4 antibodies in neuromyelitis optica. Various other myelin and non‐myelin antigens were investigated in detail for diagnostic and prognostic purposes, such as antibodies to myelin oligodendrocyte glycoprotein or to the potassium channel KIR4.1. Further, the use of biopharmaceutical treatments in multiple sclerosis led to intense research activities to identify anti‐treatment neutralizing antibodies and their clinical consequences. This review briefly summarizes the current knowledge on antibodies in the diagnosis, prognosis, disease and treatment monitoring of CNS demyelinating disorders.