Rasmussen encephalitis with active inflammation and delayed seizures onset

Three cases of atypical Rasmussen's encephalitis with delayed-onset seizures

We retrospectively analyzed the clinical characteristics of three ARE cases with delayed-onset seizures treated at Peking University First Hospital and Sanbo Brain Hospital from May 2021 to January 2023. We also reviewed previously reported atypical cases of Rasmussen's encephalitis (RE) in the literature, summarizing onset symptoms, seizure symptomatology, imaging findings, electroencephalogram (EEG) results, treatment course, and prognosis. The onset age of the three cases ranged from 1 year and 9 months to 7 years and 5 months. All three initially presented with limb motor disorders, which progressively worsened. Two cases developed focal seizures within 1 month of onset, whereas the third case had no seizures over 3 years. Brain MRIs revealed progressive unilateral hemispheric atrophy with multifocal abnormal signals, and PET-CT showed decreased metabolism in the affected hemisphere. EEGs exhibited asymmetric background rhythms with slow waves in the affected hemisphere. In the two children with seizures, epileptiform discharges from the affected hemisphere were recorded, including one case of sustained partial epilepsy. One child was initially diagnosed with autoimmune encephalitis, whereas two were suspected of having RE at onset. The two children with seizures were treated with immunotherapy and various antiseizure medications. Both underwent hemispherectomy because neither seizures nor limb motor disorders were effectively controlled. Post-surgery, neither experienced seizures during 2 years of follow-up, and both showed cognitive and motor improvements. The child without seizures received intermittent steroids and immunoglobulin therapy over 3 years. During 18 months of follow-up, the patient's motor function improved, and no seizures occurred. Seizures are common initial symptoms of RE. Such cases are often misdiagnosed or missed, leading to delays in optimal treatment. If symptoms are predominantly unilateral and EEG and imaging findings show laterality, the possibility of RE should be considered. Early diagnosis and treatment can reduce unnecessary investigations and improve prognosis. PLAIN LANGUAGE SUMMARY: Rasmussen's encephalitis (RE) is a rare disease that typically begins with seizures and generally has a poor prognosis. However, over the past 20 years, there have been reports of RE cases where the initial symptoms are not seizures. Our center has diagnosed and treated three such cases in the past 5 years. We aim to provide an overview of these atypical RE patients, focusing on clinical features, electroencephalographic (EEG) findings, and imaging characteristics to inspire early detection and diagnosis of RE, thus improving treatment timing and outcomes for RE patients.

Rasmussen Encephalitis: Clinical Features, Pathophysiology, and Management Strategies-A Comprehensive Literature Review

Rasmussen encephalitis (RE) is a rare and progressive form of chronic encephalitis that typically affects one hemisphere of the brain and primarily occurs in pediatric individuals. The current study aims to narratively review the literature about RE, including historical information, pathophysiology, and management of this condition. RE often occurs in individuals with normal development, and it is estimated that only a few new cases are identified each year in epilepsy centers. Approximately 10% of cases also occur in adolescents and adults. The hallmark feature of RE is drug-resistant focal seizures that can manifest as epilepsia partialis continua. Also, patients with RE usually develop motor and cognitive impairment throughout the years. Neuroimaging studies show progressive damage to the affected hemisphere, while histopathological examination reveals T-cell-dominated encephalitis with activated microglial cells and reactive astrogliosis. The current therapy guidelines suggest cerebral hemispherotomy is the most recommended treatment for seizures in RE, although significant neurological dysfunction can occur. Another option is pharmacological management with antiseizure medications and immunomodulatory agents. No significant progress has been made in understanding the pathophysiology of this condition in the last decades, especially regarding genetics. Notably, RE diagnosis still depends on the criteria established by Bien et al., and the accuracy can be limited and include genetically different individuals, leading to unexpected responses to management.

Rasmussen's Encephalitis: A Literary Review

Usually affecting one hemisphere of the brain, Rasmussen's encephalitis (RE) is a persistent inflammatory disease of unclear origin. Rasmussen and colleagues presumed a viral etiology of the sickness in their first description. Later, the condition was linked to autoantibodies that were in the blood. Recently, it was shown that the cause of RE was a cytotoxic T-cell reaction to neurons. RE may be identified histopathologically by cortical inflammation, neuronal degeneration, and cerebral hemispheric-specific gliosis. The hemisphere is affected by increasing multilocular inflammation. To diagnose patients sooner and to evaluate whether the aforementioned phenomena are primary or secondary, it is essential to continue the search for a primary immunological or viral component. This information is crucial for determining the effectiveness of immunotherapy. RE-related seizures can only now be managed surgically. The only procedure that works is complete hemispheric disconnection (hemidisconnection), which may be done as either a (functional) hemispherectomy or hemispherectomy. Although thalidomide has been anecdotally reported, its safety profile prevents it from being used as a first-line treatment despite having a noticeable effect on the frequency and severity of seizures. Finding the disease's root causes more quickly by combining descriptive clinical studies, genetic testing, and early histological evaluation of RE tissue specimens to check for viral and autoimmune pathogenesis. Creating appropriate in vitro or animal models will enable the study of causality, perhaps directing clinical trials.

Pathomorphological Diagnostic Criteria for Focal Cortical Dysplasias and Other Common Epileptogenic Lesions—Review of the Literature

Focal cortical dysplasia (FCD) represents a heterogeneous group of morphological changes in the brain tissue that can predispose the development of pharmacoresistant epilepsy (recurring, unprovoked seizures which cannot be managed with medications). This group of neurological disorders affects not only the cerebral cortex but also the subjacent white matter. This work reviews the literature describing the morphological substrate of pharmacoresistant epilepsy. All illustrations presented in this study are obtained from brain biopsies from refractory epilepsy patients investigated by the authors. Regarding classification, there are three main FCD types, all of which involve cortical dyslamination. The 2022 revision of the International League Against Epilepsy (ILAE) FCD classification includes new histologically defined pathological entities: mild malformation of cortical development (mMCD), mild malformation of cortical development with oligodendroglial hyperplasia in frontal lobe epilepsy (MOGHE), and “no FCD on histopathology”. Although the pathomorphological characteristics of the various forms of focal cortical dysplasias are well known, their aetiologic and pathogenetic features remain elusive. The identification of genetic variants in FCD opens an avenue for novel treatment strategies, which are of particular utility in cases where total resection of the epileptogenic area is impossible.

A Special Case of Relapsing-Remitting Bilateral Encephalitis: Without Epilepsy, but Responding to Rituximab and with a Brain Biopsy Coinciding with Rasmussen Encephalitis

A nine-year-old boy manifested with headache, progressive mild cognitive decline and hemiparesis, but without clinical epileptic seizures (with abnormal EEG waves). Brain magnetic resonance imaging (MRI) showed bilateral cortical lesions mainly on the right hemisphere, and new lesions developed in frontal, parietal, occipital and temporal lobes around the old lesions presenting as a lace-like or ring-like enhancement in T1 with contrast over a disease course of five years. A suspected diagnosis of primary angiitis of the central nervous system was initially considered. Treated with high-dose corticosteroids, intravenous immunoglobulins and monthly pulse cyclophosphamide, his symptoms worsened with the intracranial lesion progression. Brain biopsy of the right frontal lobe was performed nearly five years after onset; prominent neuronal loss, a microglial nodule, as well as parenchymal and perivascular lymphocytic infiltrate within the cortex were found, which coincided with RE pathology changes. Encouragingly, after a regimen of rituximab, lesions on the follow-up brain MRI tended to be stable. Apparently, it was immune-mediated, but did not strictly fit any known disease entity, although it was similar to RE. We summarize this unique case, including clinical characteristics, imaging and pathology findings. We also discuss the diagnosis and treatment, focusing on comparison to RE as well as other possible neurological diseases.

Rasmussen's encephalitis: Early diagnostic criteria in children

Rasmussen's encephalitis (RE) is a rare chronic inflammatory brain disorder resulting in progressive neurodegeneration in one cerebral hemisphere. The inflammatory process is accompanied by progressive loss of function of the affected hemisphere, associated with drug-resistant partial epilepsy. The diagnosis is based on a range of clinical, electroencephalographic, radiological and biochemical arguments, without any specific formal marker, which makes the diagnosis of the disease complex, especially in its initial phase. Seizures are refractory to anti-seizures medication (ASM) and to classical immunomodulatory treatments. These treatments are also ineffective to stop the degenerative process. Only surgical treatment with hemispherotomy (surgical disconnection of a cerebral hemisphere) allows definitive cessation of seizures but this leads to definitive motor and cognitive deficits. The etiology of RE is not known, but there is strong evidence for an immunopathogenic mechanism involving T-cell mediated immunity. The emergence of biotherapies targeting against various cytokines offers potential therapeutic perspectives. This disease is currently a real challenge in terms of: (i) early diagnosis, before the constitution of marked hemispheric atrophy and the appearance of neurological and cognitive consequences; (ii) recognition of incomplete form; (iii) therapeutic management due to advances in the field of targeted treatment of inflammation; (iv) surgery and recovery possibilities.

Functional hemispherectomy for patients with adult-onset Rasmussen’s encephalitis

Background

Surgical treatment for patients with adult-onset Rasmussen’s encephalitis (A-RE) is rarely reported. We investigated the clinical and surgical features of two patients with A-RE who underwent functional hemispherectomy.

Case presentation

The data of clinical manifestations, neuroimaging, surgical treatment and surgical outcomes of two patients with A-RE was reviewed. The two patients initially presented with recurrent partial seizures or secondly generalized tonic clonic seizures. Gradually, the patients showed unilateral limb paralysis as well as chronic focal epileptic status. Both patients underwent functional hemispherectomy and achieved seizure freedom in the follow-up. The contralateral neurological deficits improved gradually after rehabilitation and were acceptable for the self-care of daily living. The living quality improved prominently after surgery.

Conclusions

Despite the risk of hemiplegia, functional hemispherectomy may be a choice for patients with A-RE for favorable seizure control and improved quality of life in selected patients.

Can head trauma trigger adult-onset Rasmussen's encephalitis?

Rasmussen's encephalitis (RE) is a rare unilateral inflammatory brain disorder that causes progressive neurocognitive deterioration and refractory epilepsy including epilepsia partialis continua (EPC). We describe a patient with a unique presentation, where right upper limb EPC due to RE began within 2weeks of a concussive left frontal head injury, in a 36-year-old female without other identifiable etiology, no prior neurological deficit nor suggestion of intracranial pathology or infection, and no preceding seizures. The diagnosis of RE followed extensive investigation, excluding confounding diagnoses, with supportive histopathology, and her EPC has proven refractory to treatment. In the absence of a satisfactory alternative etiology and exclusion of differential diagnoses, the most likely cause or precipitant of this patient's RE was head trauma.

Absence of seizures in Rasmussen encephalitis with active inflammation

Severe focal motor epilepsy is considered a clinical hallmark of Rasmussen encephalitis (RE). The authors report a 6-year-old girl with progressive right sided hemiparesis, loss of language skills, left sided hemispheric atrophy, and brain pathologic features characteristic for RE. The patient did not experience seizures over a 2year period after symptom onset and for several months during follow-up. This report expands the clinical spectrum of RE and suggests that seizures are not a universal symptom of RE. Our patient's quite remarkable neurologic deficits along with active inflammation in the absence of epilepsy supports that, at least in some individuals, unilateral hemispheric progressive inflammation can occur without active seizure activity.

Rasmussen encephalitis with dual pathology in a patient without seizures: case report and literature review

PURPOSE

Rasmussen encephalitis without seizures is rare. We report a case of Rasmussen encephalitis and cortical dysplasia without epilepsy as well as describe the imaging, pathology, and clinical course and review the literature to investigate whether this may represent a rare subset of Rasmussen encephalitis.

CASE REPORT

We report the case of a 12-year-old girl with a history of cognitive decline and right arm weakness. Magnetic resonance imaging demonstrated diffuse left hemispheric cortical and subcortical atrophy suggestive of Rasmussen encephalitis. The patient had no clinical history of seizures, and electroencephalography did not demonstrate epileptiform abnormalities. Craniotomy for open brain biopsy was performed, and histopathologic evaluation identified Rasmussen encephalitis with cortical dysplasia (dual pathology).

CONCLUSIONS

To the best of our knowledge, this is the third case of Rasmussen encephalitis diagnosed by both imaging and histopathology that had no clinical or electroencephalographic evidence of seizures and is the only case of Rasmussen encephalitis with cortical dysplasia without epilepsy.

Epilepsy surgery in adult-onset Rasmussen's encephalitis: case series and review of the literature

Rasmussen's encephalitis (RE) is a rare immune-mediated condition characterized by drug-resistant focal epilepsy, progressive neurological, and cognitive deficits associated to unilateral hemispheric atrophy. The onset is typically reported in childhood, although adult cases (A-RE) have been described. While surgical strategies in childhood RE are well defined, little is known about usefulness of epilepsy surgery in A-RE patients. We describe clinical features, surgical approach, and outcome of five A-RE patients who underwent epilepsy surgery, and we review the literature with regard to surgical A-RE cases. We retrospectively studied five A-RE patients aged 21-38 years (mean age 22.8 years) who were followed after surgery for a period ranging from to 1 to 6 years. Demographic, electroclinical, and neuroimaging data were systematically reviewed. Four out of five subjects underwent invasive EEG monitoring to define epileptogenic zone. Epilepsy outcome was defined according to Engel's classification. Surgery consisted of frontal corticectomy in three patients, temporal lobectomy in one, combined temporal lobectomy plus insular, and frontobasal corticectomy in the remaining case. No permanent neurological deficits were observed after surgery. At the last follow-up observation, one patient was seizure-free, two subjects experienced rare disabling seizures, another had moderate seizure reduction, and one had no clinical improvement. Our experience, although limited to few cases, suggests that resective surgery in A-RE may play a role in the context of multidisciplinary therapeutical approach of this severe condition. Since the lack of specific data about surgical options, this topic seems to deserve further investigations and more targeted studies.

Steroid-responsive, progressive, focal measles virus brain infection

Chronic measles virus infection of the brain causes subacute sclerosing panencephalitis (SSPE), a progressive, relentless fatal disorder. We report a 52-year-old male who developed focal, chronic persistent measles virus infection of the brain following interferon and ribavirin therapy for hepatitis C, and who responded to steroid therapy. This case, diametrically different from SSPE, has 2 unique features, its focal nature and its permissive response to steroids, that may add to the understanding of the pathogenesis of SSPE and the mechanism enabling viruses to evade the immune response and establish persistent brain infection.

Rasmussen's encephalitis: clinical features, pathobiology, and treatment advances

Rasmussen's encephalitis is a rare chronic neurological disorder, characterised by unilateral inflammation of the cerebral cortex, drug-resistant epilepsy, and progressive neurological and cognitive deterioration. Neuropathological and immunological studies support the notion that Rasmussen's encephalitis is probably driven by a T-cell response to one or more antigenic epitopes, with potential additional contribution by autoantibodies. Careful analysis of the association between histopathology and clinical presentation suggests that initial damage to the brain is mediated by T cells and microglia, suggesting a window for treatment if Rasmussen's encephalitis can be diagnosed early. Advances in neuroimaging suggest that progression of the inflammatory process seen with MRI might be a good biomarker in Rasmussen's encephalitis. For many patients, families, and doctors, choosing the right time to move from medical management to surgery is a real therapeutic dilemma. Cerebral hemispherectomy remains the only cure for seizures, but there are inevitable functional compromises. Decisions of whether or when surgery should be undertaken are challenging in the absence of a dense neurological deficit, and vary by institutional experience. Further, the optimum time for surgery, to give the best language and cognitive outcome, is not yet well understood. Immunomodulatory treatments seem to slow rather than halt disease progression in Rasmussen's encephalitis, without changing the eventual outcome.

Extrarolandic electroclinical findings in the evolution of adult-onset Rasmussen's encephalitis

Rasmussen's encephalitis (RE) is a rare immunomediated disorder characterized by unilateral hemispheric atrophy, drug-resistant focal epilepsy, and progressive neurological deficits. Its onset typically occurs in childhood, though it has also been reported in adult age (A-RE) with atypical clinical features. The aim of this study was to describe the electroclinical features in a group of seven patients with A-RE. We retrospectively studied seven women aged 23-43years (mean: 32.1years) with a diagnosis of RE according to commonly accepted diagnostic criteria. All the patients were clinically evaluated and underwent prolonged video-EEG monitoring, laboratory investigations, and high-resolution MRI follow-up. All the patients displayed an ictal electroclinical pattern whose evolution varied. We identified an early phase characterized by polymorphic ictal electroclinical manifestations (temporal semiology in five cases, frontal in one, and parietal in the remaining case) and a late phase clinically characterized by viscerosensitive phenomena followed by somatosensitive signs, experiential symptoms, and motor signs in all the cases. In the late phase, the ictal EEG pattern was characterized by monomorphic, pseudorhythmic, repetitive slow-wave theta activity over the frontal and central regions, with ipsilateral propagation and/or secondary spreading to contralateral perisylvian structures. Patients were treated with a combination of AEDs and immunotherapy (steroids and IVIg); epilepsy surgery was performed in 3 cases. Our results show that A-RE is characterized by early and late clinical- and EEG-different features which may reflect a progressive involvement of a specific "extrarolandic" network in the advanced phase of the disease and may suggest that the electroclinical expression of RE varies according to the different stages of the pathological process.

Epileptic encephalitis: the role of the innate and adaptive immune system

Seizures are a prominent clinical feature of encephalitis. Recent data suggest the adaptive as well as innate immune system to be involved directly in the pathomechanism of epileptogenesis. Cytotoxic T-cells and antibody-mediated complement activation are major components of the adaptive immune system, which can induce neurodegeneration, thereby probably contributing to epileptic encephalitis. The innate immune system operates via interleukin-1 and toll-like receptor-associated mechanisms and was shown to play a direct role in epileptogenesis. Here, we review neuropathology hallmarks of various encephalitis conditions such as Rasmussen encephalitis (RE) but also introduce the more recently discovered antibody-associated voltage-gated potassium channel complex (VGKC), N-methyl-D-aspartate receptor (NMDAR) or glutamic acid decarboxylase (GAD) 65 encephalitides. Neuropathological investigations are used to determine specific cellular components and molecular mechanisms used by the immune system to provoke neurodegeneration and to promote epileptogenesis. Based on recent findings, we propose concepts for the stratification of epileptic encephalitis. Knowledge of the role of the innate immunity has already translated into clinical treatment strategies and may help to discover novel drug targets for these epileptic disorders.

The usefulness of neuronavigation in functional hemispherectomy

Catastrophic epileptic encephalopathies in children comprise devastating conditions that features cerebral dysfunction in association with refractory epileptic seizures. The diagnosis is based on the clinical findings, on magnetic resonance imaging (MRI) of the brain and on electroencephalographic findings. For these conditions, surgery remains essential for attaining seizure control. We report two cases of 5-year-old girls. The first one had a diagnosis of Rasmussen’s syndrome. The second one had a large porencephalic cyst secondary to perinatal cerebral ischemia. Despite trials of anticonvulsants, both patients deteriorated, and a functional hemispherectomy guided by neuronavigation was indicated and performed, with low morbidity and excellent seizure control. The neuronavigation proved to be a valuable guidance tool in performing the functional hemispherectomy, making the disconnections more accurate, and thus decreasing the surgical time and blood loss.

Viral meningoencephalitis: a review of diagnostic methods and guidelines for management

BACKGROUND

Viral encephalitis is a medical emergency. The prognosis depends mainly on the pathogen and host immunologic state. Correct immediate diagnosis and introduction of symptomatic and specific therapy has a dramatic influence upon survival and reduces the extent of permanent brain injury.

METHODS

We searched the literature from 1966 to 2009. Recommendations were reached by consensus. Where there was lack of evidence but consensus was clear, we have stated our opinion as good practice points.

RECOMMENDATIONS

Diagnosis should be based on medical history and examination followed by CSF analysis for protein and glucose levels, cellular analysis, and identification of the pathogen by polymerase chain reaction amplification (recommendation level A) and serology (level B). Neuroimaging, preferably by MRI, is essential (level B). Lumbar puncture can follow neuroimaging when immediately available, but if this cannot be performed immediately, LP should be delayed only under unusual circumstances. Brain biopsy should be reserved only for unusual and diagnostically difficult cases. Patients must be hospitalized with easy access to intensive care units. Specific, evidence-based, antiviral therapy, acyclovir, is available for herpes encephalitis (level A) and may also be effective for varicella-zoster virus encephalitis. Ganciclovir and foscarnet can be given to treat cytomegalovirus encephalitis, and pleconaril for enterovirus encephalitis (IV class evidence). Corticosteroids as an adjunct treatment for acute viral encephalitis are not generally considered to be effective, and their use is controversial, but this important issue is currently being evaluated in a large clinical trial. Surgical decompression is indicated for impending uncal herniation or increased intracranial pressure refractory to medical management.

MRI findings in the diagnosis and monitoring of rasmussen's encephalitis

Rasmussen's encephalitis is a devastating syndrome of multifocal brain dysfunction and focal seizures. Magnetic resonance (MR) findings, associated with clinical data and electroencephalogram (EEG), may indicate the diagnosis and could be an indicative of prognosis. We studied 5 patients with Rasmussen's encephalitis, assessing clinical history and MR images. All patients had refractory focal seizures with a predominant motor component associated with hemispheric atrophy, that was proportional to severity of disease and neurological deficits in these patients. Gray and white matter abnormal signal on T2 MR images were found in patients who had hemiparesis. It was not related to the duration of the disease but to aggressiveness. MR proton spectroscopy in severe disease showed lactate and choline increase and decreased NAA, reflecting neuronal and axonal loss, gliosis and elevated membrane turnover and recent - crisis (not controlled). MR studies, in addition to help in diagnosis, may be useful for monitoring metabolic changes and progression of disease in Rasmussen's encephalitis.

Treatment of Rasmussen encephalitis half a century after its initial description: promising prospects and a dilemma

Rasmussen encephalitis (RE), initially described half a century ago, is an inflammatory unihemispheric brain disorder. Its two clinical key facets are the progressive tissue and function loss and the epilepsy, often in form of epilepsia partialis continua. For both, treatment options are available. Anti-seizure effect of anti-epilepsy drugs is usually limited to secondarily generalized seizures and complex partial seizures whereas epilepsia partialis continua usually is totally refractory. Hemispherectomy in one of its modern variants offers a very high chance of seizure freedom, however at the price of irreversible loss of functions located in the affected hemisphere. In a proportion of patients, long-term immunotherapy is able to prevent or slow down hemispheric tissue loss and the associated functional decline. It does, however, mostly not improve the epilepsy. Whereas for many patients unequivocal treatment proposals can be readily made, a dilemma may emerge in those with severe epilepsy but still preserved hemispheric function.

Guidelines on the use of intravenous immune globulin for neurologic conditions

Canada's per capita use of intravenous immune globulin (IVIG) grew by approximately 115% between 1998 and 2006, making Canada one of the world's highest per capita users of IVIG. It is believed that most of this growth is attributable to off-label usage. To help ensure IVIG use is in keeping with an evidence-based approach to the practice of medicine, the National Advisory Committee on Blood and Blood Products (NAC) and Canadian Blood Services convened a panel of national experts to develop an evidence-based practice guideline on the use of IVIG for neurologic conditions. The mandate of the expert panel was to review evidence regarding use of IVIG for 22 neurologic conditions and formulate recommendations on IVIG use for each. A panel of 6 clinical experts, one expert in practice guideline development and 4 representatives from the NAC met to review the evidence and reach consensus on the recommendations for the use of IVIG. The primary sources used by the panel were 2 recent evidence-based reviews. Recommendations were based on interpretation of the available evidence and, where evidence was lacking, consensus of expert clinical opinion. A draft of the practice guideline was circulated to neurologists in Canada for feedback. The results of this process were reviewed by the expert panel, and modifications to the draft guideline were made where appropriate. This practice guideline will provide the NAC with a basis for making recommendations to provincial and territorial health ministries regarding IVIG use management. Recommendations for use of IVIG were made for 14 conditions, including acute disseminated encephalomyelitis, chronic inflammatory demyelinating polyneuropathy, dermatomyositis, diabetic neuropathy, Guillain-Barré syndrome, Lambert-Eaton myasthenic syndrome, multifocal motor neuropathy, multiple sclerosis, myasthenia gravis, opsoclonus-myoclonus, pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections, polymyositis, Rasmussen's encephalitis, and stiff person syndrome; IVIG was not recommended for 8 conditions including adrenoleukodystrophy, amyotropic lateral sclerosis, autism, critical illness polyneuropathy, inclusion body, myositis, intractable childhood epilepsy, paraproteinemic neuropathy (IgM variant), and POEMS syndrome. Development and dissemination of evidence-based clinical practice guidelines may help to facilitate appropriate use of IVIG.

Slowly progressive hemiparesis in childhood as a consequence of Rasmussen encephalitis without or with delayed-onset seizures

Five young children developed slowly progressive hemiparesis as the initial manifestation of Rasmussen encephalitis (RE). Three have remained seizure free over an observational period of 1.3-1.9 years. In the remaining two patients, seizures occurred after 0.5 and 0.6 years respectively. We suggest that RE might be presently underdiagnosed and should be suspected in cases of new onset hemiparesis. In this series, three out of five patients showed oligoclonal bands on examination of cerebrospinal fluid (CSF) which represented additional diagnostic hints towards an immune-mediated condition. According to recently published formal diagnostic criteria, evidence of progressive cerebral hemiatrophy or bioptic identification of RE-typical inflammation confirms the diagnosis in such cases. Long-term immunotherapy is recommended in order to prevent further tissue loss and functional decline.

Clinical characteristics and prognostic factors of postencephalitic epilepsy in children

The goal of this study was to clarify the clinical characteristics and prognostic factors of childhood postencephalitic epilepsy. Forty-four patients (20 boys and 24 girls; age range 21 months to 17 years, mean age 8.1 +/- 4.6 years) with postencephalitic epilepsy were selected from the 798 epileptic children treated and followed up at our hospital between 1993 and 2003. The clinical data included clinical features, electroencephalograms (EEGs), and neuroimages, all reviewed and analyzed retrospectively. Based on their post-treatment seizure outcomes, the children were divided into favorable (n = 20) and poor outcome groups (n = 24). Between the two groups, the age at encephalitis, cerebrospinal fluid findings, and seizure type were comparable. Factors indicating a poor prognosis for these patients during the acute phase of encephalitis were (1) status epilepticus occurring as the first seizure (P < .005), (2) slow background activity (P < .001) and multifocal spike discharges on EEGs (P < .01), and (3) herpes simplex viral encephalitis (P < .01). Our findings indicated that patients with status epilepticus and multifocal spikes on EEG during acute encephalitis have an increased risk of developing intractable epilepsy. To improve the outcome of postencephalitic epilepsy, intervention must occur earlier in the encephalitis stage.

Neue Erkenntnis zur Rasmussen-Enzephalitis

Rasmussen encephalitis (RE) is a severe and at the same time pathophysiologically fascinating condition. The chronic inflammation affects one of the two cerebral hemispheres and destroys it during the disease process that lasts from months to years. The patients -- mostly children -- suffer from frequent pharmacoresistant seizures, often in the form of epilepsia partialis continua. In parallel to the atrophy of the affected hemisphere, the neurological functions associated with it decline continuously. This results in a final stage with a usually high-grade sensorimotor hemisyndrome, hemianopia, cognitive impairment and -- if the language-dominant hemisphere is affected -- aphasia. Research results in the last 5 years have contributed to a deeper understanding of the pathogenesis of this condition. Formal diagnostic criteria have been proposed, and new therapeutic options have emerged by which the disease progression can be slowed or stopped. This article summarizes the current research results on the background of older data and gives recommendations regarding diagnostic and therapeutic procedures in RE patients.