Rasmussen's encephalitis: early characteristics allow diagnosis

Nationwide survey (incidence, clinical course, prognosis) of Rasmussen's encephalitis

PURPOSE

Rasmussen's encephalitis (RE) is a progressive and catastrophic epileptic disorder caused by chronic localized encephalitis. We performed a nationwide survey of RE to assess the clinical picture, treatment effect, and prognosis of Japanese RE patients.

SUBJECTS & METHODS

The subjects were 27 patients (male:12; female:15) from 13 medical facilities. All of them satisfied the clinical and neuroimaging criteria for RE, including 14 pathologically proven cases.

RESULTS

They were divided into the childhood-onset rapidly progressive type (CORP, n=19), and late-onset slowly progressive type (LOSP, n=8). The mean age at epilepsy onset was 4 years and 4 months in CORP, and 16 years in LOSP. The mean period between the onset age of epilepsy and development of frequent seizures was 1 year and 4 months in the former, and 3 years and 4 months in the latter. The immunomodulatory treatment including high-dose steroid (n=14) and high-dose intravenous immunoglobulin therapies (IVIgG, n=12) achieved more than a 50% reduction in the seizure frequency in 5 (36%) and 4 (33%) patients, respectively. Eight and seven patients underwent focal cortical resection and functional hemispherectomy, leading to significant improvement in 5 of the 8 patients and excellent seizure control in all 7 patients, respectively.

CONCLUSION

Although the high-dose steroid and IVIG therapies may have alleviated the exacerbation of seizures in those with RE, they could not halt the disease progression. Functional hemispherectomy is still the only curative therapy for RE, despite the fact that the early introduction of this procedure remains controversial.

Rassmussen's encephalitis: are there new, better therapeutic medical and surgical guidelines?

Neural stem cells (NSCs) are one of the candidates for grafting in the realm of cell-based therapy for temporal lobe epilepsy (TLE). Because NSCs can produce neurons synthesizing the inhibitory neurotransmitter GABA and cells secreting multiple neurotrophic factors, NSC grafting therapy has promise for restraining seizures and easing cognitive dysfunction in TLE. For an expanded treatment of this topic see Jasper’s Basic Mechanisms of the Epilepsies, Fourth Edition (Noebels JL, Avoli M, Rogawski MA, Olsen RW, Delgado-Escueta AV, eds) published by Oxford University Press. Available on NCBI Bookshelf.

Finding on brain MRI mimicking focal cortical dysplasia in early Rasmussen's encephalitis: a case report and review

INTRODUCTION

Rasmussen's encephalitis (RE) is one of the important causes of refractory seizure. The most impressive clinical manifestation of RE is epilepsia partialis continua (EPC). Others include progressive hemiparesis and neuropsychological deterioration. Currently, the best approach to RE is hemispherectomy.

CASE HISTORIES

We describe a patient whose clinical manifestations were compatible with RE; however, the initial brain MRI was interpreted as focal cortical dysplasia over right parietal region.

DISCUSSION

The follow-up brain MRI 1 year later showed diffuse atrophy of the brain with more atrophic change in right hemisphere, and the EPC disappeared after right hemispherectomy.

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.

Rasmussen encephalitis: long-term outcome after surgery

BACKGROUND AND PURPOSE

Rasmussen encephalitis (RE) is characterized by intractable epilepsy, progressive hemiparesis, and unilateral hemispheric atrophy. The progression of the symptoms to significant neurological impairment usually occurs within months to a few years. RE causes are unknown, although evidence of an autoimmune process has been extensively described in the literature. Antiepileptic drugs are usually not effective to control seizures or cerebral atrophy; despite data supporting a beneficial effect of early immunosuppressive and immunomodulatory interventions, for intractable seizures in RE patients with advanced disease, epilepsy surgery in the form of hemispheric disconnection has been considered the treatment of choice. This work describes the clinical and electrographic analyses, as well as the post-operative evolution of patients with RE.

MATERIALS AND METHODS

This work includes all the patients with RE evaluated from January 1995 to January 2008 by the Ribeirão Preto Epilepsy Surgery Program (CIREP), taking variables such as gender; age at epilepsy onset; seizure semiology; seizure frequency; interictal and ictal electroencephalographic (EEG) findings; age at surgery, when done; duration of epilepsy; surgery complications; follow-up duration; anatomo-pathological findings; post-surgery seizure; language and cognitive outcome; and anti-epileptic drug treatment after surgery into account.

RESULTS

Twenty-five patients were evaluated; thirteen were female. Mean age of epilepsy onset was 4.4+/-2.0 years. There were no differences between patients with slow and fast evolution with respect to age of epilepsy onset (p=0.79), age at surgery (p=0.24), duration of epilepsy (0.06), and follow-up (p=0.40). There were no correlations between the presence of bilateral EEG abnormalities or the absence of spikes and post-operative seizure outcome (p=0.06). Immunomodulatory therapy was tried in 12 patients (48%). Twenty-three patients underwent surgery. The mean follow-up was 63.3 months. Eleven patients had total seizure control. Twelve individuals persisted with seizures consisting of mild facial jerks (six patients), occasional hemigeneralized tonic-clonic seizures (three patients), and frequent tonic-clonic seizures (three patients). Mental and language impairment was observed in 15 and 12 patients, after surgery, respectively. Eight patients presented post-operative cognitive decline, while only two patients had cognitive improvement. Comparing pre- and post-operative language deficits, 66.7% of the 12 patients with language disturbance did not improve after surgery.

CONCLUSIONS

This retrospective study reported the clinical and electrographic analysis, as well as the evolution of 23 patients with RE. Patients were divided into two groups: fast evolution and slow evolution to hemiparesis and epilepsia partialis continua. These groups may represent different RE substrates. Fourteen patients achieved satisfactory seizure control, three patients had partial response to surgery, and five patients had maintenance of the pre-operative condition. All patients with left-side involvement presented with some language disturbance, which did not improve after surgery in 66.6% of patients. Cognitive evaluation showed that the majority of the patients did not have any significant improvement, and 38.1% had cognitive deterioration after surgery.

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.

Evaluation of quality of life and clinical status of children operated on for intractable epilepsy

AIM

The aim of the study was evaluation of surgical treatment of epilepsy measured by changes in quality of life (QOL) and in seizure frequency and severity.

MATERIALS AND METHODS

Examined group consists of 24 boys and 9 girls. We performed corpus callosotomy, lesionectomy, vagal nerve stimulation, temporal lobectomy and multiple subpial transections. Age at surgery ranged from 5 months to 19 years, with mean follow-up of 11.9 months. QOL was evaluated on the basis of the questionnaire created by us, in which parents were asked to assess the following variables before and after the surgical procedure: communication, socialization, daily living skills, movement abilities and behavioural problems. The seizure frequency was assessed with the Engel's scale, the modified Engel's scale and the Seizure Scoring System. Clinical state of all the patients was evaluated as well.

RESULTS

There were no patients with stable and worsening QOL status. In the whole group treated with callosotomy, the considerable improvement in QOL concerned 36.4% of cases. In more than 95% of cases, the reduction in seizures frequency is greater than 75%. In more than 43% of patients, there are no seizures after surgery.

CONCLUSIONS

Surgical treatment of intractable epilepsy is an effective method in terms of both seizure control and QOL improvement. Our results indicate the improvement in QOL of all operated patients. The improvement in QOL was accompanied by decrease in frequency and 'positive' changes in morphology of seizures. Improvement in QOL, as equivalent to seizure reduction rate, may influence further differentiation of qualification methods and surgical procedures of epilepsy.

Adult-Onset Rasmussen's Encephalitis: Anatomical-Electrographic-Clinical Features of 7 Italian Cases

PURPOSE

A limited number of cases of adult-onset Rasmussen's encephalitis (A-RE) have been reported, but the features of the syndrome are still unclear. The aim of this study was to verify the clinical features of A-RE, and outline a noninvasive approach that may allow its early diagnosis and treatment.

METHODS

Retrospective evaluation of extensive noninvasive work-up of seven patients with A-RE, including repeat clinical, neurophysiological, and neuroimaging investigations.

RESULTS

The study identified two distinct patterns of disease presentation, one characterized by focal motor epilepsy (the "epileptic" phenotype), and the other by focal cortical myoclonus (the "myoclonic" phenotype). Unilateral neurological deficits and brain atrophy were progressive in both phenotypes, but they were more prominent and were detected earlier in the "epileptic" phenotype.

CONCLUSIONS

The anatomo-electroclinical features of these patients allowed a noninvasive diagnosis of A-RE and identification of two distinct disease phenotypes. Early noninvasive diagnosis can allow faster initiation of treatment.

Botulinum toxin treatment of facial myoclonus in suspected Rasmussen encephalitis

Patients with Rasmussen encephalitis (RE) may develop a variety of involuntary movements. We report a 26-year-old woman who presented with a 3-year history of progressive, continuous myoclonus of the left side of the face and left arm as well as left spastic hemiparesis. Magnetic resonance imaging of the brain showed right hemisphere and basal ganglia atrophy, and 24-hour electroencephalogram demonstrated diffuse slowing with random sharp waves in both hemispheres. An 18-fluoro-deoxy-glucose positron emission tomography scan indicated hypometabolism of the right cerebral hemisphere, including basal ganglia and thalamus. We successfully treated her myoclonus with injections of botulinum toxin A into the left zygomaticus muscle.

Putaminal involvement in Rasmussen encephalitis

BACKGROUND

Rasmussen encephalitis (RE) is a rare devastating disease of childhood causing progressive neurological deficits and intractable seizures, typically affecting one hemisphere. Characteristic MRI features include progressive unihemispheric focal cortical atrophy and grey- or white-matter high-signal changes and basal ganglion involvement, particularly of the caudate nucleus.

OBJECTIVE

To analyse the pattern of involvement of different brain structures in a series of patients with RE and to attempt clinical correlation.

MATERIALS AND METHODS

We reviewed the medical records and neuroimaging data of 12 patients diagnosed with RE satisfying the European Consensus Statement diagnostic criteria.

RESULTS

The disease manifested as seizures in all patients and was refractory; epilepsia partialis continua was a notable feature (nine patients). Hemiparesis of varying grades was noted in all but one patient; none had extrapyramidal signs. Neuroimaging showed cortical involvement in the insular/periinsular regions in 11 patients. Caudate atrophy was noted in ten patients. Putaminal atrophy was seen in nine patients, six of whom had additional hyperintense signal changes.

CONCLUSIONS

Our study highlights frequent putaminal atrophy and signal changes in RE, which suggests a more extensive basal ganglion involvement than emphasized previously. Recognition of putaminal changes may be a useful additional tool in the radiological diagnosis of RE.

Difficulties in differentiation of Parry-Romberg syndrome, unilateral facial sclerodermia, and Rasmussen syndrome

INTRODUCTION

Parry-Romberg syndrome (progressive facial hemiatrophy) is a unilateral, slowly progressive atrophy affecting the skin, subcutaneous tissues, muscles, and bones. The relationship between Parry-Romberg syndrome and connective tissue disorders, especially scleroderma en coup de sabre, is still unclear. The neurological symptoms, including epilepsy, migraine, and brain lesion, on neuroimaging may be similar. Rasmussen encephalitis (RE) is connected with chronic inflammation and damage of one hemisphere. Clinically, it is manifested by epileptic partial seizures and unilateral neurological symptoms.

CASE REPORT

The authors present the case of a 10-year-old girl with features suggestive of RE, with refractory partial motor dextrolateral seizures followed by development of hemiparesis and with progressive intellectual deterioration. At the age of 2 years, some changes on the left part of the face typical of Parry-Romberg syndrome or a linear form of scleroderma were noticed.

DISCUSSION

The authors discussed the difficulties in differential diagnosis in that patient. The presented girl constitute the case from the borderline zone of the aforementioned disorders.

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.

[Recent advances in pathogenic concepts and therapeutic strategies in Rasmussen's encephalitis]

Rasmussen's encephalitis (RE) is a rare inflammatory brain disease mainly affecting children and characterised by intractable epilepsy involving a single hemisphere that undergoes progressive atrophy. RE is characterized by refractory focal seizures, often associated with epilepsia partialis continua, progressive unilateral motor defect, slow EEG activity over the entire contralateral hemisphere, with focal white matter hyperintensity and insular cortical atrophy on neuroimaging. Surgical exclusion of the affected hemisphere is the only treatment that interrupts progression of the disease. Pathogenic concepts have considered viruses, autoimmune antibodies and autoimmune cytotoxic T lymphocytes that might contribute to the initiating or perpetuating events in the central nervous system. Based on these concepts, different therapeutic strategies have been pursued, such as antiviral agents, plasmapheresis, immuno-adsorption, immunosuppression or immunomodulation with intravenous immunoglobulins. However, due to the lack of large studies, to date there is no established therapeutic strategy for this devastating condition. In this review, we give an overview of the current state of immunopathogenic concepts for Rasmussen's encephalitis and discuss the different therapeutic options for future perspectives.

Epilepsia partialis continua: acute disseminated encephalomyelitis or Rasmussen's encephalitis?

This report describes a 15-year-old male presenting with headaches and seizures after a viral illness progressing to intractable seizures of the right hand and face. This patient presented with diffuse white matter lesions on magnetic resonance imaging which disappeared with treatment. A relapse 6 months later involving the left temporal and insular regions produced epilepsia partialis continua involving the right face and hand. The relevant literature is reviewed with an emphasis on possible etiologies, including both acute disseminated encephalomyelitis and Rasmussen's encephalitis.

Diagnostic imaging in 13 cases of Rasmussen's encephalitis: can early MRI suggest the diagnosis?

Rasmussen's encephalitis (RE) is a rare, progressive, chronic encephalitis characterised by drug-resistant epilepsy, progressive hemiparesis and mental impairment. It typically involves only one cerebral hemisphere, which becomes atrophic. We present neuroradiological findings in 13 children with RE. MRI was performed in all patients, fluorodeoxyglucose positron-emission tomography (PET) in three, Tc-99m hexamethylpropylenamine oxime single-photon emission computed tomography (SPECT) in two and proton MR spectroscopy ((1)HMRS) in two. MRI showed progression of the hemisphere atrophy, always prevalent in the region primarily involved (13 patients), spread of the abnormal signal in white matter (11) and cortex (10) and progression of atrophy of the head of the caudate nucleus (nine). Associated secondary changes were: atrophy of the contralateral cerebellar hemisphere (in four patients), the ipsilateral hippocampus (in five) and the brain stem (in five). The earliest CT and MRI abnormalities, seen between 1 day and 4 months after the first seizure (in 12 patients examined, nine of whom had MRI) in one cerebral hemisphere included: high signal on T2-weighted images in the cortex (seven patients) and white matter (nine), cortical atrophy usually involving the frontoinsular region, with mild or severe enlargement of the lateral ventricle (eight) and moderate atrophy of the head of the caudate nucleus (seven). Cortical swelling in the early stage of the disease was recognisable only in two patients. PET revealed hypometabolism, SPECT decreased perfusion, and (1)HMRS reduction of N-acetylaspartate in the affected hemisphere. PET and SPECT were usually performed in the late stages and did not provide specific findings. MRI thus demonstrates the progression of RE and may suggest the diagnosis in the early stages, often before the appearance of neurological deficits. Early diagnosis of RE may be crucial for selecting patients for aggressive medical therapy or major surgical interventions such as hemispherectomy.