Chronic encephalitis and temporal lobe epilepsy: a variant of Rasmussen's syndrome?

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.

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.

Electroclinical features of seizures associated with autoimmune encephalitis

PURPOSE

We sought to characterize the electroclinical features of seizures associated with autoimmune encephalitis and their relevance to outcome.

METHODS

19 patients with seizures and autoimmune encephalitis were identified from a database of 100 patients (2008-2017) with autoimmune neurological disorders. Clinical and electroclinical characteristics were collected. Persistent seizures at last follow-up were then correlated with electroclinical features.

RESULTS

Status epilepticus (53%) and early intractability to AEDs (median time to second AED 9.5 days) marked the onset of refractory seizures (median number of AEDs 3). Seizure semiology (abdominal (16%), psychic (42%), olfactory (6%) auras), interictal temporal epileptiform discharges (42%), and ictal onset in the temporal region (63%) mirrored radiologic involvement of the medial temporal regions (on MRI in 74% and/or FDG-PET in 75%). In addition, multimodal auras, with somatosensory (26%), autonomic (26%), gustatory (11%), and visual (16%), features were seen in 82% of patients with focal aware seizures, invoking broader involvement of the perisylvian regions. A change in seizure semiology and EEG findings was often seen. Electroclinical features were similar regardless of antibody type, with the exception of the association of faciobrachial dystonic seizures with LGI1 antibodies. Eight patients had medically intractable seizures at last follow-up and were more likely than patients with seizure remission to have generalized tonic-clonic seizures and temporal lobe involvement on the basis of semiological features, interictal EEG and MRI changes.

CONCLUSIONS

Seizures associated with autoimmune encephalitis exhibit common electroclinical features which show dynamic evolution over time. We propose a role for the temporo-perisylvian regions in their generation.

A Case Series of Adult-Onset Rasmussen's Encephalitis: Diagnostic and Therapeutic Challenges

Rasmussen’s encephalitis (RE) is a rare neurologic disorder characterized by progressive cerebral hemiatrophy and medically refractory epilepsy. The majority of current literature on this topic is focused on the pediatric population. In this case series, we will review three cases of adult-onset RE, as defined by fulfillment of the 2005 Bien criteria. The diagnostic challenge of characterizing this rare disease will be highlighted by the extensive serum, CSF, and pathologic sampling in all three patients. MR imaging and EEG data will be examined over time to characterize hallmark findings as well as progression. In addition, we will review the various forms of therapy attempted in these three patients, namely anti-epileptic drug therapy and immunomodulatory therapy. We will also utilize this case series to critically evaluate the broader context of atypical presentations of this disease and the value of current diagnostic criteria.

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.

Rasmussen's encephalitis: A case report

Rasmussen's encephalitis (RE) is a rare neurological disorder of inflammatory aetiology characterised by encephalitis, intractable seizures, hemiparesis, variable motor deficits, and dementia. It is not commonly considered in the clinical differential diagnosis of a patient with a past history of a stroke-like episode presenting with status epilepticus. It is suspected mainly in children in whom the disease is more common. Here we report a case of an adult man presenting with a common symptom of seizure caused by Rasmussen's encephalitis.

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.

Childhood-onset nonprogressive chronic encephalitis

PURPOSE

The purpose of this study was to describe a series of patients with pathologically proven chronic encephalitis who had a nonprogressive course during a long follow-up, suggestive of a "benign" variant of Rasmussen's encephalitis (RE).

METHODS

Four patients who were referred to our Comprehensive Epilepsy Program at London Health Science Centre in London, Ontario, were diagnosed with chronic encephalitis on a pathological basis after epilepsy surgery to treat their partial-onset seizures.

RESULTS

None of our four cases followed the typical course of RE despite their childhood-onset seizures between ages 2 and 12years. One was preceded by a mild head trauma and fever at onset. None had epilepsia partialis continua (EPC). Their long-term follow-up revealed a nonprogressive form of the syndrome with respect to the neurological examination, EEG, MRI, and neuropsychological findings.

CONCLUSION

These cases extend the spectrum of childhood-onset intractable epilepsy with chronic encephalitis to include nonprogressive variants of RE. The absence of EPC may be a prognostic indicator of a nonprogressive course.

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 encephalopathies (including severe epilepsy syndromes)

Epileptic encephalopathies represent a group of devastating epileptic disorders that appear early in life and are characterized by pharmacoresistant generalized or focal seizures, persistent severe electroencephalography (EEG) abnormalities, and cognitive dysfunction or decline. The ictal and interictal epileptic discharges are age-specific and are the main etiologic factors causing cognitive deterioration. This is most obvious in the idiopathic group. In the symptomatic group, the most common causes are structural, congenital, or acquired and rarely some metabolic disorders. In certain cases, clinical and EEG abnormalities persist and may evolve from one type to another as the child grows older. Various factors trigger and sustain the underlying pathophysiologic process and the ongoing epileptic and epileptiform activity during the most critical periods of brain maturation, perpetuating their deleterious effect on the brain. Immune-mediated mechanisms may have a role, suggested by certain encephalopathies responding to immune-modulating treatments and by the finding of various autoimmune antibodies. The chance of a better cognitive outcome improves with early diagnosis and treatment that is appropriate and effective. Current antiepileptic drugs are, in general, not effective: we urgently need new trials in this very special epileptic category. This article briefly reviews the most common epileptic encephalopathies and analyzes the most important clinical issues.

Focal Chronic Inflammatory Epileptic Encephalopathy in a Patient with Malformations of Cortical Development, with a Review of the Spectrum of Chronic Inflammatory Epileptic Encephalopathy

PURPOSE

Chronic cellular inflammation closely associated with epilepsy without an active infection is a hallmark of Rasmussen encephalitis (RE). RE has typical and defining features lacking in other rare epilepsy patients who also have neocortical lymphocytes without an identifiable cause. A patient with malformations of cortical development had an abrupt change in frequency and epileptic focus after 22 years of a stable seizure disorder. Functional neurosurgery yielded a specimen showing a mixed cellular meningoencephalitis in the absence of a demonstrable infection.

METHODS

Historical, neurologic, electroencephalographic, pathologic, and literature data were correlated.

RESULTS

There was a subarachnoid mixed infiltrate including evidence of dendritic cells in our patient and also cytotoxic T lymphocytes adjacent to karyolytic neurons that corresponded to cells previously demonstrated to damage neurons in RE. Literature review disclosed 42 other cases similar to RE but with heterogeneous findings. The course was more protracted and often more benign than in RE. The inflammation that would have markedly decreased or disappeared in RE over that period was generally still well represented.

CONCLUSIONS

Our patient has heterogeneous features similar to, yet with differences from, RE. Literature review of chronic cellular inflammatory epileptic encephalopathy cases also similar to RE discloses important differences that may reflect idiosyncratic reactions and pace of the disease rather than a different disease. Comorbidity factors, genetic population traits, and secondary effects of the seizure disorder may lead to an expansion of the initial site of damage by an autoimmune reaction. These cases might best be grouped, probably along with RE, as secondary autoimmune diseases.

Rasmussen's encephalitis in a 58-year-old female: still a variant?

BACKGROUND

We report the case of a 58-year-old female with clinical, radiological, and histopathological evidence of Rasmussen's encephalitis, representing the oldest confirmed case to date.

CASE SUMMARY

The patient presented with complex partial seizures characterized by numbness of the left face and staring spells. These progressed to a state of epilepsia partialis continua with jerking of the left face, as well as severe cognitive impairment and loss of all communication. The patient responded well to Intravenous Immunoglobulin (IVIG) therapy despite early complications and with ongoing treatment is living independently with minimal cognitive impairment.

CONCLUSIONS

This represents the oldest confirmed case of Rasmussen's encephalitis and suggests that this diagnosis should be considered in patients of any age with an appropriate clinical picture. We recommend IVIG as a first line therapy for adult cases of Rasmussen's encephalitis.

Refractory occipital lobe epilepsy treated by surgery in a child with chronic encephalitis

An 11-year-old boy developed catastrophic occipital lobe epilepsy with progressive neurocognitive decline which led to surgical treatment. Pathological examination of the resected epileptic area showed chronic inflammatory changes. Surgery was followed by a subacute and regressive encephalopathy although the patient did not suffer further seizures. We suggest that this occipital lobe epilepsy was related to chronic nonprogressive encephalitis consistent with a variant of Rasmussen's syndrome, and that the immune and/or inflammatory process was reactivated by surgery. This case indicates that there is no direct link between the epileptic and the encephalitic processes.

No effect of immunomodulatory therapy in focal epilepsy with positive glutamate receptor type 3—antibodies

Antibodies against the glutamate receptor type 3-(GluR3) have been found in association with Rasmussen's encephalitis (RE) but were also detected in patients with non-inflammatory focal epilepsies. We report the case of an 18-year-old patient with treatment refractory left mesial temporal lobe epilepsy accompanied by high levels of GluR3 antibodies. Different from experiences in patients with RE immunomodulatory therapy by use of intravenous gammaglobulines neither altered GluR3 serum levels nor had any effect on seizure frequency in our patient. Interestingly, GluR3 serum levels remained positive after successful surgical intervention leading to patient's seizure freedom.

Aetiology of epilepsy in surgically treated patients in China

The aim of this retrospective, multicenter clinical study was to evaluate the aetiology of epilepsy in surgically treated patients in China. The detailed clinical records of all intractable partial epilepsy (IPE) were reviewed in five tertiary referral centres from June 1991 to June 2000. 1650 patients (927 males, 723 females) were recruited. 41.4% had aetiological factors, including the histories of major brain trauma (20.9%), febrile seizure (6.5%), meningitis (5.4%), encephalitis (5.0%), prenatal distress (2.1%), birth trauma (0.8%) and family history of seizure (0.7%). The pathological lesions were divided into eight groups according to the nature of the lesion: scar (19.2%), vascular malformations (VM) (17.7%), hippocampal sclerosis (HS) (16.2%), tumours (15.0%), gliosis (12.1%), neuronal migration disorders (NMDs) (7.4%), intracranial infection (4.5%), and other lesions (7.9%). In conclusion, effective management of these aetiological factors and pathological lesions may be essential to deal with IPE. Scar, HS, VM, NMDs are the most likely consequences of antecedent morbid events.

Non-herpetic acute limbic encephalitis: cerebrospinal fluid cytokines and magnetic resonance imaging findings

OBJECTIVE

Non-herpetic acute limbic encephalitis (non-herpetic ALE) is regarded as a new subgroup of limbic encephalitis. In the present study, clinical findings and cerebrospinal fluid (CSF) cytokines in patients with non-herpetic ALE were investigated.

PATIENTS AND METHODS

For adult inpatients in our hospital and related hospitals from 1996 to 2001, non-herpetic ALE was examined according to the criteria described in this study. Six patients were diagnosed as having non-herpetic ALE, and their clinical data and magnetic resonance imaging (MRI) were analyzed. In the CSF samples of the 6 patients with non-herpetic ALE and 6 patients with herpes simplex encephalitis (HSE), the concentrations of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-6, and interferon (IFN)-gamma were determined using sandwich-type enzyme-linked immunosorbent assay (ELISA) kits.

RESULTS

The six patients with non-herpetic ALE showed all the acute encephalitis features, such as fever, altered consciousness, seizures, memory impairment, and mild CSF pleocytosis. MRI demonstrated selective abnormal signals in the limbic system, including the bilateral hippocampi and amygdalae. The levels of CSF IL-6 and IFN-gamma in patients with non-herpetic ALE were significantly lower than those in patients with HSE (p<0.05 and p<0.01, respectively). The levels of both TNF-alpha and IL-1beta were below the detection limits in both groups.

CONCLUSION

Six patients were newly diagnosed as having non-herpetic ALE in this study. These patients revealed both acute limbic encephalitis and MRI abnormalities in the bilateral hippocampi and amygdalae. The levels of IL-6 and IFN-gamma in the CSF of patients with non-herpetic ALE were significantly lower than those of patients with HSE, possibly reflecting an immunological process in this type of ALE rather than direct viral infection.

The natural history of Rasmussen's encephalitis

Rasmussen's encephalitis (RE) is a chronic inflammatory disease of unknown origin, usually affecting one brain hemisphere. In the present study, a comprehensive assessment of the natural history of the disorder is presented. Seizure frequency, degree of hemiparesis and degree of cerebral hemiatrophy in 13 patients with histopathologically proven RE are analysed over the time course prior to resective epilepsy surgery or introduction of long-term immunosuppressive pharmacotherapy. For the assessment of the degree of cerebral hemiatrophy, on defined slices comprising the Sylvian fissure of hard copies of serial MRI investigations, the hemispheric ratio (HR) was determined. The data show an initial prodromal phase with an intermediate frequency of focal onset seizures and mostly no hemiparesis. The occurrence of this stage was mainly observed in the adolescent and adult patients. All patients went through an acute phase with a median duration of 8 months. During this stage, there were frequent simple partial motor seizures, development of hemiparesis and volume loss of the affected hemisphere. After this, the patients passed into a residual stage with a marked decrease in seizure frequency. Twelve months after the onset of the acute stage, the average HR was 0.72. These data allow an estimation of the prognosis of newly affected patients, and demonstrate that most of the brain damage in RE occurs during the first 8-12 months. These findings should be taken into consideration when future therapeutic approaches to RE are evaluated.