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

Abstract

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.

Successful treatment of epilepsia partialis continua due to Rassmussen encephalitis with perampanel

“…Based on the obtained brain tissue a hippocampus sclerosis and chronic leptomeningoencephalitis representing a Rasmussen encephalitis was diagnosed. Therefore the diagnosis of Rasmussen encephalitis is based on the histopathological findings in combination with the occurrence of EPC (Varadkar et al, 2014). Unfortunately, the patient suffered a perioperative intracerebral haemorrhage causing a leftward hemiparesis and dysarthria.…”

“…Inflammation and seizures in Rasmussen encephalitis may be caused by antibodies activating glutamate receptors especially GluR3. But it has to be admitted that in many patients with Rasmussen encephalitis none of the known antibodies against glutamate receptors were found (Varadkar et al, 2014) and especially antibodies to GluR3 were only infrequently found in a group of 30 patients with Rasmussen encephalitis (Watson et al, 2004). Unfortunately until now there is no commonly accepted definition of EPS.…”

The Emerging Role of Gamma-Delta (γδ) T cells in Neurological Diseases and Rasmussen Encephalitis

“…However, while treatment with tacrolimus or intravenous (i.v.) immunoglobulins may partially stabilize the conditions of the patient, they do not have any beneficial effect on the intractable seizures [10].…”

Expression of human cytomegalovirus components in the brain tissues of patients with Rasmussen’s encephalitis

“…Rasmussen's encephalitis (RE) is a rare, chronic, progressive neurological syndrome that often occurs in childhood (Varadkar et al, 2014). The major clinical characteristics of RE consist of focal epilepsy, progressive hemiparesis, and the decline of cognitive function (Bien et al, 2002b).…”

“…The etiology and pathogenesis of RE are unclear (Varadkar et al, 2014). Several factors are thought to be involved in the occurrence of this syndrome, including virus infection (Walter and Renella, 1989;Farrell et al, 1991), autoantibodies (Rogers et al, 1994), cytotoxic T cells (Bauer et al, 2002;Bien et al, 2002a), and abnormal immune modulation (Luan et al, 2013;Luan et al, 2016).…”