Medical treatment of Rasmussen's Encephalitis: A systematic review

Rasmussen's encephalitis (RE) is a severe, rare, chronic inflammatory brain disease resulting in drug-resistant epilepsy and progressive destruction of one hemisphere with loss of neurological function. RE is associated with a deterioration of background electroencepha-lography (EEG) activity, a progressive atrophy on magnetic resonance imaging (MRI) imaging and an extensive positron emission tomography hypometabolism over the affected hemi-sphere. RE is an immune-mediated disease, with a predominant role of CD8+ T cytotoxic cells, microglial cells, and activation of inflammasome pathway. The diagnosis of RE is based on clinical (intractable epilepsy and neurological deterioration), electrophysiological (uni-lateral EEG slowing) and MRI (hemiatrophy) criteria. Antiseizure medications are generally unable to stop seizures. The most effective procedure is hemispherotomy (surgical dis-connection of one cerebral hemisphere), but this is associated with permanent motor and neurological deficits. Treatments targeting the immune system are recommended espe-cially in the early stages of the disease or in patients with slow disease progression and mild deficits and/or not eligible for surgery. Based on the pathophysiology, several immuno-therapies have been tried in RE (none exhaustively: corticosteroid, intravenous immuno-globulins, tacrolimus, azathioprine, adalimumab, mycophenolate mofetil, natalizumab). However, only small cohorts have been reported without comparative study. In this review, we will summarise some pathophysiological mechanisms of RE, before reporting the literature data concerning immunotherapies. We then discuss the limitations of these studies and the prospects for further research.# 2022 Elsevier Masson SAS. All rights reserved.

Automated summary

Rasmussen's encephalitis is a severe and rare inflammatory brain disease that leads to destruction of one hemisphere and loss of neurological function. It is associated with immune system involvement, and the diagnosis is based on clinical, electrophysiological, and MRI criteria. Antiseizure medications are usually ineffective, and hemispherotomy is the most effective treatment. Immunotherapies targeting the immune system are recommended for patients in the early stages or with mild disease progression.