Not applicable

Rasmussen’s encephalitis (RE) is a rare inflammatory condition that usually attacks a single cerebral hemisphere (CH) and manifests with intractable seizures. Cerebral hemispherectomy is an effective treatment option; however, its application is limited to children but may be considered in patients in whom the inflammation and seizures are restricted to a single hemisphere. Here, we present a 25-year-old woman with a history of previously well-controlled epilepsy since early adolescence who developed super refractory status epilepticus. The patient was placed in a medically induced coma for 3 months as seizures were unresponsive to antiseizure medications.

The patient was evaluated with serial clinical exams, neuroimaging, brain biopsy, and EEG. Pathohistological features were consistent with the diagnosis. Metagenomic next-generation sequencing (mNGS) of RNA extracted from brain biopsy tissue was performed to detect pathogens. Based on previous evidence1, natalizumab (inhibitor of alpha4 integrin) was administered monthly with close monitoring by clinical examination and profiling of peripheral blood (PB) T cells.

CT head demonstrated right CH atrophy, and the brain MRI showed right CH atrophy, right ventriculomegaly, and multiple areas of cortical/subcortical hyperintensity. However, EEG recordings suggested seizure activity in both CHs. Brain biopsy revealed a predominance of CD8+ cytotoxic T cells in the brain parenchyma, including perivascular spaces, and scarcity of neurons. mNGS did not detect any pathogens. CD4+/CD8+ T cell ratio decreased in the PB after administration of natalizumab. Brain PET scan images obtained after natalizumab administration revealed metabolic activity within the right CH compared to a prior hypometabolic state. Seizure activity was dramatically decreased after the second dose of natalizumab, allowing the patient to be successfully weaned from induced-coma. She has remained free from refractory seizures for nearly 2 years.

In this patient, natalizumab was associated with a dramatic clinical improvement in a patient with RE and refractory seizures.