Dynamics of the cytokine profiles in Rasmussen's encephalitis: A case report

Although cytotoxic T cells (CTL) and activated microglia affect the pathophysiology of Rasmussen's encephalitis (RE), the correlation between these immune cells and cytokines has yet to be elucidated. We analyzed the dynamics of the cytokine profiles in a patient with RE. A 6-year-old girl without any medical history developed right hemiconvulsions. EEG showed left parietal to temporal epileptiform discharges, and positron emission tomography revealed left parietal lobe hypoperfusion. At age 9 years, the patient developed epilepsia partialis continua, with subsequent MRI showing mild atrophy of the left hemisphere, based on which a diagnosis of RE was established. Monthly methylprednisolone pulse therapy was then initiated, with the patient's cytokine profiles being recorded at four time points. In the acute phase, C-X-C motif chemokine 9 (CXCL9) increased but later decreased in the cerebrospinal fluid (CSF). Meanwhile, interleukin-6 (IL-6) was negative in the acute phase but increased in the chronic phase. Elevated CXCL9 in the CSF during the acute phase indicates increased secretion of interferon γ due to the abnormal activation of CTL, which is characteristic of RE. Hence, measuring CXCL9 levels in the CSF during the acute phase may help diagnose RE. We observed elevated IL-6 levels in the CSF during the chronic phase, which possibly reflects long-lasting central nervous system inflammation. We outline the cytokine profile dynamics in an RE patient in hopes of contributing to the early diagnosis of RE and selection of therapeutic approach.