Improvement in adult-onset Rasmussen's encephalitis with long-term immunomodulatory therapy

Objective: To study the immediate and chronic effects of high-dose, long-term human IV immunoglobulin (hIVIg) therapy in two patients with advanced adult-onset Rasmussen's encephalitis (RE). Background: Despite advances in our understanding of the autoimmune pathogenesis of RE, medical options for chronic treatment are limited. Methods: In an open-label treatment trial, treatment started with monthly cycles of high-dose hIVIg (0.4 g/kg/d for 5 days) followed by maintenance therapy (0.4 g/kg 1 day each month) after the patients' conditions began to improve. Outcome measures included clinical, psychological, functional, and laboratory assessments before and at relevant intervals throughout I year of treatment. Results: In both patients, unrelenting pretreatment deterioration halted, and after this they displayed striking improvements in seizure control, hemiparesis, and cognition that produced useful recovery of function. Improvements were delayed until after 2 to 4 monthly cycles of high-dose hIVIg and continued when patients switched to maintenance treatment. Their recoveries were accompanied by increased cerebral perfusion on interictal SPECT and suppression of inflammatory markers in CSF. Conclusions: hIVIg can be a useful, possibly disease-modifying, long-term therapy for adult-onset RE that should be considered before radical surgery is performed. Because improvements can be delayed, we propose guidelines for intensive and prolonged trials of immunomodulatory therapy in adults with this syndrome.