Drug-indiced aseptic meningitis: development of subacute sclerosing panencephalitis following repeated intraventricular infusion therapy with interferon alpha/beta

Interferon (IFN)-α was reported to be effective in longterm intrathecal treatment of subacute sclerosing panencephalitis (SSPE). However, the side effects related with longterm use of IFN-α/β are unclear. We evaluated the therapeutic effects of IFN-α/β in a 13-years-old patient with SSPE. The cerebrospinal fluid (CSF) measles antibody titer was 64 × NT/128×HI, IgG-index was 4.5, and the SSPE diagnosis was based on electroencephalography (Jabbour-stage II on admission). With Inosiplex (INP) given orally, IFN-α (3 × 10⁶ units) was infused intraventricularly twice-a-week for 1-year. Resultantly, CSF cell count was elevated (2502/3), total protein and glucose levels were normal; however, DIAM occurred repeatedly. Consequently, reduced IFN-α (5 × 10⁵ units) with hydrocorton was administered at 2-months interval for 19 months, during which, DIAM occurred four times. Therefore, IFN-β (3 × 10⁶ units; twice-a-week) therapy was started and continued for 3 years. Although the symptoms were improved considerably, DIAM recurred after 15-months therapy and CSF cell counts were also elevated (2121/3). Since SSPE progressed to Jabbour-stage IV, indicated by irreversible consciousness disorder, IFN therapy was discontinued and INP monotherapy was followed for another 3 years. We, therefore, concluded that the longterm intraventricular IFN-α/β infusion therapy of SSPE involved the potential risk of DIAM with serious irreversible neurological sequelae and should be monitored carefully.