Encephalitis associated with glutamic acid decarboxylase autoantibodies in a child: a treatable condition?

OBJECTIVE To increase the recognition of glutamic acid decarboxylase autoantibodies-related encephalitis in childhood. DESIGN Case report and review of the literature. PATIENT A 6-year-old girl who had developed refractory seizures, developmental regression, and type 1 diabetes mellitus at age 25 months. INTERVENTIONS Blood analysis, electroencephalogram, cerebral magnetic resonance imaging, positron emission tomography scan, lumbar puncture, and measurement of glutamic acid decarboxylase activity were performed. Treatment with repeated plasmapheresis and rituximab, with concomitant antiepileptic drugs, was administered. RESULTS Highly elevated titers of glutamic acid decarboxylase autoantibodies were found in the serum, as well as in the cerebrospinal fluid. Major clinical improvement in parallel with a decrease in the levels of serum and cerebrospinal fluid antibodies was observed with treatment. CONCLUSIONS Encephalitis associated with glutamic acid decarboxylase autoantibodies is a severe epileptic disorder that occurs in young children as well as adults. It may be partially reversible with aggressive immunomodulatory treatment, including plasmapheresis and rituximab. Studies are warranted to determine whether early treatment leads to complete remission.