Anti-GAD Encephalitis

Anti-GAD (glutamic acid decarboxylase) encephalitis is an autoimmune disorder characterized by antibodies targeting GAD65, an enzyme critical for GABA synthesis. Clinical presentation includes refractory seizures, stiff-person syndrome, cerebellar ataxia, and cognitive deficits. Diagnosis requires serologic detection of anti-GAD antibodies and exclusion of alternative etiologies. MRI may show T2/FLAIR hyperintensities in the temporal lobes or cerebellum. Management is immunotherapy-based, including corticosteroids, IVIG, and plasma exchange, with prognosis dependent on early recognition and response to therapy.