Rasmussen Encephalitis

Rasmussen encephalitis is a rare, progressive, immune-mediated neurological disorder typically presenting in childhood with intractable focal seizures and unilateral cortical atrophy. Etiology involves autoimmune T-cell–mediated neuronal injury. Pathophysiology includes chronic inflammation, neuronal loss, and gliosis in one cerebral hemisphere. Diagnosis is clinical, supported by MRI showing hemispheric atrophy and EEG demonstrating focal epileptiform activity. Management includes immunotherapy (steroids, IVIG, tacrolimus) and surgical hemispherectomy in refractory epilepsy; prognosis is progressive neurological decline if untreated.