Chronic Focal Encephalitis (Rasmussen's Encephalitis) is a condition characterized by a progressive hemiparesis, cognitive decline (including loss of language skills if the language dominant hemisphere is involved) and epileptic seizures that are typically refractory to medical treatment (Rasmussen). Attempts to control the seizures with anticonvulsants are ineffective and the only effective treatment to date is a hemispherectomy (surgical removal of half of the brain). Children with CFE who undergo cortical resections or hemispherectomies demonstrate an inflammatory histopathology consisting of perivascular lymphocytic cuffing, gliosis, neuronal loss, microglial nodules and later laminar necrosis and spongy degeneration