While CFE represents only a very small percentage of patients with epilepsy, the devastating progressive nature of the disease with out any adequate treatments, relegates these children to the relentless loss of cognitive and motor skills, and continuing seizures. Recent evidence suggests this condition is immune mediated and includes the development of antibodies directed against various brain components including glutamate receptors (GluR3) (Rogers). Brain samples from patients with CFE have demonstrated immunoreactivity for IgG, C4 C8, and MAC (Andrews and Whitney) and involvement of both B and T-lymphocytes. Evidence supporting a role for clonally expanded B lymphocytes was found by Baranzini . By analyzing the T-cell receptor expression in brain lesions using PCR these investigators also demonstrated the local immune response in CFE included restricted T-cell populations probably expanding from a few precursor T-cells responding to discrete antigenic epitopes (Li). Following demonstration of antibodies directed against brain elements in CFE, a patient was treated with plasma exchange which produced a significant improvement in seizure frequency, cognition and hemiparesis, lending support to the hypothesis that circulating antibodies contribute to the disease pathogenesis. Subsequently attempts to modify this disease by immune modification (plasmaphoresis, steroids, gamma globulin) have demonstrated modest improvements but the improvements have been short-lived and have not affected the natural progression of this disease. This pilot study proposes to directly attack the cells (B-cells) thought to be instrumental in the development of this condition. Should this approach to treating CFE be successful it will have a major impact on these children's lives.