LIMBIC ENCEPHALITIS AND IMMUNOLOGICAL PERTURBATIONS IN 2 PATIENTS WITH THYMOMA

Two patients with clinical and radiological evidence of limbic encepha litis associated with an invasive lymphoepithelial thymoma who improve d after thymectomy and radiotherapy are reported. The serum of both pa tients and the CSF of one of them contained different types of antibod ies that immunoreacted with human and rat brain and newborn rat thymus . After treatment of the tumour, the antibody titres decreased. Simila r antibodies were not found in various controls. Two out of 16 patient s with thymoma, myasthenia gravis, and no CNS involvement had low titr es of antibodies reacting with the brain. It is suggested that in some patients with thymoma, an autoimmune reaction involving antigens comm on to the brain and thymus is possibly misdirected against the CNS.