CYCLOSPORINE-A AS A POSSIBLE CAUSE OF UPBEATING NYSTAGMUS

Cyclosporine A (CsA) has assumed a central role in the prophylaxis of acute graft-versus-host disease after allogenic bone marrow transplant ation; however, its potential neurotoxicity can manifest in 10-35% of patients. In most cases, neurotoxicity is transient, but fatal cases h ave been described. We report a case of acute upbeating nystagmus appe aring subsequent to the hematic peak of CsA in a patient undergoing pr ophylactic treatment for acute graft-versus-host disease after bone ma rrow transplantation for chronic myeloid leukemia. Computed tomography and magnetic resonance imaging revealed no abnormalities. Although re duced, the upbeating nystagmus persisted over time. To our knowledge, this is the first case in which upbeating nystagmus manifests as a pos sible consequence of CsA therapy.