Thrombotic thrombocytopenic purpura-induced posterior leukoencephalopathy in a patient without significant renal or hypertensive complications.

A 40-year-old male with recent-onset idiopathic thrombotic thrombocytopenic purpura (TTP) developed focal transient neurological findings lasting for several hours, remitting, then recurring in a different pattern. Brain magnetic resonance imaging (MRI) was consistent with a posterior leukoencephalopathy and electroencephalography demonstrated lateralized slowing during an episode. No acute ischemic changes were found on diffusion-weighted imaging. Close monitoring in an intensive care setting revealed no significant hypertensive episodes. The patient's condition resolved with plasmapheresis and immunoglobulin therapy. The relation of TTP to reversible posterior leukoencephalopathy syndromes is discussed. Clinical features of this case suggest a mechanism for TTP-induced leukoencephalopathy independent of hypertension and renal failure.