Reversible dementia and chorea in a young woman with the lupus anticoagulant.

A 22-year-old woman gradually developed depression, dementia, and chorea over an 8-month period. She fulfilled the criteria for the primary antiphospholipid antibody syndrome but not those for systemic lupus erythematosus. Her chorea and neurobehavioral deficits responded favorably to a regimen of prednisone, hydroxychloroquine, and aspirin. This appears to be the first report of a patient with a lupus anticoagulant and reversible dementia. The response to immunosuppressive therapy implies an antibody-mediated condition similar to Sydenham's chorea.