[Lupus chorea revealing. Study in magnetic resonance imaging. Success of plasma exchanges after resistance to pulsed cortisone].

Chorea as a manifestation of SLE is infrequent (1% of all cases of SLE). A new case is reported herein. The patient, a seventeen-year-old female, was admitted with a one-week history of choreic movements of the left half of the body and arthritis of both wrists. Biologic findings confirmed the diagnosis of SLE with presence of an antiprothrombinase circulating anticoagulant. Findings upon cerebral CT scan and magnetic resonance imaging were normal. Clinical symptoms worsened despite corticosteroids in a daily dosage of 1 mg/kg with three pulses of 800 mg methylprednisolone. High-dose neuroleptic therapy was given and three plasma exchanges were performed. A dramatic improvement in clinical symptoms and biological anomalies occurred and persisted during follow-up which now exceeds one year. The lack of MRI anomalies suggests that the pathogenesis of SLE-associated chorea involves functional neurone activation by immune complexes; the dramatic effectiveness of plasma exchanges may obviate the need for using immunosuppressant agents in patients who fail to respond to corticosteroids.