IMMUNOSUPPRESSIVE TREATMENT OF MOTOR-NEURON SYNDROMES - ATTEMPTS TO DISTINGUISH A TREATABLE DISORDER

Objective: To determine if response to immunosuppressive treatment in motor neuron syndromes could be predicted on the basis of clinical fea tures, anti-GM(1) antibodies, or conduction block. Design: Prospective , uncontrolled, treatment trial using prednisone for 4 months followed by intravenous cyclophosphamide(3 g/m(2)) continued orally for 6 mont hs. Setting: All patients were referred to university hospital medical centers. Patients: Sixty-five patients with motor neuron syndromes we re treated with prednisone; 11 patients had elevated GM(1) antibody ti ters, and 11 patients had conduction block. Forty-five patients receiv ed cyclophosphamide, eight of whom had elevated GM(1) antibodies and 1 0 had conduction block. Results: One patient responded to prednisone, and five patients responded to cyclophosphamide treatment. Only patien ts with a lower motor neuron syndrome and conduction block improved wi th either treatment. Response to treatment did not correlate with GM(1 ) antibodies. Conclusions: GM(1) antibodies did not serve as a marker for improvement in patients with motor neuron syndrome treated with im munosuppressive drugs. Patients with amyotrophic lateral sclerosis fai led to improve irrespective of laboratory findings.