Response to treatment in patients with lewis–sumner syndrome

Our aim was to document the classification of Lewis–Sumner syndrome (L‐SS) based on the response to treatment and the pattern of progression over time. Methods: We retrospectively identified 15 patients with L‐SS treated for at least 12 months. Results: After 1 year, intravenous immunoglobulin was effective in 7 patients, 6 were stable, and 2 worsened. After 5 years, 5 patients had improved, and 3 were stable. These 8 patients needed repeated treatment, and 2 patients gradually worsened. Two patients worsened dramatically after steroid treatment. In 3 patients the neuropathy progressed to the other limbs and developed into an asymmetric polyneuropathy. In 12 other patients the pattern remained multifocal and asymmetric. Conclusions: The possibility of decline resulting from corticosteroids, and the fact that no neurological progression toward a diffuse pattern was observed in the majority of patients suggests that L‐SS is a different entity from chronic inflammatory demyelinating polyradiculoneuropathy. Muscle Nerve, 2011