Immune-mediated monofocal motor neuropathy: Report of two cases with long-term follow up and review of six published cases

Abstract

Background and Aim There are rare cases of multifocal motor neuropathy (MMN) with single nerve involvement published. The aim of the present study was to describe two cases of MMN with single nerve involvement and long-term follow up. The first consisted of an isolated wrist drop, which developed conduction block later in the course of the disease. The second presented with longstanding left thumb weakness and near complete radial conduction block. Both responded to intravenous immunoglobulin. Methods The clinical and electrodiagnostic findings of two cases with long–term follow up are discussed, and six cases published in the literature are reviewed. Results Both patients responded to intravenous immunoglobulin. One developed conduction block later in the course of the disease. Conclusion Monofocal motor neuropathy, a pure motor immune–mediated mononeuropathy, is a rare disorder, which responds to intravenous immunoglobulin. Although it might resemble MMN, some of its features lead us to consider it as a distinct entity.