Clinical differential diagnosis of multifocal motor neuropathy

Abstract

Multifocal motor neuropathy (MMN) is a rare, clinically well-defined condition within the spectrum of chronic, immune-mediated neuropathies. A typical patient history involves slowly or stepwise progressive, predominantly distal, asymmetrical limb weakness and muscle wasting, most frequently in the arm, that may have developed over a period of years. As a rare condition, MMN may present a diagnostic challenge for non-specialists and some patients may wait years for a correct diagnosis. Timely and accurate diagnosis is essential for patients with MMN. Unlike some motor neuropathies, MMN is treatable with intravenous immunoglobulin and untreated patients are likely to experience progressive muscle weakness that may result in serious functional impairment and impaired quality of life. The aim of this article is therefore to provide a guide for non-specialist neurologists to the clinical recognition and differential diagnosis of MMN. © TOUCH BRIEFINGS 2012.