[Multifocal motor neuropathy: diagnosis and differential diagnosis]

Abstract

Multifocal motor neuropathy (MMN) is an acquired immune mediated motor neuropathy with characteristic clinical and neurographic features.Clinically, MMN is characterized by progressive, predominantly distal and asymmetrical limb weakness. Neurographic recordings demonstrate features of multifocal demyelination with or without conduction block. Sensory nerves are not affected. Due to strict diagnostic criteria,MMN may be underdiagnosed in patients with motor neuropathies. Since intravenous immunglobulins are an efficient therapy for MMN,clinical and electrophysiological differentiation from other neuromuscular disorders is mandatory to prevent progressive impairment of motor function. We present a patient with MMN and review the clinical, electrophysiological, and histological features. In addition,pathogenesis, differential diagnosis and treatment of MMN are discussed.