Vocal Cord Paralysis in Multifocal Motor Neuropathy: A Case Report

Abstract

Multifocal motor neuropathy is characterized by slowly progressive, asymmetrical weakness of the arms without sensory loss. The disease can also cause vocal cord paralysis as it runs its course. A 34-year-old man developed progressive weakness in his hand muscles for one year and dysphonia for three weeks. Neurological examination revealed there was moderate weakness and mild muscle wasting in distal muscles of the upper limbs, predominantly in the left hand. Left laryngeal nerve palsy was also discovered during his otolaryngological examination. Nerve conduction studies revealed multiple sites of conduction block without sensory abnormalities consisting of selective involvement of motor fibers. The patient received intravenous immunoglobulin treatment after multifocal motor neuropathy diagnosis. Multifocal motor neuropathy with conduction block is rarely associated with vocal cord paralysis. This condition should be kept in mind in cases of laryngeal nerve palsy with an asymmetric motor neuropathy, as patients might benefit from immunoglobulin treatment.