The clinical spectrum of isolated peripheral motor dysfunction

Muscle Nerve. 2015 Mar;51(3):358-62. doi: 10.1002/mus.24326. Epub 2015 Jan 9.

Abstract

Introduction: Isolated peripheral motor dysfunction due to lower motor neuron or peripheral nerve disorders presents an interesting challenge to clinicians because of the diverse differential diagnosis with a broad range of prognoses.

Methods: We retrospectively reviewed clinical data of adults who presented over 12 years with muscle weakness, atrophy, or fasciculations, but without hyperreflexia or sensory involvement.

Results: In 119 patients, 52% had a motor neuron disease (MND), 13% had immune neuropathies, 11% had genetic neuronopathies, 10% had residual or post-polio syndrome, 5% had benign fasciculation, 1% had an infectious etiology, and 8% were not given a final diagnosis. Only MND patients had cognitive dysfunction or frontal release signs. Bulbar and respiratory symptoms virtually excluded consideration of immune neuropathy.

Conclusions: Only half of the patients were diagnosed with MND. A significant minority have treatable conditions. Cognitive involvement, frontal release signs, and bulbar or respiratory symptoms are strongly suggestive of MND.

Keywords: amyotrophic lateral sclerosis; isolated peripheral motor dysfunction; motor neuron disease; multifocal motor neuropathy; progressive muscular atrophy.

MeSH terms

  • Aged
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Motor Neuron Disease / diagnosis*
  • Motor Neuron Disease / physiopathology*
  • Motor Neuron Disease / therapy
  • Peripheral Nervous System Diseases / diagnosis*
  • Peripheral Nervous System Diseases / physiopathology*
  • Peripheral Nervous System Diseases / therapy
  • Retrospective Studies