Brachial Diparesis due to Motor Neuronopathy as One of the Predominant Presenting Signs of Occult Small Cell Lung Carcinoma

Intern Med. 2016;55(12):1641-3. doi: 10.2169/internalmedicine.55.4888. Epub 2016 Jun 15.


Sensory neuronopathy is a well-established presentation in paraneoplastic neurological syndromes that is mostly associated with small cell lung cancer and anti-Hu antibodies. Motor neuronopathy, on the other hand, is an extremely rare observation in this syndrome. A 56-year-old man presented with asymmetric brachial diparesis and sensory ataxia. Electrophysiological studies revealed sensory ganglionopathy and progressive anterior horn degeneration in cervical segments. Small cell lung carcinoma with associated anti-Hu antibodies was later diagnosed. The patient did not improve despite the administration of steroids and chemotherapy. Paraneoplastic syndromes may exceptionally present with a bilateral arm weakness. Cases accompanied by sensory ganglionopathy should therefore be promptly investigated for any underlying malignancy.

Publication types

  • Case Reports

MeSH terms

  • Ataxia / diagnosis
  • Ataxia / etiology*
  • Ataxia / therapy
  • Humans
  • Lung Neoplasms / complications*
  • Lung Neoplasms / diagnosis
  • Lung Neoplasms / pathology
  • Male
  • Middle Aged
  • Muscular Atrophy, Spinal / etiology*
  • Muscular Atrophy, Spinal / pathology
  • Small Cell Lung Carcinoma / complications*
  • Small Cell Lung Carcinoma / pathology