• Amyotrophic lateral sclerosis;
  • motor neuron disease;
  • pathophysiology;
  • clinical neurophysiology;
  • disease spread


Introduction: The distribution of clinical and neurophysiological abnormalities in patients with early amyotrophic lateral sclerosis (ALS) was investigated in an attempt to delineate patterns of disease spread. Methods: Clinical and electrodiagnostic data were collected from 150 ALS patients and analyzed based on the clinical region of onset. Results: Asymmetry of clinical and neurophysiological abnormalities was more marked in upper limb-onset than lower limb-onset disease. Significant rostral-caudal gradients of clinical weakness were identified in bulbar and lower limb-onset disease. Neurophysiological evidence of the ALS ‘split hand' pattern was evident irrespective of the region of disease onset. Limbs with and without evidence of clinical weakness demonstrated similar rates of abnormality on electromyography. Discussion: These findings suggest a pattern of disease spread in ALS. As such, this study may serve to guide ongoing development of disease quantitation biomarkers and the targeting of future neuroprotective strategies. © 2014 Wiley Periodicals, Inc.