Patterns of clinical and electrodiagnostic abnormalities in early amyotrophic lateral sclerosis.

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.

CONCLUSIONS

These findings suggest a pattern of disease spread in ALS. This study may serve to guide ongoing development of disease quantitation biomarkers and the targeting of future neuroprotective strategies.