Comparison of cross-sectional area and distal-proximal nerve ratios in amyotrophic lateral sclerosis.

INTRODUCTION: The present study explored potential diagnostic markers of nerve ultrasound in differentiating amyotrophic lateral sclerosis (ALS) from mimic disorders.

METHODS: Ultrasound of the median, ulnar and tibial nerves was undertaken in 53 ALS patients, 32 patients with ALS-mimic disorders and 30 controls. Nerve cross-sectional area (CSA) and distal-proximal ratios were calculated.

RESULTS: The median nerve CSA in the upper arm was decreased (7.9 ± 1.3 mm2 vs. 9.0 ± 1.4 mm2 ; p <0.05), and the median nerve wrist-upper arm ratio was increased in ALS compared to controls (1.3 ± 0.4 vs. 1.1 ± 0.2; p <0.01). In differentiating ALS from mimic presentations, assessment of median nerve CSA in the upper arm and comparison of a median and ulnar nerve CSA distal-proximal ratio provide diagnostic potential.

DISCUSSION: Assessment of nerve CSA, combined with calculation of nerve CSA distal-proximal ratio provides a useful marker to aid the diagnosis of ALS. This article is protected by copyright. All rights reserved.