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

Abstract

This study explored potential diagnostic markers of nerve ultrasound in differentiating amyotrophic lateral sclerosis (ALS) from mimic disorders. Ultrasound of the median, ulnar, and tibial nerves was conducted in 53 patients with ALS, 32 patients with ALS-mimic disorders, and 30 controls. Nerve cross-sectional area (CSA) and distal-proximal ratios were calculated. 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 patients compared with 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. Assessment of nerve CSA combined with calculation of nerve CSA distal-proximal ratio provides a useful marker to aid in the diagnosis of ALS. Muscle Nerve 58:777-783, 2018.