Features of repetitive nerve stimulation and nerve conduction studies in patients with amyotrophic lateral sclerosis

Precise diagnosis of amyotrophic lateral sclerosis (ALS) and differential diagnosis between ALS and other diseases are important. For ALS diagnosis, not only needle electromyography but also decremental responses to repetitive nerve stimulation (RNS) and a decreased abductor pollicis brevis (APB)/abductor digiti minimi (ADM) amplitude ratio in nerve conduction studies (NCS) are useful. We should know the incidence of decrement in RNS responses and the decreased amplitude ratio in NCS in ALS patients with upper limb symptoms.