Electrophysiological characteristics of Hirayama disease, amyotrophic lateral sclerosis and distal cervical spondylotic amyotrophy / 中华骨科杂志

ABSTRACT

Objective To explore the electrophysiological charaterstics of upper extremities nerves on the patients with Hirayama disease (HD),amyotrophic lateral sclerosis (ALS),and distal cervical spondylotic amyotrophy (DCSA).Methods The data of electrophysiological examination of the upper limbs of 87 patients with HD,83 with ALS and 28 with DCSA were reviewed retrospectively.Seventy-two patients with HD among 87 had unilateral upper limb's amyotrophy and the other 15 ones had bilateral amyotrophy.There were 30 patients had unilater upper limb's amyotrophy and 53 ones had bilateral amyotrophy from the group of patients with ALS; 20 patients with DSCA were affected unilaterally and 8 ones were bilaterally affected.Results Compound muscle action potential (CMAP) evoked by ulnar stimulation had a lower ampititude compared with that evoked by median stimulation in HD patients.In ALS cases that was just the opposite.However,the CMAPs were similar in DCSA cases.The mean ratio of CMAP amplitude by ulnar stimulation to by median stimulation was 0.58±0.40 in HD group; 2.28±1.25 in ALS and 1.31±0.63 in DCSA.The differences in the three groups were statistical significance.The U/M CMAP ratio was less than 0.6in 62 patients with HD,3 with ALS and 1 with DCSA,and more than 1.7 in 73 cases (57 ALS,12 HD and 4 DCSA).Conduction velocities (CV) of the sensory and motor nerves,the amplitude of the sensory nerve action potential in bilateral limbs,and the CMAP amplitude of the unaffected limb were normal in all cases.Conclusion This study could concluded that the severity of amyotropy in hypothenar mucles were higher than that in thenal muscles in patients with HD; there was just opposite in ALS cases and similar in DSCA.