INTRODUCTION: The purpose of this study was to compare the pattern of hand muscle involvement in Hirayama disease (HD) and amyotrophic lateral sclerosis (ALS). METHODS: We reviewed findings of upper limb nerve conduction studies of 46 HD patients and 60 ALS patients. The findings from 54 healthy subjects were used for comparison. RESULTS: In HD, the ulnar compound muscle action potential (CMAP) amplitude was more severely reduced than the median one, and the reverse pattern was observed in ALS. The mean ulnar/median (U/M) CMAP amplitude ratio was significantly lower in HD (0.64 ± 0.79) and abnormally higher in ALS (2.15 ± 1.77) compared with normal subjects (0.89 ± 0.23). An abnormally low U/M CMAP amplitude ratio (<0.6) was encountered in 34 patients with HD and in 1 with ALS. A U/M CMAP amplitude ratio ≥4.5 or absent median motor response was found only in ALS. CONCLUSION: Our findings demonstrate different patterns of hand muscle involvement between these two diseases.
INTRODUCTION: The purpose of this study was to compare the pattern of hand muscle involvement in Hirayama disease (HD) and amyotrophic lateral sclerosis (ALS). METHODS: We reviewed findings of upper limb nerve conduction studies of 46 HDpatients and 60 ALSpatients. The findings from 54 healthy subjects were used for comparison. RESULTS: In HD, the ulnar compound muscle action potential (CMAP) amplitude was more severely reduced than the median one, and the reverse pattern was observed in ALS. The mean ulnar/median (U/M) CMAP amplitude ratio was significantly lower in HD (0.64 ± 0.79) and abnormally higher in ALS (2.15 ± 1.77) compared with normal subjects (0.89 ± 0.23). An abnormally low U/M CMAP amplitude ratio (<0.6) was encountered in 34 patients with HD and in 1 with ALS. A U/M CMAP amplitude ratio ≥4.5 or absent median motor response was found only in ALS. CONCLUSION: Our findings demonstrate different patterns of hand muscle involvement between these two diseases.
Authors: Otto Hernandez Fustes; Cláudia Suemi Kamoi Kay; Paulo José Lorenzoni; Renata Dal-Prá Ducci; Lineu Cesar Werneck; Rosana Herminia Scola Journal: Surg Neurol Int Date: 2020-12-22