Repetitive nerve stimulation in amyotrophic lateral sclerosis / 西安交通大学学报(医学版)

ABSTRACT

ABSTRACT:Objective To evaluate the features and related factors of decremental response in amyotrophic lateral sclerosis (ALS)patients to low-frequency repetitive nerve stimulation (RNS)in proximal nerves.Methods We performed RNS studies in proximal axillary and accessory nerves with recording in deltoid and trapezius mus-cle respectively in 87 ALS patients.Decremental compound muscle action potential (CMAP)and related factors were analyzed prospectively,and abnormal group of decremental response in ALS patients was compared with 39 pa-tients with myasthenia gravis.Results ① Abnormal decremental responses were found in 43.7% and 49.4% of ALS patients with deltoid and trapezius muscle recording respectively.They were found more frequent in trapezius muscle than those of deltoid muscle.② There was no relationship of decremental response with gender,age,onset or course of disease,ALSFRS-r scores,or rate of disease progression in ALS patients.③ There was significant rela-tionship between decremental response and fluctuating muscle weakness.Decremental responses decreased more ob-viously in ALS patients with fluctuating muscle weakness than in those with nonfluctuating muscle weakness.④ Dec-remental responses were greater in patients with myasthenia gravis than that in ALS patients.Conclusion Decre-mental response with proximal muscle recording is not an uncommon feature in ALS patients;therefore,it should not be treated as a criterium to rule out ALS.Abnormal decremental response of trapezius muscle is found more fre-quent than that of deltoid muscle.Decremental response range in patients with myasthenia gravis is significantly lar-ger than that in ALS patients.One should be more careful when diagnosing ALS patients with fluctuating muscle weakness and abnormal decremental response.