Previous studies have shown that ulnar nerve compound muscle action potential recorded by the conventional“belly-tendon”montage does not accurately and completely reflect the action potential of the ulnar nerve domi...Previous studies have shown that ulnar nerve compound muscle action potential recorded by the conventional“belly-tendon”montage does not accurately and completely reflect the action potential of the ulnar nerve dominating the abductor digiti minimi muscle due to the effects of far-field potentials of intrinsic hand muscles.A new method of ulnar nerve compound muscle action potential measurement was developed in 2020,which adjusts the E2 electrode from the distal tendon of the abductor digitorum to the middle of the back of the proximal wrist.This new method may reduce the influence of the reference electrode and better reflect the actual ulnar nerve compound muscle action potential.In this prospective cross-sectional study,we included 64 patients with amyotrophic lateral sclerosis and 64 age-and sex-matched controls who underwent conventional and novel ulnar nerve compound muscle action potential measurement between April 2020 and May 2021 in Peking University Third Hospital.The compound muscle action potential waveforms recorded by the new montage were unimodal and more uniform than those recorded by traditional montage.In the controls,no significant difference in the compound muscle action potential waveforms was found between the traditional montage and new montage recordings.In amyotrophic lateral sclerosis patients presenting with abductor digiti minimi spontaneous activity and muscular atrophy,the amplitude of compound muscle action potential-pE2 was significantly lower than that of compound muscle action potential-dE2(P<0.01).Using the new method,damaged axons were more likely to exhibit more severe amplitude decreases than those measured with the traditional method,in particular for patients in early stage amyotrophic lateral sclerosis.In addition,the decline in compound muscle action potential amplitude measured by the new method was correlated with a decrease in Revised Amyotrophic Lateral Sclerosis Functional Rating Scale scores.These findings suggest that the new ulnar nerve compound muscle action potential measurement montage reduces the effects of the reference electrode through altering the E2 electrode position,and that this method is more suitable for monitoring disease progression than the traditional montage.This method may be useful as a biomarker for longitudinal follow-up and clinical trials in amyotrophic lateral sclerosis.展开更多
The dying-back hypothesis holds that the damage to neuromuscular junctions and distal axons in amyotrophic lateral sclerosis occurs at the earliest stage of the disease.Previous basic studies have confirmed early dama...The dying-back hypothesis holds that the damage to neuromuscular junctions and distal axons in amyotrophic lateral sclerosis occurs at the earliest stage of the disease.Previous basic studies have confirmed early damage to neuromuscular junctions,but it is difficult to obtain such evidence directly in clinical practice.In this prospective cross-sectional study,we recruited 22 patients with early amyotrophic lateral sclerosis with disease duration < 12 months and with clinical symptoms limited to the upper limbs.We also recruited 32 healthy controls.Repetitive nerve stimulation was performed,and patients were followed for 12 months.We found a significant change in the response to repetitive nerve stimulation in amyotrophic lateral sclerosis patients without spontaneous electromyographic activity.Patients that were prone to denervation had an increased decrement response of target muscles after repetitive nerve stimulation.These results suggest that changes in response to repetitive nerve stimulation may occur before denervation in amyotrophic lateral sclerosis patients.The damage to lower motor neurons is more obvious in patients with a higher percentage of repetitive never stimulation-related amplitude decrements.This study was approved by the Institutional Ethics Committee of Peking University Third Hospital(approval No.M2017198) on August 24,2017.展开更多
To the Editor:Motor neuron disease(MND)is a kind of progressive,fatal neurodegenerative disease involving the upper and lower motor neurons and the pyramidal tract.Currently,the etiology of MND remains unknown,and the...To the Editor:Motor neuron disease(MND)is a kind of progressive,fatal neurodegenerative disease involving the upper and lower motor neurons and the pyramidal tract.Currently,the etiology of MND remains unknown,and there are limited treatment strategies.Paraneoplastic syndrome(PNS)is a rare form of MND-mimic syndrome.There have been reports of MND-like clinical symptoms in patients with different types of cancer,including breast cancer,lung cancer,and lymphoma.Epidemiological studies have drawn different conclusions,some have suggested that there is no relation between site-specific cancers and the risk of incident amyotrophic lateral sclerosis(ALS),while others have found that the overall risk of cancer of any site is significantly reduced in cases with ALS.[1]However,the prevalence of tumors in Chinese MND patients and the characteristics of patients with MND concomitant tumors are unclear.展开更多
To the Editor:A 39-year-old man presented with progressive limb atrophy and weakness.The patient had generalized muscular hypotonia at birth;he could not run well in elementary school.Neurologic examination revealed a...To the Editor:A 39-year-old man presented with progressive limb atrophy and weakness.The patient had generalized muscular hypotonia at birth;he could not run well in elementary school.Neurologic examination revealed atrophy of the facial muscles and limited left eye adduction.In the upper limbs,the patients showed proximal muscle atrophy and weakness[Figure 1A],while in the lower extremities,the weakness was more prominent distally than proximally.Neither spontaneous or percussion myotonia nor muscle hypertrophy was observed.展开更多
基金supported by the National Natural Science Foundation of China,Nos.81873784,82071426Clinical Cohort Construction Program of Peking University Third Hospital,No.BYSYDL2019002(all to DSF)。
文摘Previous studies have shown that ulnar nerve compound muscle action potential recorded by the conventional“belly-tendon”montage does not accurately and completely reflect the action potential of the ulnar nerve dominating the abductor digiti minimi muscle due to the effects of far-field potentials of intrinsic hand muscles.A new method of ulnar nerve compound muscle action potential measurement was developed in 2020,which adjusts the E2 electrode from the distal tendon of the abductor digitorum to the middle of the back of the proximal wrist.This new method may reduce the influence of the reference electrode and better reflect the actual ulnar nerve compound muscle action potential.In this prospective cross-sectional study,we included 64 patients with amyotrophic lateral sclerosis and 64 age-and sex-matched controls who underwent conventional and novel ulnar nerve compound muscle action potential measurement between April 2020 and May 2021 in Peking University Third Hospital.The compound muscle action potential waveforms recorded by the new montage were unimodal and more uniform than those recorded by traditional montage.In the controls,no significant difference in the compound muscle action potential waveforms was found between the traditional montage and new montage recordings.In amyotrophic lateral sclerosis patients presenting with abductor digiti minimi spontaneous activity and muscular atrophy,the amplitude of compound muscle action potential-pE2 was significantly lower than that of compound muscle action potential-dE2(P<0.01).Using the new method,damaged axons were more likely to exhibit more severe amplitude decreases than those measured with the traditional method,in particular for patients in early stage amyotrophic lateral sclerosis.In addition,the decline in compound muscle action potential amplitude measured by the new method was correlated with a decrease in Revised Amyotrophic Lateral Sclerosis Functional Rating Scale scores.These findings suggest that the new ulnar nerve compound muscle action potential measurement montage reduces the effects of the reference electrode through altering the E2 electrode position,and that this method is more suitable for monitoring disease progression than the traditional montage.This method may be useful as a biomarker for longitudinal follow-up and clinical trials in amyotrophic lateral sclerosis.
文摘The dying-back hypothesis holds that the damage to neuromuscular junctions and distal axons in amyotrophic lateral sclerosis occurs at the earliest stage of the disease.Previous basic studies have confirmed early damage to neuromuscular junctions,but it is difficult to obtain such evidence directly in clinical practice.In this prospective cross-sectional study,we recruited 22 patients with early amyotrophic lateral sclerosis with disease duration < 12 months and with clinical symptoms limited to the upper limbs.We also recruited 32 healthy controls.Repetitive nerve stimulation was performed,and patients were followed for 12 months.We found a significant change in the response to repetitive nerve stimulation in amyotrophic lateral sclerosis patients without spontaneous electromyographic activity.Patients that were prone to denervation had an increased decrement response of target muscles after repetitive nerve stimulation.These results suggest that changes in response to repetitive nerve stimulation may occur before denervation in amyotrophic lateral sclerosis patients.The damage to lower motor neurons is more obvious in patients with a higher percentage of repetitive never stimulation-related amplitude decrements.This study was approved by the Institutional Ethics Committee of Peking University Third Hospital(approval No.M2017198) on August 24,2017.
基金National Natural Sciences Foundation of China(No.81873784)。
文摘To the Editor:Motor neuron disease(MND)is a kind of progressive,fatal neurodegenerative disease involving the upper and lower motor neurons and the pyramidal tract.Currently,the etiology of MND remains unknown,and there are limited treatment strategies.Paraneoplastic syndrome(PNS)is a rare form of MND-mimic syndrome.There have been reports of MND-like clinical symptoms in patients with different types of cancer,including breast cancer,lung cancer,and lymphoma.Epidemiological studies have drawn different conclusions,some have suggested that there is no relation between site-specific cancers and the risk of incident amyotrophic lateral sclerosis(ALS),while others have found that the overall risk of cancer of any site is significantly reduced in cases with ALS.[1]However,the prevalence of tumors in Chinese MND patients and the characteristics of patients with MND concomitant tumors are unclear.
文摘To the Editor:A 39-year-old man presented with progressive limb atrophy and weakness.The patient had generalized muscular hypotonia at birth;he could not run well in elementary school.Neurologic examination revealed atrophy of the facial muscles and limited left eye adduction.In the upper limbs,the patients showed proximal muscle atrophy and weakness[Figure 1A],while in the lower extremities,the weakness was more prominent distally than proximally.Neither spontaneous or percussion myotonia nor muscle hypertrophy was observed.
