title: [Phrenic nerve conduction in amyotrophic lateral sclerosis patients].
abstract: OBJECTIVE
  To investigate the features and application of phrenic nerve conduction in amyotrophic lateral scle-rosis (ALS) patients.
  
  
  METHODS
  The latency and amplitude of diaphragmatic compound muscle action potential (DCMAP) were recorded among 44 ALS patients and 31 control subjects with surface electrodes after the cervical part of phrenic nerve was stimulated with electricity. The percentage of forced vital capacity (%FVC) was examined in 28 ALS patients simultaneously.
  
  
  RESULTS
  Right and left phrenic distal motor latencies (PDML) of ALS patients were 8.4 ms +/- 2.2 ms and 7.6 ms +/- 1.4 ms respectively, longer than those of the controls, and the logarithmic value of amplitudes among ALS patients was 2.68 +/- 0.37, lower than that among the controls. Take the right side for example, although PDML was correlated with %FVC, it had no correlation with clinical respiratory dysfunction. Neither %FVC nor clinical respiratory dysfunction was correlated with the amplitude of DCMAP. The rate of abnormal PDML (47.7%) was higher than the rate of clinical dyspnea (25%).
  
  
  CONCLUSIONS
  PDML is a sensitive index in phrenic conduction parameter reflecting respiratory dysfunction in ALS. Only when the PDML is combined with the central motor conduction time of the diaphragmatic motor evoked potential the nervous system basis of the respiratory disturbance in ALS can be revealed.
authors.affiliation: Department of Neurology, Beijing Hospital, The fifth Hospital, Peking University, Beijing 100730, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhuang
authors.forename: Xiaofu
authors.initials: X
authors.lastname: Tang
authors.forename: Xianhao
authors.initials: X
authors.lastname: Xu
authors.forename: Benhong
authors.initials: B
authors.lastname: Li
authors.forename: Hua
authors.initials: H
authors.lastname: Du
authors.forename: Jingwen
authors.initials: J
authors.lastname: Jiang
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000175:diagnosis / Q000503:physiopathology*; D004417:Dyspnea / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology*; D010791:Phrenic Nerve / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D014797:Vital Capacity / Q000502:physiology*