[Phrenic nerve conduction in amyotrophic lateral sclerosis patients].
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.
Zhuang
Li
L
Department of Neurology, Beijing Hospital, The fifth Hospital, Peking University, Beijing 100730, China.
Tang
Xiaofu
X
Xu
Xianhao
X
Li
Benhong
B
Du
Hua
H
Jiang
Jingwen
J
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*