Objective: To investigate the features and application of phrenic radix conduction time (PRCT) in inflammatory demyelinating polyneuropathy (IDP) patients.
Methods: Distal motor latency (DML) was recorded by stimulating phrenic nerve electrically and phrenic nerve root magnetically in 20 IDP patients with surface electrodes at intercostal space. The difference of the two DML was calculated and compared with those recorded previously from 61 sides in 31 healthy control subjects.
Results: PRCT of the IDP patients was longer than that of the controls, and it correlated with the severity of clinical dyspnea. The abnormal rate of PRCT was higher than the incidence of clinical dyspnea.
Conclusions: PRCT could reflect the functional status of the spinal roots related to respiration in IDP patients at an electrophysiological level. It correlates well with the degree of clinical dyspnea. Its detection is helpful to find out the subclinical dyspnea in IDP patients.