Background: Hypoxemia is thought to have negative effects on the peripheral nerve system in cases with COPD. This study was designed to investigate the relationship between PN and COPD stage, smoking, severity of chronic hypoxemia by evaluating the velocity and amplitude of conduction in the peripheral sensorial and motor nerves.
Methods: 30 cases with COPD having no other apparent pathology that might cause PN, were included in the study. After a clinical neurological assessment, the velocity and amplitude of conduction in the median sensorial and motor, ulnar sensorial and motor, sural sensorial and fibular motor nerves were measured by electromyography. The patients were divided into subgroups according to their forced expiratory volume, partial arterial oxygen pressure (PaO2) and smoking history characteristics.
Results: Significant differences were found among the CV of the fibular nerve when the patients were subdivided by their FEVj values. Negative correlations were established between sural sensorial nerve CV and duration of smoking, and also between median motor nerve and ulnar motor nerve CV and age. Fibular motor nerve CV and FEV| were positively correlated. Clinically, PN was encountered in 40% of the COPD patients. The most frequent electromyography findings were demyelination, and dysfunction of axonal and mixed types.
Conclusion: PN is a frequent problem in patients with COPD, mostly affecting the sural sensorial, ulnar sensorial and fibular motor nerves. Sensorial nerves (40%) are more frequently involved than the motor nerves (6.6%). The electrophysiological findings in COPD appear to be related to age, smoking history, respiratory functions and hypoxemia level.