The polyneuropathy in patients with chronic obstructive pulmonary disease(COPD) were described several years ago, but are not widely recognized neither well documented. To investigate such polyneuropathy, 41 patients(37 males, 4 females) were included in a prospective study. The incidence, type and distribution of polyneuropathy in the patients with COPD were assessed and also analyzed the causative factor of these results.

The resalts were as follows:

1) In a selected group of 41 patients, electrophysiological signs of polyneuropathy were found in 16 patients depending on diagnostic criteria, and when these divided subgroup, as "definite" group 6 patients, "probable" group 5 patients and "possible" group 5 patients.

2) The patients which were found subclinical polyneuropathy(9 patients, 22%) were more than these that were found clinical polyneuropathy(7 patients, 17%)

3) In the patients with polyneuropathy, lesions were predominant axonal degeneration in motor nerve, and combined with demyelination and axonal degeneration in sensory nerve.

4) In the patients with polyneuropathy, the changes were more involved in leg than arm, more frequently affected sensory fibers, and not only more affected common peroneal nerve in motor nerve conduction study, also sural and ulnar nerve in sensory conduction study.

5) There was a significant correlation between FEV1 and the incidence of polyneuropathy, and then lesions which were thought to be due to hypoxia.