Is phrenic nerve conduction affected in patients with difficult-to-treat asthma?

Abstract

Objective The aim of this study was to obtain data on phrenic neuroconduction and electromyography of the diaphragm muscle in difficult-to-treat asthmatic patients and compare the results to those obtained in controls. Methods The study consisted of 20 difficult-to-treat asthmatic patients compared with 27 controls. Spirometry, maximal inspiratory and expiratory pressure, chest X-ray, phrenic neuroconduction and diaphragm electromyography data were obtained. Results The phrenic compound motor action potential area was reduced, compared with controls, and all the patients had normal diaphragm electromyography. Conclusion It is possible that a reduced phrenic compound motor action potential area, without electromyography abnormalities, could be related to diaphragm muscle fiber abnormalities due to overload activity.

Diaphragm quantitative electromyography: upgrading an important tool in the search for diaphragmatic myopathy in asthmatic patients

“…T he study of phrenic nerve conduction and needle electromyography (EMG) of the diaphragm can be useful in evaluation of patients with respiratory failure 1,2 . Although other methods have been included in the diaphragm evaluation in recent years (e.g.…”