Phrenic nerve conduction study in demyelinating neuropathies and open-heart surgery.

Objectives: The aim of this study was to determine normal values of phrenic nerve conduction (PNC) in healthy individuals; to evaluate the subclinical extent of phrenic nerve involvement in Guillain-Barré syndrome (G-B) and hereditary motor and sensory neuropathy-I (HMSN-I), and to evaluate phrenic nerve damage after cardiac surgery.

Materials And Methods: PNC was performed by transcutaneous stimulation in the neck and recording the diaphragmatic potential from surface electrodes placed at the seventh and eight intercostal spaces. PNC was performed bilaterally in 25 healthy volunteers and 25 patients before and after open-heart surgery.