Phrenic nerve conduction in man.

phrenic nerve conduction velocity in human specimens obtained at operation or from cadavers, quoting a figure of 78 m./sec. No further studies in man appear to have been made since that time; in particular no information is available on phrenic nerve conduction in vivo. Impairment of phrenic nerve conduction is usually inferred from reduced or paradoxical diaphragmatic movement seen on x-ray screening but interpretation is not always easy, especially when both halves of the diaphragm are involved. The present work arose from just such a diagnostic difficulty, when it became apparent that a more direct assessment of phrenic nerve function was needed. Previous attempts to record the electrical activity