Aging of phrenic nerve conduction in the elderly

Abstract

Objective: We elucidated the possible relationship between age and conduction parameters of phrenic nerve in subjects above the sixth decade, comparing with the data from middle-age controls.

Methods: Diaphragmatic action potentials (DAPs) were recorded on bilateral hemithoraces of 41 volunteers aged 60-101 years (old group) and 25 volunteers aged 35-55 years (middle-age group). Statistical analyses were performed to assess the effects of aging on latency, latency corrected by size (Lat/Dist), amplitude, and the right-left difference of these DAP parameters.

Results: In all 61 subjects, age showed a significant quadratic correlation with latency and with Lat/Dist, and a linear correlation with amplitude. The right-left differences ranged from 0.0 to 14.5% for latency and from 6.5 to 112.4% for amplitude in the elderly.

Conclusions: The normal ranges of DAP parameters should be determined according to age. The left-right difference may be a useful reference in diagnosing unilateral phrenic nerve lesion.

Significance: The precise normal ranges of phrenic nerve conduction parameters presented will encourage investigations of neuropathies in subjects aged above 60.