title: 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.
  
  
  CONCLUSIONS
  The precise normal ranges of phrenic nerve conduction parameters presented will encourage investigations of neuropathies in subjects aged above 60.
authors.affiliation: Department of Neurology, Sapporo Medical University School of Medicine, Chuo-ku, Japan. toimai@sapmed.ac.jp
authors.forename: Tomihiro
authors.initials: T
authors.lastname: Imai
authors.forename: Hiroo
authors.initials: H
authors.lastname: Yuasa
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kato
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Matsumoto
mesh_terms: D000200:Action Potentials; D000328:Adult; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D003964:Diaphragm / Q000502:physiology; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology*; D010791:Phrenic Nerve / Q000502:physiology*; D011930:Reaction Time; D012016:Reference Values; D012727:Sex Characteristics