Age-related change in peripheral nerve conduction: compound muscle action potential duration and dispersion.
BACKGROUND
We investigated the effect of age on nerve conduction parameters with special reference to the compound muscle action potential (CMAP) duration and duration ratio.


METHODS
We examined 295 subjects (aged 15-85 years old) with no previous history or present signs of peripheral neuropathy. The subjects were divided into 3 groups: young (15-34 years old); intermediate (35-64 years old), and old (65-85 years old).


RESULTS
CMAP amplitude was lower in the old group than in the young group; however, the CMAP ratio (proximal CMAP/distal CMAP) did not change with age. The CMAP duration and duration ratio did not differ among the 3 groups. The CMAP area was smaller in the old group, but the area ratio was almost constant among the 3 groups.


CONCLUSIONS
We suggest that age-related changes in CMAP amplitude, duration or area may occur uniformly, at least in the forearm and the calf segment, in routine nerve conduction studies. The present findings also provide useful and reliable information, regardless of age, in diagnosing peripheral neuropathy.
Kurokawa
K
K
Third Department of Internal Medicine, Hiroshima University School of Medicine, Hiroshima, Japan.
Mimori
Y
Y
Tanaka
E
E
Kohriyama
T
T
Nakamura
S
S
D000200:Action Potentials / Q000502:physiology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000502:physiology; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology*; D009431:Neural Conduction / Q000502:physiology*; D013979:Tibial Nerve / Q000502:physiology; D014459:Ulnar Nerve / Q000502:physiology