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Nerve compound action current (NCAC) measurements and morphometric analysis in the proximal segment after nerve transection and repair in a rabbit model
Author(s) -
Walbeehm Erik T.,
Michiel Dudok van Heel E. B.,
Kuypers Paul D. L.,
Terenghi Giorgio,
Hovius Steven E. R.
Publication year - 2003
Publication title -
journal of the peripheral nervous system
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1
H-Index - 67
eISSN - 1529-8027
pISSN - 1085-9489
DOI - 10.1046/j.1529-8027.2003.03014.x
Subject(s) - axon , anatomy , amplitude , nerve conduction velocity , electrophysiology , compound muscle action potential , action potential , lesion , chemistry , medicine , physics , surgery , quantum mechanics
In the evaluation of nerve regeneration using magneto‐neurography (MNG), the proximal segment showed a reproducible decrease in peak–peak amplitude of the nerve compound action current's (NCAC) of 60%. To explain these changes, morphometry of myelinated axons in the proximal segment is compared to the MNG signals. A standardised nerve transection and reconstruction was performed in rabbits. NCACs were measured approximately 5 cm proximal to the lesion from operated and control nerves after 12 weeks. Histological samples were taken from the same area of the nerve where the NCACs were obtained. Results showed a decrease of the peak–peak amplitude of the NCAC of 57% compared to the control. Conduction velocity decreased 15%(not significant). Morphometry elicited a decrease in larger (10–15 μm) axons (284 ± 134 vs 82 ± 55) and an increase in smaller (2–5 μm) axons (1445 ± 360 vs 1921 ± 393). A strong correlation existed between the decrease in amplitude and the decrease in larger axons (0.85). Peak–peak amplitude varies approximately with the square of the diameter axon. Therefore, because peak–peak amplitude is mainly dependent on the larger‐diameter axons, the decrease in peak–peak amplitude of the NCACs may be explained by a decrease in numbers of 10–15‐μm axons.