A magnetic evaluation of peripheral nerve regeneration: I. The discrepancy between magnetic and histologic data from the proximal segment.
Histologic techniques can quantify the number of axons in a nerve, but give no information about electrical conductibility. The number of functional myelinated neuronal units in a nerve can be quantified based on a magnetic recording technique. When studying reconstructed peripheral nerves a significant difference between the results found with these two techniques can be observed. A comparison was made between the long-term changes in the number of histologically and magnetoneurophysiologically measured neuronal units proximal to a nerve reconstruction. This study was performed on 6 New Zealand White rabbits, 20 weeks after the peroneal nerve had been reconstructed. The contralateral nerves were used as a control. Histologic examination demonstrates a statistically significant decrease of approximately 5% in the number of myelinated fibers. The magnetoneurophysiological results demonstrate a decrease which is estimated to be caused by the loss of approximately 50% of the functional myelinated neuronal units in the nerve. Therefore we conclude that of the initially available myelinated neuronal units, 5% degenerate completely, 45% are vital but lose their signal conducting capability, and the remaining 50% are vital and continue to conduct signals. Apparently, only this latter group of 50% of the initially available functional neuronal units appears to remain available for functional recovery.
Kuypers
P D
PD
Department of Plastic and Reconstructive Surgery, Erasmus University Rotterdam, Faculty of Medicine, The Netherlands.
van Egeraat
J M
JM
Dudok v Heel
M
M
van Briemen
L J
LJ
Godschalk
M
M
Hovius
S E
SE
D000818:Animals; D004594:Electrophysiology; D009413:Nerve Fibers, Myelinated / Q000502:physiology; D009416:Nerve Regeneration; D009431:Neural Conduction; D010525:Peripheral Nerves / Q000033:anatomy & histology* / Q000502:physiology*; D010543:Peroneal Nerve / Q000033:anatomy & histology / Q000502:physiology / Q000601:surgery; D011817:Rabbits