Microwave irradiation of peripheral nerve following injury: a structural analysis of degeneration and regeneration.
Studies of the enhancement effect of pulsed energy irradiation on nerve regeneration following injury have produced variable results. The effect of microwave treatment on the rat peroneal nerve after transection and anastomosis was analyzed by light and electron microscopy. The hindquarters were irradiated 1 h/day during the first 10 days postoperative (dpo). The nerves were fixed in situ and prepared for microscopic analysis. At 10 dpo the distal segment of the degenerating nerve had several enlarged myelin sheath profiles devoid of axoplasm. The swelling was not significantly altered by microwave treatment, but the number and density of the empty myelin sheath profiles were three to four times greater in the treatment group. At 49 dpo the regenerating nerve segment had a 43% decrease in the nerve fiber diameter compared with a normal mean of 7 microns. The number and density of remyelinated fibers showed a 50% increase in both treatment and control groups. Histologic evidence indicated no permanent enhancement on nerve regeneration by microwave treatment, even though the treatment may have delayed Wallerian degeneration.
J M
JM
Kerns
H P
HP
Weinrib
D000818:Animals; D008297:Male; D008854:Microscopy, Electron; D008872:Microwaves / Q000627:therapeutic use*; D009410:Nerve Degeneration; D009413:Nerve Fibers, Myelinated / Q000473:pathology / Q000648:ultrastructure; D009416:Nerve Regeneration; D010543:Peroneal Nerve / Q000293:injuries* / Q000473:pathology / Q000648:ultrastructure; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D014855:Wallerian Degeneration