Effects of electrical stimulation at different frequencies on regeneration of transected peripheral nerve.
BACKGROUND
Electrical stimulation of damaged peripheral nerve may aid regeneration.


OBJECTIVE
The purpose of this study was to determine whether 1 mA of percutaneous electrical stimulation at 1, 2, 20, or 200 Hz augments regeneration between the proximal and distal nerve stumps.


METHODS
A10-mm gap was made in rat sciatic nerve by suturing the stumps into silicone rubber tubes. A control group received no stimulation. Starting 1 week after transection, electrical stimulation was applied between the cathode placed at the distal stump and the anode at the proximal stump every other day for 6 weeks.


RESULTS
Higher frequency stimulation led to less regeneration compared to lower frequencies. Quantitative histology of the successfully regenerated nerves revealed that the groups receiving electrical treatment, especially at 2 Hz, had a more mature structure with a smaller cross-sectional area, more myelinated fibers, higher axon density, and higher ratio of blood vessel to total nerve area compared with the controls. Electrophysiology showed significantly shorter latency, longer duration, and faster conduction velocity.


CONCLUSIONS
Electrical stimulation can have either a positive or negative impact on peripheral nerve regeneration. Clinical trials that combine stimulation with rehabilitation must determine the parameters that are most likely to be safe and effective.
Lu
Ming-Chin
MC
School of Post Baccalaureate Chinese Medicine, China Medical University, Taichung, Taiwan.
Ho
Chien-Yi
CY
Hsu
Sheng-Feng
SF
Lee
Han-Chung
HC
Lin
Jia-Horng
JH
Yao
Chun-Hsu
CH
Chen
Yueh-Sheng
YS
D000818:Animals; D001369:Axons / Q000502:physiology / Q000648:ultrastructure; D001808:Blood Vessels / Q000166:cytology / Q000502:physiology; D015194:Diffusion Chambers, Culture; D004558:Electric Stimulation / Q000009:adverse effects / Q000379:methods*; D018482:Muscle, Skeletal / Q000294:innervation / Q000503:physiopathology; D018919:Neovascularization, Physiologic / Q000502:physiology; D009413:Nerve Fibers, Myelinated / Q000502:physiology / Q000648:ultrastructure; D009416:Nerve Regeneration / Q000502:physiology*; D019736:Prostheses and Implants; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function / Q000502:physiology; D012584:Sciatic Nerve / Q000098:blood supply / Q000293:injuries* / Q000502:physiology*; D020426:Sciatic Neuropathy / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D012828:Silicones / Q000627:therapeutic use; D016896:Treatment Outcome
D012828:Silicones