Numerous mechanisms contribute to peripheral nerve injuries such as chemical intoxication, compression, stretching and avulsion, which usually result in severe damage to the sensory and motor functions. The current approaches for evaluating nerve regeneration include expression analysis of molecular markers, histological analysis, behavior testing and electrophysiological studies. The aim of this study is to compare the diagnostic efficacy using the recently developed magnetic stimulation approach with that of conventional electrical stimulation method in different models of peripheral neuropathy and to compare in terms of latency and amplitude of the evoked response by electrical and magnetic stimulation.
Adult male Sprague Dawley rats (250-300 g, n = 24) were divided into three groups: (1) control group, (2) sciatic nerve ligation group and (3) acrylamide intoxication group. The electrophysiological studies were carried out 3 days before ligation and every 7 days after ligation for 4 weeks. The measurements included amplitude and onset latency of maximal compound nerve action potential (CMAP) in branches of sciatic nerve (nerves to the gastrocnemius, tibialis anterior), motor nerve conduction velocity, H-reflex, F-wave, amplitude and onset latency of motor evoked potential by lumbosacral motor root magnetic stimulation, and denervation by electromyography (gastrocnemius, tibialis anterior).
The results from studies using magnetic and electrical stimulation showed prominent reduction of CMAP amplitude in rats of sciatic nerve ligation and acrylamide intoxication group. The CMAP amplitude measured by magnetic stimulation was 76~85% of that by electrical stimulation. By either magnetic stimulation or electrical stimulation, there was no significant difference in the mean onset latency of CMAP between control and neuropathy groups. Volume conduction accounts for the interference of waveform and error is inevitable. Because of the short distance of hind limb of the rat, the nerve conduction velocity (NCV), H-reflex and F-wave could not be determined using magnetic stimulation. In contrast, electrophysiological analysis by electrical stimulation revealed slowed NCV, prolonged or absent H-reflex and F-wave in animals of neuropathy groups. Electromyography showed prominent denervation potentials over the sampling muscles in both models.
In conclusion, magnetic stimulation of lumbosacral motor root is non-invasive and convenient. However, further improvement and establishment of basic parameters are required to facilitate a reliable tool in evaluation of peripheral nerve injury.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0615106-230734 |
| Date | 15 June 2006 |
| Creators | Hwang, Chiao-wen |
| Contributors | Ming-hong Tai, Jau-cheng, Liou, Zhi-hong, Wen |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0615106-230734 |
| Rights | unrestricted, Copyright information available at source archive |
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