MethodTwenty-three subjects with chronic low back pain were allocated randomly to repetitive magnetic stimulation group (n=13) and transcutaneous electrical nerve stimulation group (n=10). Each treatment consisted of 10-minutes sessions each day, totally 10 sessions over 2 weeks. Subjects were evaluated pre-treatment and post-treatment at 8 hours and 2 weeks. Outcome was measured with the Oswestry disability index, McGill pain questionnaire, and daily mean pain numeric rating scale.

ResultsAt 8 hours and 2 weeks post-treatment, transcutaneous electrical nerve stimulation therapy group showed a significant improvement in the mean pain numeric rating scale. Two weeks post-treatment, transcutaneous electrical nerve stimulation therapy group showed a significant improvement in the Oswestry disability index. But there were no significant therapeutic effect of repetitive magnetic stimulation therapy group at all period.

ConclusionThis study showed that repetitive magnetic stimulation therapy may be less effective than transcutaneous electrical nerve stimulation therapy for the treatment of chronic low back pain.

Objective: This study was conducted to assess the effect of intramuscular electrical stimulation (IMES) and compared it with that of transcutaneous electrical nerve stimulation (TENS) and dry needling in the patients with myofascial pain syndrome (MPS).

Method: Forty five patients with MPS was assigned randomly to TENS group (n=15), dry needling group (n=15) and IMES group (n=15). In TENS group, TENS was applied to the trigger point. In dry needling group, dry needling was applied to the trigger point. In IMES group, IMES was applied to the trigger point. Duration of treatment was 2 weeks. Effects were assessed before treatment, 1 day, 3 days, 7 days and 14 days after treatment by visual analogue scale (VAS) and McGill pain questionnaire (MPQ). Thermography was performed before treatment, 7 days and 14 days after treatment.

Results: Significant change of VAS improvement ratio was noticed in IMES group from the 1 day after treatment compared with other groups. Significant change of MPQ improvement ratio was noticed in IMES group from the 3 days after treatment compared with other groups. The skin temperature difference was significantly improved in IMES group at 14 days after treatment.

Conclusion: These results showed that IMES is effective treatment method for pain control in patients with MPS. (J Korean Acad Rehab Med 2002; 26: 562-566)

Objective: The present study was conducted to investigate the effects of transcutaneous electrical nerve stimulation (TENS) and microcurrent electrical neuromuscular stimulation (MENS) on pain-like behaviors developed in rats with an experimental neuropathy.

Method: Neuropathic surgery was done by a unilateral ligation of L5 and L6 spinal nerves of the rat. Allodynic behavior was examined by measuring foot withdrawal frequency in response to 10 applications of a von Frey filament (2.5 g) to the plantar surface of the foot. Ongoing pain behavior was examined by measuring cumulative time in 3 min that the rat lifted its foot off a plate held at cold temperature (5^oC). TENS (square pulses; 3 Hz, 30 mA) or MENS (bipolar pulses; 10 Hz, 300 μA) was applied for 15 min or 5 min, respectively, to the skin of the affected foot.

Results: Behavioral signs of mechanical allodynia and cold-induced ongoing pain had developed after nerve injury. Either TENS or MENS, when applied once, alleviated allodynic behavior, lasting up to 2 hrs. Such an alleviation lasted much longer when TENS or MENS was applied repeatedly (once a day for 6 days); 3 days by TENS and 1 day by MENS. Cold-induced ongoing pain behavior, however, was not affected by the repeated application of either TENS or MENS.

Conclusion: The results suggest that both TENS and MENS are useful tools for the treatment of mechanical allodynia. Repeated application of TENS or MENS is more effective in alleviating mechanical allodynia than its single application. Either TENS or MENS, however, seems not effective in alleviating cold-induced ongoing pain.

Spasticity is common stroke in patients, and its management has been considered as one of the major problems in stroke rehabilitation. The goal of this study was to determine if transcutaneous electrical nerve stimulation(TENS) and acupuncture would reduce the muscle spasticity. To estimate the efficacy of electrical stimulation for the treatment of spasticity TENS(100 Hz, asymmetric bipolar pulse current) was applied to the skin over the extensor muscles of spastic limbs for 20 minutes, once a day in six stroke patients. In addition, acupuncture was also applied to the acupoints of extensor muscles of all extremities and face for 20 minutes twice a day to determine the efficacy of acupuncture for the treatment of spasticity in six stroke patients. As controls subjects, six stroke patients were examined without TENS or acupuncture treatment. In experimental groups, the efficacy of treatment was measured 1, 5, 10, 15 days and 20 days after treatment with either TENS or acupuncture using the spasticity measurement methods (modified Ashworth scale, ankle clonus score, and H/M ratio). Based on the results from the present study, we have concluded that the H/M ratios of affected spastic limbs were significantly higher than those of unaffected limbs (p＜0.05). TENS and acupuncture therapies lessened the spasticity of affected limbs of stroke patients when measured with the modified Ashworth scale however not with the H/M ratios nor with the ankle clonus scores.

Due to lack of evidences on the central and peripheral mechanisms of electrical stimulation in vivo, the purpose of this study was to investigate the influence of afferent stimuli, transcutaneous electrical nerve stimulation and microcurrent, on the electrodiagnostic study of normal subjects.

Electrodiagnostic study was performed before and after the application of afferent stimulion of the right popliteal fossa on 30 healthy female volunteers. After the transcutaneous electrical nerve stimulation, latencies of SEP, H-reflex, and F-wave, and H-amplitude changed significantly(p＜0.01). After the microcurrent stimulation, latencies of SEP, H-reflex, and F-wave, and motor nerve conduction velocity changed significantly(p＜0.01).

The results of this study prove that transcutaneous electrical nerve stimulation and microcurrent may cause changes of the anterior horn excitability and the conduction of the nervous system in vivo. Microcurrent may have a different mechanism of action compared to transcutaneous electrical nerve stimulation by having more localized inhibitory effects on the peripheral nerve. However, further investigation is needed to assess their mechanisms of action and the precise relevance of stimulation parameters.

Objective: To investigate the influence of high frequency transcutaneous electrical nerve stimulation (TENS) on cutaneous silent period.

Method: Cutaenous silent period was recorded before and after high frequency TENS application in sixteen healthy adults (11 males, 5 females). Onset latency, duration, and minimum stimulation intensity to evoke cutaneous silent period were compared. In 7 male subjects, temporal changes of cutaneous silent period were observed after TENS application.

Results: Minimum stimulation intensity to evoke cutaneous silent period was significantly increased after high frequency TENS application (p＜0.05) and yet, onset latency and duration showed no significant change. The increase in minimum stimulation intensity to evoke cutaneous silent period was maintained for 30 minutes after TENS and returned to the baseline level thereafter.

Conclusions: These results suggest that high frequency TENS increase the depolarization threshold of A-δ fiber and this peripheral effect may be one of the pain control mechanisms of TENS.