***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Chronic pain is a common consequence of spinal cord injury ( SCI ) . No therapeutic drugs or drug groups are proven to be superior for neuropathic pain and treatments only aim to convert pain from dull to tolerable levels and not to remove it . OBJECTIVE This study was planned to compare the effect of visual illusion ( VI ) and transcutaneous electrical nerve stimulation ( TENS ) on pain intensity , pain quality and functional capacity in SCI patients with neuropathic pain . METHODS Twenty-four patients were included and r and omly categorized into two groups . In the first group ( n= 12 ) , visual illusion was applied for first two weeks , 1 week wash out period and then TENS was applied for 2 weeks . In second group ( n= 12 ) , TENS was applied firstly , 1 week wash out and then % visual illusion VI were applied . Pain severity , pain quality , and functional capacity were assessed with the visual analog scale ( VAS ) , the neuropathic pain scale ( NPS ) , and the brief pain inventory ( BPI ) , respectively . A pre-post-treatment and cross over design was used . RESULTS Wilcoxon signed-rank tests were used for within group analyses . Mann-Whitney U tests were used for analyses that compared different groups . It was observed that pain intensity decrease immediately after both applications ( VI : p= 0.07 , TENS : p= 0.08 ) . After TENS application for 2 weeks , it was observed that significant decrease in most ( p= 0.04 ) and less ( p= 0.02 ) pain intensity ; while there was no significant decrease in pain intensity after 2 weeks for VI ( p > 0.05 ) . When findings of NPS were analyzed , hot ( p= 0.047 ) , sharp ( p= 0.02 ) , unpleasant ( p= 0.03 ) and deep items ( p= 0.047 ) decreased after VI application . When the results of BPI were detected , they were observed that the negative effect of pain on moving ability ( p= 0.04 ) after visual illusion application and the negative effect of pain on mood ( p= 0.03 ) , relationships with others ( p= 0.04 ) and sleep ( p= 0.04 ) after TENS application decreased significantly . CONCLUSION TENS and VI therapies can be successfully used in clinical practice as an alternative treatment or as a supportive method separetely or together Sciatica is a common pain problem and current pharmacologic therapies have proven inadequate for many patients . The objective of this sham-controlled investigation was to compare a novel non-pharmacologic technique , percutaneous electrical nerve stimulation ( PENS ) , to transcutaneous electrical nerve stimulation ( TENS ) in the management of the radicular pain associated with sciatica . Sixty-four consenting patients with sciatica due to lumbar disc herniation were treated with PENS , TENS and sham-PENS according to a r and omized , single-blinded , cross-over study . All patients had been maintained on a stable oral non-opioid analgesic regimen for at least 6 weeks prior to entering the study . Each treatment modality was administered for a period of 30 min three times per week for 3 weeks , with 1 week ' off ' between each modality . Both PENS and TENS treatments were administered using a stimulation frequency of 4 Hz . The pre-treatment assessment included the health status survey short form ( SF-36 ) , as well as visual analog scales ( VAS ) for radicular pain , physical activity and quality of sleep . The pain VAS was also repeated after each treatment session . At the end of each 3-week treatment block , the SF-36 was repeated . After receiving all three treatment modalities , a global assessment question naire was completed . Both PENS ( 42 % ) and TENS ( 23 % ) were significantly more effective than the sham ( 8 % ) treatments in decreasing VAS pain scores . The daily oral analgesic requirements were also significantly reduced compared to the pre-treatment values with PENS ( P<0.01 ) and TENS ( P<0.05 ) . However , PENS was significantly more effective than TENS ( and sham-PENS ) in improving physical activity and quality of sleep . The SF-36 evaluation confirmed the superiority of PENS ( versus TENS and sham-PENS ) with respect to post-treatment functionality . In the overall assessment , 73 % of the patients reported that PENS was the most desirable modality ( versus 21 % for TENS and 6 % for sham-PENS ) . Finally , 71 % of the patients stated that they would be willing to pay extra to receive PENS therapy compared to 22 % and 3 % for TENS and sham-PENS , respectively . In this sham-controlled study , we concluded that PENS was more effective than TENS when administered at a stimulation frequency of 4 Hz in providing short-term pain relief and improved functionality in patients with sciatica AIM The aim of the study was to compare LASER versus transcutaneous electrical nerve stimulation ( TENS ) in reducing pain and paraesthesia ; and in improving motor and sensory median nerve conduction parameters in mild to moderate carpal tunnel syndrome ( CTS ) . DESIGN R and omised blinded pilot study . Patients and staff administered treatments and outcome measures were blinded . SETTING Outpatient ; Research and Care Rehabilitation Institute . PARTICIPANTS Twenty CTS symptomatic patients . INTERVENTIONS Fifteen sessions of : 1 ) 100 Hz TENS ( 30 minutes ; rectangular waves ; 80 ms width , intensity below muscle contraction ) ; 2 ) combined 830 - 1064 nm LASER ( radiating dose : 250 J cm-2 delivered to the skin overlying the course of the median nerve at the wrist for 100 s at 25 W ( 18 W [ 1064 nm ] + 7 W [ 830 nm ] ) via a fiber-optic probe with a spot size of ~1 cm2 ) . Outcome measures . Visual analogue scale ( VAS ) for pain and paresthesia ; median nerve distal motor latency and sensory nerve conduction velocity . RESULTS LASER improved both positive and negative sensory symptoms .  TENS induced clinical improvement but this was not statistically significant and was limited to pain reduction . LASER but not TENS favourably modified the neurophysiological parameters . CONCLUSION High-intensity combined LASER wavelengths of 830 nm and 1064 nm , which produce a better transparency with less scattering and a high energy transfer , are better than TENS in improving both pain and paraesthesia as well as neurophysiological parameters in CTS UNLABELLED Transcutaneous electrical nerve stimulation ( TENS ) is an electrophysical modality used for pain management . This study investigated the dose response of different TENS intensities on  experimentally induced pressure pain . One hundred and thirty TENS naïve healthy individuals ( 18 - 64 years old ; 65 males , 65 females ) were r and omly allocated to 5 groups ( n = 26 per group ) :  Strong Non Painful TENS ; Sensory Threshold TENS ; Below Sensory Threshold TENS ; No Current Placebo TENS ; and Transient Placebo TENS . Active TENS ( 80 Hz ) was applied to the forearm for 30 minutes . Transient Placebo TENS was applied for 42 seconds after which the current amplitude automatically reset to 0 mA. Pressure pain thresholds ( PPT ) were recorded from 2 points on the h and and forearm before and after TENS to measure hypoalgesia . There were significant differences between groups at both the h and and forearm ( ANOVA ; P = .005 and .002 ) . At 30 minutes , there was a significant hypoalgesic effect in the Strong Non Painful TENS group compared to : Below Sensory Threshold TENS , No Current Placebo TENS and Transient Placebo TENS groups ( P < .0001 ) at the forearm ; Transient Placebo TENS and No Current Placebo TENS groups at the h and ( P = .001 ) . There was no significant difference between Strong Non Painful TENS and Sensory Threshold TENS groups . The area under the curve for the changes in PPT significantly correlated with the current amplitude ( r(2 ) = .33 , P = .003 ) . These data therefore show that there is a dose-response effect of TENS with the largest effect occurring with the highest current amplitudes . PERSPECTIVE This study shows a dose response for the intensity of TENS for pain relief with the strongest intensities showing the greatest effect ; thus , we suggest that TENS intensity should be titrated to achieve the strongest possible intensity to achieve maximum pain relief [ Purpose ] To investigate the effects of transcutaneous electrical nerve stimulation ( TENS ) on pain in patients with spinal cord injury . [ Subjects and Methods ] Fifty-two spinal cord injury patients with central pain were r and omly allocated into two groups TENS and control with 26 subjects per group . The patients in TENS and control groups were treated with TENS and sham TENS for 20 min ( three times a week ) for 12 consecutive weeks , respectively . The two group ’s pain was assessed using visual analog scale ( VAS ) and the McGill Pain Question naire ( including pain rating index-total , pain rating index-affective , pain rating index-sensory , present pain intensity , and number of words chosen ) before and after the treatment . [ Results ] After the intervention , we found significant differences in VAS , pain rating index-total , pain rating index-affective , pain rating index-sensory , present pain intensity , and number of words chosen between the TENS group and the control group . [ Conclusion ] Our results suggest that TENS effectively decreases pain in patients with spinal cord injury Summary Pain and fatigue during movement , but not at rest , are reduced by a onetime 30‐m treatment with active transcutaneous electrical nerve stimulation ( TENS ) in individuals with fibromyalgia . Abstract Because transcutaneous electrical nerve stimulation ( TENS ) works by reducing central excitability and activating central inhibition pathways , we tested the hypothesis that TENS would reduce pain and fatigue and improve function and hyperalgesia in people with fibromyalgia who have enhanced central excitability and reduced inhibition . The current study used a double‐blinded r and omized , placebo‐controlled cross‐over design to test the effects of a single treatment of TENS with people with fibromyalgia . Three treatments were assessed in r and om order : active TENS , placebo TENS and no TENS . The following measures were assessed before and after each TENS treatment : pain and fatigue at rest and in movement ; pressure pain thresholds , 6‐m walk test , range of motion ; 5‐time sit‐to‐st and test , and single‐leg stance . Conditioned pain modulation was completed at the end of testing . There was a significant decrease in pain and fatigue with movement for active TENS compared to placebo and no TENS . Pressure pain thresholds increased at the site of TENS ( spine ) and outside the site of TENS ( leg ) when compared to placebo TENS or no TENS . During active TENS  , conditioned pain modulation was significantly stronger compared to placebo TENS and no TENS . No changes in functional tasks were observed with TENS . Thus , the current study suggests TENS has short‐term efficacy in relieving symptoms of fibromyalgia while the stimulator is active . Future clinical trials should examine the effects of repeated daily delivery of TENS , similar to the way in which TENS is used clinical ly on pain , fatigue , function , and quality of life in individuals with fibromyalgia Background : Painful diabetic peripheral neuropathy ( DPN ) is a long-term complication of type 1 and type 2 diabetes that majorly impacts quality of life . Its prevalence increases with age and duration of diabetes . It is more common in patients who have suboptimal glycemic control over several years . Because DPN may be resistant to conventional treatments , it is common for patients to only have partial pain relief . Therefore , new therapeutic options are needed for the condition . Objectives : The aim of the present study was to compare the efficacy of transcutaneous electrical nerve stimulation ( TENS ) and pulsed radiofrequency ( PRF ) lumbar sympathectomy in treating painful DPN . Patients and Methods : Sixty-five patients with painful DPN refractory to conventional treatment were r and omly and evenly assigned to either the TENS or PRF lumbar sympathectomy groups . Pain evaluations were based on the 10-point numerical rating scale ( NRS ) . Subjects were followed for three months and had a total of four study visits ( baseline and 1 week , 1 month , and 3 months after treatment ) . Results : Sixty patients completed all study visits . In both groups , the NRS rating significantly decreased after treatment , with a marked pain reduction observed at the first follow-up evaluation . In the PRF group , the NRS decreased from 6.46 at baseline to 2.76 at the 1 week visit . One and 3 months after treatment , the NRS was 4.30 and 5.13 , respectively ( P < 0.0001 ) . In the TENS group , the NRS decreased from 6.10 at baseline to 3.96 at the 1 week visit . One and 3 months after treatment , the NRS was 5.23 and 5.90 , respectively ( P < 0.0001 ) . Unfortunately , the NRS steady increased almost back to baseline levels in the TENS group . The NRS only slightly increased during the follow-up period in the PRF group , but did not reach baseline levels . Conclusions : Both TENS and PRF lumbar sympathectomy are promising pain relief treatments for painful DNP . However , PR 
    Output:
    
Of the comparisons , we had planned to explore , we were only able to undertake a quantitative synthesis for TENS versus sham TENS .
In this review , we reported on the comparison between TENS and sham TENS .
The quality of the evidence was very low meaning we were unable to confidently state whether TENS is effective for pain control in people with neuropathic pain .