A Model to Predict Psychological- and Health-Related Adjustment in Men with Prostate Cancer: The Role of Post Traumatic Growth, Physical Post Traumatic Growth, Resilience and Mindfulness.

Background: Post traumatic growth (PTG) can be defined as positive change following a traumatic event. The current conceptualization of PTG encompasses five main dimensions, however, there is no dimension which accounts for the distinct effect of a physical trauma on PTG. The purpose of the present research was to test the role of PTG, physical post traumatic growth (PPTG), resilience and mindfulness in predicting psychological and health related adjustment. Method: Ethical approval was obtained from relevant institutional ethics committees. Participants (N = 241), who were at least 1 year post prostate cancer treatment, were invited to complete a battery of questionnaires either through an online survey or a paper and pencil package received in the post The sample ranged in age from 44 to 88 years (M = 64.02, SD = 7.76). Data were analysis using confirmatory factor analysis and structural equation modeling. Results: The physical post traumatic growth inventory (P-PTGI) was used to evaluate the role of PPTG in predicting adjustment using structural equation modeling. P-PTGI predicted lower distress and improvement of quality of life, whereas conversely, the traditional PTG measure was linked with poor adjustment. The relationship between resilience and adjustment was found to be mediated by P-PTGI. Conclusion: Findings suggest the central role of PTG in the prostate cancer survivorship experience is enhanced by the inclusion of PPTG. Adjusting to a physical trauma such as illness (internal transgressor) is unlike a trauma with an external transgressor as the physical trauma creates an entirely different framework for adjustment. The current study demonstrates the impact of PPTG on adjustment. This significantly adds to the theory of the development of PTG by highlighting the interplay of resilience with PTG, PPTG, and adjustment.

Effects of transcutaneous electrical nerve stimulation on pain, pain sensitivity, and function in people with knee osteoarthritis: a randomized controlled trial.

BACKGROUND: Transcutaneous electrical nerve stimulation (TENS) is commonly used for the management of pain; however, its effects on several pain and function measures are unclear. OBJECTIVE: The purpose of this study was to determine the effects of high-frequency TENS (HF-TENS) and low-frequency TENS (LF-TENS) on several outcome measures (pain at rest, movement-evoked pain, and pain sensitivity) in people with knee osteoarthritis. DESIGN: The study was a double-blind, randomized clinical trial. SETTING: The setting was a tertiary care center. PARTICIPANTS: Seventy-five participants with knee osteoarthritis (29 men and 46 women; 31-94 years of age) were assessed. INTERVENTION: Participants were randomly assigned to receive HF-TENS (100 Hz) (n=25), LF-TENS (4 Hz) (n=25), or placebo TENS (n=25) (pulse duration=100 microseconds; intensity=10% below motor threshold). MEASUREMENTS: The following measures were assessed before and after a single TENS treatment: cutaneous mechanical pain threshold, pressure pain threshold (PPT), heat pain threshold, heat temporal summation, Timed "Up & Go" Test (TUG), and pain intensity at rest and during the TUG. A linear mixed-model analysis of variance was used to compare differences before and after TENS and among groups (HF-TENS, LF-TENS, and placebo TENS). RESULTS: Compared with placebo TENS, HF-TENS and LF-TENS increased PPT at the knee; HF-TENS also increased PPT over the tibialis anterior muscle. There was no effect on the cutaneous mechanical pain threshold, heat pain threshold, or heat temporal summation. Pain at rest and during the TUG was significantly reduced by HF-TENS, LF-TENS, and placebo TENS. LIMITATIONS: This study tested only a single TENS treatment. CONCLUSIONS: Both HF-TENS and LF-TENS increased PPT in people with knee osteoarthritis; placebo TENS had no significant effect on PPT. Cutaneous pain measures were unaffected by TENS. Subjective pain ratings at rest and during movement were similarly reduced by active TENS and placebo TENS, suggesting a strong placebo component of the effect of TENS.

A comparison of the hypoalgesic effects of transcutaneous electrical nerve stimulation (TENS) and non-invasive interactive neurostimulation (InterX(®)) on experimentally induced blunt pressure pain using healthy human volunteers.

OBJECTIVES: Non-invasive interactive neurostimulation (InterX(®)) delivers high amplitude electrical pulsed currents at points of low impedance on the skin. This study compared the hypoalgesic effect of non-invasive interactive neurostimulation with transcutaneous electrical nerve stimulation (TENS). MATERIALS AND METHODS: A repeated measures parallel group study on healthy human volunteers randomized to receive strong non-painful TENS or non-invasive interactive neurostimulation for 21 min on the forearm (N= 10/group). Pressure algometry was used to determine blunt pressure pain threshold at baseline, 10, and 20 min during stimulation, and 5 min post stimulation. RESULTS: Low impedance sites were found in half of the participants receiving non-invasive interactive neurostimulation. ANOVA found no effects for intervention (p= 0.923), time × intervention interaction (p= 0.21), or time (p= 0.094). CONCLUSIONS: Given the limited power of this study, we show that there were no significant differences in hypoalgesia between non-invasive interactive neurostimulation and TENS. Unlike our previous studies we also failed to detect a change pain threshold during TENS. Nevertheless, our findings can be used to inform the design of an appropriately powered study on pain patients.

Exercise and Auricular Acupuncture for Chronic Low-back Pain: A Feasibility Randomized-controlled Trial.

OBJECTIVES: To evaluate the feasibility of a randomized-controlled trial (RCT) investigating the effects of adding auricular acupuncture (AA) to exercise for participants with chronic low-back pain (CLBP). METHODS: Participants with CLBP were recruited from primary care and a university population and were randomly allocated (n=51) to 1 of 2 groups: (1) "Exercise Alone (E)"-12-week program consisting of 6 weeks of supervised exercise followed by 6 weeks unsupervised exercise (n=27); or (2) "Exercise and AA (EAA)"-12-week exercise program and AA (n=24). Outcome measures were recorded at baseline, week 8, week 13, and 6 months. The primary outcome measure was the Oswestry Disability Questionnaire. RESULTS: Participants in the EAA group demonstrated a greater mean improvement of 10.7% points (95% confidence interval, -15.3,-5.7) (effect size=1.20) in the Oswestry Disability Questionnaire at 6 months compared with 6.7% points (95% confidence interval, -11.4,-1.9) in the E group (effect size=0.58). There was also a trend towards a greater mean improvement in quality of life, LBP intensity and bothersomeness, and fear-avoidance beliefs in the EAA group. The dropout rate for this trial was lower than anticipated (15% at 6 mo), adherence with exercise was similar (72% E; 65% EAA). Adverse effects for AA ranged from 1% to 14% of participants. DISCUSSION: Findings of this study showed that a main RCT is feasible and that 56 participants per group would need to be recruited, using multiple recruitment approaches. AA was safe and demonstrated additional benefits when combined with exercise for people with CLBP, which requires confirmation in a fully powered RCT.

Hypoalgesia in response to transcutaneous electrical nerve stimulation (TENS) depends on stimulation intensity.

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 randomly 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 hand and forearm before and after TENS to measure hypoalgesia. There were significant differences between groups at both the hand 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 hand (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.

Adjusting pulse amplitude during transcutaneous electrical nerve stimulation (TENS) application produces greater hypoalgesia.

UNLABELLED: Transcutaneous electrical nerve stimulation (TENS) is a noninvasive technique used for pain modulation. During application of TENS there is a fading of current sensation. Textbooks of electrophysical agents recommend that pulse amplitude should be constantly adjusted. This seems to be accepted clinically despite the fact that there is no direct experimental evidence. The aim of the current study was to investigate the hypoalgesic effect of adjusting TENS pulse amplitude on pressure pain thresholds (PPTs) in healthy humans. Fifty-six healthy TENS naïve participants were recruited and randomly assigned to 1 of 4 groups (n = 14 per group): control, placebo TENS, fixed pulse amplitude TENS, and adjusted pulse amplitude TENS. Both active and placebo TENS were applied to the dominant forearm. PPTs were recorded from 2 points on the dominant forearm and hand before, during, and after 40 minutes of TENS. TENS increased the PPTs on the forearm (P = .003) and hand (P = .003) in the group that received the adjusted pulse amplitude when compared to all other groups. The mean final pulse amplitude for the adjusted pulse amplitude TENS group was 35.51 mA when compared to the fixed pulse amplitude TENS group, which averaged 31.37 mA (P = .0318). PERSPECTIVE: These results suggest that it is important to adjust the pulse amplitude during TENS application to get the maximal analgesic effect. We propose that the fading of current sensation allows the use of higher pulse amplitudes, which would activate a greater number of and deeper tissue afferents to produce greater analgesia.

An investigation of the development of analgesic tolerance to TENS in humans.

Transcutaneous electrical nerve stimulation (TENS) is a noninvasive modality used to control pain. Animal models show that repeated TENS application produces analgesic tolerance and cross-tolerance at spinal opioid receptors. The aim of the present investigation was to examine whether repeated application of TENS produces analgesic tolerance in humans. One hundred healthy subjects were randomly assigned to 1 of 4 groups: control, placebo, low-frequency (4Hz) or high-frequency (100Hz) TENS. TENS was applied daily for 5days to the nondominant upper limb; pressure-pain threshold (PPT) measurements were recorded before and after TENS. Temporal summation to mechanical stimulation was recorded on days 1 and 5, before and after TENS. Diffuse noxious inhibitory control (DNIC) was tested on day 5 using the cold pressor test and PPT measurements. There was an initial increase in PPTs in both low- and high-frequency TENS groups when compared with placebo or control groups. However, by day 5 this TENS-induced increase in PPT did not occur, and there was no difference between active TENS and placebo or control groups. High-frequency TENS decreased temporal summation on day 1 when compared with day 5. DNIC increased the PPT similarly in all groups. These data suggest that repeated daily application of TENS results in a decrease in its hypoalgesic effect by the fifth day and that the tolerance-like effect to repeated TENS results from tolerance at centrally located opioid receptors. The lack of change in DNIC response suggests that TENS and DNIC utilize separate pathways to produce analgesia. Repeated high-frequency and low-frequency transcutaneous electrical nerve stimulation produce analgesic tolerance in humans by the fourth and fifth day of treatment, respectively.

A new transient sham TENS device allows for investigator blinding while delivering a true placebo treatment.

UNLABELLED: This study compared a new transient sham transcutaneous electrical nerve stimulation (TENS) that delivers current for 45 seconds to an inactive sham and active TENS to determine the degree of blinding and influence on pain reduction. Pressure-pain thresholds (PPT), heat-pain thresholds (HPT), and pain intensities to tonic heat and pressure were measured in 69 healthy adults before and after randomization. Allocation investigators and subjects were asked to identify the treatment administered. The transient sham blinded investigators 100% of the time and 40% of subjects compared to the inactive sham that blinded investigators 0% of the time and 21% of subjects. Investigators and subjects were blinded only 7% and 13% of the time, respectively, with active TENS. Neither placebo treatment resulted in significant changes in PPT, HPT, or pain intensities. Subjects using higher active TENS amplitudes (> or =17 mAs) had significantly higher PPTs and lower pain intensities to tonic pressure than subjects using lower amplitudes (<17 mAs). HPTs and pain intensities to tonic heat were not significantly changed. The transient TENS completely blinds investigators to treatment and does not reduce pain, thereby providing a true placebo treatment. PERSPECTIVE: This article presents the benefits of a new transient sham TENS device for use in prospective, randomized, clinical trials. This device facilitates blinding of subjects and investigators to eliminate expectation bias and determine the true efficacy of TENS for use in clinical populations.

An investigation of the hypoalgesic effects of TENS delivered by a glove electrode.

UNLABELLED: This randomized, placebo-controlled, blinded study investigated the hypoalgesic effects of high-frequency transcutaneous electrical nerve stimulation (TENS) delivered via a glove electrode compared with standard self-adhesive electrodes. Fifty-six TENS-naïve, healthy individuals (18 to 50 years old; 28 men, 28 women) were randomly allocated to 1 of 4 groups (n = 14 per group): glove electrode; placebo TENS using a glove electrode; standard electrode; and no treatment control. Active TENS (continuous stimulus, 100 Hz, strong but comfortable intensity) was applied to the dominant forearm/hand for 30 minutes. Placebo TENS was applied using a burst stimulus, 100-Hz frequency, 5-second cycle time for 42 seconds, after which the current amplitude was automatically reset to 0 mA. Pressure pain thresholds (PPTs) were recorded from 3 points on the dominant and nondominant upper limbs before and after TENS. Statistical analyses of dominant PPT data using between-within groups ANOVA showed significant differences between groups at all 3 recording points (P = .01). Post hoc Scheffe tests indicated no significant difference between the standard electrode and glove electrode groups. There was a significant hypoalgesic effect in the standard electrode group compared with the control group and between the glove electrode group and both the control and placebo TENS groups. There was no significant interactive effect between time and group at any of the recording points (P > .05). PERSPECTIVE: This study presents a comparison of the hypoalgesic effects of 2 different types of TENS electrode, a novel glove electrode and standard self-adhesive rectangular electrodes. The glove electrode provides a larger contact area with the skin, thereby stimulating a greater number of nerve fibers. The results show that both electrodes have similar hypoalgesic effects and therefore give the clinician another choice in electrode.

Transcutaneous electrical nerve stimulation for acute pain.

BACKGROUND: Transcutaneous Electrical Nerve Stimulation (TENS) is a non-pharmacological agent, based on delivering low voltage electrical currents to the skin. TENS is used for the treatment of a variety of pain conditions. OBJECTIVES: To assess the analgesic effectiveness of TENS for acute pain in adults to see if it had any clear analgesic effect in its own right. SEARCH STRATEGY: The following databases were searched: Cochrane Pain, Palliative and Supportive Care Group Specialised Register; the Cochrane Central Register of Controlled Trials, CENTRAL (in The Cochrane Library); MEDLINE; EMBASE; CINAHL; AMED; PEDro; OTseeker; OpenSIGLE; and, reference lists of included studies. The most recent search was undertaken in August 2008. SELECTION CRITERIA: Randomised controlled trials (RCTs) of adults with acute pain (less than 12 weeks) were included if they examined TENS given as a sole treatment and assessed pain with subjective pain scales. Studies were eligible if they compared TENS to placebo TENS, no treatment controls, pharmacological interventions or non-pharmacological interventions. Studies on experimental pain, case reports, clinical observations, letters, abstracts or reviews were excluded. Studies on TENS and labour pain, pain due to dental procedures and primary dysmenorrhoea were excluded. Studies where TENS was given with another treatment as part of the formal study design were also excluded. No restrictions were made regarding language. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trial eligibility and extracted data. Data were extracted on the following: types of participants and pain condition, study design and methods, treatment parameters, adverse effects, and outcome measures. Study authors were contacted for additional information if necessary. MAIN RESULTS: Of 1479 studies identified in the search, 132 were identified as relevant. Of these, 116 were excluded; the vast majority of these were excluded due to TENS being given with another treatment. Four studies were categorised as awaiting classification as the information provided in the full text failed to clarify their eligibility. Twelve RCTs involving 919 participants at entry were included. The types of acute pain conditions included procedural pain, e.g. cervical laser treatment, venipuncture, screening flexible sigmoidoscopy and non-procedural pain, e.g. postpartum uterine contractions, rib fractures. It was not possible to perform a meta-analysis due to insufficient data. AUTHORS' CONCLUSIONS: Due to insufficient extractable data in the studies included in this review, we are unable to make any definitive conclusions about the effectiveness of TENS as an isolated treatment for acute pain in adults.

Effectiveness of transcutaneous electrical nerve stimulation for treatment of hyperalgesia and pain.

Transcutaneous electrical nerve stimulation (TENS) is a nonpharmacologic treatment for pain relief. TENS has been used to treat a variety of painful conditions. This review updates the basic and clinical science regarding the use of TENS that has been published in the past 3 years (ie, 2005-2008). Basic science studies using animal models of inflammation show changes in the peripheral nervous system, as well as in the spinal cord and descending inhibitory pathways, in response to TENS. Translational studies show mechanisms to prevent analgesic tolerance to repeated application of TENS. This review also highlights data from recent randomized, placebo-controlled trials and current systematic reviews. Clinical trials suggest that adequate dosing, particularly intensity, is critical to obtaining pain relief with TENS. Thus, evidence continues to emerge from both basic science and clinical trials supporting the use of TENS for the treatment of a variety of painful conditions while identifying strategies to increase TENS effectiveness.

Efficacy of transcutaneous electrical nerve stimulation (tens) for chronic low-back pain in a multiple sclerosis population: a randomized, placebo-controlled clinical trial.

OBJECTIVE: This study was designed to investigate the hypoalgesic effects of self-applied transcutaneous electrical nerve stimulation (TENS) on chronic low-back pain (LBP) in a multiple sclerosis (MS) population. METHODS: Ninety participants with probable or definite MS (aged 21 to 78 y) presenting with chronic LBP were recruited and randomized into 3 groups (n=30 per group): (1) low-frequency TENS group (4 Hz, 200 micros); (2) high-frequency TENS group (110 Hz, 200 micros); and (3) placebo TENS. Participants self-applied TENS for 45 minutes, a minimum of twice daily, for 6 weeks. Outcome measures were recorded at weeks 1, 6, 10, and 32. Primary outcome measures included: Visual Analog Scale for average LBP and the McGill Pain Questionnaire. Secondary outcome measures included: Visual Analog Scale for worst and weekly LBP, back and leg spasm; Roland Morris Disability Questionnaire; Barthel Index; Rivermead Mobility Index; Multiple Sclerosis Quality of Life-54 Instrument, and a daily logbook. Data were analyzed blind using parametric and nonparametric tests, as appropriate. RESULTS: Results indicated a statistically significant interactive effect between groups for average LBP (P=0.008); 1-way analysis of covariance did not show any significant effects at any time point once a Bonferonni correction was applied (P>0.05). However, clinically important differences were observed in some of the outcome measures in both active treatment groups during the treatment and follow-up periods. DISCUSSION: Although not statistically significant, the observed effects may have implications for the clinical prescription and the use of TENS within this population.

Acupuncture in the management of chronic low back pain: a blinded randomized controlled trial.

OBJECTIVE: To assess the efficacy of acupuncture in the treatment of chronic low back pain. METHODS: Patients (n = 60) with chronic low back pain were recruited and randomly allocated to either Acupuncture therapy or Placebo transcutaneous electrical nerve stimulation (TENS) groups. Patients were treated weekly for 6 weeks, and blinded assessments were carried out pre- and post-treatment using the McGill Pain Questionnaire (MPQ) and visual analog scales (VAS) for pain, the Short-form 36 quality-of-life questionnaire, and a simple range of motion measurement. A total of 46 patients completed the trial and were followed up at 6 months. RESULTS: Analysis of results using t tests showed that in both groups there were significant pre-post improvements for all scores, except for MPQ scores in the Placebo-TENS group. There was no significant difference between the 2 groups for any of the outcome measures at the end of treatment. Results from the 6-month follow-up would suggest that the response was better in the acupuncture group. DISCUSSION: Further research is necessary to fully assess the efficacy of this treatment in combating chronic low back pain using larger sample sizes or alternative control groups.

Transcutaneous electric nerve stimulation: the effect of intensity on local and distal cutaneous blood flow and skin temperature in healthy subjects.

OBJECTIVE: To determine what effect transcutaneous electric nerve stimulation (TENS) intensity has on local and distal cutaneous blood flow and skin temperature. DESIGN: Double-blind conditions. SETTING: University research laboratory. PARTICIPANTS: Forty subjects (20 men, 20 women) randomly assigned to 1 of 4 groups (10 per group): control, above-motor-threshold TENS, below-motor-threshold TENS, or perception-threshold TENS. INTERVENTION: TENS (4Hz, 200micros) was applied over the median nerve of the right forearm for 15 minutes. MAIN OUTCOME MEASURES: Blood flow measured by laser Doppler flowmeter and skin temperature measured by skin thermistor were recorded during TENS and for 15 minutes after it. RESULTS: Significant differences occurred between groups for forearm (P <.0001; repeated-measures analysis of variance) but not fingertip cutaneous blood flow. Post hoc Fisher tests showed a significant increase in forearm blood flow during TENS application in the above-motor-threshold TENS group compared with the other 3 groups. No significant differences between groups for skin temperature data were observed. CONCLUSIONS: The effect of TENS on cutaneous blood flow depends on whether muscle activity is induced. Low-frequency TENS applied above the motor threshold significantly increases local cutaneous blood flow. There were no significant differences between groups for skin temperature.

The lack of hypoalgesic efficacy of H-wave therapy on experimental ischaemic pain.

The hypoalgesic effect of H-wave therapy (HWT) at various frequencies (2-60 Hz) was assessed using a standardised form of the submaximal effort tourniquet technique (SETT). Healthy human volunteers (n = 112; 56 men, 56 women) were required to attend on two occasions; on the first, baseline pain scores were obtained and on the second, 48 h later, subjects were randomly assigned to control, placebo or 1 of 5 H-wave treatment conditions. In the treatment groups 2 self-adhesive electrodes were attached to the ipsilateral Erb's point and just lateral to the spinous processes of C6/C7. H-wave stimulation commenced 10 min prior to pain induction and continued throughout the 12-min duration of the technique. In the placebo group electrodes were attached as normal but leads were connected to a dummy power output. Analysis of variance of the differences in visual analogue scale and McGill Pain Questionnaire scores showed no significant differences in the treatment groups compared to placebo or controls. These results do not provide convincing evidence for any hypoalgesic effects of HWT at the frequency parameters stated on the experimental model of pain used.

A double-blind investigation of the hypoalgesic effects of transcutaneous electrical nerve stimulation upon experimentally induced ischaemic pain.

The hypoalgesic effect of transcutaneous electrical nerve stimulation (TENS) at 2 different frequencies was assessed under double-blind conditions using a standardised form of the submaximum effort tourniquet technique. For the purpose of pain induction, 32 healthy naive female subjects attended on 2 occasions, the first during which baseline data were obtained and the second during which the women were randomly allocated to 1 of 4 groups: Control, Placebo, TENS-1 (110 Hz) or TENS-2 (4 Hz). In the treatment groups, 2 hydrogel electrodes were positioned over Erb's point and lateral to C6 and C7 vertebral spines. A TENS machine was applied for 10 min before the cuff was inflated and remained on for the duration of the pain procedure (12 min). Pain was measured using visual analogue scales (VAS) and the McGill Pain Questionnaire (MPQ) to assess 'current pain intensity' and 'worst pain experienced', respectively. Analysis of VAS scores showed significant differences between groups (ANOVA, P = 0.02), with the TENS-2 group showing a greater hypoalgesic effect than the other groups. One-factor ANOVA showed no significant differences in MPQ scores between groups. The results of this study have provided evidence of the hypoalgesic effects of TENS upon experimental ischaemic pain which were found to be frequency specific with the lower frequency used here (4 Hz) demonstrating the only significant effect.