Can neuropathic screening tools be used as outcome measures?

OBJECTIVE: To examine whether the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) screening tool can satisfy Rasch model expectations and therefore be transformed into an interval level measurement scale, suitable for use as an outcome measure in clinical studies. DESIGN: Rasch analysis (using the software RUMM2020) of LANSS data from both a random selection of all chronic pain patients and also specific chronic pain diagnostic categories. PATIENTS: Original LANSS data from a previous study of 2,480 patients with chronic pain were used. Specific diagnostic groups examined included diabetic neuropathy, postsurgical pain, osteoarthritis, posttraumatic injury, and low back pain. OUTCOME MEASURES: The following assessments were made: fit to the Rasch model, scale reliability, scale multi-dimensionality, and differential item functioning. RESULTS: The overall fit to the Rasch model was only acceptable in two groups; diabetic neuropathy and chronic postsurgical pain. For these groups, the scale is unidimensional (measures a single construct) and there is no evidence of differential item functioning across gender and age groups. The scale only has reliability consistent with use at the group level. CONCLUSIONS: Neuropathic screening tools such as the LANSS have been used as outcome measures in clinical studies. Rasch analysis demonstrates that the LANSS can be used as such in specific populations of patients with neuropathic pain, however it's reliability in this context does not support use at the individual level and it cannot be used as a generalised measurement tool across pain diagnostic groups. The LANSS remains primarily a diagnostic tool.

Feasibility study of Transcutaneous Electrical Nerve Stimulation (TENS) for cancer bone pain.

UNLABELLED: This multicenter study assessed the feasibility of conducting a phase III trial of transcutaneous electrical nerve stimulation (TENS) in patients with cancer bone pain recruited from palliative care services. Eligible patients received active and placebo TENS for 1 hour at site of pain in a randomized crossover design; median interval between applications 3 days. Responses assessed at 30 and 60 minutes included numerical and verbal ratings of pain at rest and on movement, and pain relief. Recruitment, tolerability, adverse events, and effectiveness of blinding were also evaluated. Twenty-four patients were randomised and 19 completed both applications. The intervention was well tolerated. Five patients withdrew: 3 due to deteriorating performance status, and 2 due to increased pain (1 each following active and placebo TENS). Confidence interval estimation around the differences in outcomes between active and placebo TENS suggests that TENS has the potential to decrease pain on movement more than pain on rest. Nine patients did not consider that a placebo was used; the remaining 10 correctly identified placebo TENS. Feasibility studies are important in palliative care prior to undertaking clinical trials. Our findings suggest that further work is required on recruitment strategies and refining the control arm before evaluating TENS in cancer bone pain. PERSPECTIVE: Cancer bone pain is common and severe, and partly mediated by hyperexcitability. Animal studies suggest that Transcutaneous Electrical Nerve Stimulation can reduce hyperalgesia. This study examined the feasibility of evaluating TENS in patients with cancer bone pain in order to optimize methods before a phase III trial.

Can chronic neuropathic pain following thoracic surgery be predicted during the postoperative period?

Chronic pain following thoracic surgery is common and associated with neuropathic symptoms, however, the proportion of patients with neuropathic pain in the immediate postoperative period is unknown. We aimed to determine the proportion of patients who have neuropathic symptoms and signs immediately after, and at three months following thoracic surgery. The study was designed as a prospective observational cohort study. We identified patients with pain of predominantly neuropathic origin using the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) score in the immediate postoperative period and the self-report LANSS (S-LANSS) version three months after surgery. One hundred patients undergoing video assisted thoracic surgery (VATS) or thoracotomy completed LANSS scores preoperatively and in the immediate postoperative period. Eighty-seven percent completed three months S-LANSS follow-up scores. Eight percent of patients had positive LANSS scores in the immediate postoperative period; 22% of patients had positive S-LANSS scores three months following surgery. There was a significant association between positive scores in the acute and chronic periods (relative risk (RR) 3.5, [95% confidence interval (CI) 1.7-7.2]). Identifying pain of predominantly neuropathic origin in the postoperative period with a simple pain score can help identify those at risk of developing chronic pain with these features following thoracic surgery.

Transcutaneous electrical nerve stimulation (TENS) for cancer bone pain.

In the cancer population, painful bony metastases are common, difficult to treat and significantly reduce quality of life. Common treatments include opioid analgesics, bisphosphonates, and radiotherapy; yet these have significant side effects and are not universally effective. Transcutaneous electrical nerve stimulation (TENS) is inexpensive, relatively free from side effects, and widely available. We present a case study of successful TENS therapy in a patient with cancer bone pain and discuss the rationale for using TENS in this setting.

A cochrane systematic review of transcutaneous electrical nerve stimulation for cancer pain.

Cancer-related pain is complex and multi-dimensional; yet, the mainstay of cancer pain management has been the biomedical approach. There is a need for nonpharmacological and innovative pain management strategies. Transcutaneous electrical nerve stimulation (TENS) may have a role. The aim of this systematic review was to determine the effectiveness of TENS for cancer-related pain in adults. The Cochrane Library, MEDLINE, EMBASE, CINAHL, PsychINFO, AMED, and PEDro databases were searched for randomized controlled trials (RCTs) investigating the use of TENS for the management of cancer-related pain in adults. Once relevant studies were identified, two pairs of reviewers assessed eligibility for inclusion in the review based on a study eligibility form and using the 5-point Oxford Quality Scale. Two RCTs met the study eligibility criteria (these involved 64 patients). These studies were heterogeneous with respect to study population, methodology, and outcome measures. This prevented meta-analysis. In one RCT, there were no significant differences between TENS and placebo in women with chronic pain secondary to breast cancer treatment. In the other RCT, there were no significant differences between acupuncture-like TENS (AL-TENS) and sham in palliative care patients; this study was significantly underpowered. There is insufficient available evidence to determine the effectiveness of TENS in treating cancer-related pain. Further research is needed to help guide clinical practice, and large multi-center RCTs are required to assess the value of TENS in the management of cancer-related pain in adults.