Neuropathic pain is defined as a lesion or disease of the somatosensory system, and may involve the central or peripheral nervous systems. Treatment of neuropathic pain is a challenge for clinicians involved in affected patients' care. In 2007, the first guidelines for the treatment of neuropathic pain in the Canadian context were produced by the Canadian Pain Society. This update to these guidelines incorporates new evidence published since the first guidelines were released.

Neuropathic pain (NeP), generated by disorders of the peripheral and central nervous system, can be particularly severe and disabling. Prevalence estimates indicate that 2% to 3% of the population in the developed world suffer from NeP, which suggests that up to one million Canadians have this disabling condition. Evidence-based guidelines for the pharmacological management of NeP are therefore urgently needed. Randomized, controlled trials, systematic reviews and existing guidelines focusing on the pharmacological management of NeP were evaluated at a consensus meeting. Medications are recommended in the guidelines if their analgesic efficacy was supported by at least one methodologically sound, randomized, controlled trial showing significant benefit relative to placebo or another relevant control group. Recommendations for treatment are based on degree of evidence of analgesic efficacy, safety, ease of use and cost-effectiveness. Analgesic agents recommended for first-line treatments are certain antidepressants (tricyclics) and anticonvulsants (gabapentin and pregabalin). Second-line treatments recommended are serotonin noradrenaline reuptake inhibitors and topical lidocaine. Tramadol and controlled-release opioid analgesics are recommended as third-line treatments for moderate to severe pain. Recommended fourth-line treatments include cannabinoids, methadone and anticonvulsants with lesser evidence of efficacy, such as lamotrigine, topiramate and valproic acid. Treatment must be individualized for each patient based on efficacy, side-effect profile and drug accessibility, including cost. Further studies are required to examine head-to-head comparisons among analgesics, combinations of analgesics, long-term outcomes, and treatment of pediatric and central NeP.

A single, preoperative i.v. dose of dexamethasone 40 mg has a prolonged suppressive effect on the inflammatory response and decreases dynamic pain 24 h after total hip arthroplasty.

The present study assessed the role of pain and pain-related psychological variables in the persistence of post-traumatic stress symptoms following whiplash injury. Individuals (N=112) with whiplash injuries who had been admitted to a standardized multidisciplinary rehabilitation program were asked to complete measures of pain, post-traumatic stress symptoms, physical function and pain-related psychological variables at three different points during their treatment program. The findings are consistent with previous research showing that indicators of injury severity such as pain, reduced function and disability, and scores on pain-related psychological were associated with more severe post-traumatic stress symptoms in individuals with whiplash injuries. Contrary to expectations, indicators of pain severity did not contribute to the persistence of post-traumatic stress symptoms. Univariate analyses revealed that self-reported disability, pain catastrophizing and perceived injustice were significant determinants of the persistence of post-traumatic stress symptoms. In multivariate analyses, only perceived injustice emerged as a unique predictor of the persistence of post-traumatic stress symptoms. The results suggest that early adequate management of pain symptoms and disability consequent to whiplash injury might reduce the severity of post-traumatic stress symptoms. The development of effective intervention techniques for targeting perceptions of injustice might be important for promoting recovery of post-traumatic stress symptoms consequent to whiplash injury.

Although most cases of temporomandibular muscle and joint disorders (TMJD) are mild and self-limiting, about 10% of TMJD patients develop severe disorders associated with chronic pain and disability. It has been suggested that depression and catastrophizing contributes to TMJD chronicity. This article assesses the effects of catastrophizing and depression on clinically significant TMJD pain (Graded Chronic Pain Scale [GCPS] II-IV). Four hundred eighty participants, recruited from the Minneapolis/St. Paul area through media advertisements and local dentists, received examinations and completed the GCPS at baseline and at 18-month follow-up. In a multivariable analysis including gender, age, and worst pain intensity, baseline catastrophizing (β 3.79, P<0.0001) and pain intensity at baseline (β 0.39, P<0.0001) were positively associated with characteristic of pain intensity at the 18th month. Disability at the 18-month follow-up was positively related to catastrophizing (β 0.38, P<0.0001) and depression (β 0.17, P=0.02). In addition, in the multivariable analysis adjusted by the same covariates previously described, the onset of clinically significant pain (GCPS II-IV) at the 18-month follow-up was associated with catastrophizing (odds ratio [OR] 1.72, P=0.02). Progression of clinically significant pain was related to catastrophizing (OR 2.16, P<0.0001) and widespread pain at baseline (OR 1.78, P=0.048). Results indicate that catastrophizing and depression contribute to the progression of chronic TMJD pain and disability, and therefore should be considered as important factors when evaluating and developing treatment plans for patients with TMJD.