Ongoing efforts to develop mechanisms-based assessment and treatment of chronic pain have been hindered by the lack of assessment tools differentially sensitive to various phenomena underlying different mechanisms of pain. This study describes the development of an assessment instrument intended to measure neuropathic pain based on qualities of pain as they are inferred from pain descriptors. Subjects were 528 chronic pain patients from several clinics. Of these, 149 had strictly neuropathic pain, while 233 had non-neuropathic pain. Subjects completed a 32 item preliminary questionnaire, which asked them to rate their usual pain on multiple descriptors, as well as the degree to which their pain differed in response to various internal and external factors. This preliminary questionnaire was submitted to factor analysis, and this yielded 6 factors. Representatives of each of these factors were combined with additional items that demonstrated significant differences between neuropathic and non-neuropathic pain groups, to yield a 12 item Neuropathic Pain Questionnaire (NPQ). These items were able to differentiate neuropathic pain patients from non-neuropathic pain patients in a holdout sample with 66.6% sensitivity and 74.4% specificity. The newly developed instrument, NPQ, may be used for the initial screening of neuropathic pain patients. It also has the ability to provide a quantitative measure for the descriptors important in the diagnosis and assessment of neuropathic pain. Consequently, it can be used for monitoring of neuropathic pain treatments and as an outcome measure.

Peripheral neuropathy affects about 30% of people with diabetes mellitus. Between 16% and 26% of diabetes patients experience chronic pain. This may be referred to as diabetic neuropathic pain (DNP) or diabetic peripheral neuropathic pain (DPNP). Minimum requirements for diagnosis of DPNP should include assessment of pain and symptoms and neurological examination, with the accent on sensory examination. Given that depression and other co-morbidities are commonly associated with this condition, a broad approach to management is essential. Lifestyle intervention and optimisation of glycaemic control are recommended as initial steps in management. An evidence-based treatment algorithm for DPNP has been proposed, recommending initial use of either a tri-cyclic antidepressant, selective serotonin noradrenaline re-uptake inhibitor or alpha-2-delta agonist, depending on patient co-morbidities and contra-indications. Addition of an opioid agonist may be required in the event of inadequate pain control. Irrespective of which treatment is offered, only about one third of patients are likely to achieve more than 50% pain relief. Further research to improve the diagnosis and management of DPNP is needed.

The response to painful stimulation depends not only on peripheral nociceptive input but also on the cognitive and affective context in which pain occurs. One contextual variable that affects the neural and behavioral response to nociceptive stimulation is the degree to which pain is perceived to be controllable. Previous studies indicate that perceived controllability affects pain tolerance, learning and motivation, and the ability to cope with intractable pain, suggesting that it has profound effects on neural pain processing. To date, however, no neuroimaging studies have assessed these effects. We manipulated the subjects' belief that they had control over a nociceptive stimulus, while the stimulus itself was held constant. Using functional magnetic resonance imaging, we found that pain that was perceived to be controllable resulted in attenuated activation in the three neural areas most consistently linked with pain processing: the anterior cingulate, insular, and secondary somatosensory cortices. This suggests that activation at these sites is modulated by cognitive variables, such as perceived controllability, and that pain imaging studies may therefore overestimate the degree to which these responses are stimulus driven and generalizable across cognitive contexts.

Abstract-Based on the available evidence, the Therapeutics and Technology Assessment subcommittee concluded that 1) epidural steroid injections may result in some improvement in radicular lumbosacral pain when assessed between 2 and 6 weeks following the injection, compared to control treatments (Level C, Class I-III evidence). The average magnitude of effect is small and generalizability of the observation is limited by the small number of studies, highly selected patient populations, few techniques and doses, and variable comparison treatments; 2) in general, epidural steroid injection for radicular lumbosacral pain does not impact average impairment of function, need for surgery, or provide long-term pain relief beyond 3 months. Their routine use for these indications is not recommended (Level B, Class I-III evidence); 3) there is insufficient evidence to make any recommendation for the use of epidural steroid injections to treat radicular cervical pain (Level U). NEUROLOGY 2007;68:723-729 Chronic back pain and its associated disabilities represent an important health problem. 1 The rising prevalence of obesity may increase the impact of chronic back pain. The competitive nature of the modern workplace places individuals with less than perfect health and, in particular, those with painful conditions at a disadvantage. Workplace accommodation may not be an option for many occupations and, even where possible, is frequently linked with economic losses for employee and employer alike.In 1998, individuals with back pain in the United States were estimated to have incurred total health care expenditures of $90.7 billion.2 Inpatient care accounted for 31% of the expenditure, followed by expenditure for office-based visits (26%), prescription drugs (15.6%), and outpatient services (13.1%). Emergency department visits and home health visits each accounted for 3%. Of the $90.7 billion total expenditures incurred by these individuals, the expenditures attributable directly to the back pain totaled approximately $26.3 billion, 2 of which 42% were for office-based visits, 18% for outpatient services, 17% for inpatient care, 15% for prescription drugs, and 4% for emergency room visits. The estimated cost of treatments for spinal pain (medical therapy, epidural steroid injections, spinal cord stimulation, and intrathecal narcotics) for 1990 was at least $13 billion, growing by 7% per year.3 Medicare part B claims in 1999 for 40.4 million covered individuals were $49.9 million for lumbar epidural steroid injections, $8.5 million for lumbar facet or peri-facet joint injections, and $5.6 million for cervical or thoracic epidural steroid injections. 4 Low back pain may occur without or with radicular features (the latter often referred to as sciatica). In the strictest sense, sciatica refers to pain running down the posterior aspect of the lower extremity. A less restrictive usage to refer to lower back pain with

The degree to which perceived controllability alters the way a stressor is experienced varies greatly among individuals. We used functional magnetic resonance imaging to examine the neural activation associated with individual differences in the impact of perceived controllability on self-reported pain perception. Subjects with greater activation in response to uncontrollable (UC) rather than controllable (C) pain in the pregenual anterior cingulate cortex (pACC), periaqueductal gray (PAG), and posterior insula/SII reported higher levels of pain during the UC versus C conditions. Conversely, subjects with greater activation in the ventral lateral prefrontal cortex (VLPFC) in anticipation of pain in the UC versus C conditions reported less pain in response to UC versus C pain. Activation in the VLPFC was significantly correlated with the acceptance and denial subscales of the COPE inventory [Carver, C. S., Scheier, M. F., & Weintraub, J. K. Assessing coping strategies: A theoretically based approach. Journal of Personality and Social Psychology, 56, 267-283, 1989], supporting the interpretation that this anticipatory activation was associated with an attempt to cope with the emotional impact of uncontrollable pain. A regression model containing the two prefrontal clusters (VLPFC and pACC) predicted 64% of the variance in pain rating difference, with activation in the two additional regions (PAG and insula/SII) predicting almost no additional variance. In addition to supporting the conclusion that the impact of perceived controllability on pain perception varies highly between individuals, these findings suggest that these effects are primarily top-down, driven by processes in regions of the prefrontal cortex previously associated with cognitive modulation of pain and emotion regulation.