By Christopher J. Gilligan and David Borsook | Pain Medicine | July 27, 2015
The dramatic impact of chronic pain was captured in a recent European study that followed patients suffering with chronic pain for 1 year: 40% of those patients had more pain and 40% had less pain, but 100% reported major, negative impacts of chronic pain on their quality of life [1]. Half of patients believed that everything possible had been done to manage their pain. This insight into how patients with chronic pain fare reveals a number of salient points, perhaps most importantly highlighting this condition that persists without cure. Furthermore, accumulating evidence suggests that emotional processing in brain networks is more involved in chronic pain [2] alluding to the nature of the associated suffering with the condition.
Despite significant advances in pain neurobiology, there remains an urgent need to define outcome measures for treatment options and to understand both short-term (i.e., symptom control) and long-term (i.e., disease modification) approaches to treatments that really work. Unfortunately, pain remains one of the most difficult conditions to live with and to treat. One of the major problems is that because treatments are not highly effective across populations, a wide variety of approaches is frequently used combining various pharmacological, interventional, and behavioral treatments outside of the setting of a coordinated interdisciplinary program. In academic pain clinics, where a more rational approach to treatment may be possible because of hospital standards and relevant lack of financial conflict of interests, financial pressures remain a factor. Patients will continue to reach out in hope that some current or new treatment will be highly effective. Without question, some patients receive treatments that are highly effective such as spinal cord stimulation for chronic radicular leg pain in the setting of postlaminectomy syndrome, but this is generally not defined in a rigorous way as compared to treatment for an infection, that is often determined by defining specific organisms and specific antibiotics. The real conundrum is the lack of outcome studies. Thus, treatment is typically started with more conservative options (e.g., pharmacological, psychological, or physical Rx) followed, if necessary, by more invasive ones (e.g., spinal cord stimulation, brain motor cortex stimulation).
Despite the fact that outcome studies or evidence based studies on the treatment of chronic pain are overall weak; many treatments are applied to patients. On the opposite side, some treatments that have low levels of evidence for efficacy are in high demand by patients (e.g., acupuncture). Some approaches are more effective than others including those that include an intensive biopsychosocial intervention [3], some drugs may be more effective than others for different conditions as summarized in Cochrane reports [4]. It should be noted, however, that the overall evidence for many drugs is summarized in such reviews as noted in the following example for levetiracetam “….the amount of evidence for levetiracetam in neuropathic pain conditions was very small” [5] or there is no top tier evidence for drug or other intervention. Clinical academic pain medicine needs to take a leading and active role in providing more evidence-based approaches to treatments through new trials and data repositories within the constraints of available resources. Specifically, large, prospective, sham controlled, double-blinded trials that would provide greater statistical power and higher levels of evidence compared to small and/or observational trials. In addition, the use of more innovative trial designs including the N of 1 approach where multiple crossover studies are conducted in the same individual [6,7] could be considered in situations that are difficult or impossible to perform (e.g., for ethical reasons) standard placebo controlled trials.