RESUMO
Objectives. In spinal cord stimulation (SCS) therapy, limited pain relief during the temporary trial period is generally considered to be predictive of poor long-term benefit. To validate or refute this perception, the long-term outcomes of subjects who reported less than 50% pain relief during a temporary SCS trial were examined. Materials and Methods. Twelve subjects with intractable pain underwent implantation of trial SCS systems. After a trial period in which they reported less than 50% pain relief, they each received a permanent SCS implant. Pain ratings and complications were tracked for 6-18 months. Results. At the end of the temporary trial period, the average pain relief was 21%; no subject reported 50% or better pain relief. More favorable outcomes were reported after activation of the permanent system, however. At all follow-up time points, at least a third of the subjects reported better than 50% pain relief, and the average pain relief varied over time between 44% and 83%. All complications were readily resolved and no subjects withdrew from the study. Conclusions. Although SCS provided limited pain relief during the trial period, efficacy was more satisfactory after permanent implantation. Several subjects went on to experience nearly complete pain relief for up to 18 months (the maximum follow-up visit for study purposes), and no subject chose to discontinue SCS therapy. SCS appears to be a viable treatment option for patients who fail trials, raising some doubt as to the predictive sensitivity and specificity of the trial period. Thus, although outcome of a temporary trial period may be suggestive of later efficacy with SCS, it may not be the sole predictor of success. Alternatively, the arbitrary benchmark of 50% pain relief that is typically used to define the success of a temporary trial may be too stringent and unreliable.
RESUMO
Objectives. The probability of success with spinal cord stimulation (SCS) depends largely on appropriate patient selection. Here, we have assessed the predictive value of pain etiology as it relates to pain relief with SCS as part of a prospective multicenter clinical trial. Methods. Sixty-five subjects with chronic and intractable pain tested an epidural SCS system. Subjects reported pain ratings (visual analog scale) with stimulation off and stimulation on at scheduled follow-up visits for up to 18 months after activation of the system. Visual analog scale scores were averaged and stratified by dominant pain etiologies, comprising failed back surgery syndrome, complex regional pain syndrome, and a subgroup of subjects with miscellaneous other pain etiologies. Results. More than 70% of subjects in each subgroup had successful outcomes during the temporary trial period and similar percentages of subjects from each etiology subgroup subsequently went on to permanent implantation. After permanent implantation, all subgroups reported more than 50% pain relief, on average, at each follow-up time point. No predictive value of pain etiology was observed. Conclusions. Spinal cord stimulation is an effective therapy for neuropathic pain arising from a variety of causes. Failed back surgery syndrome, complex regional pain syndrome, and pain of other etiologies responded equally well to SCS.
RESUMO
Objectives. A prospective, open label, multicenter clinical trial confirmed the functionality of a new spinal cord stimulation (SCS) system for the treatment of chronic, intractable pain of the trunk and/or limbs. Materials and Methods. Sixty-five subjects tested a rechargeable 16-channel SCS system with individual current control of each contact on one or two percutaneous eight-contact epidural leads. After baseline measurements, subjects were tracked on pain ratings and complication rates for up to 18 months. Results. After a trial period, 75% of subjects underwent permanent implantation of the entire SCS system. More than one-half the implanted subjects experienced 50% or greater relief of pain after permanent implantation; some subjects reported relief of 90% or more of their pain. The most common complications after permanent implantation were lead migration, uncomfortable stimulation, and component failure; most resolved after reprogramming or device replacement. Conclusions. The new SCS system provided good pain relief to a majority of subjects, and the results confirm a favorable safety and efficacy profile for the SCS system.
RESUMO
... We will turn our attention to the current state of pain relief technology and the ethical questions surrounding the use of advanced technology, otherwise referred to as "high-tech," pain relief. It is obvious that pain may decrease the quality of life for cancer patients. The availability of long-acting narcotics, such as MS Contin or methadone, affords cancer patients long-duration pain relief at minimal cost. The use of adjuvant medications may also be important. Clinical examples of the effective use of adjuvant medications include the addition of a nonsteroidal, anti-inflammatory agent to help patients cope with bone pain and the use of a serotonin blocking agent to reduce the transmission of pain impulses in the spinal cord. Only a small percentage of patients are good candidates for high-tech delivery systems for narcotic administration. In our pain management clinic, all patients are initially placed on oral medications. When the side effects of oral medications become excessive, or the patient becomes unable to take oral medications, high-tech modalities are considered for use.
