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Operant conditioning in Fibromyalgia Syndrome: Impact on central pain processing
Abstracts
S77
(875) Operant conditioning in Fibromyalgia Syndrome: Impact on central pain processing
(877) Number of intrathecal pumps being used for chronic intractable neuropathic pain
K. Thieme, H. Flor; University of Washington, Seattle, WA The operant model of chronic pain suggests that reinforcement of pain behaviors may lead to the maintenance of chronic pain and disability. The goal of the present study was to examine the influence of the operant conditioning on central pain processing in Fibromyalgia Syndrome (FMS). Pain and tolerance thresholds, EEG levels as baseline, habituation, acquisition, and extinction in 20 FMS and 22 healthy controls. Four shock intensities were administered: pain threshold, 25%, 50%, and 75% of the distance between pain tolerance and threshold. During habituation, 15 electric stimuli at each of the 4 intensity levels (N⫽60) were administered. The training phase consisted of the application of 20 electric stimuli of each intensity (N⫽80). During extinction, 15 stimuli of each level were presented (N⫽60). Half of each group was positively reinforced for increased and half for decreased pain reports in the acquisition period (last 10 trials for each intensity level in the habituation period). Pain ratings and N150, P260 and P390 amplitudes of somatosensory evoked potential and the cortisol production in blood serum were recorded. Pain threshold (F(2; 36) ⫽ 112.34, p ⬍ .001) and tolerance (F(2; 36) ⫽ 89.64, p ⬍ .001) were significantly lower in FMS than in HC. The FMS patients showed significantly slower extinction in N 150, P260, and P390 amplitudes and verbal pain responses. The significantly negative correlation between N150 component and cortisol production supports the relations between pain coping and stress. These results indicate that operant conditioning can induce self-regulation of the brain and might be important in the maintenance and in the development of chronic pain. Supported by grants of Deutsche Forschungsgemeinschaft to KT (Th 988-1/2), and HF (FL 156/26, Clinical Research Unit 107) the Max-Planck-Award for International Cooperation
C. Roland, J. Biskupiak; The University of Utah, Dept. of Pharmacotherapy, Pharmacotherapy Outcomes Research Center, Salt Lake City, UT The patient with chronic pain that is not well managed by more traditional therapeutic means may be considered for implantation of an intrathecal (IT) pump. The number of patients with chronic intractable pain and the number of patients who have IT pumps in place is not known. In an effort to estimate the number of patients with chronic intractable neuropathic pain treated with IT analgesics, we conducted a retrospective review of a medical claims database. We queried the MEDSTAT’S MarketScan databases which reflect the healthcare experience of employees and dependants covered by health benefit programs of large employers. The claims data are collected from approximately 100 different insurance companies and third party administrators (160 million Americans or 57% of total population). The database does not include Medicaid or worker’s compensation (120 million Americans). Historically, the MarketScan database represents approximately 4 million covered lives. The years queried included 2000 and 2001 or 1.75 years. First, we identified all unique patients that experienced a procedure related to an implantable infusion pump. A total of 3,269 patients were identified and represented a total of 291 unique diagnoses. We then focused on diagnoses related to neuropathic pain which made up 84 of the 291 original diagnoses identified. These 84 diagnoses represented 2,809 unique patients with an implantable infusion pump. The total of 2,809 patients over 1.75 years represents 1,605 patients per year or 0.04% of the total number of patients in the database (4 million). Therefore, 0.04% of the 160 million Americans represent 64,200 patients with neuropathic pain requiring an implantable infusion pump. If an equivalent prevalence is assumed for the other 120 million Americans, then the total would be approximately 112,000 patients. In conclusion, we estimate that there are approximately 100,000 Americans with neuropathic pain and an IT implanted pump.
G08 - Pain Epidemiology
(878) Chronic pain in individuals with spinal cord injury: A survey and longitudinal study
(876) Nature and scope of pain in multiple sclerosis T. Osborne, D. Ehde, M. Jensen, M. Hanley, K. Raichle, G. Kraft; University of Washington School of Medicine, Seattle, WA Pain has recently been identified as a common problem in multiple sclerosis (MS). The current cross-sectional study is one of the first to comprehensively describe pain problems in a community sample of persons with MS using several standardized pain assessment measures. Participants completed a survey that included measures of pain intensity, variability, location, and interference. The sample (N ⫽ 181) was 78% female with a mean age of 50.3 years and had been diagnosed with MS an average of 13 years. Sixty-six percent of the sample reported current or recent pain. Just over a third (34%) of those with pain reported constant pain with little variability in pain intensity. Participants endorsing pain reported an average pain intensity rating of 4.8 (SD ⫽ 2.34) for the prior week (0-10 numeric rating scale); 48% of these individuals reported mild pain, 27% reported moderate pain, and 25% reported severe pain. Persons with pain reported an average of 6.7 distinct pain sites. The most common pain sites were legs (74.8%), lower back (60.5%), and neck (52.1%). Average pain intensity ratings (0-10 scale) for pain locations were highest for legs (M ⫽ 5.53), lower back (M ⫽ 5.47), and feet (M ⫽ 5.26). Finally, the average level of overall pain interference for the prior week (as measured using the Brief Pain Inventory) was 3.33 (0-10 scale) among the group reporting pain. The highest levels of pain interference were reported for sleep (M ⫽ 4.12), recreational activities (M ⫽ 4.00), and work in and outside the home (M ⫽ 3.67). The findings are consistent with previous reports indicating that pain is common in persons with MS and is severe in a substantial subset of these individuals. Future research is needed to determine the adequacy and efficacy of available treatments for pain problems in persons with MS.
M. Jensen, A. Hoffman, D. Cardenas; University of Washington, Seattle, WA Chronic pain is a significant problem for many individuals with spinal cord injury (SCI), but there is much that is still not known about the scope and impact of this problem. The current study was performed in order to: (1) compare the severity of pain in persons with spinal cord injury (SCI) to national norms, (2) examine the association between pain and measures of psychological functioning, community integration and pain interference with daily activities, and (3) examine the change in the incidence and intensity of chronic pain over time. 147 adults with SCI who had completed a survey 2 to 6 years previously completed a second survey that included measures of: the presence or absence of pain in general and at specific body sites, average pain intensity (0 – 10 rating scale), pain interference (modified Brief Pain Inventory Pain Interference scale), pain severity (SF-36 Bodily Pain scale), psychological functioning (SF-36 Mental Health scale), and community integration (Community Integration Questionnaire). The results indicated that: (1) pain was more severe, on average, in this sample of patients with SCI than it is in normative samples; (2) the presence of pain was associated with poorer psychological functioning and social integration, (3) the intensity of pain was associated with interference with activities of daily living, and (4) little systematic change was found in pain over a 2 to 6 year period, although there was some evidence that the incidence of shoulder pain increases over time. The findings underscore the serious nature of pain in persons with SCI, and provide additional support for the need to identify effective treatments for SCI-related pain.
S77
(875) Operant conditioning in Fibromyalgia Syndrome: Impact on central pain processing
(877) Number of intrathecal pumps being used for chronic intractable neuropathic pain
K. Thieme, H. Flor; University of Washington, Seattle, WA The operant model of chronic pain suggests that reinforcement of pain behaviors may lead to the maintenance of chronic pain and disability. The goal of the present study was to examine the influence of the operant conditioning on central pain processing in Fibromyalgia Syndrome (FMS). Pain and tolerance thresholds, EEG levels as baseline, habituation, acquisition, and extinction in 20 FMS and 22 healthy controls. Four shock intensities were administered: pain threshold, 25%, 50%, and 75% of the distance between pain tolerance and threshold. During habituation, 15 electric stimuli at each of the 4 intensity levels (N⫽60) were administered. The training phase consisted of the application of 20 electric stimuli of each intensity (N⫽80). During extinction, 15 stimuli of each level were presented (N⫽60). Half of each group was positively reinforced for increased and half for decreased pain reports in the acquisition period (last 10 trials for each intensity level in the habituation period). Pain ratings and N150, P260 and P390 amplitudes of somatosensory evoked potential and the cortisol production in blood serum were recorded. Pain threshold (F(2; 36) ⫽ 112.34, p ⬍ .001) and tolerance (F(2; 36) ⫽ 89.64, p ⬍ .001) were significantly lower in FMS than in HC. The FMS patients showed significantly slower extinction in N 150, P260, and P390 amplitudes and verbal pain responses. The significantly negative correlation between N150 component and cortisol production supports the relations between pain coping and stress. These results indicate that operant conditioning can induce self-regulation of the brain and might be important in the maintenance and in the development of chronic pain. Supported by grants of Deutsche Forschungsgemeinschaft to KT (Th 988-1/2), and HF (FL 156/26, Clinical Research Unit 107) the Max-Planck-Award for International Cooperation
C. Roland, J. Biskupiak; The University of Utah, Dept. of Pharmacotherapy, Pharmacotherapy Outcomes Research Center, Salt Lake City, UT The patient with chronic pain that is not well managed by more traditional therapeutic means may be considered for implantation of an intrathecal (IT) pump. The number of patients with chronic intractable pain and the number of patients who have IT pumps in place is not known. In an effort to estimate the number of patients with chronic intractable neuropathic pain treated with IT analgesics, we conducted a retrospective review of a medical claims database. We queried the MEDSTAT’S MarketScan databases which reflect the healthcare experience of employees and dependants covered by health benefit programs of large employers. The claims data are collected from approximately 100 different insurance companies and third party administrators (160 million Americans or 57% of total population). The database does not include Medicaid or worker’s compensation (120 million Americans). Historically, the MarketScan database represents approximately 4 million covered lives. The years queried included 2000 and 2001 or 1.75 years. First, we identified all unique patients that experienced a procedure related to an implantable infusion pump. A total of 3,269 patients were identified and represented a total of 291 unique diagnoses. We then focused on diagnoses related to neuropathic pain which made up 84 of the 291 original diagnoses identified. These 84 diagnoses represented 2,809 unique patients with an implantable infusion pump. The total of 2,809 patients over 1.75 years represents 1,605 patients per year or 0.04% of the total number of patients in the database (4 million). Therefore, 0.04% of the 160 million Americans represent 64,200 patients with neuropathic pain requiring an implantable infusion pump. If an equivalent prevalence is assumed for the other 120 million Americans, then the total would be approximately 112,000 patients. In conclusion, we estimate that there are approximately 100,000 Americans with neuropathic pain and an IT implanted pump.
G08 - Pain Epidemiology
(878) Chronic pain in individuals with spinal cord injury: A survey and longitudinal study
(876) Nature and scope of pain in multiple sclerosis T. Osborne, D. Ehde, M. Jensen, M. Hanley, K. Raichle, G. Kraft; University of Washington School of Medicine, Seattle, WA Pain has recently been identified as a common problem in multiple sclerosis (MS). The current cross-sectional study is one of the first to comprehensively describe pain problems in a community sample of persons with MS using several standardized pain assessment measures. Participants completed a survey that included measures of pain intensity, variability, location, and interference. The sample (N ⫽ 181) was 78% female with a mean age of 50.3 years and had been diagnosed with MS an average of 13 years. Sixty-six percent of the sample reported current or recent pain. Just over a third (34%) of those with pain reported constant pain with little variability in pain intensity. Participants endorsing pain reported an average pain intensity rating of 4.8 (SD ⫽ 2.34) for the prior week (0-10 numeric rating scale); 48% of these individuals reported mild pain, 27% reported moderate pain, and 25% reported severe pain. Persons with pain reported an average of 6.7 distinct pain sites. The most common pain sites were legs (74.8%), lower back (60.5%), and neck (52.1%). Average pain intensity ratings (0-10 scale) for pain locations were highest for legs (M ⫽ 5.53), lower back (M ⫽ 5.47), and feet (M ⫽ 5.26). Finally, the average level of overall pain interference for the prior week (as measured using the Brief Pain Inventory) was 3.33 (0-10 scale) among the group reporting pain. The highest levels of pain interference were reported for sleep (M ⫽ 4.12), recreational activities (M ⫽ 4.00), and work in and outside the home (M ⫽ 3.67). The findings are consistent with previous reports indicating that pain is common in persons with MS and is severe in a substantial subset of these individuals. Future research is needed to determine the adequacy and efficacy of available treatments for pain problems in persons with MS.
M. Jensen, A. Hoffman, D. Cardenas; University of Washington, Seattle, WA Chronic pain is a significant problem for many individuals with spinal cord injury (SCI), but there is much that is still not known about the scope and impact of this problem. The current study was performed in order to: (1) compare the severity of pain in persons with spinal cord injury (SCI) to national norms, (2) examine the association between pain and measures of psychological functioning, community integration and pain interference with daily activities, and (3) examine the change in the incidence and intensity of chronic pain over time. 147 adults with SCI who had completed a survey 2 to 6 years previously completed a second survey that included measures of: the presence or absence of pain in general and at specific body sites, average pain intensity (0 – 10 rating scale), pain interference (modified Brief Pain Inventory Pain Interference scale), pain severity (SF-36 Bodily Pain scale), psychological functioning (SF-36 Mental Health scale), and community integration (Community Integration Questionnaire). The results indicated that: (1) pain was more severe, on average, in this sample of patients with SCI than it is in normative samples; (2) the presence of pain was associated with poorer psychological functioning and social integration, (3) the intensity of pain was associated with interference with activities of daily living, and (4) little systematic change was found in pain over a 2 to 6 year period, although there was some evidence that the incidence of shoulder pain increases over time. The findings underscore the serious nature of pain in persons with SCI, and provide additional support for the need to identify effective treatments for SCI-related pain.