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(701)
Abstracts
S29
(701) Serum hyaluronic acid (HA) in patients with fibromyalgia syndrome (FMS) and healthy normal controls (HNC)
(703) Diffuse noxious inhibitory controls: Abnormal pain modulation in chronic pain patients
B Upadhyaya, Y Xiao, W Haynes, J Michalek, O Lim, I Russell; The University of Texas Health Science Center, San Antonio, TX The FMS is a common, chronic disorder characterized by wide spread body pain and allodynia. It is diagnosed using the 1990 ACR criteria. Morning stiffness (AMStif) is a painful symptom that can impair a patient’s ability to work. It would help to have a biochemical marker for this symptom. It was predicted that serum HA might be such a marker. Serum HA levels are elevated in patients with rheumatoid arthritis, where early morning HA is elevated, and falls as the AMStif improves. In FMS, serum HA levels are controversial. The aims of the current study were to measure early morning serum HA levels and to seek demographic correlations. The AMStif was documented using the visual analog scale in the Fibromyalgia Impact Questionnaire. Serum HA was measured using a highly sensitive commercial ELISA kit. Group differences were analyzed by two-tailed, T test. Correlational analysis for continuous variables was by the Pearson. Consecutive patients with FMS (N⫽59, mean age⫾SEM ⫽ 49.9⫾1.8) and HNC (N⫽23, age⫾SEM⫽ 36.6⫾2.1) were recruited and blood samples obtained at 8:30am. The severities of AMStif in the two groups were 6.9⫾0.3 cm for FMS and 2.1⫾0.1cm for HNC. Serum HA levels were 32.9⫾4.2 ng/ml and 17.0⫾3.2 ng/ml, respectively [p⫽0.006]. The proportion of FMS with HA levels⬎the HNC mean⫹1SD was 32.2%. Among the FMS cohort, the morning HA level correlated with the age (r⫽0.36: P⬍0.005), but not with AMStif, gender or ethnicity. The early morning levels of serum HA were significantly higher in FMS than in HNC but a relationship to AMStif was not confirmed. As the sample base of HNC is expanded in this study, it will be important to age-match the HNC to the FMS. It is still hoped that serum HA will prove be a useful marker in FMS.
T Currie, J Riley, H Gremillion, J Fisher, A Lovell, J Green, A Mauderli; Department of Prosthodontics, Gainesville, FL Diffuse noxious inhibitory control (DNIC) is the phenomenon where a painful stimulus at a local area of the body (experimental stimulus) is inhibited by a second painful stimulus at a distal body site (DNIC conditioning stimulus). This study examined the effect of DNIC on 8 patients with Irritable Bowel Syndrome (IBS) and 8 patients with Myofascial Pain Disorder (MPD) compared to 16 age and sex matched controls. The experimental stimulus was a series of 30-second thermal stimuli trials administered to the palm. The DNIC conditioning stimulus was immersion of the right foot in a cold-water bath. To adjust for individual differences in pain thresholds, the temperature of the stimuli for the experiment sessions was determined such that subjects gave a peak rating of 40-50 on a scale of 0-100 for heat stimuli and a rating of 20-30 on a scale of 0-100 for cold stimuli. The study consisted of two experimental sessions, a control session using a 23C water bath and a DNIC session with the temperature of the water bath set at the pre-determined temperature above the pain threshold (4-16C). The results of repeated measures analysis of variance indicated that IBS and MPD patients rated more intense pain during the DNIC trials than the control trial, whereas for the control subjects, the opposite pattern was observed. In addition, IBS and MPD patients reported significantly more pain during the first trial of the DNIC-temperature water bath compared to the their second and third DNIC trials. Controls experienced consistent pain inhibition during all DNIC trials. This pattern was seen for peak pain and overall average pain but not for the time to peak pain. These findings suggest that patients with chronic pain may experience abnormal pain processing compared to healthy controls.
(702) Fibromyalgia and hypervigilance: New data on an old theory
(704) Fibromyalgia pain flares are not predictable by high levels of pain and distress
K Sauro, C Villemure, G Bennett, C Bushnell; McGill University, Montreal, QC, Canada Fibromyalgia (FM) is a chronic, widespread pain syndrome with no clear peripheral etiology. Recent studies suggest that FM may be due to changes in the CNS, including reduced inhibitory processes, however, prior work suggests that FM patients are hypervigilant to noxious stimuli. Data from normal subjects show that focusing attention on pain increases the perceived intensity of the pain and pain-evoked brain activity. Thus, if FM patients are unable to disengage attention from pain, their pain experience should be enhanced. To examine the hypervigilance model, we compared FM patients and matched healthy controls (HC) on a cross-modality attention task. If the model is correct, FM patients would be less able than HC subjects to shift attention away from the pain. Nine female FM patients (mean age 53.9) and 9 HC subjects (mean age 54.2) received simultaneous pairs of 5s painful heat pulses (⬃46oC & 47oC) and pairs of 5s odor pulses. Attention was moved between pain and olfaction by asking subjects to attend to one or the other modality and requiring them to determine whether the pulses in that modality were the same or different. As expected, HC subjects rated pain as more intense when attending to heat than when attending to odors (6.06 vs 4.19, p⬍0.05). FM patients showed the same difference in pain ratings (7.22 vs 6.22, p⬍0.05), even though perceiving the heat stimuli as more intense. Moreover, task performance was not different between groups (p⫽0.17), further suggesting that FM could indeed shift attention away from the pain. These findings suggest that FM patients are as able to disengage attention from pain as HC subjects, and attentional focus affects pain perception similarly in FM patients and HC subjects. These findings do not disprove the hypervigilance model; however they suggest that other mechanisms may be involved in this syndrome.
R Staud, E Koo, M Rodriguez, R Patel, M Robinson; University of Florida, Gainesville, FL Fibromyalgia (FM) pain is dynamic and can fluctuate greatly over time. Intermittent increases of FM pain are described as Pain Flares. Anecdotally, many FM patients have associated these flares with trauma and stress. We hypothesized that FM patients would report pain flares frequently (⬎1/month) and would be associated with distress and high pain levels. Thirty two female FM patients were followed for up to 208 days (mean 54⫾44 days). All patients rated pain, depression, fatigue, and anxiety using a visual analogue scale (VAS). Ratings were recorded daily by phone. Inititally, pain ratings were collected to establish a baseline and to determine individual pain variability. Flare definition: increase in daily pain ratings by ⬎ 1 STD over baseline. Age of study subjects was 48.5⫾13.7 years. Study subjects fulfilled the ACR Criteria for FM. TP count: 16.5. Clinical pain: 3.3⫾1.6 VAS. 10 FM subjects fulfilled Flare requirements. Flare patients had lower depression, fatigue, and anxiety ratings (3.0, 1.6, 3.6, and 1.5 VAS) than those patients who did not (4.5, 3.2, 4.7, and 2.9 VAS) (p ⬍ .05). Mean flare duration: 4.9⫾3.1 days. Flare pain increased from 3.0⫾0.6 to 4.3⫾0.8 VAS (p ⬍ .05). Negative affect and fatigue remained unchanged during and after a flare (p ⬎.05). Somatic focus and physical function did not differ between FM patients who flared and those who did not. We conclude that FM patients with low levels of pain and distress (VAS ⬍ 3.0) were more likely to experience a Pain Flare. During the study period only 28% of FM patients experienced a Pain Flare. Flares pain increases were mild (1.2 VAS) and short (4.9 days). Pain, mood and fatigue did not significantly change before and after a flare. It appears that low levels of FM pain are associated with a higher risk of flares.
S29
(701) Serum hyaluronic acid (HA) in patients with fibromyalgia syndrome (FMS) and healthy normal controls (HNC)
(703) Diffuse noxious inhibitory controls: Abnormal pain modulation in chronic pain patients
B Upadhyaya, Y Xiao, W Haynes, J Michalek, O Lim, I Russell; The University of Texas Health Science Center, San Antonio, TX The FMS is a common, chronic disorder characterized by wide spread body pain and allodynia. It is diagnosed using the 1990 ACR criteria. Morning stiffness (AMStif) is a painful symptom that can impair a patient’s ability to work. It would help to have a biochemical marker for this symptom. It was predicted that serum HA might be such a marker. Serum HA levels are elevated in patients with rheumatoid arthritis, where early morning HA is elevated, and falls as the AMStif improves. In FMS, serum HA levels are controversial. The aims of the current study were to measure early morning serum HA levels and to seek demographic correlations. The AMStif was documented using the visual analog scale in the Fibromyalgia Impact Questionnaire. Serum HA was measured using a highly sensitive commercial ELISA kit. Group differences were analyzed by two-tailed, T test. Correlational analysis for continuous variables was by the Pearson. Consecutive patients with FMS (N⫽59, mean age⫾SEM ⫽ 49.9⫾1.8) and HNC (N⫽23, age⫾SEM⫽ 36.6⫾2.1) were recruited and blood samples obtained at 8:30am. The severities of AMStif in the two groups were 6.9⫾0.3 cm for FMS and 2.1⫾0.1cm for HNC. Serum HA levels were 32.9⫾4.2 ng/ml and 17.0⫾3.2 ng/ml, respectively [p⫽0.006]. The proportion of FMS with HA levels⬎the HNC mean⫹1SD was 32.2%. Among the FMS cohort, the morning HA level correlated with the age (r⫽0.36: P⬍0.005), but not with AMStif, gender or ethnicity. The early morning levels of serum HA were significantly higher in FMS than in HNC but a relationship to AMStif was not confirmed. As the sample base of HNC is expanded in this study, it will be important to age-match the HNC to the FMS. It is still hoped that serum HA will prove be a useful marker in FMS.
T Currie, J Riley, H Gremillion, J Fisher, A Lovell, J Green, A Mauderli; Department of Prosthodontics, Gainesville, FL Diffuse noxious inhibitory control (DNIC) is the phenomenon where a painful stimulus at a local area of the body (experimental stimulus) is inhibited by a second painful stimulus at a distal body site (DNIC conditioning stimulus). This study examined the effect of DNIC on 8 patients with Irritable Bowel Syndrome (IBS) and 8 patients with Myofascial Pain Disorder (MPD) compared to 16 age and sex matched controls. The experimental stimulus was a series of 30-second thermal stimuli trials administered to the palm. The DNIC conditioning stimulus was immersion of the right foot in a cold-water bath. To adjust for individual differences in pain thresholds, the temperature of the stimuli for the experiment sessions was determined such that subjects gave a peak rating of 40-50 on a scale of 0-100 for heat stimuli and a rating of 20-30 on a scale of 0-100 for cold stimuli. The study consisted of two experimental sessions, a control session using a 23C water bath and a DNIC session with the temperature of the water bath set at the pre-determined temperature above the pain threshold (4-16C). The results of repeated measures analysis of variance indicated that IBS and MPD patients rated more intense pain during the DNIC trials than the control trial, whereas for the control subjects, the opposite pattern was observed. In addition, IBS and MPD patients reported significantly more pain during the first trial of the DNIC-temperature water bath compared to the their second and third DNIC trials. Controls experienced consistent pain inhibition during all DNIC trials. This pattern was seen for peak pain and overall average pain but not for the time to peak pain. These findings suggest that patients with chronic pain may experience abnormal pain processing compared to healthy controls.
(702) Fibromyalgia and hypervigilance: New data on an old theory
(704) Fibromyalgia pain flares are not predictable by high levels of pain and distress
K Sauro, C Villemure, G Bennett, C Bushnell; McGill University, Montreal, QC, Canada Fibromyalgia (FM) is a chronic, widespread pain syndrome with no clear peripheral etiology. Recent studies suggest that FM may be due to changes in the CNS, including reduced inhibitory processes, however, prior work suggests that FM patients are hypervigilant to noxious stimuli. Data from normal subjects show that focusing attention on pain increases the perceived intensity of the pain and pain-evoked brain activity. Thus, if FM patients are unable to disengage attention from pain, their pain experience should be enhanced. To examine the hypervigilance model, we compared FM patients and matched healthy controls (HC) on a cross-modality attention task. If the model is correct, FM patients would be less able than HC subjects to shift attention away from the pain. Nine female FM patients (mean age 53.9) and 9 HC subjects (mean age 54.2) received simultaneous pairs of 5s painful heat pulses (⬃46oC & 47oC) and pairs of 5s odor pulses. Attention was moved between pain and olfaction by asking subjects to attend to one or the other modality and requiring them to determine whether the pulses in that modality were the same or different. As expected, HC subjects rated pain as more intense when attending to heat than when attending to odors (6.06 vs 4.19, p⬍0.05). FM patients showed the same difference in pain ratings (7.22 vs 6.22, p⬍0.05), even though perceiving the heat stimuli as more intense. Moreover, task performance was not different between groups (p⫽0.17), further suggesting that FM could indeed shift attention away from the pain. These findings suggest that FM patients are as able to disengage attention from pain as HC subjects, and attentional focus affects pain perception similarly in FM patients and HC subjects. These findings do not disprove the hypervigilance model; however they suggest that other mechanisms may be involved in this syndrome.
R Staud, E Koo, M Rodriguez, R Patel, M Robinson; University of Florida, Gainesville, FL Fibromyalgia (FM) pain is dynamic and can fluctuate greatly over time. Intermittent increases of FM pain are described as Pain Flares. Anecdotally, many FM patients have associated these flares with trauma and stress. We hypothesized that FM patients would report pain flares frequently (⬎1/month) and would be associated with distress and high pain levels. Thirty two female FM patients were followed for up to 208 days (mean 54⫾44 days). All patients rated pain, depression, fatigue, and anxiety using a visual analogue scale (VAS). Ratings were recorded daily by phone. Inititally, pain ratings were collected to establish a baseline and to determine individual pain variability. Flare definition: increase in daily pain ratings by ⬎ 1 STD over baseline. Age of study subjects was 48.5⫾13.7 years. Study subjects fulfilled the ACR Criteria for FM. TP count: 16.5. Clinical pain: 3.3⫾1.6 VAS. 10 FM subjects fulfilled Flare requirements. Flare patients had lower depression, fatigue, and anxiety ratings (3.0, 1.6, 3.6, and 1.5 VAS) than those patients who did not (4.5, 3.2, 4.7, and 2.9 VAS) (p ⬍ .05). Mean flare duration: 4.9⫾3.1 days. Flare pain increased from 3.0⫾0.6 to 4.3⫾0.8 VAS (p ⬍ .05). Negative affect and fatigue remained unchanged during and after a flare (p ⬎.05). Somatic focus and physical function did not differ between FM patients who flared and those who did not. We conclude that FM patients with low levels of pain and distress (VAS ⬍ 3.0) were more likely to experience a Pain Flare. During the study period only 28% of FM patients experienced a Pain Flare. Flares pain increases were mild (1.2 VAS) and short (4.9 days). Pain, mood and fatigue did not significantly change before and after a flare. It appears that low levels of FM pain are associated with a higher risk of flares.