DIFFERENCES IN PAIN SENSITIVITY BETWEEN MEN AND WOMEN, CAN THEY EXPLAIN THE FEMALE DOMINANCE AMONG FIBROMYALGIA PATIENTS ?

Stefan Lautenbacher, Marburg, Germany

Fibromyalgia is a chronic pain condition with widespread pain and multiple tender points The two pathological signs are not closely correlated in the late phases of fibromyalgia but may cause each other during the early phases of pathogenesis (Kosek et al, 1996 , Lautenbacher et al 1994) The tender points have appeared to be the most pain sensitive sites in extremely pain sensitive persons (Tunks et al, 1988) In other words, fibromyalgia patients suffer from a generalized form of hyperalgesia, which becomes most dramatic at the tender points In recent studies, evidence has been accumulated that the increase in pain sensitivity is clearly most pronounced when pain was induced by mechanical stimuli but that also other physical stressors like heat and electrical current can be used to demonstrate hyperalgesia in fibromyalgia (Arroyo & Cohen, 1993 , Kosek et al, 1996 Lautenbacher et al 1994)

The preponderance of women (60% 80 %) amongst fibromyalgia sufferers is well known In summary, fibromyalgia sufferers are mainly women with an increased sensitivity to pain, which becomes most evident when experimental pain is induced by mechanical stimuli These facts resemble those obtained when healthy women are compared to healthy men in psychophysical studies The two sexes differ to small or moderate degrees when experimental pain is induced by thermal or electrical stimuli (Riley et al, 1998) Consequently, the occurrence of sex differences in pain sensitivity appears tentative in these cases However, the existence of sex differences is beyond any doubt with women appearing clearly more pain sensitive than men, when experimental pain is induced by pressure (Riley et al, 1998) Hence, it is tempting to assume that it is this tendency towards mechanical hyperalgesia, which is seen in many healthy women, that predisposes them to the more pathological forms of mechanical hyperalgesia, which is seen in many female fibromyalgia sufferers Accordingly, it is of outstanding clinical relevance to detect the factors which make women that sensitive to pressure pain It is conceivable that especially muscle nociceptors, which are better tested by superficial application of pressure than of heat or electrical current, show a higher sensitivity in women, which predisposes them to fibromyalgia (Sorensen et al 1998) However, the stable sex differences might alternatively be due to the elastic properties of the female skin, which allow nociceptors to be very easily stimulated by pressure Future studies will show whether these or other explanations help to understand the pathogenesis of fibromyalgia

References

(1) Arroyo JF Cohen ML Abnormal responses to electrocutaneous stimulation in fibromyalgia Journal of Rheumatology 1993 20 1925 1931

(2) Kosek E Ekholm J Hansson P Sensory dysfunction in fibromyalgia patients with implications for pathogenic mechanisms Pain 1996 68 375 383

(3) Lautenbacher S Rollman GB McCam GA Multi method assessment of experimental and clinical pain in patients with fibromyalgia Pain 1994 59 45 53

(4) Riley JL 3rd, Robinson ME, Wise EA Myers CD Filhngim RB Sex differences in the perception of noxious experimental stimuli a meta analysis Pain 1998 74 181 187

(5) Sorensen J, Graven Nielsen T, Hennksson KG, Bengtsson M, Arendt Nielsen L Hyperexcitabihty in fibromyalgia Journal of Rheumatology 1998,25 152-5

(6) Tunks E Crook J Norman G Kalaher S Tender points in fibromyalgia Pain 1988 34 11 19

PAIN IN WOMEN

Dr Beverly-Jane Collett Consultant in Pain Management and Anesthesia Leicester Royal Infirmary UK

Several studies on experimental pain show that women have lower pain thresholds, (Fillmgim and Maixner,1995), report more pain and have a lower tolerance than men (Berkley, 1997) Epidemiological studies reveal that women report more frequent pain, pain of longer duration and more severe levels of pain than men (Unruh 1996)

Gender differences have been identified in the following conditions

Facial pain

Women report more facial pain, pain in the temporo mandibular joint and tenderness in the jaw muscles than men

Headache

Women have higher prevalence rates for chronic tension headache, migraine, post lumbar puncture headache and cervicogenic headache Men have a higher prevalence for chronic cluster headaches The prevalence of migraine is similar for girls and boys in the school age years However there is an increase in the rates for girls during adolescence Five per cent of women have migraine in the 2 days preceding menstruation, the first day of menstruation or at ovulation Improvement of migraine often occurs with pregnancy and the prevalence decreases following the menopause-though rates continue to be higher than for men

Musculoskeletal pain

Women report more musculoskeletal pain than men, particularly in the neck, shoulders upper limbs and hips Osteoarthntis, rheumatoid arthritis and fibromyalgia are more prevalent in women (Verbrugge et al 1991) and may in pan account for this

Abdominal pain

More abdominal pain is reported in girls and women although some of this may be associated with dysmenorrheoa However, even when dysmenorrheoa is excluded, abdominal pain is more common in women than men

Female pelvic anatomy can be responsible for certain specific painful conditions In addition, uterine pain can give nse to generalised muscle and subcutaneous hyperalgesia (Giamberardmo et al 1997)

Experimental pain sensitivity has been shown to vary at puberty, menstruation, pregnancy, and lactation and with the use of exogenous hormones New data are emerging that pain symptomatology of many illnesses, (not only gynaecological) vanes with reproductive status, especially puberty across the menstrual cycle, during and immediately after pregnancy and during and after the menopause This implies that there can be considerable variability in womens' pain experience

Berkley and Holdcroft have considered the following factors are important influences with regard to gender differences in pain - a) Genetics , b)Physiology, body composition , c) Pelvic anatomy , d) Stress , e) Steroid Hormones f) CNS function and Neuroactive agents , g) Life-style and sociocultulral events (Berkely and Holdcroft 1999)

Gender differences have implications for both pain assessment and therapy

Ischaemia produces a different pattern of chest pain in women than in men (Douglas and Gmsburg 1996) Body composition and sex-hormone-related differences between men and women can modify dmg pharmacokmetics and pharmacodynamics In addition, the analgesic effects of K-agonists such as buprenorphme, nalbuphme and pentazocme is enhanced in females compared to males (Gear et al 1996)

Women use health care resources more than men and there is evidence that their management within pain clinics may be different (Lack 1982) Further implications for the management of pain in women will be discussed

References

Berkley KJ. Sex differences in pain. Behav. Brain Sci 1997 ; 20 : 371-380

Berkely KJ, Holdcroft A. Sex and gender differences in pain. In Wall PD, Melzack R, eds. A Textbook of Pain. Edinburgh : Churchill

Livmgstone, 1999, 951-965

Douglas PS Ginsburg GS. The evaluation of chest pain in women. New England Journal of Medicine 1996 ; 334 : 1311-1315

Fillmgim RB, Maixner W. Gender differences in response to painful stimuli. Pain Forum 1995 ; 4 : 209-211.

Gear RW, Miaskowski C, Gordon NC, Paul SM, Heller PH, Levme JD. Kappa-opioids produce significantly greater analgesia in women than in men Nature Medicine 1996 ; 2 : 1248-1250

Giamberardmo MA, Berkely KJ, lezzi S, de Bigontina P, Vecchiet L Pain threshold variations in somatic wall tissues as a function of menstrual cycle, segmental site and tissue depth in non-dysmenorrheic women, dysmenorrheic women and men. Pain 1997 ; 71 : 187-197.

Lack DZ. Women and pain : another feminist issue. Women Ther 1985 : 1 : 55-64

Unruh A. M. Gender variations in clinical pain experience Pain 1996 ; 65 : 123-1667

Verbrugge, LM, Lepkowski JM and Konkol LL. Levels of disability among U S. adults with arthritis J Gerontol. Soc. Sci. 1991 ; 46 : S71-83

DOES PAIN INFLUENCE THE RECALL OF MEMORIES OF PAIN?

Stephen Morley. Amra Saleem, Academic Unit of Psychiatry & Behavioural Sciences, School of Medicine, University of Leeds, Leeds, LS2 9JT, UK.

Aim of Investigation We tested the hypothesis that the presence of pain increased the probability of recalling autobiographical memories of pain. Additional supplementary hypothesis concerning the specificity of recalled memories were also tested.

Methods 22 young women with recurrent menstrual pain were tested on two occasions; at mid-cycle and at menstruation. A control group (n=16) of women without menstrual pain were also tested. All participants completed standardised assessments of pain, mood and menstrual state and an autobiographical memory task.

Results There were no demographic differences between the groups and their pain, and mood status was not different at mid-cycle, however the menstrual pain group expenenced significantly more pain during menstruation. The pain group recalled more memories of physical pain. Memories of physical pain were more likely to be retrieved to a pain-related cue. Participants with menstrual pain, when tested first during menstruation recalled proportionately more memories of physical pain (mean = 0.56) than they did when tested first in mid-cycle (mean = 0.48). In contrast participants in the control group recalled more memories when tested first in mid-cycle (mean = 0.50) than when tested first dunng menstruation (mean = 0.26). Importantly there were no significant effects attributable to state at the time of testing or to its interaction with any other factor for either physical pain or non-pain memories.

Conclusions The data do not support the research hypothesis. We suggest that the influence of cue type overrode any potential Group X State interaction. The data yielded supplementary information on the specificity of recalled memories.

HYPERMOBILITY AND POSTPARTUM CHRONIC SPINAL PAIN.

 Andrew 0 Frank'. Vidyut Sharma2, Mona Romney', Caroline Dore\ Lorraine De Souza2, Bemadette Loughnan'. 1 Departments of Rehabilitation Medicine, Obstetrics and Anaesthetics, Northwick Park Hospital & Institute of Medical Research, Harrow HA1 3UJ, UK; 'Dept Health Studies, Brunei University, Isleworth TW7 5DU, UK. 'Imperial College School of Medicine, London W12 ONN, UK.

Aim of Investigation: To investigate the relationship between hypermobihty to postpartum spinal pain.

Methods: Participants in a randomised controlled trial of analgesia in labour were sent a follow up questionnaire asking for the presence or absence of back pain. Those answering "yes" were offered a clinical review by a back pain physician (1) during which data were collected on presence of back pain prior to conception, Roland Disability score and the Modified Zung Depression score. Clinical examination by the same observer scored peripheral and spinal mobility by the Beighton score (range 0-9) and tested straight leg raise (SLR). Interrelationships between variables were assessed using KendalFs tau. Significant factors contributing to spinal pain were determined by multiple regression.

Results: Ninety-eight women were seen 7-14 months after delivery. Significant relationships were found between the Beighton score and both the SLR test (p<0.001), and the Roland Disability score (p<0.003). For those women with new back pain post delivery (N=73) it was found that both Beighton scores(p=0.003) and Modified Zung scores (p=0.05)were significant predictors of the Roland disability score.

Conclusions: Hyper-mobility may be a predisposing factor for postpartum back pain and requires further study. Should these women be identified as being at risk of developing back pain, appropriate physiotherapeutic advice may be provided prophylactically during pregnancy.

Acknowledgements: North West Thames Regional Health Authority and Brunei University for financial support.

(1) Frank AO, Sharma V, Romney M, Frank AD, McAuley JH, De Souza LH, Loughnan B. Comparison of postpartum low back pain with that of patients referred to a back pain clinic. Proceedings of the 9th World Congress of Pain 1999, page 184 (abstract)

THE COMPARISON OF INTRAPERITONEAL TRAMADOL AND TENOXICAM IN POSTOPERATIVE PAIN CONTROL AFTER LAPAROSCOPIC PROCEDURES

Karsly B.Kavacan N.YyImaz M, Bigat Z, El-man M.

Affiliation: Akdeniz University, Faculty of Medicine, Dept.of Anesth and Rean.Antalya/Turkey

Introduction: Recently non-steroid anti-inflammatory drug and opioid administration have been widely used in postoperative pain management.The aim of this study was to compare the analgesic effectiveness of intraperitoneal tramadol and tenoxicam.

Methods: After institutional ethics committee approval, the study was perform 45 healty patients, ASAI-II undergoing gynecological laparoscopic procedures.Opioid drugs were not given during the maintenance of anesthesia. At the end of the surgery,one of the study solutions were injected into infraumblical incision before removal of the laparoscope. In Group A, 20mg tenoxicam(10 ml volume); 50mg tramadol(10 ml volume) in Group B were injected into intraperitoneal cavity. Patients of Group C(control) received 10 ml saline intraperitoneally.The anesthetist who was blinded about which drug was injected.Postoperative pain was assessed using 0-10 cm visual analogue scale(VAS) and verbal pain score(VPS). VAS and VPS scores were recorded 30* min.l , 2' and 4 h postoperatively. Total consumption of analgesic for postoperative 24 h were recorded.

Results: The pain scores of Group A at postoperative 30 min,l , 2 and 4 h were significantly lower than theGroup B and C. There were not found statistically significant difference at postoperatively 4 h for pain between Group A and B. The pain scores of Group A and B were significantly lower than control group.Total analgesic requirement in control group was higher than other two group, this difference was statistically significant.

Conclusion: Intraperitoneal tenoxicam and tramadol are simple and effective technique to reduce pain after laparoscopic gynecological operations.

References: l.Anesth Analg ]999;88(4):939-42 2. Anesthesia 1999:54(1):72-6.

LOOSING THE CONTROL OVER OWN'S LIFE: EXPERIENCES OF LIVING WITH FIBROMYALGIA

Lillemor R-M. Hallberg & Ulrika Passe The Nordic School of Public Health, Box 121 33, S-402 42 Goteborg, Sweden

Aim of investigation: The aim was to describe, from the perspective of women with fibromyalgia, their experiences of living with chronic pain.

Method: The women were active members of a self-help group. In-depth interviews were conducted and transcribed verbatim. Grounded theory methodology was used in analysing the data. The aim of such a method is to generate categories and to explore the conceptual relationships between separate categories and their subcategories.

Results: A core category, describing the women's lost control over their lives, whereas pain had taken over the control. The women described repeated periods of sick-leaves due to prominent pain, leading to a vicious circle of pain, despair and decreasing quality of life. The personality of the women was characterised by over-compensatory perseverance in combination with low need for self-assertion. Despite being very ambitious, the women had always had a weak self-reliance. The women had been "good girls" which was perceived as very demanding to them. However, due to continuous performance and engagements the women acquired their self-esteem. It was obvious that the pain, at the time for the interviews, demanded a life without internal and external demands. The pain became a necessary boundary-line to them, resulting in increasing awareness of their own needs and increasing quality of life. Most women perceived the cause of fibromyalgia as biological and supported, despite not being validated, the medical doctors' seeking for the "biological fault".

Conclusions: Women with fibromyalgia use pain as a necessary boundary-line against perceived internal and external demands.

MIDAZOLAM (M) VERSUS KETAMINE (K) COMBINED WITH REMIFENTANIL (R) FOR OOCYTE RETRIEVAL

 Panagiota Xenitos. MD, Fabienne Roelants, MD, Patricia Lavand'homme, MD, PhD.

Anaesthesiology Dept, Universite Catholique de Louvain, 1200 Brussels, Belgium.

Aim of investigation : oocyte retrieval by transvaginal puncture is a painful but short lasting procedure for which various techniques of anaesthesia/analgesia have been reported'. The ultrashort action or R makes it an ideal agent for ambulatory patients. This study compares the benefit of using a small dose of either M or K, combined with continuous R infusion.

Methods : 70 unpremedicated patients received an Initial bolus of R 25 pg followed by a continuous R Infusion of 0.075 ug/kg/min. Group M (n=35) had 1.5 mg intravenous M at the beginning of the procedure and group K (n=35) 0.2 mg/kg intravenous K. Patients got supplemental doses of R (25 ug) as needed. All patients had 6 L/min oxygen with a facial mask. Total R doses, vital parameters, oxygen saturation, adverse drug effects, perioperative sedation score (0-4 : alert, sleepy, asleep, not arousable), pain score (VAS 0-100) after the procedure, satisfaction (score 0-5) and postoperative analgesics requirements (postop A R) were recorded. Statistical analysis used ANOVA ; p ? 0.05 significant.

Results : There were no significant difference in patients' parameters and procedure duration between groups. No adverse drug effects were noticed. Results are xpressed in tho Tot-.lo

 

 

Group M Group K P
Opioids

(ug/kg/min)*

0.11 ±0.02 0.11 ±0.02 ns
Sedation

(0-4)*

0.97±0.6 1.03±0.6 ns
Satisfaction (0-5)* 3.6±1.4 3.4±1 ns
VAS(O-IOO)* 25±22 8±18 0.03
Postop A R (n patients) 31/35 22/35 <0.05
*mean ± SD

 

Conclusions : Patients expressed similar satisfaction for M or K combination with R infusion. K use produced higher postoperative comfort but did not reduce intraoperative R doses.

Reference : (1) Anaesthetist 1999 48(10) :698-704.

ASSESSING MENSTRUAL PAIN USING THE MULTIDIMENSIONAL AFFECT AND PAIN SURVEY (MAPS)

Denis Martin & Caroline Simpson Scottish Network for Chronic Pain Research, Queen Margaret University College, Edinburgh, Scotland, UK. EH6 8HF.

Aim of Investigation: To describe and compare profiles of menstrual pain using MAPS*: combined oral contraceptive pill users and non-users.

Methods: MAPS, a questionnaire derived from cluster analysis, describes sensory, suffering and well-being dimensions of pain. 37 randomly selected students aged between 18-25 years gave their informed written consent to take part in the study. 18 combined oral contraceptive pill users (mean age = 22.9) and 19 non-users (mean age =21.9) completed MAPS during the time they judged to be in their worst pain associated with menstruation. They also marked areas of pain on a body chart and where there was more than one area (generally abdomen and lower back) they scored them separately on the same questionnaire. Independent t-tests compared sensory, suffering and well-being mean cluster scores for abdominal pain between users and non-users of combined oral contraceptive pill. (Back pain reports were too few for analysis.)

Results: There was no relationship between site of pain and pill use. For abdominal pain, sensory (mean difference = 0.33; 95% C.I. = 0.11, 0.54) and suffering scores (mean difference = 0.75; 95% C.I. = 0.38, 1.12), but not well-being (mean difference = 0.39; 95% C.I. = -0.86, 0.82), were significantly lower in users than non-users. Visually, the same pattern was apparent for back pain though well being was markedly higher in users.

Conclusions: Based on MAPS scores, use of the combined contraceptive pill appeared to reduce the sensory and suffering dimensions of menstrual-related pain. Well-being was not altered.

* Clark WC (1999). Pain emotion and drug-induced subjective states: Analysis by multidimensional scaling. In Adelman G & Smith BH eds. Elsevier's Encyclopaedia of Neuroscience 2ed. PI 561-1565

Pain in Europe III. EFIC 2000, Nice, France, September 26-29, 2000. Abstracts book, p. 137, 154, 253, 261, 264 ,266, 321, 360