Biomedical subjects

Hans Madsen

Publications and source records attributed to Hans Madsen.

5 recordsLinked to original sources

PubMed2006

[Abdominal pain].

Abdominal and pelvic pain are the most common causes of referral to a gastroenterologist or gynaecologist, and the understanding of visceral pain mechanisms may contribute to a better diagnosis and treatment. Visceral pain is often perceived as a deep, dull and vague sensation with referral to somatic and other visceral structures, but when the peritoneum is involved the pain is more distinct and localised. Long duration or recurrence of the pain may produce permanent changes in the central nervous system, resulting in an increased sensitivity to external stimuli. These changes often involve other organs and somatic structures in the referred pain area. Finally, options for treating visceral pain are described.

Abdominal Pain↗

PubMed2003

Endometriosis is associated with central sensitization: a psychophysical controlled study.

Endometriosis is a pain syndrome representing a major cause of pelvic pain in women of reproductive age. The aim of this study was to test the hypothesis that persistent nociceptive input from endometriotic tissues leads to central sensitization manifested by somatic hyperalgesia and increased referred pain areas to experimental saline-induced muscle pain in patients with endometriosis, compared to healthy control subjects. Ten women with laparoscopically confirmed endometriosis and 10 healthy, age-matched women participated in the study. Hypertonic saline (0.5 mL, 5.8%) was injected intramuscularly, in random succession, into 1 site of menstrual pain referral (the multifidus muscle at the low back) and into 1 non-pain control site (first dorsal interosseous muscle [FDI] of the hand). The post-saline pain intensity and pain areas at the FDI were significantly greater in patients with endometriosis than in control subjects (P <.05) but were not different between the groups for the back. An absence of enhancement of post-saline pain responses at the back in the endometriosis group suggests that saline-induced pain at the back appears to activate segmental inhibitory systems in patients with endometriosis. Manifestation of central sensitization in women with endometriosis is demonstrated by increased muscle nociceptor input in the form of increased post-saline pain intensity, pain areas at the FDI, and hypersensitivity to pressure stimulation. These findings provide new insights into the complex pain mechanisms associated with endometriosis.

Adult↗

PubMed2002

Controlled dilatation of the uterine cervix--an experimental visceral pain model.

Pain originating from the female reproductive organs is a substantial clinical problem to treat. Experimental models may be a tool for the study of visceral pain mechanisms and hence provide information to aid in formulating new treatment strategies. The aim was to develop and evaluate the performance and safety of a model for nociceptive stimulation of the uterine cervix by balloon dilatation using impedance planimetry. Three consecutive (repeated) dilatations at 1 ml/min, an isovolumetric and a fast dilatation at 2 ml/min were performed. Pilot studies were conducted in vitro on hysterectomy specimens, followed by application of the model in 14 healthy females. Subjects indicated the quality of perception and pain during dilatations by verbal reports and the McGill Pain Questionnaire (MPQ), and the intensity by a continuous electronic visual analog scale. The pain location was marked on an anatomical map. The balloon cross-sectional area (CSA) was measured simultaneously. The experimental procedure was atraumatic. Pain was evoked in all subjects, with referral to the hypogastric and low back regions. The word descriptors on the MPQ and the areas of referred sensations were similar to that seen clinically in abortion, labor and menstrual pain. The pain intensity correlated with balloon CSA (r=0.9, P<0.001). No significant differences were found for the balloon volumes (4.2, 3.8 and 3.9 ml) or CSA (163, 122 and 123 mm(2)) to pain threshold (PT) for repeated dilatations, suggesting the reliability of the model. There was significant correlation between the balloon volume and CSA to reach the PT for single and repeated cervical dilatations. During isovolumetric distension, greater overall pain intensity was demonstrated for the prolonged as compared to the shorter duration cervical stimulation. In conclusion, this is the first human experimental pain model for dilatation of the uterine cervix, providing a safe, controlled, quantifiable stimulus that evoked reliable pain scores. The model thus provides a new possibility to study gynecological pain and may lead to better characterization and treatment of female visceral pain syndromes.

Adult↗

PubMed2002

Antenatal women with or without pelvic pain can be characterized by generalized or segmental hypoalgesia in late pregnancy.

The aims of the present study were to determine the influence of pregnancy on somatosensory responses in women with or without pelvic/lumbosacral pain. Thirty pregnant women participated and were divided into pain (n = 12) and nonpain (n = 18) groups on the basis of pain complaints and positive pain-provoking tests associated with pelvic or lumbosacral pain during the current pregnancy. In the pain group, 9 reported initial pain in trimester 1, 2 in trimester 2, and 1 in trimester 3. Quantitative sensory testing with pressure pain threshold (PPT), heat pain threshold (HPT), and tactile threshold (TT) was performed once during each of the 3 trimesters at referred pain sites (sacrum, back, and pubis) and no pain control sites (thigh, arm, and sternum). All subjects in the pain group reported back pain, and 91% also had pain at the sacrum and pubis. The pain group exhibited significantly greater pain sensitivity than the nonpain group. The HPT and PPT were higher in trimester 3 as compared to trimesters 1 and 2 (P < .012). The increase in thresholds, or hypoalgesia, was generalized and present at both referred pain and control sites in the pain group. In the nonpain group hypoalgesia was localized to the presumed referred pain sites at the back and sacrum. There were no significant variations in the TT in any trimester. The study demonstrates for the first time that hypoalgesia in late pregnancy is generalized in women with pelvic pain and localized in women without pelvic pain. This suggests that the descending noxious inhibitory system is activated in late pregnancy and is probably more intense and generally activated in women with pelvic pain and only segmentally activated in women without pain.

Journal Article↗

PubMedDate not supplied

A comparison of modality-specific somatosensory changes during menstruation in dysmenorrheic and nondysmenorrheic women.

OBJECTIVE: The objective was to evaluate somatosensory thresholds to a multimodality stimulation regimen applied both within and outside areas of referred menstrual pain in dysmenorrheic women, over four phases of confirmed ovulatory cycles, and to compare them with thresholds in nondysmenorrheic women during menstruation. DESIGN: Twenty dysmenorrheic women with menstrual pain scoring 5.45 +/- 0.39 cm (mean +/- standard error of mean) on a visual analog scale (10 cm) participated. Fifteen nondysmenorrheic women with a menstrual pain score of 0.4 +/- 0.2 cm participated as controls. Ovulation was confirmed by an enzyme-multiplied immunoassay technique. Menstrual pain was described with the McGill Pain Questionnaire. Areas within menstrual pain referral were two abdominal sites and the midline of the low back, and the arm and thigh were the control areas. The pressure pain threshold (PPT) and pinch pain threshold were determined by a hand-held electronic pressure algometer, the heat pain threshold (HPT) by a contact thermode, and the tactile threshold with von Frey hairs. RESULTS: In dysmenorrheic women the McGill Pain Questionnaire showed a larger sensory and affective component of pain than the evaluative and miscellaneous groups. The HPT and PPT were lower in the menstrual phase than in the ovulatory, luteal, and premenstrual phases, both within and outside areas of referred menstrual pain (p <0.01), with a more pronounced decrease at the referral pain areas. The pinch pain threshold was lower in the menstrual phase than in the ovulatory phase (p <0.02), and the tactile threshold did not differ significantly across the menstrual phases or within any site. Dysmenorrheic women had a lower HPT at the control sites and a lower PPT at the abdomen, back, and control sites, than in those of nondysmenorrheic women in the menstrual phase. CONCLUSIONS: The results show reduced somatosensory pain thresholds during menstruation to heat and pressure stimulation, both within and outside areas of referred menstrual pain in dysmenorrheic women. Dysmenorrheic women showed a lower HPT at the control sites and a lower PPT at all the sites than those for nondysmenorrheic women in the menstrual phase. The altered somatosensory thresholds may be dependent on a spinal mechanism of central hyperexcitability, induced by recurrent moderate to severe menstrual pain.

Adult↗