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Biomedical subjects

J Olesen

Publications and source records attributed to J Olesen.

At least 145 records · Page 8Linked to original sources
PubMed1997

Evidence of qualitatively altered nociception in patients with fibromyalgia.

OBJECTIVE: To investigate the perception of pain in tender muscles of patients with fibromyalgia. METHODS: Twenty-five women with fibromyalgia and 25 healthy women were examined. Seven different pressure intensities were used to palpate a highly tender muscle and a largely normal muscle. Subjects then recorded their response to induced pain on a visual analog scale. The examiner was blinded to each subject's response. RESULTS: The stimulus-response function for pressure versus pain recorded for normal muscle was well described by a power function. For highly tender muscle, the stimulus-response function was displaced toward lower pressures and, more importantly, it was linear, i.e., qualitatively different from that of normal muscle. CONCLUSION: This study demonstrates that nociception is qualitatively altered in patients with fibromyalgia, which is consistent with recent findings in other patients with tender muscles. The data strongly indicate that fibromyalgic pain, at least in part, is due to aberrant central pain mechanisms.

Adult↗
PubMed1997

Role of endothelium and nitric oxide in histamine-induced responses in human cranial arteries and detection of mRNA encoding H1- and H2-receptors by RT-PCR.

1. Histamine induces relaxation of human cranial arteries. Studies have revealed that the relaxant histamine H1-receptor predominates in human cerebral and the H2-receptor in temporal arteries, while H1- and H2-receptors are of equal importance in the middle meningeal artery. The purpose of the present study was to examine the role of the endothelium and nitric oxide in histamine-induced responses and to show the presence of mRNA encoding H1- and H2-receptors in human cranial arteries. 2. Electrophoresis of polymerase chain reaction (PCR) products from human cerebral, middle meningeal and temporal arteries, demonstrated products corresponding to mRNA encoding both H1- and H2-receptors in arteries with and without endothelium. The amplified PCR products were sequenced and showed 100% homology with the published sequences of these histamine receptors. 3. A sensitive in vitro system was used to study vasomotor responses to histamine. In precontracted cerebral, middle meningeal and temporal arteries with and without endothelium, histamine caused a concentration-dependent relaxation with Imax values between 87% and 81% and pIC50 values between 8.14 and 7.15. In arteries without endothelium the histamine-induced relaxation was significantly less potent (Imax values between 87% and 66% and pIC50 values between 7.01 and 6.67) than in cranial arteries with an intact endothelium. 4. This addition of histamine to arteries without endothelium and pretreated with the histamine H2-antagonist, cimetidine (10(-5) M), caused a concentration-dependent contraction of the cranial arteries with Emax values between 86% and 29% and pEC50 values between 7.53 and 6.77. This contraction was blocked by the histamine H1-receptor antagonist, mepyramine (10(-7) M), and even turned into a relaxation with Imax values between 84% and 14% and pIC50 values between 7.42 and 5.86. 5. The nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME, 3 x 10(-5) M) significantly inhibited the relaxant response to histamine in cerebral and temporal arteries (pIC50 values between 7.43 and 7.13). The combined treatment with L-NAME (3 x 10(-5) M) and cimetidine (10(-5) M) caused a further displacement of the concentration-response curve (pIC50 values between 7.14 and 6.57) and decreased the maximum relaxant responses in all three cranial arteries (Imax values between 62% and 39%). 6. In conclusion, this is the first study which show mRNA encoding histamine H1- and H2-receptors in human cranial arteries. The results indicate that histamine-induced relaxation of human cranial arteries is partially mediated via an endothelial H1-receptor coupled to the production of nitric oxide and partially via a H2-receptor associated with the smooth muscle cells. In addition, there is evidence for a contractile H1-receptor in the smooth muscle cells in these arteries.

Cerebral Arteries↗
PubMed1997

Serotonin metabolism in chronic tension-type headache.

Serotonergic neurons play a major role in the regulation of pain and may therefore also be involved in the pathophysiology of tension-type headache. Platelets are important in the regulation of the free serotonin level in plasma and may be a model of serotonergic neurons. The aim of the present study was to investigate the peripheral serotonin (5HT) metabolism in patients with chronic tension-type headache. The 5HT levels in platelets and in plasma, the beta-thromboglobulin (beta-TG) levels in plasma, and the urinary excretion of 5-hydroxyindoleacetic acid (5HIAA) were measured in 40 patients with chronic tension-type headache and in 40 healthy controls. The platelet uptake index was calculated as the ratio between platelet 5HT and plasma 5HT levels. There were no significant differences in platelet 5HT, plasma 5HT, beta-TG, or 5HIAA between patients and controls. The platelet uptake index was significantly lower in patients 243 (136-367) than in controls 352 (202-508), p=0.03. Our results indicate that the peripheral 5HT metabolism is largely normal in patients with chronic tension-type headache.

Adult↗
PubMed1996

[Prevalence and sex distribution of different forms of migraine].

The aim of this study was to provide prevalence and sex-ratio of subtypes of migraine diagnosed by neurological interview according to the criteria of the International Headache Society. In all, 3000 males and 1000 females aged 40 years were randomly selected from the Danish population. They received a mailed questionnaire regarding migraine. The questionnaire response rate was 87%. People with self-reported migraine and a random sample of those reporting no migraine were invited to a headache interview, and a physical and a neurological examination. Those not reacting to the invitation were interviewed by telephone. Participation in the interview was 87%. Kappa was 0.77 validating self-reported migraine in the questionnaire against the diagnosis of the clinical interview. Lifetime prevalences of migraine without aura, migraine with aura, migraine aura without headache, and migrainous disorder were 8%, 4%, 1% and 1% in males and 16%, 7%, 3% and 2% in females. Overall lifetime prevalence of any type of migraine was 18%, 12% in males and 24% in females. This is lower than the sum of the prevalences since migraine diagnoses are not mutually exclusive. The male:female ratios of migraine without aura, migraine with aura, migraine aura without headache, and migrainous disorder were approximately 1:2.

Adult↗
PubMed1996

Decreased pain detection and tolerance thresholds in chronic tension-type headache.

OBJECTIVE: To study nociceptive processing in patients with chronic tension-type headache. METHODS: Forty patients with chronic tension-type headache and 40 healthy controls were examined. Pericranial tenderness was recorded by manual palpation, pressure pain detection and tolerance thresholds were recorded with an electronic pressure algometer, and the relative (pain detection minus sensory detection) electrical pain threshold was recorded with a constant current stimulator. RESULTS: Patients were considerably more tender than controls at all the locations examined by manual palpation (P<.001). Pressure pain detection and tolerance thresholds recorded in the finger were significantly lower in patients than in controls (P<.001). A nonsignificant similar trend was observed in the temple (P < or =.12). Detection and tolerance thresholds were decreased to a similar degree in patients compared with controls, and pain thresholds recorded in the finger and in the temple were highly correlated (r=.84, P<.001). The relative electrical pain threshold recorded at the labial commissure was significantly decreased in patients compared with controls (P=.03). All of the examined pain thresholds were significantly correlated to the pericranial tenderness recorded by palpation (r=-.35 to -.53, P < or = .03). CONCLUSION: The present finding of a general hypersensitivity to pain stimuli in chronic tension-type headache indicates that central factors play an important role in the pathogenesis of this disorder.

Adult↗
PubMed1996

Histamine-1 receptor blockade does not prevent nitroglycerin induced migraine. Support for the NO-hypothesis of migraine.

It has previously been shown that in migraine sufferers infusion of glyceryl trinitrate (GTN) and histamine causes an immediate headache during the infusion and a genuine migraine attack one to several hours after the infusion. This identical time profile indicates a common mechanism of action. To evaluate whether GTN causes headache via liberation of histamine, we studied the effect of GTN 0.5 micrograms.kg-1.min-1 for 20 min in seven migraine sufferers, once after pretreatment with the histamine-1 (H1)-receptor blocker mepyramine (0.5 mg.kg-1) and once without pretreatment. This mepyramine dose is known to completely abolish histamine-induced headache. After pretreatment with mepyramine five patients experienced migraine, and without pretreatment six patients did so. The median peak headache score was 7 on a 0-10 scale with and without mepyramine pretreatment. The arterial responses, evaluated with transcranial Doppler, were also unaffected by the mepyramine pretreatment. Our results demonstrate that neither headache nor arterial dilatation due to GTN infusion is caused by histamine release. In all likelihood the common mediator of migraine induction by GTN and histamine is nitric oxide.

Adult↗
PubMed1996

A comparison of tension-type headache in migraineurs and in non-migraineurs: a population-based study.

The prevalence, sex-ratio and clinical characteristics of tension-type headache were analyzed in 4000 people from the general population. The one-year-period prevalence of tension-type headache was not significantly different in people with migraine without aura (83%), in people with migraine with aura (75%) and in people who had never had migraine (76%). The male/female ratio varied from 1:1.19 to 1:1.23 and was not significantly different in the three subgroups. Tension-type headache was significantly more frequent within the last year and lasted longer in migraineurs than in people who had never had migraine. The pain characteristics and accompanying symptoms were very similar in the three subgroups. Tension-type headache was often precipitated by stress, mental tension and tiredness. Only migraineurs had episodes of tension-type headache precipitated by alcohol, over-matured cheese, chocolate and physical activity. We conclude that tension-type headache and migraine are separate disorders and not part of a continuum of headache disorders. However, migraine may aggravate and precipitate tension-type headache possibly due to convergence of various noxious peripheral input into the trigeminal nucleus.

Adult↗
PubMed1996

The family history of migraine. Direct versus indirect information.

Migraine assessed by proband report was evaluated in a family study of migraine. A clinical interview of spouses and first-degree relatives by a physician was used as an index of validity. The operational diagnostic criteria of the International Headache Society were used. Of the 378 probands from the general population, 126 had migraine without aura, 127 had migraine with aura, 17 had both migraine without aura and migraine with aura and 108 had never had migraine. Spouses (n = 229) and first-degree relatives (n = 1109) were included in the analyses. Sensitivity, specificity, predictive values and chance-corrected agreement rate for the diagnosis of migraine were 49%, 93%, 81% (PVpos), 77% (PVneg) and 0.47, respectively. The corresponding values for migraine without aura were 58%, 87%, 63% (PVpos), 84% (PVneg) and 0.46 respectively, while the values for migraine with aura were 52%, 88%, 61% (PVpos), 83% (PVneg) and 0.42, respectively. Migraine assessed by proband report is not satisfactory for diagnosing migraine in relatives, since the number of affected relatives is highly underestimated. Our results emphasize the necessity of a clinical interview of the relatives in family studies of migraine.

Case-Control Studies↗
PubMed1996

Effect of a nitric oxide donor (glyceryl trinitrate) on nociceptive thresholds in man.

Several animal studies suggest that nitric oxide (NO) plays a role in central and peripheral modulation of nociception. Glyceryl trinitrate (GTN) exerts its physiological actions via donation of NO. The purpose of the present study was to examine the effect of this NO donor on nociceptive thresholds in man. On two different study days separated by at least a week 12 healthy subjects received a staircase infusion of GTN (0.015, 0.25, 1.0, 2.0 micrograms/kg/min, 20 min each dose) or placebo in a randomized double-blind crossover design. Before the infusion and after 15 min of infusion on each dose, pressure pain detection and tolerance thresholds were determined by pressure algometry (Somomedic AB, Sweden) in three different anatomic regions (finger, a temporal region with interposed myofascial tissue and a temporal region without interposed myofascial tissue). Relative to placebo, the three higher GTN doses induced a decrease in both detection and tolerance thresholds in the temporal region with interposed myofascial tissue (p = 0.003 detection and p = 0.002 tolerance thresholds, Friedman). No such changes were observed in the other two stimulated regions. These results could reflect central facilitation of nociception by NO. However, we regard convergence of nociceptive input from pericranial myofascial tissue and from cephalic blood vessels dilated by NO as a more likely explanation of our findings.

Adult↗
PubMed1996

Initiating mechanisms of experimentally induced tension-type headache.

To elucidate possible myofascial mechanisms of tension-type headache, the effect of 30 min of sustained tooth clenching (10% of maximal EMG-signal) was studied in 58 patients with tension-type headache and in 30 age- and sex-matched controls. Pericranial tenderness, mechanical and thermal pain detection and tolerance thresholds and EMG levels were recorded before and after the clenching procedure. Within 24 h, 69% of patients and 17% of controls developed a tension-type headache. Shortly after clenching, tenderness was increased in the group who subsequently developed headache, whereas tenderness was stable in the group of patients who remained headache free. Mechanical pain thresholds evaluated by pressure algometry remained unchanged in the group which developed headache, whereas thresholds increased in the group which did not develop headache. Thermal pain detection and tolerance thresholds remained unchanged in both groups. These findings indicate that, although there may be several different mechanisms of tension-type headache, one of them is sustained muscle contraction. A peripheral mechanism of tension-type headache is therefore possible, whereas a secondary segmental central sensitization seems to be involved in subjects with frequent tension-type headache. Finally, the increase in pressure pain thresholds in patients who did not develop headache suggested that clenching activated their antinociceptive system, whereas those developing headache were unable to do so.

Adult↗
PubMed1996

Migraine without aura and migraine with aura are distinct clinical entities: a study of four hundred and eighty-four male and female migraineurs from the general population.

The clinical characteristics of migraine without aura (MO) and migraine with aura (MA) were compared in 484 migraineurs from the general population. We used the criteria of the International Headache Society. The lifetime prevalence of MO was 14.7% with a M:F ratio of 1:2.2; that of MA was 7.9% with a M:F ratio of 1:1.5. The female preponderance was significant in both MO and MA. The female preponderance was present in all age groups in MA, but was first apparent after menarche in MO, suggesting that female hormones are an initiating factor in MO, but not likely so in MA. The age at onset of MO followed a normal distribution, whereas the age at onset of MA was bimodally distributed, which could be explained by a composition of two normal distributions. The estimated separation between the two groups of MA was at age 26 years among the females and age 31 years among the males. The observed number of persons with co-occurrence of MO and MA was not significantly different from the expected number. The specificity and importance of premonitory symptoms are questioned, but prospective studies are needed. Bright light was a precipitating factor in MA, but not in MO. Menstruation was a precipitating factor in MO, but not likely in MA. Both MO and MA improved during pregnancy. The clinical differences indicate that MO and MA are distinct entities.

Adult↗