Biomedical subjects

L Bendtsen

Publications and source records attributed to L Bendtsen.

42 records · Page 3Linked to original sources

PubMed1996

A non-selective (amitriptyline), but not a selective (citalopram), serotonin reuptake inhibitor is effective in the prophylactic treatment of chronic tension-type headache.

OBJECTIVES: Although the tricyclic antidepressant amitriptyline is extensively used in the prophylactic treatment of chronic tension-type headache, only few studies have investigated the efficacy of this treatment and the results are contradictory. In addition, the new selective serotonin reuptake inhibiting antidepressants, which are widely used in depression and of potential value in pain management, have never been investigated in a placebo controlled study of tension-type headache. The aim was to evaluate the efficacy of amitriptyline and of the selective serotonin reuptake inhibitor citalopram in chronic tension-type headache. METHODS: Forty non-depressed patients with chronic tension type headache were included in a 32 week, double blind, placebo controlled, three-way crossover study. RESULTS: Thirty four patients completed the trial. Amitriptyline reduced area under the headache curve by 30% compared with placebo (P = 0.002), whereas citalopram had no significant effect (P = 0.68). Explanatory analyses showed that amitriptyline significantly reduced the duration of headache (P = 0.01), headache frequency (P = 0.01), and intake of analgesics (P = 0.02) but not headache intensity (P = 0.12). CONCLUSION: Although amitriptyline did not eliminate the headache, it provided a clinically important reduction of headache in the majority of otherwise treatment resistant patients. The differential effect of amitriptyline and citalopram indicates that mechanisms other than inhibition of serotonin reuptake are involved in the analgesic effect of the tricyclic antidepressants. Amitriptyline, but not citalopram, is valuable in the prophylactic treatment of chronic tension type headache.

Adolescent↗

PubMed1996

Amitriptyline, a combined serotonin and noradrenaline re-uptake inhibitor, reduces exteroceptive suppression of temporal muscle activity in patients with chronic tension-type headache.

Although reflexes in human jaw muscles have been extensively studied, the neurotransmitters involved in the regulation of these reflexes are not well known. The aim of the present study was to investigate whether amitriptyline, a combined serotonin and noradrenaline re-uptake inhibitor, modulates the late exteroceptive suppression period (ES2) of temporal muscle activity in chronic tension-type headache. ES2 was recorded with a previously evaluated method and assessed by a blinded observer in 35 patients with chronic tension-type headache. Thereafter, ES2 was recorded in 27 of these patients during a double-blind, placebo-controlled, 3-way crossover trial investigating the prophylactic effect of amitriptyline, the selective serotonin re-uptake inhibitor citalopram, and placebo. ES2 duration was significantly shorter during treatment with amitriptyline than during placebo, P = 0.02, while ES2 duration only tended to be shorter during treatment with citalopram, P = 0.34. ES2 was not significantly correlated to the prophylactic effect of amitriptyline or to a range of clinical and experimental pain parameters. Our results demonstrate that amitriptyline reduces ES2 and indicate that ES2 is modulated by serotonergic as well as noradrenergic neuronal pathways.

Adult↗

PubMed1995

Pressure-controlled palpation: a new technique which increases the reliability of manual palpation.

The objective of the present study was to investigate whether the reliability of tenderness evaluation can be increased by using a new technique called "pressure-controlled palpation" (pcp). The technique has been made possible by a newly invented piece of equipment called a palpometer, with which a pressure-sensitive plastic film attached to the index finger records the pressure exerted. In 15 patients with chronic tension-type headache and in 15 healthy volunteers, 2 investigators studied myofascial tenderness using conventional palpation and pressure-controlled palpation. Tenderness was scored on a 4-point scale in each of the examined pericranial regions. The sum of tenderness scores recorded by two observers using conventional palpation differed significantly (p = 0.0003), while results did not differ between observers using pressure-controlled palpation (p = 0.89). During palpation with seven different pressure intensities a positive and linear relation between pressure and pain intensity was found (p = 0.00006). Pain intensity reported by the subjects correlated highly with tenderness scored by the observer (rs = 0.95, p < 0.0001). These results demonstrate for the first time that tenderness scores can be compared between observers if palpation pressure is controlled. Pressure-controlled palpation represents a major improvement on current palpation techniques and should be standard in future research on myofascial pain disorders.

Adult↗

PubMed1993

Exteroceptive suppression periods in jaw-closing muscles. Variability and relation to experimental pain and sustained muscle contraction.

The duration of the late exteroceptive suppression period (ES2) of temporal muscle EMG activity has been reported to be reduced in patients suffering from chronic tension-type headache. Methods of recording and analysing ES2 have varied between centers and reproducibility of results within subjects, although insufficiently studied, has generally been poor. ES2 was investigated in 30 healthy subjects, using a computerized technique of recording, rectifying and averaging the EMG signals. Hour to hour and week to week variations of ES2 durations were calculated, and the influence of pain during a cold pressor test and of sustained muscle contraction on ES2 durations was investigated. The intra-individual variation of ES2 durations was 16.0% from hour to hour and 20.7% from week to week. The inter-individual variation was 36.7%. The present method for analysis of ES2 periods proved to be reliable, as the intra-observer variation was 4.2% and the inter-observer variation 4.6%. ES2 periods were significantly shorter on the first compared to the second day of examination (p = 0.006) and during experimental pain (p = 0.0005). We recommend the use of the computerized average technique in future studies and caution against the dependence of results upon factors such as conditioning and pain.

Adult↗

PubMed1990

Evidence that the newly cloned low-density-lipoprotein receptor related protein (LRP) is the alpha 2-macroglobulin receptor.

The human placental receptor (alpha 2MR) for alpha 2-macroglobulin-proteinase complexes contains 3 polypeptides of approx. 500 kDa, 85 kDa, and 40 kDa. N-terminal sequence analysis of the 500 kDa and 85 kDa polypeptides, analysis of a random selection of peptides convering 536 residues from these polypeptides, and analysis of a 1772 bp cDNA encoding part of the 500 kDa polypeptide provide evidence that the 500 kDa and 85 kDa chains are the alpha- and beta-subunits, respectively, of a recently cloned hepatic membrane protein, termed the low density lipoprotein receptor related protein (LRP) (Herz, J., Hamann, U., Rogne, S., Myklebost, O., Gausepohl, H. and Stanley, K.K. (1988) EMBO J. 7, 4119-4127; Herz, J., Kowal, R.C., Goldstein, J.L. and Brown, M.S. (1990) EMBO J. 9, 1769-1776). N-terminal sequence analysis of the 40 kDa polypeptide shows that it is of distinct genetic origin. It is suggested that LRP is the functional receptor for alpha 2-macroglobulin-proteinase complexes (alpha 2MR) and in addition may have as yet unsettled functions in lipoprotein metabolism.

Amino Acid Sequence↗

PubMedDate not supplied

Qualitatively altered nociception in chronic myofascial pain.

The aim of the present study was to investigate the stimulus-response function for pressure versus pain in patients with myofascial pain. Forty patients with chronic tension-type headache and 40 healthy controls were examined. Tenderness in 8 pericranial muscles and tendon insertions was evaluated by manual palpation with a standardized evaluated methodology. Thereafter, a highly tender muscle and a largely normal muscle were palpated with 7 different pressure intensities using a palpometer, and the induced pain was recorded by the subjects on a visual analogue scale blinded for the observer. Pericranial myofascial tenderness was considerably higher in patients than in controls (P < 0.00001). The stimulus-response function recorded from normal muscle was well described by a power function. From highly tender muscle, the stimulus-response function was displaced towards lower pressures and, more importantly, it was linear, i.e., qualitatively different from normal muscle. Our results demonstrate for the first time that nociceptive processes are qualitatively altered in patients with chronic myofascial pain and suggest that myofascial pain may be mediated by low-threshold mechanosensitive afferents projecting to sensitized dorsal horn neurons. Further investigations of these mechanisms may lead to an increased understanding and better treatment of these common and often incapacitation pain disorders.

Adolescent↗