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Biomedical subjects

S Lautenbacher

Publications and source records attributed to S Lautenbacher.

At least 19 recordsLinked to original sources
PubMed2006

EEG responses to tonic heat pain.

The aim of the present study was to characterize the EEG response pattern specific for tonic pain which is an experimental pain model resembling clinical pain more closely than phasic pain. Tonic experimental pain was produced by a series of heat pulses 1 degree C above pain threshold over 10 min. A series of heat pulses 0.3 degree C below pain threshold and a constant temperature of 37 degrees C served as non-painful heat control and as baseline condition, respectively. The level of attention was experimentally manipulated by instruction and by a distraction task. Twenty male, pain-free subjects had to rate the sensation intensity and sensation unpleasantness during thermal stimulation. Furthermore, a German version of the McGill Pain Questionnaire was to be filled out after tonic painful heat stimulation. The EEG was recorded via 10 leads according to 10/20 convention. Power density was calculated for the usual frequency bands. The ratings showed that tonic painful heat was experienced clearly distinct from tonic non-painful heat. An EEG response pattern emerged characterized by a rather generalized increased delta(2) activity, a left-biased fronto-temporally diminished theta activity, a fronto-temporal decrease in the alpha(1) activity and a left-sided temporal increase in the beta(1) activity. This observation agrees well with the findings of others. However, there was no evidence in our data that these EEG changes are specific to tonic heat pain as opposed to changes observed during tonic non-painful heat stimulation. Accordingly, the repeatedly reported EEG patterns are also likely to be produced by other forms of strong somatosensory stimuli and to be not specific for pain.

Adult↗
PubMed2004

[The impact of Alzheimer's disease on the pain processing].

It is well known that patients with Alzheimer's disease report less pain in comparison to their age group. However, little is yet known about the underlying mechanisms causing the decreased pain report. In order to learn more about these mechanisms, experimental studies are indispensable, since only in experimental settings, noxious input and pain experience can be assessed independently. We therefore report on experimental data on pain perception in Alzheimer's disease in this review. The experimental data suggest that the threshold for pain tolerance is markedly increased and the autonomic pain reaction is, at least in part, considerably diminished. On the other hand, pain threshold and pain event-related brain potentials remain largely unchanged. As possible explanations we discuss age-related changes in pain perception and neuroanatomical changes in Alzheimer's disease. Particularly the atrophy of limbic structures may have a modifying impact on the pain experience. We also discuss what influence communicational deficits have on pain report.

Aged↗
PubMed2001

[A structured pain interview for geriatric patients].

BACKGROUND: In old age, assessment of pain often is hampered by sensory and cognitive deficits that do not allow the patients to fill in standardized questionnaires without help from significant others. Therefore, as an alternative, we developed a structured pain interview, and examined its properties and acceptance in a sample of geriatric patients with pain. METHODS: The interview covers site of pain, intensity of pain, its duration and persistency, pain related disability and, finally, emotional and cognitive variables. In addition, the interviewer addresses significant others to get information about medication, previous treatment, and residence, and administers the Mini-Mental-State-Examination (MMSE). The analysis includes 128 patients of pain centers older than 74 years, of whom 80% are female. RESULTS: Forty percent of the subjects score below the critical MMSE value < or =23 indicative of cognitive impairment. These patients are responsible for 36 out of a total of 39 missing values. A significant increase of missing values is observed in patients with a MMSE score below 10. Cognitive impairment goes along with greater functional and social disability. On the other hand, cognitive impairment is unrelated to localization, intensity, and duration of pain. The memory item of the MMSE can be used as a screening tool for cognitive impairment. Patients, who are unable to recall any of the three objects, comprise 80% of the total of missing values and demonstrate a low MMSE score. CONCLUSION: As long as geriatric patients are able to communicate verbally, they are most likely to profit from the structured pain interview in spite of existing cognitive impairment. A MMSE score <10 indicates that the interpretation of the data obtained may be difficult, especially due to a high frequency of missing values.

Aged↗
PubMed2001

Spatial summation of heat pain in males and females.

Sex differences in pain sensitivity have been found to vary between considerable and negligible. It has appeared that the pain stimulation method is critical in this context. It was assumed this might be due to the different degrees of spatial summation associated with the different pain stimulus modalities. Hence, sex differences were investigated in spatial summation of heat pain in 20 healthy women and 20 healthy men of similar age. Pain thresholds were assessed by a tracking procedure and responses to supra-threshold pain stimulation by numerical ratings. Heat stimuli were administered by a thermode with contact areas of 1, 3, 6 and 10 cm2. Pain thresholds were significantly higher with smaller areas stimulated than with larger ones. No significant effect of area was found for the ratings of the supra-threshold stimuli, the intensities of which were tailored to the individual pain threshold. Consequently, spatial summation of heat pain appeared to result mainly in a shift of the pain threshold on the ordinate and not a change of slope of the stimulus-response function in the pain range. In neither of the two pain parameters were there any sex differences. Therefore, the present study demonstrated that sex differences in spatial summation of heat pain are unlikely.

Female↗
PubMed2001

Sex differences in musculoskeletal pain.

Epidemiologic, clinical, and experimental evidence points to sex differences in musculoskeletal pain. Adult women more often have musculoskeletal problems than do men. Discrepant findings regarding the presence of such differences during childhood and adolescence continue. Biologic and psychosocial factors might account for these differences. The authors review evidence showing that mechanically induced pressure is more likely to show sex differences than other noxious stimuli and to discriminate between individuals suffering from musculoskeletal pain and matched controls. The authors suggest that a state of increased pain sensitivity, with a peripheral or central origin, predisposes individuals to chronic muscle pain conditions, and that there are sex differences in the operation of these mechanisms; women are vulnerable to the development and maintenance of musculoskeletal pain conditions.

Humans↗
PubMed2000

[New investigations on the melancholic type personality structure in migraine patients].

In an earlier published study [16, 17, 18], it was demonstrated that migraine sufferers have personality traits significantly more strongly associated with the typus melancholicus than healthy individuals and patients with other mental and physical illnesses. They display a fixation on tidiness which manifests itself in an excessive striving for quality and quantity in performance-oriented situations. The main features of their social relationships are excessive helpfulness combined with an exaggerated tendency towards guilt avoidance and symbiotic attachment to their own families. They do not differ from unipolar depressives in these respects. The major aim of the new study is to examine whether the concept of the typus melancholicus in relation to migraine sufferers as proposed in the first study is adaptable to explaining the personality characteristics of migraine sufferers ("typus migraenicus"). Age-matched samples of 42 female migraine sufferers, 40 female patients with unipolar depression, and 41 female control subjects took part in the new study. The test instruments used were von Zerssen's Munich Personality Test (MPT) and a questionnaire specially designed by the first author for assessing the typus migraenicus (German "Fragebogen zur Erfassung des Typus migraenicus," or FETM). The results obtained using univariate and multivariate analyses demonstrate a confirmation of the typus migraenicus concept, although to a less pronounced degree than the previous study. This can be seen as supporting evidence that, independently of the study sample and the investigators, migraine sufferers display with higher random frequency a personality profile very similar to the premorbid personality structure in unipolar depressives.

Adult↗
PubMed1999

Region-specific encoding of sensory and affective components of pain in the human brain: a positron emission tomography correlation analysis.

Brain imaging with positron emission tomography has identified some of the principal cerebral structures of a central network activated by pain. To discover whether the different cortical and subcortical areas process different components of the multidimensional nature of pain, we performed a regression analysis between noxious heat-related regional blood flow increases and experimental pain parameters reflecting detection of pain, encoding of pain intensity, as well as pain unpleasantness. The results of our activation study indicate that different functions in pain processing can be attributed to different brain regions; ie, the gating function reflected by the pain threshold appeared to be related to anterior cingulate cortex, the frontal inferior cortex, and the thalamus, the coding of pain intensity to the periventricular gray as well as to the posterior cingulate cortex, and the encoding of pain unpleasantness to the posterior sector of the anterior cingulate cortex.

Adult↗
PubMed1999

Corticotropin-releasing-hormone lacks analgesic properties: an experimental study in humans, using non-inflammatory pain.

The antinociceptive potency of corticotropin-releasing-hormone (CRH) has been established in several animal studies in which both central and peripheral sites of action were considered. However, there have not yet been any experimental trials, besides one attempt using clinical dental pain demonstrating the potential analgesic properties of CRH in humans. For this reason, we studied the effect of CRH on experimental heat pain sensitivity in 18 healthy men, using a double-blind, cross-over and placebo-controlled design. A dose of 100 microg (i.v.) was chosen because of its well-known neuroendocrine effects in humans. The pain parameters assessed were, visual analog scale (VAS) ratings for pain intensity and pain unpleasantness, pain thresholds and scores for discrimination ability. To differentiate between a direct analgesic effect of CRH and indirect effects via evoked hormonal responses in the hypothalamic-pituitary-adrenocortical (HPA) system (beta-endorphin, ACTH, cortisol), CRH was applied with and without a pre-treatment with dexamethasone. In neither of the two conditions was there any systematic change in our pain parameters. This failure to find any evidence suggesting an analgesic action of CRH or of the subsequent hormones of the HPA system was obtained despite the fact that CRH produced clear neuroendocrine responses such as increases in the plasma concentration of beta-endorphin and cortisol. It is unclear whether the lack of analgesic action of CRH is due to its non-existence in humans, due to the use of a pain model which does not assess minute changes in pain sensitivity and does not trigger substantial inflammatory responses, or due to an insufficient dose of CRH.

Adult↗
PubMed1999

Plasma leptin levels do not change in healthy humans shortly after a hydrocortisone challenge.

The acute response of plasma leptin levels to a hydrocortisone challenge was measured in 16 healthy volunteers. We additionally asessed insulin which is known to play a regulatory role in the leptin system. While plasma cortisol levels increased significantly after the administration of hydrocortisone, this rise was not associated with any change in leptin and insulin concentrations during the 3.5-hour experimental period. This result corroborates the assumption that glucocorticoid-induced increases in leptin levels, as described in the literature, occur delayed and are due rather to an activation of leptin synthesis than to a mere leptin release.

Adult↗
PubMed1998

Attentional control of pain perception: the role of hypochondriasis.

The role of hypochondriasis in the attentional control of pain perception was investigated in 28 in-patients (12 women and 16 men) at a hospital for psychosomatic disorders, who had been classified into high- and low-hypochondriacal categories by means of the Illness Attitude Scales (IAS). The two groups did not differ in their basic pain sensitivity based on their heat pain thresholds. Attentional control was manipulated by a mental arithmetic task, resulting in one experimental condition with distraction and one without distraction. In both of the conditions, subjects rated the intensity and the unpleasantness of nonpainful and painful heat stimuli on visual analog scales (VAS). Distraction significantly reduced the perceived intensity and unpleasantness of the stimuli at painful levels but not at nonpainful levels. Contrary to our expectation, the individual level of hypochondriasis did not influence this result. Although distraction seemed to have a strong influence on pain perception, hypochondriasis as a symptom or a trait did not contribute to this effect.

Adult↗
PubMed1997

Tender points, depressive and functional symptoms: comparison between fibromyalgia and major depression.

The degree of symptomatic overlap between fibromyalgia and major depression should be estimated by assessing the amount of local tenderness and the frequency and severity of depressive and functional symptoms. Tender points were assessed by palpation and symptoms by psychometric scales in 30 patients with fibromyalgia and 26 patients with major depression. The patients with fibromyalgia had markedly more tender points (16.5) than the depressive patients (1.3). In contrast, depressive and functional symptoms were present in both groups of patients, and some depressive patients (26%) also suffered from clinical pain. An increased sensitivity to pressure pain clearly distinguishes fibromyalgia from depression even if there is an overlap of other symptoms.

Adult↗
PubMed1997

Possible deficiencies of pain modulation in fibromyalgia.

OBJECTIVE: To examine possible deficiencies in endogenous pain modulating mechanisms in fibromyalgia patients compared with matched pain-free control subjects. DESIGN/SUBJECTS/METHODOLOGY: Pain reduction was investigated in 25 female patients with fibromyalgia and 26 age-matched healthy women using the diffuse noxious inhibitory controls (DNIC) paradigm. Tonic thermal stimuli at painful and nonpainful intensities, tailored to individual heat pain thresholds, were employed to induce pain inhibition. The anticipated effect was assessed by measuring the electrical pain threshold and detection threshold, using a double staircase method. Only nontender control points were stimulated (thermode on the foot, electrodes on the inner forearm). RESULTS: The patients with fibromyalgia had significantly lower heat pain thresholds than the healthy subjects, but similar electrical detection and pain thresholds. The repeatedly applied electrical stimuli resulted in a degree of perceptual adaptation that was similar between the two groups. However, concurrent tonic thermal stimuli, at both painful and nonpainful levels, significantly increased the electrical pain threshold in the healthy subjects but not in the fibromyalgia patients. The electrical detection threshold was not affected in either group. CONCLUSIONS: Pain modulation, produced by a concurrent tonic stimulus in healthy persons, was not seen in the fibromyalgia group. The patients either had deficient pain modulation or were unable to tolerate a tonic stimulus intense enough to engage a modulatory process. It remains to be established whether the pain reduction found in the healthy subjects was the conventional DNIC effect, another effect (e.g., distraction), or a combination of both.

Adaptation, Psychological↗
PubMed1997

Perception of body size and body satisfaction in recovered anorexic women: comparison with restrained and unrestrained eaters.

The perception of body size, measured by three different methods, and body satisfaction were assessed in 23 formerly anorexic inpatients with an "intermediate" (n = 9) or a "good" outcome (n = 14) and compared with the data obtained from 21 restrained and 20 unrestrained eaters. Using the Kinaesthetic Size Estimation Apparatus, overestimation and uncertainty in the perception of body size became apparent in both groups of former patients. The other two methods, Video Distortion Technique and Image Marking Procedure, did not produce comparable results. There was only a trend towards higher scores on body dissatisfaction, as measured by the Body Shape Questionnaire, in the patients' groups in comparison with the group of unrestrained eaters, whereas the patients' scores on body dissatisfaction were quite similar to those of the restrained eaters. None of these measures discriminated between the two outcome categories of "intermediate" and "good.". These findings suggest that restoration of body weight, by itself, obviously does not cause a normalization of body experience in all its components in patients with anorexia nervosa.

Adolescent↗
PubMed1995

Tonic pain evoked by pulsating heat: temporal summation mechanisms and perceptual qualities.

The properties of a newly developed tonic heat pain model (THPM), which makes use of pulsating contact heat, were investigated in 18 young men. The most important feature of this model is that repetitive heat pulses with an intensity of 1 degree C above the individual pain threshold are employed. This approach was used to tailor the tonic pain stimulation to the individual pain sensitivity. In the first of two experiments, the effects of pulse frequencies ranging from 5 to 30 pulses per minute (ppm) on ratings of pain intensity and pain unpleasantness (visual analogue scales) were examined. At all frequencies, both ratings increased steadily over the 5-min test period. Frequencies of 15 ppm or more appeared to enhance pain intensity throughout the test period compared to the lower frequencies, but did not appear to alter pain unpleasantness. This suggests that only pain intensity is influenced by slow temporal summation and that a sort of frequency threshold exists for this kind of summation. In the second experiment, the THPM was compared to a well-established form of tonic pain stimulation, the cold-pressor test (CPT); visual analogue scales were again used, and in addition the McGill Pain Questionnaire was employed. The CPT appeared to produce stronger tonic pain than the THPM. However, as is typical with tonic pain, both tonic pain models induced relatively higher values on the affective pain dimension than on the sensory pain dimension. The time course of pain was dynamic in the CPT, with an increase followed by a plateau phase, at least in those subjects who could tolerate the CPT for more than 60 sec. In contrast, as in the first experiment, the pain ratings in the THPM were characterized by a slow and steady increase over time. Moreover, there was absolutely no indication of a dichotomy between "pain-sensitive" and "pain-tolerant" individuals in the THPM, although such a dichotomy was evident in the CPT. This implies that the distinction between pain-sensitive and pain-tolerant individuals can be made only with the CPT, and that this distinction represents individual differences in peripheral vascular reactions to cold rather than in pain perception. In conclusion, the THPM appears to produce a stable and predictable temporal pattern of tonic pain with a predominant affective component, and to be suitable for application in the majority of individuals without causing undue discomfort.

Adult↗
PubMed1994

Multi-method assessment of experimental and clinical pain in patients with fibromyalgia.

Experimental measures of responsiveness to painful and non-painful stimuli as well as measures of typical and present clinical pain were assessed in 26 female patients with fibromyalgia and in an equal number of age-matched healthy women. Pressure pain thresholds, determined by means of a dolorimeter, were lower in the patients compared to the control subjects both at a tender point (trapezius) and at a non-tender control point (inner forearm). The same was true for the heat pain thresholds, measured using a contact thermode. In contrast, the pain thresholds for electrocutaneous stimuli were decreased only at the tender point. The detection thresholds for non-painful stimuli (warmth, cold and electrical stimuli) seemed to be less affected in the fibromyalgia patients, with only the detection threshold for cold being lower at both sites. Tender points were more sensitive than control points for mechanical pressure. The reverse was found for the other modalities which were tested. Although the 3 experimental pain thresholds showed patterns of either generalized or site-specific pain hyperresponsiveness, the between-methods correlations were not very high. While the correlations between the experimental pain thresholds and the various measures of clinical pain (Localized Pain Rating, McGill Pain Questionnaire) in the patients were generally low, there were significant negative correlations between pressure pain thresholds at the two sites and the level of present pain assessed by the Localized Pain Rating. We conclude that a pattern of pain hyperresponsiveness, generalized across the site of noxious stimulation and across the physical nature of the stressor, is associated with fibromyalgia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Theoretical and empirical considerations on the relation between 'body image', body scheme and somatosensation.

The authors first discuss possible interactions between the hitherto neglected neurophysiological and neuropsychological factors and the traditionally accepted cognitive and affective factors in 'body image' formation. They then report on a study of the relation between body size perception (video distortion technique, image marking procedure, kinaesthetic size estimation apparatus) and somatosensation (thermal, pain and vibration thresholds) in young women. Included in the study were questionnaires on eating behaviour and motivation, body attitude or body satisfaction, and depressive mood and thoughts. Neither the somatosensory nor the questionnaire variables explained the difference between 'overestimators' and 'underestimators' of body size. However, these variables did explain the difference between 'good perceivers' and 'poor perceivers' (degree of deviation from actual body size) in the video distortion technique, with a somewhat larger contribution by the somatosensory variables. The latter finding, although clearly preliminary, should stimulate further investigations of the relationship between somatosensory variables and body size perception.

Adult↗