151
|
Test Order of Quantitative Sensory Testing Facilitates Mechanical Hyperalgesia in Healthy Volunteers. THE JOURNAL OF PAIN 2012; 13:73-80. [DOI: 10.1016/j.jpain.2011.10.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2011] [Revised: 10/10/2011] [Accepted: 10/18/2011] [Indexed: 11/21/2022]
|
152
|
Treister R, Pud D, Ebstein RP, Laiba E, Raz Y, Gershon E, Haddad M, Eisenberg E. Association Between Polymorphisms in Serotonin and Dopamine-Related Genes and Endogenous Pain Modulation. THE JOURNAL OF PAIN 2011; 12:875-83. [DOI: 10.1016/j.jpain.2011.02.348] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Revised: 01/17/2011] [Accepted: 02/07/2011] [Indexed: 12/16/2022]
|
153
|
Hollins M, Harper D, Maixner W. Changes in pain from a repetitive thermal stimulus: the roles of adaptation and sensitization. Pain 2011; 152:1583-1590. [PMID: 21454015 DOI: 10.1016/j.pain.2011.02.049] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2010] [Revised: 01/19/2011] [Accepted: 02/24/2011] [Indexed: 11/16/2022]
Abstract
This study examined processes that contribute to the changing painfulness of a repeatedly presented thermal (heat) stimulus. The 3-second pulses were presented to the side of the hand at a rate of 4/min, too slow to engage wind-up. Over the course of 32 trials, pain intensity (measured by verbal report on a 0-100 scale) first declined and then (in most cases) rose again, indicating adaptation and sensitization, respectively. The magnitude of adaptation grew across a series of 3 runs, indicating that adaptation has a slow as well as a fast component. The rate of sensitization depended on stimulus temperature, but not on subjective pain intensity; this result implies that sensitization takes place at an early processing stage. Adaptation and sensitization were comparable in participants with fibromyalgia, temporomandibular disorders, and in healthy controls, indicating that these processes occur before the perceptual amplification that characterizes fibromyalgia and temporomandibular disorders. The ability of vibration to reduce pain has previously been shown to involve segmental inhibition; the finding in the present study that vibratory gating of pain is significantly (inversely) related to the rate of sensitization suggests that the latter also reflects segmental processes. Several lines of evidence thus point to the conclusion that adaptation and sensitization occur at early stages of sensory information processing.
Collapse
Affiliation(s)
- Mark Hollins
- Department of Psychology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA Department of Endodontics, School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA Center for Neurosensory Disorders, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | | | | |
Collapse
|
154
|
Guergova S, Dufour A. Thermal sensitivity in the elderly: a review. Ageing Res Rev 2011; 10:80-92. [PMID: 20685262 DOI: 10.1016/j.arr.2010.04.009] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2010] [Revised: 04/19/2010] [Accepted: 04/19/2010] [Indexed: 10/19/2022]
Abstract
Aging is associated with a progressive decrease in thermal perception, as revealed by increased thermal detection thresholds in the elderly. This reduction in thermosensitivity follows a distal-proximal pattern, with more pronounced decrements observed in the limbs and in the perception of warmth vs. cold. The main underlying causes of this seem to be aging of the skin and subsequent reductions in thermoreceptor density and superficial skin blood flow. However, the results from some animal studies also suggest that changes in the peripheral nerve system, particularly fiber loss and decreased conduction velocity, may also be involved. In this paper, we review age-related changes in the thermal sensitivity of humans, their underlying mechanisms, and the strengths and limitations of some of the methodologies used to assess these changes.
Collapse
|
155
|
Casanova-Molla J, Grau-Junyent JM, Morales M, Valls-Solé J. On the relationship between nociceptive evoked potentials and intraepidermal nerve fiber density in painful sensory polyneuropathies. Pain 2010; 152:410-418. [PMID: 21185650 DOI: 10.1016/j.pain.2010.11.012] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2010] [Revised: 09/19/2010] [Accepted: 11/11/2010] [Indexed: 11/27/2022]
Abstract
This study analyzed the relationship between the density of intraepidermal nerve fibers (IENF) and the characteristics of either nociceptive laser-evoked potentials (LEPs) or contact heat-evoked potentials (CHEPs) in patients with painful sensory polyneuropathy with the aim to determine which parameters of LEPs and CHEPs more reliably reflect IENF loss. A total of 96 patients and 35 healthy volunteers took part in the study. Based on clinical examination, nerve conduction tests, and quantitative sensory testing, we identified 52 patients with small-fiber neuropathy (SFN), 40 with mixed (small-fiber and large-fiber) neuropathy (MFN), and 4 who were excluded from the analysis because of no evidence of involvement of small fibers. The latency of the N2 was delayed for both LEPs and CHEPs in patients with MFN and for CHEPs only in patients with SFN. The amplitude of the vertex N2/P2 potential was similarly reduced in both types of neuropathy, but LEPs were more frequently absent than CHEPs in MFN patients (68% vs 40%). In general, latency and amplitude of LEPs and CHEPs were well correlated with IENF density. SFN patients were characterized by abnormal EPs and slightly decreased but morphologically abnormal IENF. MFN patients were characterized by frequently absent LEPs and CHEPs and a rather severe IENF loss. The correlation between nociceptive evoked potentials (laser-evoked potentials and contact heat-evoked potentials) and skin biopsy aids in the diagnosis of painful neuropathies.
Collapse
Affiliation(s)
- Jordi Casanova-Molla
- Department of Neurology, Hospital Clínic, Barcelona, Spain IDIBAPS (Institut d'Investigació Augustí Pi i Sunyer), University of Barcelona, Barcelona, Spain Department of Internal Medicine, Hospital Clínic, Barcelona, Spain
| | | | | | | |
Collapse
|
156
|
Kuhtz-Buschbeck JP, Andresen W, Göbel S, Gilster R, Stick C. Thermoreception and nociception of the skin: a classic paper of Bessou and Perl and analyses of thermal sensitivity during a student laboratory exercise. ADVANCES IN PHYSIOLOGY EDUCATION 2010; 34:25-34. [PMID: 20522893 DOI: 10.1152/advan.00002.2010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
About four decades ago, Perl and collaborators were the first ones who unambiguously identified specifically nociceptive neurons in the periphery. In their classic work, they recorded action potentials from single C-fibers of a cutaneous nerve in cats while applying carefully graded stimuli to the skin (Bessou P, Perl ER. Response of cutaneous sensory units with unmyelinated fibers to noxious stimuli. J Neurophysiol 32: 1025-1043, 1969). They discovered polymodal nociceptors, which responded to mechanical, thermal, and chemical stimuli in the noxious range, and differentiated them from low-threshold thermoreceptors. Their classic findings form the basis of the present method that undergraduate medical students experience during laboratory exercises of sensory physiology, namely, quantitative testing of the thermal detection and pain thresholds. This diagnostic method examines the function of thin afferent nerve fibers. We collected data from nearly 300 students that showed that 1) women are more sensitive to thermal detection and thermal pain at the thenar than men, 2) habituation shifts thermal pain thresholds during repetititve testing, 3) the cold pain threshold is rather variable and lower when tested after heat pain than in the reverse case (order effect), and 4) ratings of pain intensity on a visual analog scale are correlated with the threshold temperature for heat pain but not for cold pain. Median group results could be reproduced in a retest. Quantitative sensory testing of thermal thresholds is feasible and instructive in the setting of a laboratory exercise and is appreciated by the students as a relevant and interesting technique.
Collapse
|
157
|
Rennefeld C, Wiech K, Schoell ED, Lorenz J, Bingel U. Habituation to pain: further support for a central component. Pain 2010; 148:503-508. [PMID: 20097005 DOI: 10.1016/j.pain.2009.12.014] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2009] [Revised: 12/22/2009] [Accepted: 12/22/2009] [Indexed: 10/19/2022]
Abstract
Habituation to repetitive painful stimulation may represent an important protection mechanism against the development of chronic pain states. However, the exact neurobiological mechanisms of this phenomenon remain unclear. In this study we (i) explore the somatotopic specificity of pain attenuation over time and (ii) investigate the role of the endogenous opioid system in its development. We investigated 24 healthy volunteers with a paradigm of daily painful stimulation of the left volar forearm for 1 week. Habituation was assessed by comparing pain-related responses (ratings and thresholds) between days 1 and 8. To test whether a repetition-dependent attenuation of pain is restricted to the site of stimulus application or induces additional systemic effects indicative of a central mechanism, we also measured pain-related responses at the contralateral arm and the left leg. To assess the role of the endogenous opioid system in this mechanism, we used the opioid-receptor antagonist naloxone in a double-blind design. Repetitive painful stimulation over several days resulted in a significant habituation to pain at the site of daily stimulation. In addition, we also observed significant pain attenuation at the non-stimulated limbs. This effect was less pronounced at the untreated arm compared to the treated arm and even weaker in the leg, displaying a significant Stimulation-Site x Time interaction. The development of pain habituation was unaffected by the opioid antagonist naloxone. Taken together, these results strongly support the role of central components in the mechanism of pain habituation that do not directly involve the endogenous opioid system.
Collapse
Affiliation(s)
- C Rennefeld
- Department of Neurology, University of Hamburg (UKE), Germany NeuroImage Nord, Department of Systems Neuroscience, University of Hamburg (UKE), Germany Department of Human Biology, University of Hamburg, Germany Oxford Centre for Functional MRI on the Brain, Department of Clinical Neurology & Nuffield Department of Anaesthetics, Oxford University, John Radcliffe Hospital, Oxford, UK Hamburg University of Applied Sciences, Germany
| | | | | | | | | |
Collapse
|
158
|
Tiede W, Magerl W, Baumgärtner U, Durrer B, Ehlert U, Treede RD. Sleep restriction attenuates amplitudes and attentional modulation of pain-related evoked potentials, but augments pain ratings in healthy volunteers. Pain 2010; 148:36-42. [DOI: 10.1016/j.pain.2009.08.029] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2008] [Revised: 08/12/2009] [Accepted: 08/25/2009] [Indexed: 11/25/2022]
|
159
|
Roeska K, Ceci A, Treede RD, Doods H. Effect of high trait anxiety on mechanical hypersensitivity in male rats. Neurosci Lett 2009; 464:160-4. [DOI: 10.1016/j.neulet.2009.08.031] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2009] [Revised: 08/12/2009] [Accepted: 08/13/2009] [Indexed: 10/20/2022]
|
160
|
Abstract
In an earlier study, we reported the antinociceptive effects of a special repetitive transcranial magnetic stimulation paradigm: continuous theta-burst stimulation (cTBS), when applied to human motor cortex. Here, we investigated whether the reduced subjective pain perception of 10 healthy individuals could be measured by changes in laser-evoked potentials, a reflection of pain related activations in the operculoinsular and midcingulate cortex. To minimize the effect of habituation during repeated laser stimulation, a bioadaptive design was used. However, both pain ratings and laser-evoked potential amplitudes were reduced after real and sham cTBS. When compared with sham stimulation, cTBS resulted in a significantly greater diminution of pain ratings and N2-P2 amplitudes on the hand contralateral to the site of motor cortex stimulation.
Collapse
|
161
|
Differentiation of pain ratings in combat-related posttraumatic stress disorder. Pain 2009; 143:179-185. [DOI: 10.1016/j.pain.2008.12.018] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2008] [Revised: 11/10/2008] [Accepted: 12/09/2008] [Indexed: 11/19/2022]
|
162
|
Greffrath W, Schwarz ST, Büsselberg D, Treede RD. Heat-induced action potential discharges in nociceptive primary sensory neurons of rats. J Neurophysiol 2009; 102:424-36. [PMID: 19439674 DOI: 10.1152/jn.90916.2008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Although several transducer molecules for noxious stimuli have been identified, little is known about the transformation of the resulting generator currents into action potentials (APs). Therefore we investigated the transformation process for stepped noxious heat stimuli (42-47 degrees C, 3-s duration) into membrane potential changes and subsequent AP discharges using the somata of acutely dissociated small dorsal root ganglion (DRG) neurons (diameter<or=32.5 microm) of adult rats as a model for their own peripheral terminals. Three types of heat-induced membrane potential changes were differentiated: type 1, heat-induced AP discharges (approximately 37% of the neurons); type 2, heat-induced membrane depolarization (40%); and type 3, responses not exceeding those of switching the superfusion (23%). Warming neurons from room temperature to 35 degrees C increased their background conductance, nearly doubled the AP threshold current, and led to smaller and narrower APs. Adaptation of heat-induced AP discharges was seen in about half of the type 1 neurons. The remaining half displayed accelerating discharges to both heat stimuli and depolarizing current injection. Repeated heat stimulation induced marked suppression of AP discharges. Under rapid calcium buffering using BAPTA, repolarization of heat-induced APs stopped at a plateau potential slowly decreasing from +16.5+/-2.9 to -2.2+/-5.5 mV, resulting in no further AP discharges. This study demonstrates that heat-induced AP discharges can be elicited in the soma of a subgroup of DRG neurons. These discharges display suppression on repetitive stimulation, but either adaptation or sensitization during prolonged stimuli. AP threshold and AP shape during these discharges suggest temperature dependence of background conductance and repolarizing currents.
Collapse
Affiliation(s)
- Wolfgang Greffrath
- Division of Neurophysiology, Center of Biomedicine and Medical Technology Mannheim, CBTM Ludolf-Krehl-Strasse 13-17, Medical Faculty Mannheim, Ruprecht-Karls-University Heidelberg, D-68167 Mannheim, Germany.
| | | | | | | |
Collapse
|
163
|
Affiliation(s)
- Kurt Gray
- Harvard University, Department of Psychology, Cambridge, MA 02138, USA.
| | | |
Collapse
|
164
|
Smith BW, Tooley EM, Montague EQ, Robinson AE, Cosper CJ, Mullins PG. The role of resilience and purpose in life in habituation to heat and cold pain. THE JOURNAL OF PAIN 2009; 10:493-500. [PMID: 19345153 DOI: 10.1016/j.jpain.2008.11.007] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Revised: 09/29/2008] [Accepted: 11/10/2008] [Indexed: 02/08/2023]
Abstract
UNLABELLED This study examined the role of resilience in habituation to heat and cold pain in healthy women (n = 47). Heat and cold pain thresholds were each assessed across 5 equally spaced trials. Resilience, purpose in life, optimism, social support, and neuroticism were assessed using self-report measures. The hypothesis was that the resilience and the associated resilience factors would be positively related to habituation to heat and cold pain while controlling for neuroticism. Multilevel modeling was used to test the hypothesis. When considering each characteristic separately, resilience and purpose in life predicted greater habituation to heat pain while resilience, purpose in life, optimism, and social support predicted greater habituation to cold pain. When controlling for the other characteristics, both resilience and purpose in life predicted greater habituation to heat and cold pain. Resilience and associated characteristics such as a sense of purpose in life may be related to enhanced habituation to painful stimuli. Future research should further examine the relationship between resilience, purpose in life, and habituation to pain and determine whether psychosocial interventions that target resilience and purpose in life improve habituation and reduce vulnerability to chronic pain. PERSPECTIVE This article showed that resilience and a sense of purpose in life were both related to the ability to habituate to heat and cold pain in healthy women. These personal characteristics may enhance habituation to pain by providing the confidence and motivation to persist in the face of painful stimuli.
Collapse
Affiliation(s)
- Bruce W Smith
- Department of Psychology, University of New Mexico, Albuquerque, New Mexico 87131, USA.
| | | | | | | | | | | |
Collapse
|
165
|
|
166
|
Roberts K, Papadaki A, Gonçalves C, Tighe M, Atherton D, Shenoy R, McRobbie D, Anand P. Contact Heat Evoked Potentials Using Simultaneous Eeg And Fmri And Their Correlation With Evoked Pain. BMC Anesthesiol 2008; 8:8. [PMID: 19091117 PMCID: PMC2625333 DOI: 10.1186/1471-2253-8-8] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2008] [Accepted: 12/17/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The Contact Heat Evoked Potential Stimulator (CHEPS) utilises rapidly delivered heat pulses with adjustable peak temperatures to stimulate the differential warm/heat thresholds of receptors expressed by Adelta and C fibres. The resulting evoked potentials can be recorded and measured, providing a useful clinical tool for the study of thermal and nociceptive pathways. Concurrent recording of contact heat evoked potentials using electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI) has not previously been reported with CHEPS. Developing simultaneous EEG and fMRI with CHEPS is highly desirable, as it provides an opportunity to exploit the high temporal resolution of EEG and the high spatial resolution of fMRI to study the reaction of the human brain to thermal and nociceptive stimuli. METHODS In this study we have recorded evoked potentials stimulated by 51° C contact heat pulses from CHEPS using EEG, under normal conditions (baseline), and during continuous and simultaneous acquisition of fMRI images in ten healthy volunteers, during two sessions. The pain evoked by CHEPS was recorded on a Visual Analogue Scale (VAS). RESULTS Analysis of EEG data revealed that the latencies and amplitudes of evoked potentials recorded during continuous fMRI did not differ significantly from baseline recordings. fMRI results were consistent with previous thermal pain studies, and showed Blood Oxygen Level Dependent (BOLD) changes in the insula, post-central gyrus, supplementary motor area (SMA), middle cingulate cortex and pre-central gyrus. There was a significant positive correlation between the evoked potential amplitude (EEG) and the psychophysical perception of pain on the VAS. CONCLUSION The results of this study demonstrate the feasibility of recording contact heat evoked potentials with EEG during continuous and simultaneous fMRI. The combined use of the two methods can lead to identification of distinct patterns of brain activity indicative of pain and pro-nociceptive sensitisation in healthy subjects and chronic pain patients. Further studies are required for the technique to progress as a useful tool in clinical trials of novel analgesics.
Collapse
|
167
|
Smith BW, Tooley EM, Montague EQ, Robinson AE, Cosper CJ, Mullins PG. Habituation and sensitization to heat and cold pain in women with fibromyalgia and healthy controls. Pain 2008; 140:420-428. [PMID: 18947923 DOI: 10.1016/j.pain.2008.09.018] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2008] [Revised: 09/06/2008] [Accepted: 09/16/2008] [Indexed: 11/27/2022]
Abstract
The purpose of this study was to examine differences in habituation to heat and cold pain in women with fibromyalgia (FM; n=33) and in women who were healthy controls (HC; n=44). Quantitative sensory testing (QST) was used to assess pain thresholds during five consecutive trials of ascending heat and descending cold stimulation. Anxiety, depression, fatigue, and pain during the previous week were assessed using self-report measures. The overall hypotheses were that there would be differences between groups in pain thresholds and in the rate of habituation to heat and cold pain stimuli. Multilevel modeling was used to test the hypotheses. There were large overall differences in pain thresholds, with the FM group showing greater sensitivity to heat and cold pain stimuli compared with the HC group. While habituation occurred in both of the groups for heat pain, the HC group had stronger habituation across trials than the FM group. Conversely, while the HC group habituated to cold pain stimuli, the FM group showed sensitization and had decreased cold pain thresholds across trials (they felt cold pain at higher temperatures). In addition, anxiety, depression, fatigue, and pain were related to decreased heat and cold pain thresholds in the overall sample. However, when group was controlled, none of these variables were related to thresholds or rates of habituation or sensitization. The differences between women with FM and healthy women in habituation and sensitization may have important implications for the etiology, diagnosis, and treatment of FM and other chronic pain conditions.
Collapse
Affiliation(s)
- Bruce W Smith
- Department of Psychology, University of New Mexico, MSC03 2220, Albuquerque, NM 87131, USA School of Psychology, Bangor University, Addeliad Brigantia, Bangor, LL57 2AS, UK
| | | | | | | | | | | |
Collapse
|
168
|
Klauenberg S, Maier C, Assion HJ, Hoffmann A, Krumova EK, Magerl W, Scherens A, Treede RD, Juckel G. Depression and changed pain perception: hints for a central disinhibition mechanism. Pain 2008; 140:332-343. [PMID: 18926637 DOI: 10.1016/j.pain.2008.09.003] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2008] [Revised: 08/10/2008] [Accepted: 09/03/2008] [Indexed: 01/28/2023]
Abstract
Although patients with a depressive disorder report often of pain, their sensitivity to experimental pain is controversial, probably due to differences in sensory testing methods and to the lack of normal values. Therefore, we used a standardized and validated comprehensive sensory testing paradigm to assess the peripheral and central nervous system performance in depressive patients compared to healthy controls and chronic pain patients with fibromyalgia syndrome (FMS), in which depression is a common comorbidity. Twenty-five depressive psychiatric inpatients (pain-free: n=20), 35 FMS outpatients and 25 healthy controls underwent quantitative sensory testing (QST), including thermal and mechanical detection and pain thresholds, pain sensitivity and responsiveness to repetitive noxious mechanical stimuli (wind-up). In depressive disorder (to a lesser extent also in FMS), significantly decreased cold pain thresholds and an increased wind-up were found, although the mechanical pain thresholds and pain sensitivity were comparable to those of the healthy controls. All the detection thresholds were within the normal range in all the groups. In depressive disorder, there were no significant side differences in the detection and pain thresholds. The results contradict the former assumption of a general insensitivity to experimental pain in depressive disorder. In the mostly pain-free patients signs of an enhanced central hyperexcitability are even more pronounced than usually found in chronic pain patients (e.g. FMS), indicating common mechanisms in depressive disorder and chronic pain in accordance with the assumption of non-pain associated mechanisms in depressive disorder for central hyperexcitability, e.g. by inhibited serotonergic function. Furthermore, this trial demonstrates the feasibility of QST in depressive patients.
Collapse
Affiliation(s)
- Sabrina Klauenberg
- Department of Pain Management, Berufsgenossenschaftliche Universitätsklinik Bergmannsheil GmbH, Ruhr University Bochum, Bürkle-de-la-Camp-Platz 1, 44789 Bochum, Germany Department of Psychiatry, Ruhr University Bochum, LWL University Hospital, Alexandrinenstrasse 1, 44791 Bochum, Germany Private Practice of Rheumatology, Richard-Wagner-Strasse 13-17, 50674 Cologne, Germany Division of Neurophysiology, CBTM, Medical Faculty Mannheim, Ruprecht Karls University Heidelberg, Ludolf-Krehl-Strasse 13-17, 68167 Mannheim, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
169
|
Schestatsky P, Lladó-Carbó E, Casanova-Molla J, Álvarez-Blanco S, Valls-Solé J. Small fibre function in patients with meralgia paresthetica ☆. Pain 2008; 139:342-348. [DOI: 10.1016/j.pain.2008.05.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2007] [Revised: 04/27/2008] [Accepted: 05/01/2008] [Indexed: 10/21/2022]
|
170
|
Nir RR, Lev R, Moont R, Granovsky Y, Sprecher E, Yarnitsky D. Neurophysiology of the cortical pain network: revisiting the role of S1 in subjective pain perception via standardized low-resolution brain electromagnetic tomography (sLORETA). THE JOURNAL OF PAIN 2008; 9:1058-69. [PMID: 18708299 DOI: 10.1016/j.jpain.2008.06.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2008] [Revised: 06/10/2008] [Accepted: 06/17/2008] [Indexed: 11/15/2022]
Abstract
UNLABELLED Multiple studies have supported the usefulness of standardized low-resolution brain electromagnetic tomography (sLORETA) in localizing generators of scalp-recorded potentials. The current study implemented sLORETA on pain event-related potentials, primarily aiming at validating this technique for pain research by identifying well-known pain-related regions. Subsequently, we pointed at investigating the still-debated and ambiguous topic of pain intensity coding at these regions, focusing on their relative impact on subjective pain perception. sLORETA revealed significant activations of the bilateral primary somatosensory (SI) and anterior cingulate cortices and of the contralateral operculoinsular and dorsolateral prefrontal (DLPFC) cortices (P < .05 for each). Activity of these regions, excluding DLPFC, correlated with subjective numerical pain scores (P < .05 for each). However, a multivariate regression analysis (R = .80; P = .024) distinguished the contralateral SI as the only region whose activation magnitude significantly predicted the subjective perception of noxious stimuli (P = .020), further substantiated by a reduced regression model (R = .75, P = .008). Based on (1) correspondence of the pain-activated regions identified by sLORETA with the acknowledged imaging-based pain-network and (2) the contralateral SI proving to be the most contributing region in pain intensity coding, we found sLORETA to be an appropriate tool for relevant pain research and further substantiated the role of SI in pain perception. PERSPECTIVE Because the literature of pain intensity coding offers inconsistent findings, the current article used a novel tool for revisiting this controversial issue. Results suggest that it is the activation magnitude of SI, which solely establishes the significant correlation with subjective pain ratings, in accordance with the classical clinical thinking, relating SI lesions to diminished perception of pain. Although this study cannot support a causal relation between SI activation magnitude and pain perception, such relation might be insinuated.
Collapse
Affiliation(s)
- Rony-Reuven Nir
- Laboratory of Clinical Neurophysiology, Department of Neurology, Rambam Health Care Campus, Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | | | | | | | | | | |
Collapse
|