1
|
Matsuda S, Igawa Y, Uchisawa H, Iki S, Osumi M. Thermal Grill Illusion in Post-Stroke Patients: Analysis of Clinical Features and Lesion Areas. J Pain Res 2023; 16:3895-3904. [PMID: 38026455 PMCID: PMC10656876 DOI: 10.2147/jpr.s433309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 11/08/2023] [Indexed: 12/01/2023] Open
Abstract
Purpose In the thermal grill illusion, participants experience a feeling similar to burning pain. The illusion is induced by simultaneously touching warm and cool stimuli in alternating positions. In post-stroke pain, central sensitization is caused by a variety of factors, including damage to the spinothalamic tract and shoulder pain. Because the thermal grill illusion depends on central mechanisms, it has recently been suggested that it may be a useful indicator of central sensitization. Therefore, we hypothesized that post-stroke patients who are more likely to experience central sensitization may also be more likely to experience a thermal grill sensation of pain and discomfort than the likelihood among those who are less likely to experience central sensitization. However, the effects of the thermal grill illusion in post-stroke patients have not yet been reported. In this pilot study, we conducted the thermal grill illusion procedure in post-stroke patients and analyzed the relationship between clinical somatosensory functions and thermal grill sensations. We also conducted brain imaging analysis to identify brain lesion areas that were associated with thermal grill sensations. Patients and Methods Twenty patients (65.7 ± 11.9 years old) with post-stroke patients participated in this study. The thermal grill illusion procedure was performed as follows: patients simultaneously touched eight water-filled copper bars, with the water temperature adjusted to provide alternate warm (40°C) and cold (20°C) stimuli. Results Thermal grill sensation of pain and discomfort tended to be associated with the wind-up phenomenon in bedside quantitative sensory testing and thermal grill sensation of discomfort was also related to damage to the thalamic lateral nucleus. Conclusion These findings suggest that the thermal grill illusion might measure central sensitization, and that secondary brain hyperactivity might lead to increased thermal grill sensations.
Collapse
Affiliation(s)
| | - Yuki Igawa
- Graduate School of Health Sciences, Kio University, Nara, Japan
- Department of Rehabilitation, Nishiyamato Rehabilitation Hospital, Nara, Japan
| | - Hidekazu Uchisawa
- Graduate School of Health Sciences, Kio University, Nara, Japan
- Department of Rehabilitation, Nishiyamato Rehabilitation Hospital, Nara, Japan
| | - Shinya Iki
- Department of Rehabilitation, Kawaguchi Neurosurgery Rehabilitation Clinic, Osaka, Japan
| | - Michihiro Osumi
- Graduate School of Health Sciences, Kio University, Nara, Japan
- Neurorehabilitation Research Center, Kio University, Nara, Japan
| |
Collapse
|
2
|
Bäumler P, Brenske A, Winkelmann A, Irnich D, Averbeck B. Strong and aversive cold processing and pain facilitation in fibromyalgia patients relates to augmented thermal grill illusion. Sci Rep 2023; 13:15982. [PMID: 37749154 PMCID: PMC10520026 DOI: 10.1038/s41598-023-42288-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 09/07/2023] [Indexed: 09/27/2023] Open
Abstract
The thermal grill illusion (TGI) is assumed to result from crosstalk between the thermoreceptive and nociceptive pathways. To elucidate this further, we compared 40 female fibromyalgia patients to 20 healthy women in an exploratory cross-sectional study. Sensations (cold, warm/heat, unpleasantness, pain and burning) evoked by 20 °C, 40 °C and alternating 20 °C/40 °C (TGI) and somatosensory profiles according to standardized quantitative sensory testing (QST) were assessed on the palm of the dominant hand. Compared to healthy controls, fibromyalgia patients reported stronger thermal grill-evoked cold, warm, unpleasantness and pain as well as stronger and more aversive 20 °C- and 40 °C-evoked sensations. They showed a loss in warm, mechanical and vibration detection, a gain in thermal pain thresholds and higher temporal summation (TS). Among QST parameters higher TS in fibromyalgia patients was most consistently associated with an augmented TGI. Independently, an increased TGI was linked to cold (20 °C) but less to warm (40 °C) perception. In fibromyalgia patients all thermal grill-evoked sensations were positively related to a higher 20 °C-evoked cold sensation and/or 20 °C-evoked unpleasantness. In conclusion, the TGI appears to be driven mainly by the cold-input. Aversive cold processing and central pain facilitation in fibromyalgia patients seem to independently augment the activation of the pain pathway.
Collapse
Affiliation(s)
- Petra Bäumler
- Multidisciplinary Pain Center, Department of Anaesthesiology, LMU University Hospital, LMU Munich, Munich, Germany
| | - Anna Brenske
- Multidisciplinary Pain Center, Department of Anaesthesiology, LMU University Hospital, LMU Munich, Munich, Germany
- Walter Brendel Center of Experimental Medicine (WBex), Biomedical Center Munich (BMC), LMU Munich, Großhaderner Str. 9, 82152, Planegg-Martinsried, Germany
| | - Andreas Winkelmann
- Multidisciplinary Pain Center, Department of Anaesthesiology, LMU University Hospital, LMU Munich, Munich, Germany
- Department of Orthopaedics and Trauma Surgery, Musculoskeletal University Center Munich (MUM), LMU University Hospital, LMU Munich, Munich, Germany
| | - Dominik Irnich
- Multidisciplinary Pain Center, Department of Anaesthesiology, LMU University Hospital, LMU Munich, Munich, Germany
| | - Beate Averbeck
- Walter Brendel Center of Experimental Medicine (WBex), Biomedical Center Munich (BMC), LMU Munich, Großhaderner Str. 9, 82152, Planegg-Martinsried, Germany.
| |
Collapse
|
3
|
Kim HC, Chang MC, Oh SH, Lee SB, Yang SY, Shin DA. Thermal Grill Illusion in Chronic Lower Back Pain: A Case-Control Study. J Pain Res 2023; 16:1573-1579. [PMID: 37220633 PMCID: PMC10200102 DOI: 10.2147/jpr.s403387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 05/08/2023] [Indexed: 05/25/2023] Open
Abstract
Purpose This study aimed to use thermal grill illusion (TGI), an experimental model of pain processing and central mechanisms, to evaluate the perception of TGI-related sensations or pain in patients with chronic lower back pain (CLBP). Patients and Methods The perception of TGI (warmth/heat, cold, unpleasantness, pain, burning, stinging, and prickling) was examined in 66 patients with CLBP and compared with that in 22 healthy participants. The visual analog scale (VAS) scores for CLBP, Oswestry Disability Index (ODI), and 12-Item Short Form Survey (SF-12) scores were obtained from the included patients with CLBP. Results The CLBP group showed a less intense perception of TGI for sensations of warmth/heat, unpleasantness, and pain than the control group. The CLBP group felt burning sensations lesser than the control (2.77 vs 4.55, P=0.016). In the CLBP group, there were significant correlations between the ODI and the degree of unpleasantness (r=0.381, P=0.002) and prickling sensation (r=0.263, P=0.033). There were also significant correlations between the mental component score of the SF-12 and the degree of warmth/heat (r=-0.246, P=0.046), unpleasantness (r=-0.292, P=0.017), pain (r=-0.292, P=0.017), and burning sensations (r=-0.280, P=0.023). Conclusion Our results may be useful for clinicians to evaluate the effectiveness of drugs or interventions to manage centralized LBP.
Collapse
Affiliation(s)
- Hyung Cheol Kim
- Department of Neurosurgery, Bundang Jesaeng General Hospital, Seongnam-si, Gyeonggi-do, Republic of Korea
| | - Min Cheol Chang
- Department of Physical Medicine and Rehabilitation, College of Medicine, Yeungnam University, Namku, Taegu, Republic of Korea
| | - Sung Han Oh
- Department of Neurosurgery, Bundang Jesaeng General Hospital, Seongnam-si, Gyeonggi-do, Republic of Korea
| | - Su Bin Lee
- Department of Neurosurgery, Spine and Spinal Cord Institute, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Soo Young Yang
- Department of Neurosurgery, Spine and Spinal Cord Institute, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Dong Ah Shin
- Department of Neurosurgery, Spine and Spinal Cord Institute, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| |
Collapse
|
4
|
Schaldemose EL, Raaschou-Nielsen L, Böhme RA, Finnerup NB, Fardo F. It is one or the other: No overlap between healthy individuals perceiving thermal grill illusion or paradoxical heat sensation. Neurosci Lett 2023; 802:137169. [PMID: 36898653 DOI: 10.1016/j.neulet.2023.137169] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 02/23/2023] [Accepted: 03/06/2023] [Indexed: 03/11/2023]
Abstract
Paradoxical heat sensation (PHS) and the thermal grill illusion (TGI) are both related to the perception of warmth or heat from innocuous cold stimuli. Despite being described as similar perceptual phenomena, recent findings suggested that PHS is common in neuropathy and related to sensory loss, while TGI is more frequently observed in healthy individuals. To clarify the relationship between these two phenomena, we conducted a study in a cohort of healthy individuals to investigate the association between PHS and TGI. We examined the somatosensory profiles of 60 healthy participants (34 females, median age 25 years) using the quantitative sensory testing (QST) protocol from the German Research Network on Neuropathic Pain. The number of PHS was measured using a modified thermal sensory limen (TSL) procedure where the skin was transiently pre-warmed, or pre-cooled before the PHS measure. This procedure also included a control condition with a pre-temperature of 32 °C. The number of TGI responses was quantified during simultaneous application of warm and cold innocuous stimuli. All participants had normal thermal and mechanical thresholds compared to the reference values from the QST protocol. Only two participants experienced PHS during the QST procedure. In the modified TSL procedure, we found no statistically significant differences in the number of participants reporting PHS in the control condition (N = 6) vs. pre-warming (N = 3; min = 35.7 °C, max = 43.5 °C) and pre-cooling (N = 4, min = 15.0 °C, max = 28.8 °C) conditions. Fourteen participants experienced TGI, and only one participant reported both TGI and PHS. Individuals with TGI had normal or even increased thermal sensation compared to individuals without TGI. Our findings demonstrate a clear distinction between individuals experiencing PHS or TGI, as there was no overlap observed when using identical warm and cold temperatures that were alternated either temporally or spatially. While PHS was previously related to sensory loss, our study revealed that TGI is associated with normal thermal sensitivity. This suggests that an efficient thermal sensory function is essential in generating the illusory sensation of pain of the TGI.
Collapse
Affiliation(s)
- Ellen Lund Schaldemose
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
| | - Line Raaschou-Nielsen
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Rebecca Astrid Böhme
- Center of Functionally Integrative Neuroscience, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Nanna Brix Finnerup
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Department of Neurology, Aarhus University Hospital, Aarhus, Denmark
| | - Francesca Fardo
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Center of Functionally Integrative Neuroscience, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| |
Collapse
|
5
|
Adam F, Jouët P, Sabaté JM, Perrot S, Franchisseur C, Attal N, Bouhassira D. Thermal grill illusion of pain in patients with chronic pain: a clinical marker of central sensitization? Pain 2023; 164:638-644. [PMID: 35972466 DOI: 10.1097/j.pain.0000000000002749] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 07/14/2022] [Indexed: 11/25/2022]
Abstract
ABSTRACT The thermal grill illusion of pain (TGIP) is a paradoxical burning pain sensation elicited by the simultaneous application of innocuous cutaneous warm and cold stimuli with a thermode ("thermal grill") consisting of interlaced heated and cooled bars. Its neurophysiological mechanisms are unclear, but TGIP may have some mechanisms in common with pathological pain, including central sensitization in particular, through the involvement of N-methyl- d -aspartate receptors. However, few studies have investigated TGIP in patients with chronic pain and its clinical relevance is uncertain. We hypothesized that the TGIP would be increased in comparison with controls in patients with fibromyalgia or irritable bowel syndrome, which are regarded as typical "nociplastic" primary pain syndromes related to changes in central pain processing. We compared the sensations elicited by a large range of combinations of temperature differentials between the warm and cold bars of a thermal grill applied to the hand between patients with fibromyalgia (n = 30) or irritable bowel syndrome (n= 30) and controls (n = 30). The percentage of TGIP responses and the intensity and unpleasantness of TGIP were significantly greater in patients than controls. Furthermore, positive correlations were found between TGIP intensity and clinical pain intensity and between TGIP intensity and the cold pain threshold measured on the hand. These results are consistent with our working hypothesis of shared mechanisms between TGIP and clinical pain mechanisms in patients with nociplastic chronic pain syndromes and suggest that TGIP might represent a clinical marker of central sensitization in these patients.
Collapse
Affiliation(s)
- Frédéric Adam
- Inserm U987, APHP, UVSQ, Paris-Saclay University, Ambroise Pare Hospital, Boulogne-Billancourt, France
- Department of Anesthesiology, Saint Joseph Hospital, Paris, France
| | - Pauline Jouët
- Inserm U987, APHP, UVSQ, Paris-Saclay University, Ambroise Pare Hospital, Boulogne-Billancourt, France
- Gastroenterology and Digestive Oncology Department, Avicenne Hospital, AP-HP, Bobigny, France
| | - Jean-Marc Sabaté
- Inserm U987, APHP, UVSQ, Paris-Saclay University, Ambroise Pare Hospital, Boulogne-Billancourt, France
- Gastroenterology and Digestive Oncology Department, Avicenne Hospital, AP-HP, Bobigny, France
| | - Serge Perrot
- Inserm U987, APHP, UVSQ, Paris-Saclay University, Ambroise Pare Hospital, Boulogne-Billancourt, France
- Pain Clinic, Cochin Hospital, University of Paris, Paris, France
| | - Claire Franchisseur
- Inserm U987, APHP, UVSQ, Paris-Saclay University, Ambroise Pare Hospital, Boulogne-Billancourt, France
| | - Nadine Attal
- Inserm U987, APHP, UVSQ, Paris-Saclay University, Ambroise Pare Hospital, Boulogne-Billancourt, France
| | - Didier Bouhassira
- Inserm U987, APHP, UVSQ, Paris-Saclay University, Ambroise Pare Hospital, Boulogne-Billancourt, France
| |
Collapse
|
6
|
Osumi M, Sumitani M, Nobusako S, Sato G, Morioka S. Pain quality of thermal grill illusion is similar to that of central neuropathic pain rather than peripheral neuropathic pain. Scand J Pain 2022; 22:40-47. [PMID: 34019750 DOI: 10.1515/sjpain-2021-0020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 04/07/2021] [Indexed: 11/15/2022]
Abstract
OBJECTIVES Application of spatially interlaced innocuous warm and cool stimuli to the skin elicits illusory pain, known as the thermal grill illusion (TGI). This study aimed to discriminate the underlying mechanisms of central and peripheral neuropathic pain focusing on pain quality, which is considered to indicate the underlying mechanism(s) of pain. We compared pain qualities in central and peripheral neuropathic pain with reference to pain qualities of TGI-induced pain. METHODS Experiment 1:137 healthy participants placed their hand on eight custom-built copper bars for 60 s and their pain quality was assessed by the McGill Pain Questionnaire. Experiment 2: Pain quality was evaluated in patients suffering from central and peripheral neuropathic pain (42 patients with spinal cord injury, 31 patients with stroke, 83 patients with trigeminal neuralgia and 131 patients with postherpetic neuralgia). RESULTS Experiment 1: Two components of TGI-induced pain were found using principal component analysis: component 1 included aching, throbbing, heavy and burning pain, component 2 included itching, electrical-shock, numbness, and cold-freezing. Experiment 2: Multiple correspondence analysis (MCA) and cross tabulation analysis revealed specific pain qualities including aching, hot-burning, heavy, cold-freezing, numbness, and electrical-shock pain were associated with central neuropathic pain rather than peripheral neuropathic pain. CONCLUSIONS We found similar qualities between TGI-induced pain in healthy participants and central neuropathic pain rather than peripheral neuropathic pain. The mechanism of TGI is more similar to the mechanism of central neuropathic pain than that of neuropathic pain.
Collapse
Affiliation(s)
- Michihiro Osumi
- Graduate School of Health Science, Kio University, Nara, Japan
- Neurorehabilitation Research Center, Kio University, Nara, Japan
| | - Masahiko Sumitani
- Department of Pain and Palliative Medicine, The University of Tokyo Hospital, Tokyo, Japan
| | - Satoshi Nobusako
- Graduate School of Health Science, Kio University, Nara, Japan
- Neurorehabilitation Research Center, Kio University, Nara, Japan
| | - Gosuke Sato
- Neurorehabilitation Research Center, Kio University, Nara, Japan
| | - Shu Morioka
- Graduate School of Health Science, Kio University, Nara, Japan
- Neurorehabilitation Research Center, Kio University, Nara, Japan
| |
Collapse
|
7
|
Shin DA, Chang MC. A Review on Various Topics on the Thermal Grill Illusion. J Clin Med 2021; 10:jcm10163597. [PMID: 34441893 PMCID: PMC8396808 DOI: 10.3390/jcm10163597] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/11/2021] [Accepted: 08/13/2021] [Indexed: 11/16/2022] Open
Abstract
The thermal grill illusion (TGI) is a paradoxical perception of burning heat and pain resulting from the simultaneous application of interlaced warm and cold stimuli to the skin. The TGI is considered a type of chronic centralized pain and has been used to apply nociceptive stimuli without inflicting harm to human participants in the study of pain mechanisms. In addition, the TGI is an interesting phenomenon for researchers, and various topics related to the TGI have been investigated in several studies, which we will review here. According to previous studies, the TGI is generated by supraspinal interactions. To evoke the TGI, cold and warm cutaneous stimuli should be applied within the same dermatome or across dermatomes corresponding to adjacent spinal segments, and a significant difference between cold and warm temperatures is necessary. In addition, due the presence of chronic pain, genetic factors, and sexual differences, the intensity of the TGI can differ. In addition, cold noxious stimulation, topical capsaicin, analgesics, self-touch, and the presence of psychological diseases can decrease the intensity of the TGI. Because the TGI corresponds to chronic centralized pain, we believe that the findings of previous studies can be applied to future studies to identify chronic pain mechanisms and clinical practice for pain management.
Collapse
Affiliation(s)
- Dong Ah Shin
- Department of Neurosurgery, College of Medicine, Yonsei University, Seodaemun-gu, Seoul 03722, Korea;
| | - Min Cheol Chang
- Department of Physical Medicine and Rehabilitation, College of Medicine, Yeungnam University, Namku, Taegu 42415, Korea
- Correspondence: ; Tel.: +82-53-620-4682
| |
Collapse
|
8
|
Rivel M, Achiron A, Dolev M, Stern Y, Zeilig G, Defrin R. Central neuropathic pain in multiple sclerosis is associated with impaired innocuous thermal pathways and neuronal hyperexcitability. PAIN MEDICINE 2021; 22:2311-2323. [PMID: 33734398 DOI: 10.1093/pm/pnab103] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE About a third of patients with multiple sclerosis (MS) suffer from chronic and excruciating central neuropathic pain (CNP). The mechanism underlying CNP in MS is not clear, since previous studies are scarce and their results are inconsistent. Our aim was to determine whether CNP in MS is associated with impairment of the spinothalamic-thalamocortical pathways (STTCs) and/or increased excitability of the pain system. DESIGN Cross sectional study. SETTING General hospital. SUBJECTS 47 MS patients with CNP, 42 MS patients without CNP, and 32 healthy controls. METHODS Sensory testing included the measurement of temperature, pain, and touch thresholds and the thermal grill illusion (TGI) for evaluating STTCs function, and hyperpathia and allodynia as indicators of hyperexcitability. CNP was characterized using interviews and questionnaires. RESULTS The CNP group had higher cold and warm thresholds (p < 0.01), as well as higher TGI perception thresholds (p < 0.05), especially in painful body regions compared to controls, whereas touch and pain thresholds values were normal. The CNP group also had a significantly greater prevalence of hyperpathia and allodynia. Regression analysis revealed that whereas presence of CNP was associated with a higher cold threshold, CNP intensity, and the number of painful body regions were associated with allodynia and hyperpathia, respectively. CONCLUSIONS CNP in MS is characterized by a specific impairment of STTC function; the innocuous thermal pathways, and by pain hyperexcitability. Whereas CNP presence is associated with STTC impairment, its severity and extent are associated with pain hyperexcitability. Interventions that reduce excitability level may therefore mitigate CNP severity.
Collapse
Affiliation(s)
- Michal Rivel
- Department of Physical Therapy, School of Health Professions, Sackler Faculty of Medicine Tel Aviv University.,Sagol School of Neuroscience, Tel-Aviv University
| | - Anat Achiron
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer.,Sackler Faculty of Medicine, Tel-Aviv University
| | - Mark Dolev
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer
| | - Yael Stern
- Multiple Sclerosis Center, Sheba Medical Center, Tel Hashomer
| | - Gaby Zeilig
- Sackler Faculty of Medicine, Tel-Aviv University.,Department of Neurological Rehabilitation, Sheba Medical Center, Tel Hashomer
| | - Ruth Defrin
- Department of Physical Therapy, School of Health Professions, Sackler Faculty of Medicine Tel Aviv University.,Sagol School of Neuroscience, Tel-Aviv University
| |
Collapse
|
9
|
Forstenpointner J, Berry D, Baron R, Borsook D. The cornucopia of central disinhibition pain - An evaluation of past and novel concepts. Neurobiol Dis 2020; 145:105041. [PMID: 32800994 DOI: 10.1016/j.nbd.2020.105041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 07/18/2020] [Accepted: 08/08/2020] [Indexed: 12/12/2022] Open
Abstract
Central disinhibition (CD), as applied to pain, decreases thresholds of endogenous systems. This provokes onset of spontaneous or evoked pain in an individual beyond the ability of the nervous system to inhibit pain resulting from a disease or tissue damage. The original CD concept as proposed by Craig entails a shift from the lateral pain pathway (i.e. discriminative pain processing) towards the medial pain pathway (i.e. emotional pain processing), within an otherwise neurophysiological intact environment. In this review, the original CD concept as proposed by Craig is extended by the primary "nociceptive pathway damage - CD" concept and the secondary "central pathway set point - CD". Thereby, the original concept may be transferred into anatomical and psychological non-functional conditions. We provide examples for either primary or secondary CD concepts within different clinical etiologies as well as present surrogate models, which directly mimic the underlying pathophysiology (A-fiber block) or modulate the CD pathway excitability (thermal grill). The thermal grill has especially shown promising advancements, which may be useful to examine CD pathway activation in the future. Therefore, within this topical review, a systematic review on the thermal grill illusion is intended to stimulate future research. Finally, the authors review different mechanism-based treatment approaches to combat CD pain.
Collapse
Affiliation(s)
- Julia Forstenpointner
- Division of Neurological Pain Research and Therapy, Department of Neurology, University Hospital Schleswig-Holstein, Campus Kiel, Arnold-Heller-Str. 3, 24105 Kiel, Germany; Center for Pain and the Brain, Boston Children's Hospital, Department of Anesthesia, Critical Care and Pain Medicine, Harvard Medical School, Boston, MA, USA.
| | - Delany Berry
- Center for Pain and the Brain, Boston Children's Hospital, Department of Anesthesia, Critical Care and Pain Medicine, Harvard Medical School, Boston, MA, USA
| | - Ralf Baron
- Division of Neurological Pain Research and Therapy, Department of Neurology, University Hospital Schleswig-Holstein, Campus Kiel, Arnold-Heller-Str. 3, 24105 Kiel, Germany
| | - David Borsook
- Center for Pain and the Brain, Boston Children's Hospital, Department of Anesthesia, Critical Care and Pain Medicine, Harvard Medical School, Boston, MA, USA
| |
Collapse
|
10
|
Fardo F, Beck B, Allen M, Finnerup NB. Beyond labeled lines: A population coding account of the thermal grill illusion. Neurosci Biobehav Rev 2020; 108:472-479. [DOI: 10.1016/j.neubiorev.2019.11.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 11/21/2019] [Accepted: 11/25/2019] [Indexed: 10/25/2022]
|
11
|
Fardo F, Finnerup NB, Haggard P. Organization of the Thermal Grill Illusion by Spinal Segments. Ann Neurol 2018; 84:463-472. [PMID: 30063258 PMCID: PMC6175302 DOI: 10.1002/ana.25307] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 07/23/2018] [Accepted: 07/25/2018] [Indexed: 12/31/2022]
Abstract
Objective A common symptom of neuropathy is the misperception of heat and pain from cold stimuli. Similar cold allodynic sensations can be experimentally induced using the thermal grill illusion (TGI) in humans. It is currently unclear whether this interaction between thermosensory and nociceptive signals depends on spinal or supraspinal integration mechanisms. To address this issue, we developed a noninvasive protocol to assess thermosensory integration across spinal segments. Methods We leveraged anatomical knowledge regarding dermatomes and their spinal projections to investigate potential contributions of spinal integration to the TGI. We simultaneously stimulated a pair of skin locations on the arm or lower back using 1 cold (∼20°C) and 1 warm thermode (∼40°C). The 2 thermodes were always separated by a fixed physical distance on the skin, but elicited neural activity across a varying number of spinal segments, depending on which dermatomal boundaries the 2 stimuli spanned. Results Participants consistently overestimated the actual cold temperature on the skin during combined cold and warm stimulation, confirming the TGI effect. The TGI was present when cold and warm stimuli were delivered within the same dermatome, or across dermatomes corresponding to adjacent spinal segments. In striking contrast, no TGI effect was found when cold and warm stimuli projected to nonadjacent spinal segments. Interpretation These results demonstrate that the strength of the illusion is modulated by the segmental distance between cold and warm afferents. This suggests that both temperature perception and thermal–nociceptive interactions depend upon low‐level convergence mechanisms operating within a single spinal segment and its immediate neighbors. Ann Neurol 2018;84:463–472
Collapse
Affiliation(s)
- Francesca Fardo
- Institute of Cognitive Neuroscience, University College London, London, United Kingdom.,Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Interacting Minds Center, Aarhus University, Aarhus, Denmark
| | - Nanna Brix Finnerup
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Patrick Haggard
- Institute of Cognitive Neuroscience, University College London, London, United Kingdom
| |
Collapse
|