1
|
Chiriac VF, Ciurescu D, Moșoiu DV. Cancer Pain and Non-Invasive Brain Stimulation-A Narrative Review. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:1957. [PMID: 38004006 PMCID: PMC10673188 DOI: 10.3390/medicina59111957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 10/22/2023] [Accepted: 10/31/2023] [Indexed: 11/26/2023]
Abstract
Background and Objectives: Pain is the most prevalent symptom in cancer patients. There is a paucity of data regarding non-invasive brain stimulation (NIBS) for the treatment of chronic pain in patients with cancer. The purpose of this article is to review the techniques of NIBS and present the published experiences of the oncological population. Materials and Methods: Databases including MEDLINE, Scopus, Web of Science, and the Cochrane Library were searched for articles on cancer patients with pain that was managed with non-invasive brain stimulation techniques. We included articles in English that were published from inception to January 2023. As studies were limited in number and had different designs and methodologies, a narrative review was considered as the best option to integrate data. Results: Four studies focusing on transcranial magnetic stimulation, six articles on transcranial direct current stimulation, and three articles regarding cranial electric stimulation were found and reviewed. Conclusions: Data are limited and not robust. Further studies in this field are required. Guidelines on NIBS for non-malignant chronic pain conditions provide good premises for cancer-related chronic pain.
Collapse
Affiliation(s)
- Valentina-Fineta Chiriac
- Departament of Medical Oncology, “Dr Pompei Samarian” County Emergency Hospital, 910071 Călărași, Romania
- Faculty of Medicine, Transilvania University, 500036 Brașov, Romania
| | - Daniel Ciurescu
- Faculty of Medicine, Transilvania University, 500036 Brașov, Romania
| | - Daniela-Viorica Moșoiu
- Faculty of Medicine, Transilvania University, 500036 Brașov, Romania
- HOSPICE Casa Sperantei, 500074 Brașov, Romania
| |
Collapse
|
2
|
Moncho D, Poca MA, Rahnama K, Sánchez Roldán MÁ, Santa-Cruz D, Sahuquillo J. The Role of Neurophysiology in Managing Patients with Chiari Malformations. J Clin Med 2023; 12:6472. [PMID: 37892608 PMCID: PMC10607909 DOI: 10.3390/jcm12206472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 09/25/2023] [Accepted: 10/06/2023] [Indexed: 10/29/2023] Open
Abstract
Chiari malformation type 1 (CM1) includes various congenital anomalies that share ectopia of the cerebellar tonsils lower than the foramen magnum, in some cases associated with syringomyelia or hydrocephalus. CM1 can cause dysfunction of the brainstem, spinal cord, and cranial nerves. This functional alteration of the nervous system can be detected by various modalities of neurophysiological tests, such as brainstem auditory evoked potentials, somatosensory evoked potentials, motor evoked potentials, electromyography and nerve conduction studies of the cranial nerves and spinal roots, as well as brainstem reflexes. The main goal of this study is to review the findings of multimodal neurophysiological examinations in published studies of patients with CM1 and their indication in the diagnosis, treatment, and follow-up of these patients, as well as their utility in intraoperative monitoring.
Collapse
Affiliation(s)
- Dulce Moncho
- Department of Clinical Neurophysiology, Vall d’Hebron University Hospital, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain; (K.R.); (M.Á.S.R.); (D.S.-C.)
- Neurotraumatology and Neurosurgery Research Unit, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain;
| | - Maria A. Poca
- Neurotraumatology and Neurosurgery Research Unit, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain;
- Department of Neurosurgery, Vall d’Hebron University Hospital, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain
- Department of Surgery, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain
| | - Kimia Rahnama
- Department of Clinical Neurophysiology, Vall d’Hebron University Hospital, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain; (K.R.); (M.Á.S.R.); (D.S.-C.)
| | - M. Ángeles Sánchez Roldán
- Department of Clinical Neurophysiology, Vall d’Hebron University Hospital, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain; (K.R.); (M.Á.S.R.); (D.S.-C.)
| | - Daniela Santa-Cruz
- Department of Clinical Neurophysiology, Vall d’Hebron University Hospital, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain; (K.R.); (M.Á.S.R.); (D.S.-C.)
| | - Juan Sahuquillo
- Neurotraumatology and Neurosurgery Research Unit, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain;
- Department of Neurosurgery, Vall d’Hebron University Hospital, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain
- Department of Surgery, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain
| |
Collapse
|
3
|
Guo Z, Ni H, Cui Z, Zhu Z, Kang J, Wang D, Ke Z. Pain sensitivity related to gamma oscillation of parvalbumin interneuron in primary somatosensory cortex in Dync1i1 -/- mice. Neurobiol Dis 2023:106170. [PMID: 37257662 DOI: 10.1016/j.nbd.2023.106170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 05/09/2023] [Accepted: 05/24/2023] [Indexed: 06/02/2023] Open
Abstract
Cytoplasmic dynein is an important intracellular motor protein that plays an important role in neuronal growth, axonal polarity formation, dendritic differentiation, and dendritic spine development among others. The intermediate chain of dynein, encoded by Dync1i1, plays a vital role in the dynein complex. Therefore, we assessed the behavioral and related neuronal activities in mice with dync1i1 gene knockout. Neuronal activities in primary somatosensory cortex were recorded by in vivo electrophysiology and manipulated by optogenetic and chemogenetics. Nociception of mechanical, thermal, and cold pain in Dync1i1-/- mice were impaired. The activities of parvalbumin (PV) interneurons and gamma oscillation in primary somatosensory were also impaired when exposed to mechanical nociceptive stimulation. This neuronal dysfunction was rescued by optogenetic activation of PV neurons in Dync1i1-/- mice, and mimicked by suppressing PV neurons using chemogenetics in WT mice. Impaired pain sensations in Dync1i1-/- mice were correlated with impaired gamma oscillations due to a loss of interneurons, especially the PV type. This genotype-driven approach revealed an association between impaired pain sensation and cytoplasmic dynein complex.
Collapse
Affiliation(s)
- Zhongzhao Guo
- Academy of Integrative Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Hong Ni
- Academy of Integrative Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Zhengyu Cui
- Department of Traditional Chinese Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 201203, China
| | - Zilu Zhu
- School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Jiansheng Kang
- Clinical Systems Biology Laboratories East District of The first affiliated hospital of ZhengZhou University, Zhengzhou 450018, China
| | - Deheng Wang
- School of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
| | - Zunji Ke
- Academy of Integrative Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
| |
Collapse
|
4
|
Assessment of C Fibers Evoked Potentials in Healthy Subjects by Nd : YAP Laser. Pain Res Manag 2022; 2022:7737251. [PMID: 36601434 PMCID: PMC9807303 DOI: 10.1155/2022/7737251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 11/11/2022] [Accepted: 12/03/2022] [Indexed: 12/28/2022]
Abstract
Introduction Although laser stimuli activate both Ad- and C-fibres, the corresponding laser evoked potentials (LEPs) remain restricted to the Ad-fibers input, while the C-fibers related potential is hardly detectable. Aims To evaluate multichannel ultralate LEPs (U-LEPs) by using Nd : Yap laser pulses in healthy volunteers to stimulation of face and lower and upper limbs, in order to estimate the reliability of C-LEPs elicited from both trigeminal and somatic sites. Methods Twenty healthy volunteers participated in two stimulation sessions to record Aδ-LEPs and C-LEPs. We used a Nd : YAP Laser and 62 EEG recording electrodes. Stimuli parameters were set to activate either small myelinated (Aδ), eliciting purely warmth sensations, or unmyelinated (C) afferents, and eliciting pinprick sensations. Results At the trigeminal level, we obtained a negative-positive complex in a time interval compatible with the C fibers activation. In the somatic districts, the averaged responses consisted of an earlier negative-positive complex, followed by a later one. Single trials analysis of U-LEPs showed a maximal positive peak in a time interval in the range of C fibers. Topographical analysis of U-LEPs resembled that of LEPs. All subjects exhibited readable U-LEPs in at least 2 stimulated sites. Discussion. A purely warmth sensation seems to correspond to Aδ and C-fibers coactivation, at least in the somatic districts. While the related cortical waves seem hardly readable, their total absence could be a sign of systemic involvement of warm related C-fibers in specific clinical conditions.
Collapse
|
5
|
Magnetoencephalographic evaluation of repaired lip sensation in patients with cleft lip. PLoS One 2022; 17:e0274405. [PMID: 36137110 PMCID: PMC9498931 DOI: 10.1371/journal.pone.0274405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 08/26/2022] [Indexed: 11/19/2022] Open
Abstract
Background
Cleft lip is the most common congenital anomaly worldwide. Nevertheless, lip somatosensory characteristics of patients with cleft lip after cheiloplasty have not yet been determined. The present study used magnetoencephalography to objectively evaluate the lip sensation in patients with unilateral cleft lip to establish a new objective evaluation method.
Methods
Participants were 15 patients with unilateral cleft lip after cheiloplasty (UCL group), and 30 healthy young subjects (control group). Five points of the upper and lower lips were stimulated electrically to measure somatosensory evoked magnetic fields (SEFs). The sources of the magnetic fields were modeled as single equivalent current dipoles (ECDs). ECDs located on the central sulcus by superimposition on magnetic resonance images were analyzed. Latency and intensity at 50–75 ms (cP60m) observed in the UCL group were compared with those in the control group. Thresholds of tactile stimuli in both groups were obtained using Semmes–Weinstein monofilaments for subjective sensory evaluation.
Results
No significant difference was found in the intensity of the cP60m or subjective evaluation between the groups. However, the latency of the cP60m was significantly longer in the upper lip of the UCL group than in the control group.
Conclusions
SEFs showed a difference in lip sensation between the UCL group and the control group, suggesting that longer latency might be caused by the effects of surgical scarring on the neurotransmission pathway. These results suggest SEFs as useful for the objective evaluation of lip sensations. This study might improve future surgical procedures and lip functions of patients with cleft lip.
Collapse
|
6
|
Verdugo RJ, Matamala JM, Inui K, Kakigi R, Valls-Solé J, Hansson P, Bernhard Nilsen K, Lombardi R, Lauria G, Petropoulos IN, Malik RA, Treede RD, Baumgärtner U, Jara PA, Campero M. Review of techniques useful for the assessment of sensory small fiber neuropathies: Report from an IFCN expert group. Clin Neurophysiol 2022; 136:13-38. [DOI: 10.1016/j.clinph.2022.01.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 01/04/2022] [Accepted: 01/06/2022] [Indexed: 02/09/2023]
|
7
|
Mahmutoglu MA, Baumgärtner U, Rupp A. Posterior insular activity contributes to the late laser-evoked potential component in EEG recordings. Clin Neurophysiol 2021; 132:770-781. [PMID: 33571885 DOI: 10.1016/j.clinph.2020.11.042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 11/13/2020] [Accepted: 11/24/2020] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Nociceptive activity in some brain areas has concordantly been reported in EEG source models, such as the anterior/mid-cingulate cortex and the parasylvian area. Whereas the posterior insula has been constantly reported to be active in intracortical and fMRI studies, non-invasive EEG and MEG recordings mostly failed to detect activity in this region. This study aimed to determine an appropriate inverse modeling approach in EEG recordings to model posterior insular activity, assuming the late LEP (laser evoked potential) time window to yield a better separation from other ongoing cortical activity. METHODS In 12 healthy volunteers, nociceptive stimuli of three intensities were applied. LEP were recorded using 32-channel EEG recordings. Source analysis was performed in specific time windows defined in the grand-average dataset. Two distinct dipole-pairs located close to the operculo-insular area were compared. RESULTS Our results show that posterior insular activity yields a substantial contribution to the latest part (positive component) of the LEP. CONCLUSIONS Even though the initial insular activity onset is in the early LEP time window,modelingthe insular activity in the late LEP time window might result in better separation from other ongoing cortical activity. SIGNIFICANCE Modeling the late LEP activity might enable to distinguish posterior insular activity.
Collapse
Affiliation(s)
- Mustafa Ahmed Mahmutoglu
- Section of Biomagnetism, Department of Neurology, Heidelberg University Hospital, Heidelberg, Germany; Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany.
| | - Ulf Baumgärtner
- Chair of Neurophysiology, Centre for Biomedicine and Medical Technology Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany; Department of Physiology/Physics, University of Applied Sciences and Medical University, Medical School Hamburg, Hamburg, Germany
| | - André Rupp
- Section of Biomagnetism, Department of Neurology, Heidelberg University Hospital, Heidelberg, Germany
| |
Collapse
|
8
|
Blom AB, van den Bosch MH, Blaney Davidson EN, Roth J, Vogl T, van de Loo FA, Koenders M, van der Kraan PM, Geven EJ, van Lent PL. The alarmins S100A8 and S100A9 mediate acute pain in experimental synovitis. Arthritis Res Ther 2020; 22:199. [PMID: 32854769 PMCID: PMC7457270 DOI: 10.1186/s13075-020-02295-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 08/17/2020] [Indexed: 01/15/2023] Open
Abstract
Background Synovitis-associated pain is mediated by inflammatory factors that may include S100A8/9, which is able to stimulate nociceptive neurons via Toll-like receptor 4. In this study, we investigated the role of S100A9 in pain response during acute synovitis. Methods Acute synovitis was induced by streptococcal cell wall (SCW) injection in the knee joint of C57Bl/6 (WT) and S100A9−/− mice. The expression of S100A8/A9 was determined in serum and synovium by ELISA and immunohistochemistry. Inflammation was investigated by 99mTc accumulation, synovial cytokine release, and histology at days 1, 2, and 7. To assess pain, weight distribution, gait analysis, and mechanical allodynia were monitored. Activation markers in afferent neurons were determined by qPCR and immunohistochemistry in the dorsal root ganglia (DRG). Differences between groups were tested using a one-way or two-way analysis of variance (ANOVA). Differences in histology were tested with a non-parametric Mann–Whitney U test. p values lower than 0.05 were considered significant. Results Intra-articular SCW injection resulted in increased synovial expression and serum levels of S100A8/A9 at day 1. These increased levels, however, did not contribute to the development of inflammation, since this was equal in S100A9−/− mice. WT mice showed a significantly decreased percentage of weight bearing on the SCW hind paw on day 1, while S100A9−/− mice showed no reduction. Gait analysis showed increased “limping” behavior in WT, but not S100A9−/− mice. Mechanical allodynia was observed but not different between WT and S100A9−/− when measuring paw withdrawal threshold. The gene expression of neuron activation markers NAV1.7, ATF3, and GAP43 in DRG was significantly increased in arthritic WT mice at day 1 but not in S100A9−/− mice. Conclusions S100A8/9, released from the synovium upon inflammation, is an important mediator of pain response in the knee during the acute phase of inflammation.
Collapse
Affiliation(s)
- Arjen B Blom
- Experimental Rheumatology, Radboud university medical center, Geert Grooteplein 28, 6525 GA, Nijmegen, The Netherlands.
| | - Martijn H van den Bosch
- Experimental Rheumatology, Radboud university medical center, Geert Grooteplein 28, 6525 GA, Nijmegen, The Netherlands
| | - Esmeralda N Blaney Davidson
- Experimental Rheumatology, Radboud university medical center, Geert Grooteplein 28, 6525 GA, Nijmegen, The Netherlands
| | - Johannes Roth
- Institute of Immunology, University of Münster, Münster, Germany
| | - Thomas Vogl
- Institute of Immunology, University of Münster, Münster, Germany
| | - Fons A van de Loo
- Experimental Rheumatology, Radboud university medical center, Geert Grooteplein 28, 6525 GA, Nijmegen, The Netherlands
| | - Marije Koenders
- Experimental Rheumatology, Radboud university medical center, Geert Grooteplein 28, 6525 GA, Nijmegen, The Netherlands
| | - Peter M van der Kraan
- Experimental Rheumatology, Radboud university medical center, Geert Grooteplein 28, 6525 GA, Nijmegen, The Netherlands
| | - Edwin J Geven
- Experimental Rheumatology, Radboud university medical center, Geert Grooteplein 28, 6525 GA, Nijmegen, The Netherlands
| | - Peter L van Lent
- Experimental Rheumatology, Radboud university medical center, Geert Grooteplein 28, 6525 GA, Nijmegen, The Netherlands
| |
Collapse
|
9
|
Yoshida A, Iwatsuki K, Hoshiyama M, Hirata H. Disturbance of somatotopic spatial cognition and extra-territorial pain in carpal tunnel syndrome. NeuroRehabilitation 2020; 46:423-431. [PMID: 32250335 DOI: 10.3233/nre-193007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Several studies on carpal tunnel syndrome have reported pain that exists beyond the median nerve territory of the affected hand. However, the mechanism is unknown. PURPOSE We investigated the cause of extra-territorial pain by the analysis of clinical assessments and cortical activity using magnetoencephalography. METHODS To compare patients with and without extra-territorial pain, fourteen patients with carpal tunnel syndrome were assessed using clinical examination, such as patients' profile, paresthesia, physical tests, and psychological tests. The physical assessment included tactile threshold and static and moving two-point discrimination sensations on digital pulp. Neural activation in the cerebral cortex was also measured using z-scores calculated by magnetoencephalography. RESULTS Among fourteen patients, ten patients had pain in the affected median nerve territory only and four patients had extra-territorial pain. When comparing the groups, the static and moving two-point discrimination sensation values in patients with extra-territorial pain were larger than those of patients without the pain (p < 0.05). The supra-marginal gyrus, mid-part of the precentral sulcus, angular gyrus in the left hemisphere, bilateral sensorimotor areas for legs, and bilateral isthmus-cingulate areas showed larger z-scores in patients with extra-territorial pain than in patients without the pain (p < 0.05). CONCLUSIONS The static and moving two-point discrimination sensations signify the ability of tactile spatial acuity. Bilateral sensorimotor areas were activated in sites that were not the hand. Furthermore, the inferior parietal lobule in the left hemisphere, which synthesizes and integrates multiple sensations showed high activation. Our findings suggested that the mechanism of extra-territorial pain was associated with dysfunction of spatial cognition.
Collapse
Affiliation(s)
- Akihito Yoshida
- Department of Hand Surgery, Nagoya University Graduate School of Medicine, Aichi, Japan.,Department of Rehabilitation, Nagoya University Hospital, Aichi, Japan.,Department of Rehabilitation Science, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Katsuyuki Iwatsuki
- Department of Hand Surgery, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Minoru Hoshiyama
- Brain and Mind Research Center, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Hitoshi Hirata
- Department of Hand Surgery, Nagoya University Graduate School of Medicine, Aichi, Japan
| |
Collapse
|
10
|
Zheng P, Lyu Z, Jackson T. Effects of trait fear of pain on event‐related potentials during word cue presentations that signal potential pain. Eur J Neurosci 2019; 50:3365-3379. [DOI: 10.1111/ejn.14495] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 04/10/2019] [Accepted: 06/10/2019] [Indexed: 12/15/2022]
Affiliation(s)
- Panpan Zheng
- Key Laboratory of Cognition and Personality China Education Ministry Southwest University Chongqing China
| | - Zhenyong Lyu
- School of Education Science Xinyang Normal University Xinyang China
| | - Todd Jackson
- Key Laboratory of Cognition and Personality China Education Ministry Southwest University Chongqing China
- Department of Psychology University of Macau Macau, S.A.R. China
| |
Collapse
|
11
|
Electroencephalography and magnetoencephalography in pain research-current state and future perspectives. Pain 2019; 159:206-211. [PMID: 29944612 DOI: 10.1097/j.pain.0000000000001087] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
12
|
Zhou L, Wei H, Zhang H, Li X, Bo C, Wan L, Lu X, Hu L. The Influence of Expectancy Level and Personal Characteristics on Placebo Effects: Psychological Underpinnings. Front Psychiatry 2019; 10:20. [PMID: 30804816 PMCID: PMC6370695 DOI: 10.3389/fpsyt.2019.00020] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 01/11/2019] [Indexed: 11/13/2022] Open
Abstract
Placebo effects benefit a wide range of clinical practice, which can be profoundly influenced by expectancy level and personal characteristics. However, research on the issue of whether these factors independently or interdependently affect the placebo effects is still in its infancy. Here, we adopted a 3-day between-subject placebo analgesia paradigm (2-day conditioning and 1-day test) to investigate the influence of expectancy levels (i.e., No, Low, and High) and personal characteristics (i.e., gender, dispositional optimism, and anxiety state) on placebo effects in 120 healthy participants (60 females). Our results showed that the reduction of pain intensity in the test phase was influenced by the interaction between expectancy and gender, as mainly reflected by greater reductions of pain intensity in females at Low expectancy level than females at No/High expectancy levels, and greater reductions of pain intensity in males than in females at High expectancy level. Additionally, the reduction of pain unpleasantness was not only modulated by the interaction between expectancy and gender, but also by the interaction between expectancy and dispositional optimism, as well as the interaction between expectancy and anxiety state. Specifically, participants who were more optimistic in Low expectancy group, or those who were less anxious in High expectancy group showed greater reductions of pain unpleasantness. To sum up, we emphasized on regulating the expectancy level individually based on the assessment of personal characteristics to maximize placebo effects in clinical conditions.
Collapse
Affiliation(s)
- Lili Zhou
- CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.,Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Hua Wei
- Key Laboratory of Cognition and Personality, Ministry of Education, Faculty of Psychology, Southwest University, Chongqing, China
| | - Huijuan Zhang
- CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.,Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Xiaoyun Li
- Key Laboratory of Cognition and Personality, Ministry of Education, Faculty of Psychology, Southwest University, Chongqing, China
| | - Cunju Bo
- Department of Pain Management, The State Key Clinical Specialty in Pain Medicine, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Li Wan
- Department of Pain Management, The State Key Clinical Specialty in Pain Medicine, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Xuejing Lu
- CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.,Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Li Hu
- CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.,Department of Psychology, University of Chinese Academy of Sciences, Beijing, China.,Key Laboratory of Cognition and Personality, Ministry of Education, Faculty of Psychology, Southwest University, Chongqing, China.,Department of Pain Management, The State Key Clinical Specialty in Pain Medicine, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| |
Collapse
|
13
|
Wang C, Tian J. Reminders of Mortality Alter Pain-Evoked Potentials in a Chinese Sample. Front Psychol 2018; 9:1667. [PMID: 30245659 PMCID: PMC6137269 DOI: 10.3389/fpsyg.2018.01667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 08/20/2018] [Indexed: 01/25/2023] Open
Abstract
Pain is of evolutionary importance to human survival. However, the perception of pain could be changed when death-related thoughts are accessible. Although the influence of mortality salience (MS) on pain processing has been investigated in Westerners recently, it is unclear whether this effect is constrained by specific culture context since humans may employ cultural worldviews to defend the existence problem. The current study tested whether and how MS affected pain processing in a Chinese male sample. We primed participants with sentences indicating MS or negative affect (NA) on either of two days. Both before and after the priming, event-related potentials (ERPs) elicited by painful and non-painful electrical stimulations were recorded. Results showed that pain-evoked potentials were identified as an early negative complex N60-P90-N130 and a late positivity P260. Pain-evoked N130 after MS priming was larger than that after NA priming. Meanwhile, pain-evoked P260 decreased after MS priming but not after NA priming. These findings indicate that reminders of mortality affect both early sensory and late cognitive neural responses related to physical pain. Although previous studies reporting an increased effect of MS on perceived pain intensity in Westerners, we found an unchanged or possibly reduced effect in Chinese. Thus, the current work provides insight into a culture-sensitive perspective on how pain processing would be modulated when existential problem occurs.
Collapse
Affiliation(s)
- Chenbo Wang
- Faculty of Education, East China Normal University, Shanghai, China.,Key Laboratory of Brain Functional Genomics (MOE&STCSM), Shanghai Changning-ECNU Mental Health Center, School of Psychology and Cognitive Science, East China Normal University, Shanghai, China
| | - Jing Tian
- Teachers College, Columbia University, New York, NY, United States
| |
Collapse
|
14
|
Does High Frequency Transcutaneous Electrical Nerve Stimulation (TENS) Affect EEG Gamma Band Activity? J Biomed Phys Eng 2018; 8:271-280. [PMID: 30320031 PMCID: PMC6169118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Accepted: 01/14/2018] [Indexed: 11/02/2022]
Abstract
BACKGROUND Transcutaneous electrical nerve stimulation (TENS) is a noninvasive, inexpensive and safe analgesic technique used for relieving acute and chronic pain. However, despite all these advantages, there has been very little research into the therapeutic effects of TENS on brain activity. To the best of our knowledge, there is no evidence on the effect of high frequency TENS on the gamma band activity. OBJECTIVE Investigation of the effect of high frequency TENS on the electroencephalographic (EEG) gamma band activity after inducing ischemic pain in healthy volunteers is considered. MATERIAL AND METHODS The modified version of Submaximal effort tourniquet test was carried out to induce tonic pain in 15 right-handed healthy volunteers. The high frequency TENS (150µs in duration, frequency of 100 Hz) was applied for 20 minutes. Pain intensity was assessed at using Visual Analog Scale (VAS) in two conditions (after-pain, after-TENS). EEG gamma band activity was recorded by a 19-channel EEG in three conditions (baseline, after-pain and after- TENS). The repeated measure ANOVA and paired-sample T- tests were used for data analysis. RESULTS EEG analysis showed an increase in gamma total power after inducing pain as compared to baseline and a decrease after the application of TENS (mean±SD: .043±.029 to .088±.042 to .038±.022 μV2 ).The analysis of VAS values demonstrated that the intensity of induced pain (mean±SD: 51.53±9.86) decreased after the application of TENS (mean±SD: 18.66±10.28). All these differences were statistically significant (p<.001). CONCLUSION The results of this study revealed that the high frequency TENS can reduce the enhanced gamma band activity after the induction of tonic pain in healthy volunteers. This finding might help as a functional brain biomarker which could be useful for pain treatment, specifically for EEG-based neurofeedback approaches.
Collapse
|
15
|
Hari R, Baillet S, Barnes G, Burgess R, Forss N, Gross J, Hämäläinen M, Jensen O, Kakigi R, Mauguière F, Nakasato N, Puce A, Romani GL, Schnitzler A, Taulu S. IFCN-endorsed practical guidelines for clinical magnetoencephalography (MEG). Clin Neurophysiol 2018; 129:1720-1747. [PMID: 29724661 PMCID: PMC6045462 DOI: 10.1016/j.clinph.2018.03.042] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 03/18/2018] [Accepted: 03/24/2018] [Indexed: 12/22/2022]
Abstract
Magnetoencephalography (MEG) records weak magnetic fields outside the human head and thereby provides millisecond-accurate information about neuronal currents supporting human brain function. MEG and electroencephalography (EEG) are closely related complementary methods and should be interpreted together whenever possible. This manuscript covers the basic physical and physiological principles of MEG and discusses the main aspects of state-of-the-art MEG data analysis. We provide guidelines for best practices of patient preparation, stimulus presentation, MEG data collection and analysis, as well as for MEG interpretation in routine clinical examinations. In 2017, about 200 whole-scalp MEG devices were in operation worldwide, many of them located in clinical environments. Yet, the established clinical indications for MEG examinations remain few, mainly restricted to the diagnostics of epilepsy and to preoperative functional evaluation of neurosurgical patients. We are confident that the extensive ongoing basic MEG research indicates potential for the evaluation of neurological and psychiatric syndromes, developmental disorders, and the integrity of cortical brain networks after stroke. Basic and clinical research is, thus, paving way for new clinical applications to be identified by an increasing number of practitioners of MEG.
Collapse
Affiliation(s)
- Riitta Hari
- Department of Art, Aalto University, Helsinki, Finland.
| | - Sylvain Baillet
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Gareth Barnes
- Wellcome Centre for Human Neuroimaging, University College of London, London, UK
| | - Richard Burgess
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Nina Forss
- Clinical Neuroscience, Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Joachim Gross
- Centre for Cognitive Neuroimaging, University of Glasgow, Glasgow, UK; Institute for Biomagnetism and Biosignalanalysis, University of Muenster, Germany
| | - Matti Hämäläinen
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA; Harvard Medical School, Boston, MA, USA; NatMEG, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Ole Jensen
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK
| | - Ryusuke Kakigi
- Department of Integrative Physiology, National Institute of Physiological Sciences, Okazaki, Japan
| | - François Mauguière
- Department of Functional Neurology and Epileptology, Neurological Hospital & University of Lyon, Lyon, France
| | | | - Aina Puce
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA
| | - Gian-Luca Romani
- Department of Neuroscience, Imaging and Clinical Sciences, Università degli Studi G. D'Annunzio, Chieti, Italy
| | - Alfons Schnitzler
- Institute of Clinical Neuroscience and Medical Psychology, and Department of Neurology, Heinrich-Heine-University, Düsseldorf, Germany
| | - Samu Taulu
- Institute for Learning & Brain Sciences, University of Washington, Seattle, WA, USA; Department of Physics, University of Washington, Seattle, WA, USA
| |
Collapse
|
16
|
The Influence of Expectation on Nondeceptive Placebo and Nocebo Effects. Pain Res Manag 2018; 2018:8459429. [PMID: 29755621 PMCID: PMC5884148 DOI: 10.1155/2018/8459429] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 01/30/2018] [Indexed: 12/20/2022]
Abstract
Nondeceptive placebo has demonstrated its efficiency in clinical practice. Although the underlying mechanisms are still unclear, nondeceptive placebo effect and nondeceptive nocebo effect may be mediated by expectation. To examine the extent to which expectation influences these effects, the present study compared nondeceptive placebo and nocebo effects with different expectation levels. Seventy-two healthy female participants underwent a standard conditioning procedure to establish placebo and nocebo effects. Sequentially, participants were randomized to one of the four experimental groups—baseline (BL), no expectation intervention (NoEI), expectation increasing (EI), and expectation decreasing (ED) groups, to receive either no intervention or interventions through different verbal suggestions that modulated their expectation. Placebo and nocebo effects were established in all four groups after the conditioning phase. However, after disclosing the placebo and nocebo, the analgesic and the hyperalgesic effects only persisted in the EI group, when compared with the BL group. Our results provide evidence highlighting the critical role of increased expectation in nondeceptive placebo and nocebo effects. The finding suggests that open-label placebo or nocebo per se might be insufficient to induce strong analgesic or hyperalgesic response and sheds insights into administrating open-label placebo and avoiding open-label nocebo in clinical practice.
Collapse
|
17
|
Zhang H, Zhou L, Wei H, Lu X, Hu L. The sustained influence of prior experience induced by social observation on placebo and nocebo responses. J Pain Res 2017; 10:2769-2780. [PMID: 29263691 PMCID: PMC5727107 DOI: 10.2147/jpr.s147970] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Background Social observation is one of the main ways to gain experience. Similar to first-person experience, observational experience affects the effectiveness of subsequent treatments. Yet, it is still undetermined whether the influence of social observation on placebo and nocebo effects to subsequent treatments remains even if related experience occurred a few days ago. Methods Eighty-two participants were recruited and each of them was randomly assigned to one of the four experimental groups acquiring first-person or observational experience, which was either effective or ineffective. For the first-person groups, participants were presented with pain cues paired with pain stimuli in person. In the effective condition, low pain cues were paired with low pain stimuli, and high pain cues were paired with high pain stimuli. In contrast, the associations between cues and pain stimuli were not established in the ineffective condition. Similarly, for the observational groups, participants received effective/ineffective treatment through observation. Five or six days later, all participants underwent a conditioning phase followed by a test phase composed of two tests, where participants were asked to report their perceived pain. Results Placebo and nocebo responses to subsequent treatments can be affected by prior experience gained several days ago regardless of acquisition ways, and both placebo and nocebo responses in the effective condition were significantly larger than those in the ineffective condition. Furthermore, once placebo and nocebo effects were elicited, the latter was more persistent, while the former was more likely to diminish. Conclusion First-person and observational experience obtained a few days ago could affect the following treatments, which advance our understanding of the crucial and sustained influence of social observation on placebo analgesia and nocebo hyperalgesia, and provide insights into clinical applications.
Collapse
Affiliation(s)
- Huijuan Zhang
- Faculty of Psychology, Southwest University, Chongqing, China
| | - Lili Zhou
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China.,Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Hua Wei
- Faculty of Psychology, Southwest University, Chongqing, China
| | - Xuejing Lu
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China.,Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Li Hu
- Faculty of Psychology, Southwest University, Chongqing, China.,CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China.,Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
18
|
Bradley C, Bastuji H, Garcia-Larrea L. Evidence-based source modeling of nociceptive cortical responses: A direct comparison of scalp and intracranial activity in humans. Hum Brain Mapp 2017; 38:6083-6095. [PMID: 28925006 DOI: 10.1002/hbm.23812] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 08/27/2017] [Accepted: 09/05/2017] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Source modeling of EEG traditionally relies on interplay between physiological hypotheses and mathematical estimates. We propose to optimize the process by using evidence gathered from brain imaging and intracortical recordings. METHODS We recorded laser-evoked potentials in 18 healthy participants, using high-density EEG. Brain sources were modeled during the first second poststimulus, constraining their initial position to regions where nociceptive-related activity has been ascertained by intracranial EEG. These comprised the two posterior operculo-insular regions, primary sensorimotor, posterior parietal, anterior cingulate/supplementary motor (ACC/SMA), bilateral frontal/anterior insular, and posterior cingulate (PCC) cortices. RESULTS The model yielded an average goodness of fit of 91% for individual and 95.8% for grand-average data. When compared with intracranial recordings from 27 human subjects, no significant difference in peak latencies was observed between modeled and intracranial data for 5 of the 6 assessable regions. Morphological match was excellent for operculo-insular, frontal, ACC/SMA and PCC regions (cross-correlation > 0.7) and fair for sensori-motor and posterior parietal cortex (c-c ∼ 0.5). CONCLUSIONS Multiple overlapping activities evoked by nociceptive input can be disentangled from high-density scalp EEG guided by intracranial data. Modeled sources accurately described the timing and morphology of most activities recorded with intracranial electrodes, including those coinciding with the emergence of stimulus awareness. Hum Brain Mapp 38:6083-6095, 2017. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Claire Bradley
- NEUROPAIN lab, Centre de Recherche en Neurosciences de Lyon, Inserm U1028 - CNRS UMR5292, Université Claude Bernard Lyon 1, Lyon, France
| | - Hélène Bastuji
- NEUROPAIN lab, Centre de Recherche en Neurosciences de Lyon, Inserm U1028 - CNRS UMR5292, Université Claude Bernard Lyon 1, Lyon, France
| | - Luis Garcia-Larrea
- NEUROPAIN lab, Centre de Recherche en Neurosciences de Lyon, Inserm U1028 - CNRS UMR5292, Université Claude Bernard Lyon 1, Lyon, France
| |
Collapse
|
19
|
Omori S, Isose S, Misawa S, Watanabe K, Sekiguchi Y, Shibuya K, Beppu M, Amino H, Kuwabara S. Pain-related evoked potentials after intraepidermal electrical stimulation to Aδ and C fibers in patients with neuropathic pain. Neurosci Res 2017; 121:43-48. [DOI: 10.1016/j.neures.2017.03.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Revised: 03/09/2017] [Accepted: 03/13/2017] [Indexed: 11/26/2022]
|
20
|
Misra G, Ofori E, Chung JW, Coombes SA. Pain-Related Suppression of Beta Oscillations Facilitates Voluntary Movement. Cereb Cortex 2017; 27:2592-2606. [PMID: 26965905 DOI: 10.1093/cercor/bhw061] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Increased beta oscillations over sensorimotor cortex are antikinetic. Motor- and pain-related processes separately suppress beta oscillations over sensorimotor cortex leading to the prediction that ongoing pain should facilitate movement. In the current study, we used a paradigm in which voluntary movements were executed during an ongoing pain-eliciting stimulus to test the hypothesis that a pain-related suppression of beta oscillations would facilitate the initiation of a subsequent voluntary movement. Using kinematic measures, electromyography, and high-density electroencephalography, we demonstrate that ongoing pain leads to shorter reaction times without affecting the kinematics or accuracy of movement. Reaction time was positively correlated with beta power prior to movement in contralateral premotor areas. Our findings corroborate the view that beta-band oscillations are antikinetic and provide new evidence that pain primes the motor system for action. Our observations provide the first evidence that a pain-related suppression of beta oscillations over contralateral premotor areas leads to shorter reaction times for voluntary movement.
Collapse
Affiliation(s)
- Gaurav Misra
- Laboratory for Rehabilitation Neuroscience, Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Edward Ofori
- Laboratory for Rehabilitation Neuroscience, Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Jae Woo Chung
- Laboratory for Rehabilitation Neuroscience, Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Stephen A Coombes
- Laboratory for Rehabilitation Neuroscience, Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| |
Collapse
|
21
|
|
22
|
Jin HK, Hwang TY, Cho SH. Effect of Electrical Stimulation on Blood Flow Velocity and Vessel Size. Open Med (Wars) 2017; 12:5-11. [PMID: 28401194 PMCID: PMC5385976 DOI: 10.1515/med-2017-0002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Accepted: 12/15/2016] [Indexed: 11/15/2022] Open
Abstract
Interferential current electrical stimulation alters blood flow velocity and vessel size. We aimed to investigate the changes in the autonomic nervous system depending on electrical stimulation parameters. Forty-five healthy adult male and female subjects were studied. Bipolar adhesive pad electrodes were used to stimulate the autonomic nervous system at the thoracic vertebrae 1-4 levels for 20 min. Using Doppler ultrasonography, blood flow was measured to determine velocity and vessel size before, immediately after, and 30 min after electrical stimulation. Changes in blood flow velocity were significantly different immediately and 30 min after stimulation. The interaction between intervention periods and groups was significantly different between the exercise and pain stimulation groups immediately after stimulation (p<0.05). The vessel size was significantly different before and 30 min after stimulation (p<0.05). Imbalances in the sympathetic nervous system, which regulates balance throughout the body, may present with various symptoms. Therefore, in the clinical practice, the parameters of electrical stimulation should be selectively applied in accordance with various conditions and changes in form.
Collapse
Affiliation(s)
- Hee-Kyung Jin
- Department of Physical Therapy, Nambu University, Gwangju city, Republic of Korea
| | - Tae-Yeon Hwang
- Department of Physical Therapy, Nambu University, Gwangju city, 23 Cheomdanjungang-ro, Gwangsan-gu, Gwangju 506-706, Republic of Korea
| | - Sung-Hyoun Cho
- Department of Physical Therapy, Chunnam Techno College, Gokseong-gun, Jeollanam-do, Republic of Korea
| |
Collapse
|
23
|
Palm U, Chalah MA, Padberg F, Al-Ani T, Abdellaoui M, Sorel M, Dimitri D, Créange A, Lefaucheur JP, Ayache SS. Effects of transcranial random noise stimulation (tRNS) on affect, pain and attention in multiple sclerosis. Restor Neurol Neurosci 2016; 34:189-99. [PMID: 26890095 DOI: 10.3233/rnn-150557] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
PURPOSE Pain and cognitive impairment are frequent symptoms in patients with multiple sclerosis (MS). Neglecting experimental pain and paying attention to demanding tasks is reported to decrease the pain intensity. Little is known about the interaction between chronic neuropathic pain and attention disorders in MS. Recently, transcranial direct current stimulation (tDCS) was used to modulate various cognitive and motor symptoms in MS. We aimed to study the effects of transcranial random noise stimulation (tRNS), a form of transcranial electric stimulation, over the left dorsolateral prefrontal cortex (DLPFC) on attention and neuropathic pain in MS patients. METHODS 16 MS patients were included in a randomized, sham-controlled, cross-over study. Each patient randomly received two tRNS blocks, separated by three weeks of washout interval. Each block consisted of three consecutive daily sessions of either active or sham tRNS. The patients were evaluated for pain, attention and mood and further underwent an electrophysiological evaluation. RESULTS Compared to sham, tRNS showed a trend to decrease the N2-P2 amplitudes of pain related evoked potentials and improve pain ratings. Attention performance and mood scales did not change after stimulations. CONCLUSIONS This study suggests the role of tRNS in pain modulation, which could have been more evident with longer stimulation protocols.
Collapse
Affiliation(s)
- Ulrich Palm
- Department of Physiology, Henri Mondor Hospital, Assistance Publique - Hôpitaux de Paris, Créteil, France.,Department of Psychiatry and Psychotherapy, Ludwig-Maximilian University Munich, Munich, Germany
| | - Moussa A Chalah
- Department of Physiology, Henri Mondor Hospital, Assistance Publique - Hôpitaux de Paris, Créteil, France.,EA 4391, Nerve Excitability and Therapeutic Team, Faculty of Medicine, Paris Est Créteil University, Créteil, France
| | - Frank Padberg
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilian University Munich, Munich, Germany
| | - Tarik Al-Ani
- EA 4391, Nerve Excitability and Therapeutic Team, Faculty of Medicine, Paris Est Créteil University, Créteil, France
| | - Mohamed Abdellaoui
- Department of Neurology, Henri Mondor Hospital, Assistance Publique - Hôpitaux de Paris, Créteil, France
| | - Marc Sorel
- EA 4391, Nerve Excitability and Therapeutic Team, Faculty of Medicine, Paris Est Créteil University, Créteil, France
| | - Dalia Dimitri
- Department of Neurology, Henri Mondor Hospital, Assistance Publique - Hôpitaux de Paris, Créteil, France
| | - Alain Créange
- EA 4391, Nerve Excitability and Therapeutic Team, Faculty of Medicine, Paris Est Créteil University, Créteil, France.,Department of Neurology, Henri Mondor Hospital, Assistance Publique - Hôpitaux de Paris, Créteil, France
| | - Jean-Pascal Lefaucheur
- Department of Physiology, Henri Mondor Hospital, Assistance Publique - Hôpitaux de Paris, Créteil, France.,EA 4391, Nerve Excitability and Therapeutic Team, Faculty of Medicine, Paris Est Créteil University, Créteil, France
| | - Samar S Ayache
- Department of Physiology, Henri Mondor Hospital, Assistance Publique - Hôpitaux de Paris, Créteil, France.,EA 4391, Nerve Excitability and Therapeutic Team, Faculty of Medicine, Paris Est Créteil University, Créteil, France
| |
Collapse
|
24
|
|
25
|
Huishi Zhang C, Sohrabpour A, Lu Y, He B. Spectral and spatial changes of brain rhythmic activity in response to the sustained thermal pain stimulation. Hum Brain Mapp 2016; 37:2976-91. [PMID: 27167709 DOI: 10.1002/hbm.23220] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 03/26/2016] [Accepted: 04/07/2016] [Indexed: 01/01/2023] Open
Abstract
The aim of this study was to investigate the neurophysiological correlates of pain caused by sustained thermal stimulation. A group of 21 healthy volunteers was studied. Sixty-four channel continuous electroencephalography (EEG) was recorded while the subject received tonic thermal stimulation. Spectral changes extracted from EEG were quantified and correlated with pain scales reported by subjects, the stimulation intensity, and the time course. Network connectivity was assessed to study the changes in connectivity patterns and strengths among brain regions that have been previously implicated in pain processing. Spectrally, a global reduction in power was observed in the lower spectral range, from delta to alpha, with the most marked changes in the alpha band. Spatially, the contralateral region of the somatosensory cortex, identified using source localization, was most responsive to stimulation status. Maximal desynchrony was observed when stimulation was present. The degree of alpha power reduction was linearly correlated to the pain rating reported by the subjects. Contralateral alpha power changes appeared to be a robust correlate of pain intensity experienced by the subjects. Granger causality analysis showed changes in network level connectivity among pain-related brain regions due to high intensity of pain stimulation versus innocuous warm stimulation. These results imply the possibility of using noninvasive EEG to predict pain intensity and to study the underlying pain processing mechanism in coping with prolonged painful experiences. Once validated in a broader population, the present EEG-based approach may provide an objective measure for better pain management in clinical applications. Hum Brain Mapp 37:2976-2991, 2016. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Clara Huishi Zhang
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota
| | - Abbas Sohrabpour
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota
| | - Yunfeng Lu
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota
| | - Bin He
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota.,Institute for Engineering in Medicine, University of Minnesota, Minneapolis, Minnesota
| |
Collapse
|
26
|
Sohn JH, Kim CH, Choi HC. Differences in central facilitation between episodic and chronic migraineurs in nociceptive-specific trigeminal pathways. J Headache Pain 2016; 17:35. [PMID: 27084694 PMCID: PMC4833765 DOI: 10.1186/s10194-016-0637-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 04/12/2016] [Indexed: 01/03/2023] Open
Abstract
Background The trigeminal nociceptive system plays a pivotal role in the pathophysiology of migraines. The present study investigated whether there are differences between patients with episodic migraine (EM) and patients with chronic migraine (CM) in trigeminal pain processing at the brainstem and cortical levels using the nociceptive blink reflex (nBR) and pain-related evoked potentials (PREP). Methods This study assessed 68 female migraineurs (38 EM patients and 30 CM patients) and 40 age-matched controls using simultaneous recordings of nBR and PREP during the interictal period. Results In terms of the nBR, EM patients displayed significantly decreased latencies and larger amplitudes and area-under-the-curve (AUC) values for the R2 component, whereas CM patients showed significantly prolonged latencies and smaller amplitudes and AUC values for the R2 component (p < 0.05). In terms of PREP, both the EM and CM patients had decreased latencies (N1, P1), with larger amplitude compared with the controls (p < 0.05), which indicates facilitation at the cortical level. Additionally, the amplitude and AUC values of the R2 component exhibited a negative correlation, whereas the latency of the R2 component for the nBR showed a positive correlation, with the frequency of headaches in migraineurs (p < 0.01). Conclusions In the present study, the facilitation in the trigeminal nociceptive pathway of the EM group suggests the occurrence of migraine-specific hyperexcitability. Additionally, the suppression of R2 at the brainstem level in the CM group may relate to impaired or dysfunctional descending pain modulation. These findings suggest that there are adaptive or maladaptive responses due to the chronification of migraine attacks.
Collapse
Affiliation(s)
- Jong-Hee Sohn
- Department of Neurology, Chuncheon Sacred Heart Hospital, Hallym University College of Medicine, 153 Gyo-dong, Chuncheon-si, Gangwon-do, 200-704, Republic of Korea.
| | - Chul-Ho Kim
- Department of Neurology, Chuncheon Sacred Heart Hospital, Hallym University College of Medicine, 153 Gyo-dong, Chuncheon-si, Gangwon-do, 200-704, Republic of Korea
| | - Hui-Chul Choi
- Department of Neurology, Chuncheon Sacred Heart Hospital, Hallym University College of Medicine, 153 Gyo-dong, Chuncheon-si, Gangwon-do, 200-704, Republic of Korea
| |
Collapse
|
27
|
Ayache SS, Palm U, Chalah MA, Al-Ani T, Brignol A, Abdellaoui M, Dimitri D, Sorel M, Créange A, Lefaucheur JP. Prefrontal tDCS Decreases Pain in Patients with Multiple Sclerosis. Front Neurosci 2016; 10:147. [PMID: 27092048 PMCID: PMC4824778 DOI: 10.3389/fnins.2016.00147] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Accepted: 03/21/2016] [Indexed: 01/17/2023] Open
Abstract
Background: In the last few years, transcranial direct current stimulation (tDCS) has emerged as an appealing therapeutic option to improve brain functions. Promising data support the role of prefrontal tDCS in augmenting cognitive performance and ameliorating several neuropsychiatric symptoms, namely pain, fatigue, mood disturbances, and attentional impairment. Such symptoms are commonly encountered in patients with multiple sclerosis (MS). Objective: The main objective of the current work was to evaluate the tDCS effects over the left dorsolateral prefrontal cortex (DLPFC) on pain in MS patients.Our secondary outcomes were to study its influence on attention, fatigue, and mood. Materials and Methods: Sixteen MS patients with chronic neuropathic pain were enrolled in a randomized, sham-controlled, and cross-over study.Patients randomly received two anodal tDCS blocks (active or sham), each consisting of three consecutive daily tDCS sessions, and held apart by 3 weeks. Evaluations took place before and after each block. To evaluate pain, we used the Brief Pain Inventory (BPI) and the Visual Analog Scale (VAS). Attention was assessed using neurophysiological parameters and the Attention Network Test (ANT). Changes in mood and fatigue were measured using various scales. Results: Compared to sham, active tDCS yielded significant analgesic effects according to VAS and BPI global scales.There were no effects of any block on mood, fatigue, or attention. Conclusion: Based on our results, anodal tDCS over the left DLPFC appears to act in a selective manner and would ameliorate specific symptoms, particularly neuropathic pain. Analgesia might have occurred through the modulation of the emotional pain network. Attention, mood, and fatigue were not improved in this work. This could be partly attributed to the short protocol duration, the small sample size, and the heterogeneity of our MS cohort. Future large-scale studies can benefit from comparing the tDCS effects over different cortical sites, changing the stimulation montage, prolonging the duration of protocol, and coupling tDCS with neuroimaging techniques for a better understanding of its possible mechanism of action.
Collapse
Affiliation(s)
- Samar S Ayache
- EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-CréteilCréteil, France; Service de Physiologie - Explorations Fonctionnelles, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de ParisCréteil, France; Neurology Division, Lebanese American University Medical Center - Rizk HospitalBeirut, Lebanon
| | - Ulrich Palm
- EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-CréteilCréteil, France; Department of Psychiatry and Psychotherapy, Ludwig-Maximilian-UniversityMunich, Germany
| | - Moussa A Chalah
- EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-CréteilCréteil, France; Service de Physiologie - Explorations Fonctionnelles, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de ParisCréteil, France
| | - Tarik Al-Ani
- EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-Créteil Créteil, France
| | - Arnaud Brignol
- Département d'Informatique et de Recherche Opérationnelle, Université de Montréal Montréal, QC, Canada
| | - Mohamed Abdellaoui
- Service de Neurologie, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de Paris Créteil, France
| | - Dalia Dimitri
- Service de Neurologie, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de Paris Créteil, France
| | - Marc Sorel
- EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-Créteil Créteil, France
| | - Alain Créange
- EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-CréteilCréteil, France; Service de Neurologie, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de ParisCréteil, France
| | - Jean-Pascal Lefaucheur
- EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-CréteilCréteil, France; Service de Physiologie - Explorations Fonctionnelles, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de ParisCréteil, France
| |
Collapse
|
28
|
Onesti E, Gori MC, Frasca V, Inghilleri M. Transcranial magnetic stimulation as a new tool to control pain perception. World J Anesthesiol 2016; 5:15-27. [DOI: 10.5313/wja.v5.i1.15] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Revised: 10/07/2015] [Accepted: 12/15/2015] [Indexed: 02/06/2023] Open
Abstract
Treatment for chronic pain is frequently unsuccessful or characterized by side-effects. The high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) has been suggested in the management of refractory chronic pain. Various studies have shown that HF-rTMS sessions of long-duration applied at primary motor cortex induce pain relief through mechanisms of plastic changes. Efficacy of rTMS mostly depends on stimulation parameters, but this aspect requires better characterization. A rationale to target other cortical areas exists. Current data are promising, but a careful analysis of stimulation settings and maintenance treatment design are need.
Collapse
|
29
|
Azevedo E, Silva A, Martins R, Andersen ML, Tufik S, Manzano GM. Activation of C-fiber nociceptors by low-power diode laser. ARQUIVOS DE NEURO-PSIQUIATRIA 2016; 74:223-7. [DOI: 10.1590/0004-282x20160018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 10/28/2015] [Indexed: 11/21/2022]
Abstract
ABSTRACT Objective The evaluation of selective activation of C-fibers to record evoked potentials using the association of low-power diode laser (810 nm), tiny-area stimulation and skin-blackening. Method Laser-evoked potentials (LEPs) were obtained from 20 healthy young subjects. An aluminum plate with one thin hole was attached to the laser probe to provide tiny-area stimulation of the hand dorsum and the stimulated area was covered with black ink. Results The mean intensity used for eliciting the ultra-late laser-evoked potential (ULEP) was 70 ± 32 mW. All subjects showed a clear biphasic potential that comprised a negative peak (806 ± 61 ms) and a positive deflection (1033 ± 60 ms), corresponding to the ULEP related to C-fiber activation. Conclusion C-fiber-evoked responses can be obtained using a very low-power diode laser when stimulation is applied to tiny areas of darkened skin. This strategy offers a non-invasive and easy methodology that minimizes damage to the tissue.
Collapse
|
30
|
Hayashi K, Ikemoto T, Ueno T, Arai YCP, Shimo K, Nishihara M, Suzuki S, Ushida T. Higher pain rating results in lower variability of somatosensory cortex activation by painful mechanical stimuli: An fMRI study. Clin Neurophysiol 2016; 127:1923-8. [PMID: 26971472 DOI: 10.1016/j.clinph.2016.01.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2015] [Revised: 12/30/2015] [Accepted: 01/07/2016] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The aim of this study was to find pain-related brain activity which corresponds to self-report pain ratings based on degree of response and repeatability. METHODS Three painful mechanical stimuli were applied to the right hands of 25 healthy volunteers using monofilaments (forces of 0.98N, 2.94N, and 5.88N). Simultaneously, brain activities were evaluated using functional MRI for a constant stimulus conducted three times in a session. In first assessment, the average percent signal change (PSC) of neuronal response was measured for each region of interest (ROI), secondary repeatability of PSC conducted three times over the session was evaluated for each ROI. RESULTS Although the average PSCs for trice stimuli conducted in one session increased in accordance with pain ratings in the somatosensory cortex (S1) and anterior cingulate cortex (ACC), there was a different response between S1 and ACC when subjects rated intense pain; a stable response in S1 against a variable response in ACC. CONCLUSIONS These results imply that there are different cognitive responses between sensory discrimination and affective component to constant painful stimulus each time. SIGNIFICANCE Consistency of brain activity based on PSC may be an important biomarker which, along with its neuronal activity, gauges self-report pain ratings.
Collapse
Affiliation(s)
- Kazuhiro Hayashi
- Multidisciplinary Pain Center, Aichi Medical University, Japan; Department of Rehabilitation, Nagoya University Hospital, Japan.
| | - Tatsunori Ikemoto
- Multidisciplinary Pain Center, Aichi Medical University, Japan; Institute of Physical Fitness, Sports Medicine and Rehabilitation, Aichi Medical University, Japan
| | - Takefumi Ueno
- National Hospital Organization, Hizen Psychiatric Center, Japan
| | | | - Kazuhiro Shimo
- Multidisciplinary Pain Center, Aichi Medical University, Japan; Institute of Physical Fitness, Sports Medicine and Rehabilitation, Aichi Medical University, Japan
| | | | - Shigeyuki Suzuki
- Department of Physical and Occupational Therapy, Graduate School of Medicine, Nagoya University, Japan
| | - Takahiro Ushida
- Multidisciplinary Pain Center, Aichi Medical University, Japan; Institute of Physical Fitness, Sports Medicine and Rehabilitation, Aichi Medical University, Japan
| |
Collapse
|
31
|
Hüllemann P, Shao Y, Manthey G, Binder A, Baron R. Central habituation and distraction alter C-fibre-mediated laser-evoked potential amplitudes. Eur J Pain 2015; 20:377-85. [DOI: 10.1002/ejp.735] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/05/2015] [Indexed: 11/10/2022]
Affiliation(s)
- P. Hüllemann
- Division of Neurological Pain Research and Therapy; Department of Neurology; University Clinic Schleswig-Holstein; Kiel Germany
| | - Y.Q. Shao
- Division of Neurological Pain Research and Therapy; Department of Neurology; University Clinic Schleswig-Holstein; Kiel Germany
| | - G. Manthey
- Division of Neurological Pain Research and Therapy; Department of Neurology; University Clinic Schleswig-Holstein; Kiel Germany
| | - A. Binder
- Division of Neurological Pain Research and Therapy; Department of Neurology; University Clinic Schleswig-Holstein; Kiel Germany
| | - R. Baron
- Division of Neurological Pain Research and Therapy; Department of Neurology; University Clinic Schleswig-Holstein; Kiel Germany
| |
Collapse
|
32
|
Mochizuki H, Kakigi R. Itch and brain. J Dermatol 2015; 42:761-7. [DOI: 10.1111/1346-8138.12956] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 04/16/2015] [Indexed: 01/23/2023]
Affiliation(s)
- Hideki Mochizuki
- Department of Dermatology; Temple University School of Medicine; Temple Itch Center; Philadelphia Pennsylvania USA
| | - Ryusuke Kakigi
- Department of Integrative Physiology; National Institute for Physiological Sciences; Okazaki Japan
| |
Collapse
|
33
|
Merkies ISJ, Faber CG, Lauria G. Advances in diagnostics and outcome measures in peripheral neuropathies. Neurosci Lett 2015; 596:3-13. [PMID: 25703220 DOI: 10.1016/j.neulet.2015.02.038] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 02/05/2015] [Accepted: 02/17/2015] [Indexed: 12/13/2022]
Abstract
Peripheral neuropathies are a group of acquired and hereditary disorders presenting with different distribution and nerve fiber class involvement. The overall prevalence is 2.4%, increasing to 8% in the elderly population. However, the frequency may vary depending on the underlying pathogenesis and association with systemic diseases. Distal symmetric polyneuropathy is the most common form, though multiple mononeuropathies, non-length dependent neuropathy and small fiber neuropathy can occur and may require specific diagnostic tools. The use of uniform outcome measures in peripheral neuropathies is important to improve the quality of randomized controlled trials, enabling comparison between studies. Recent developments in defining the optimal set of outcome measures in inflammatory neuropathies may serve as an example for other conditions. Diagnostic and outcome measure advances in peripheral neuropathies will be discussed.
Collapse
Affiliation(s)
- Ingemar S J Merkies
- Department of Neurology, Spaarne Hospital, Hoofddorp, The Netherlands; Department of Neurology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Catharina G Faber
- Department of Neurology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Giuseppe Lauria
- 3rd Neurology Unit, IRCCS Foundation "Carlo Besta" Neurological Institute, Milan, Italy.
| |
Collapse
|
34
|
Kirveskari E, Vartiainen NV, Kallio-Laine K, Kalso E, Forss N. Normal laser-evoked cortical responses in patients with chronic hemibody pain. Eur J Pain 2014; 19:1168-76. [PMID: 25523148 DOI: 10.1002/ejp.642] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2014] [Indexed: 11/07/2022]
Abstract
BACKGROUND Patients with widespread unilateral chronic pain associated with recurrent herpes simplex virus (HSV) infections show functional and/or structural changes in the insula, anterior cingulate cortex, frontal and prefrontal cortices, as well as the thalamus, suggesting central dysfunction of the pain system in these patients. Central pain has been associated with attenuated laser-evoked cortical responses. We aimed to clarify whether the observed deficient activation of these areas to acute nociceptive stimuli is due to a lesion at a lower level of pain processing pathways. METHODS We explored the functional integrity of the ascending nociceptive pathways by recording the cortical-evoked responses to noxious laser stimulation using magnetoencephalography and electroencephalography in eight patients (age 41-51 years, mean 46) with recurrent HSV infections and a history of chronic, spontaneous, widespread unilateral pain, and in nine age-matched healthy control subjects. RESULTS The cortical-evoked fields of the HSV patients originating from the secondary somatosensory and posterior parietal cortices, as well as the evoked potentials recorded from the midline, did not differ from those of the control subjects, indicating functionally intact ascending nociceptive pathways. CONCLUSIONS The present results show that our patients with chronic hemibody pain do not show signs of spinothalamic tract lesion. This indicates normal processing of sensory aspects of painful stimuli, while higher pain processing areas show altered activation. We conclude that normal laser-evoked magnetic fields (LEF) or laser-evoked potentials (LEP) may not exclude central pain condition.
Collapse
Affiliation(s)
- E Kirveskari
- Brain Research Unit and MEG Core, O.V. Lounasmaa Laboratory, Aalto Neuroimaging, School of Science, Aalto University, Espoo, Finland.,Department of Clinical Neurophysiology, HUS Medical Imaging Center, Helsinki University Central Hospital, Finland.,Department of Neurological Sciences, University of Helsinki, Finland
| | - N V Vartiainen
- Brain Research Unit and MEG Core, O.V. Lounasmaa Laboratory, Aalto Neuroimaging, School of Science, Aalto University, Espoo, Finland
| | - K Kallio-Laine
- Department of Anaesthesia and Intensive Care Medicine, Pain Clinic, Helsinki University Central Hospital, Finland
| | - E Kalso
- Department of Anaesthesia and Intensive Care Medicine, Pain Clinic, Helsinki University Central Hospital, Finland.,Institute of Clinical Medicine, Faculty of Medicine, University of Helsinki, Finland
| | - N Forss
- Brain Research Unit and MEG Core, O.V. Lounasmaa Laboratory, Aalto Neuroimaging, School of Science, Aalto University, Espoo, Finland.,Department of Neurological Sciences, University of Helsinki, Finland.,Department of Neurology, Helsinki University Central Hospital, Finland
| |
Collapse
|
35
|
Nakata H, Sakamoto K, Kakigi R. Meditation reduces pain-related neural activity in the anterior cingulate cortex, insula, secondary somatosensory cortex, and thalamus. Front Psychol 2014; 5:1489. [PMID: 25566158 PMCID: PMC4267182 DOI: 10.3389/fpsyg.2014.01489] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 12/03/2014] [Indexed: 12/31/2022] Open
Abstract
Recent studies have shown that meditation inhibits or relieves pain perception. To clarify the underlying mechanisms for this phenomenon, neuroimaging methods, such as functional magnetic resonance imaging, and neurophysiological methods, such as magnetoencephalography and electroencephalography, have been used. However, it has been difficult to interpret the results, because there is some paradoxical evidence. For example, some studies reported increased neural responses to pain stimulation during meditation in the anterior cingulate cortex (ACC) and insula, whereas others showed a decrease in these regions. There have been inconsistent findings to date. Moreover, in general, since the activities of the ACC and insula are correlated with pain perception, the increase in neural activities during meditation would be related to the enhancement of pain perception rather than its reduction. These contradictions might directly contribute to the ‘mystery of meditation.’ In this review, we presented previous findings for brain regions during meditation and the anatomical changes that occurred in the brain with long-term meditation training. We then discussed the findings of previous studies that examined pain-related neural activity during meditation. We also described the brain mechanisms responsible for pain relief during meditation, and possible reasons for paradoxical evidence among previous studies. By thoroughly overviewing previous findings, we hypothesized that meditation reduces pain-related neural activity in the ACC, insula, secondary somatosensory cortex, and thalamus. We suggest that the characteristics of the modulation of this activity may depend on the kind of meditation and/or number of years of experience of meditation, which were associated with paradoxical findings among previous studies that investigated pain-related neural activities during meditation.
Collapse
Affiliation(s)
- Hiroki Nakata
- Department of Integrative Physiology, National Institute for Physiological Sciences Okazaki, Japan ; Department of Health Sciences, Faculty of Human Life and Environment, Nara Women's University Nara, Japan
| | - Kiwako Sakamoto
- Department of Integrative Physiology, National Institute for Physiological Sciences Okazaki, Japan
| | - Ryusuke Kakigi
- Department of Integrative Physiology, National Institute for Physiological Sciences Okazaki, Japan
| |
Collapse
|
36
|
Mochizuki H, Kakigi R. Central mechanisms of itch. Clin Neurophysiol 2014; 126:1650-60. [PMID: 25534483 DOI: 10.1016/j.clinph.2014.11.019] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 10/31/2014] [Accepted: 11/18/2014] [Indexed: 10/24/2022]
Abstract
Itch is a complex sensory and emotional experience. Functional brain imaging studies have been performed to identify brain regions associated with this complex experience, and these studies reported that several brain regions are activated by itch stimuli. The possible roles of these regions in itch perception and difference in cerebral mechanism between healthy subjects and chronic itch patients are discussed in this review article. Additionally, the central itch modulation system and cerebral mechanisms of contagious itch, pleasurable sensation evoked by scratching have also been investigated in previous brain imaging studies. We also discuss how these studies advance our understanding of these mechanisms.
Collapse
Affiliation(s)
- Hideki Mochizuki
- Department of Integrative Physiology, National Institute for Physiological Sciences, Okazaki, Aichi, Japan; Department of Dermatology and Temple Itch Center, Temple University School of Medicine, Philadelphia, PA, USA.
| | - Ryusuke Kakigi
- Department of Integrative Physiology, National Institute for Physiological Sciences, Okazaki, Aichi, Japan
| |
Collapse
|
37
|
|
38
|
Daood HG, Halasz G, Palotás G, Palotás G, Bodai Z, Helyes L. HPLC Determination of Capsaicinoids with Cross-Linked C18 Column and Buffer-Free Eluent. J Chromatogr Sci 2014; 53:135-43. [DOI: 10.1093/chromsci/bmu030] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
|
39
|
Ludvigsen S, Stenklev NC, Johnsen HK, Laukli E, Matre D, Aas-Hansen Ø. Evoked potentials in the Atlantic cod following putatively innocuous and putatively noxious electrical stimulation: a minimally invasive approach. FISH PHYSIOLOGY AND BIOCHEMISTRY 2014; 40:173-181. [PMID: 23896862 PMCID: PMC3901938 DOI: 10.1007/s10695-013-9834-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Accepted: 07/20/2013] [Indexed: 06/02/2023]
Abstract
Aspects of peripheral and central nociception have previously been studied through recording of somatosensory evoked potentials (SEPs) to putative noxious stimuli in specific brain regions in a few freshwater fish species. In the present study, we describe a novel, minimally invasive method for recording SEPs from the central nervous system of the Atlantic cod (Gadus morhua). Cutaneous electric stimulation of the tail in 15 fish elicited SEPs at all stimulus intensities (2, 5, 10 and 20 mA) with quantitative properties corresponding to stimulus intensity. In contrast to previous fish studies, the methodological approach used in Atlantic cod in the current study uncovered a number of additional responses that could originate from multiple brain regions. Several of these responses were specific to stimulation at the highest stimulus intensities, possibly representing qualitative differences in central processing between somatosensory and nociceptive stimuli.
Collapse
Affiliation(s)
- Stian Ludvigsen
- Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, University of Tromsø, 9037 Tromsö, Norway
- Present Address: Faculty of Health Sciences, Institute of Medical Biology, University of Tromsø, 9037 Tromsö, Norway
| | - Niels C. Stenklev
- Faculty of Health Sciences, Institute of Clinical Medicine, University of Tromsø, 9037 Tromsö, Norway
| | - Helge K. Johnsen
- Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, University of Tromsø, 9037 Tromsö, Norway
| | - Einar Laukli
- Faculty of Health Sciences, Institute of Clinical Medicine, University of Tromsø, 9037 Tromsö, Norway
| | - Dagfinn Matre
- Department of Work Psychology and Physiology, National Institute of Occupational Health, 0033 Oslo, Norway
| | - Øyvind Aas-Hansen
- Norwegian Institute of Food, Fisheries and Aquaculture Research (Nofima), Muninbakken 9-13, P.O. Box 6122, 9291 Breivika, Norway
| |
Collapse
|
40
|
Limongi F, Radaelli S, Noale M, Maggi S, Crepaldi G. Somatosensory Evoked Potentials and pain assessment in Alzheimer's disease. Eur Geriatr Med 2013. [DOI: 10.1016/j.eurger.2013.09.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
41
|
Mouraux A, De Paepe AL, Marot E, Plaghki L, Iannetti GD, Legrain V. Unmasking the obligatory components of nociceptive event-related brain potentials. J Neurophysiol 2013; 110:2312-24. [DOI: 10.1152/jn.00137.2013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
It has been hypothesized that the human cortical responses to nociceptive and nonnociceptive somatosensory inputs differ. Supporting this view, somatosensory-evoked potentials (SEPs) elicited by thermal nociceptive stimuli have been suggested to originate from areas 1 and 2 of the contralateral primary somatosensory (S1), operculo-insular, and cingulate cortices, whereas the early components of nonnociceptive SEPs mainly originate from area 3b of S1. However, to avoid producing a burn lesion, and sensitize or fatigue nociceptors, thermonociceptive SEPs are typically obtained by delivering a small number of stimuli with a large and variable interstimulus interval (ISI). In contrast, the early components of nonnociceptive SEPs are usually obtained by applying many stimuli at a rapid rate. Hence, previously reported differences between nociceptive and nonnociceptive SEPs could be due to differences in signal-to-noise ratio and/or differences in the contribution of cognitive processes related, for example, to arousal and attention. Here, using intraepidermal electrical stimulation to selectively activate Aδ-nociceptors at a fast and constant 1-s ISI, we found that the nociceptive SEPs obtained with a long ISI are no longer identified, indicating that these responses are not obligatory for nociception. Furthermore, using a blind source separation, we found that, unlike the obligatory components of nonnociceptive SEPs, the obligatory components of nociceptive SEPs do not receive a significant contribution from a contralateral source possibly originating from S1. Instead, they were best explained by sources compatible with bilateral operculo-insular and/or cingulate locations. Taken together, our results indicate that the obligatory components of nociceptive and nonnociceptive SEPs are fundamentally different.
Collapse
Affiliation(s)
- A. Mouraux
- Institute of Neuroscience (IoNS), Université catholique de Louvain, Brussels, Belgium
| | - A. L. De Paepe
- Department of Experimental Clinical and Health Psychology, Ghent University, Ghent, Belgium; and
| | - E. Marot
- Institute of Neuroscience (IoNS), Université catholique de Louvain, Brussels, Belgium
| | - L. Plaghki
- Institute of Neuroscience (IoNS), Université catholique de Louvain, Brussels, Belgium
| | - G. D. Iannetti
- Department of Neuroscience, Physiology, and Pharmacology, University College London, London, United Kingdom
| | - V. Legrain
- Institute of Neuroscience (IoNS), Université catholique de Louvain, Brussels, Belgium
- Department of Experimental Clinical and Health Psychology, Ghent University, Ghent, Belgium; and
| |
Collapse
|
42
|
Stancak A, Fallon N. Emotional modulation of experimental pain: a source imaging study of laser evoked potentials. Front Hum Neurosci 2013; 7:552. [PMID: 24062659 PMCID: PMC3775006 DOI: 10.3389/fnhum.2013.00552] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 08/21/2013] [Indexed: 11/23/2022] Open
Abstract
Negative emotions have been shown to augment experimental pain. As induced emotions alter brain activity, it is not clear whether pain augmentation during noxious stimulation would be related to neural activation existing prior to onset of a noxious stimulus or alternatively, whether emotional stimuli would only alter neural activity during the period of nociceptive processing. We analyzed the spatio-temporal patterns of laser evoked potentials (LEPs) occurring prior to and during the period of cortical processing of noxious laser stimuli during passive viewing of negative, positive, or neutral emotional pictures. Independent component analysis (ICA) was applied to series of source activation volumes, reconstructed using local autoregressive average model (LAURA). Pain was the strongest when laser stimuli were associated with negative emotional pictures. Prior to laser stimulus and during the first 100 ms after onset of laser stimulus, activations were seen in the left and right medial temporal cortex, cerebellum, posterior cingulate, and rostral cingulate/prefrontal cortex. In all these regions, positive or neutral pictures showed stronger activations than negative pictures. During laser stimulation, activations in the right and left anterior insula, temporal cortex and right anterior and posterior parietal cortex were stronger during negative than neutral or positive emotional pictures. Results suggest that negative emotional stimuli increase activation in the left and right anterior insula and temporal cortex, and right posterior and anterior parietal cortex only during the period of nociceptive processing. The role of background brain activation in emotional modulation of pain appears to be only permissive, and consisting in attenuation of activation in structures maintaining the resting state of the brain.
Collapse
Affiliation(s)
- Andrej Stancak
- Department of Experimental Psychology, Institute of Psychology, Health, and Society, University of Liverpool Liverpool, UK
| | | |
Collapse
|
43
|
Laser-evoked potentials as a novel tool for sensibility assessment following inferior pedicle breast reduction. EUROPEAN JOURNAL OF PLASTIC SURGERY 2013. [DOI: 10.1007/s00238-012-0803-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
44
|
Bastuji H, Mazza S, Perchet C, Frot M, Mauguière F, Magnin M, Garcia-Larrea L. Filtering the reality: functional dissociation of lateral and medial pain systems during sleep in humans. Hum Brain Mapp 2012; 33:2638-49. [PMID: 21922606 PMCID: PMC6869894 DOI: 10.1002/hbm.21390] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2011] [Revised: 05/17/2011] [Accepted: 05/31/2011] [Indexed: 11/11/2022] Open
Abstract
Behavioral reactions to sensory stimuli during sleep are scarce despite preservation of sizeable cortical responses. To further understand such dissociation, we recorded intracortical field potentials to painful laser pulses in humans during waking and all-night sleep. Recordings were obtained from the three cortical structures receiving 95% of the spinothalamic cortical input in primates, namely the parietal operculum, posterior insula, and mid-anterior cingulate cortex. The dynamics of responses during sleep differed among cortical sites. In sleep Stage 2, evoked potential amplitudes were similarly attenuated relative to waking in all three cortical regions. During paradoxical, or rapid eye movements (REM), sleep, opercular and insular potentials remained stable in comparison with Stage 2, whereas the responses from mid-anterior cingulate abated drastically, and decreasing below background noise in half of the subjects. Thus, while the lateral operculo-insular system subserving sensory analysis of somatic stimuli remained active during paradoxical-REM sleep, mid-anterior cingulate processes related to orienting and avoidance behavior were suppressed. Dissociation between sensory and orienting-motor networks might explain why nociceptive stimuli can be either neglected or incorporated into dreams without awakening the subject.
Collapse
Affiliation(s)
- Hélène Bastuji
- Central Integration of Pain Lab-Lyon Neuroscience Research Center, INSERM, U1028, CNRS, UMR5292, Bron, F-69677, France.
| | | | | | | | | | | | | |
Collapse
|
45
|
Increased brain responses during subjectively-matched mechanical pain stimulation in fibromyalgia patients as evidenced by MEG. Clin Neurophysiol 2012; 124:752-60. [PMID: 23121899 DOI: 10.1016/j.clinph.2012.09.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Revised: 08/24/2012] [Accepted: 09/25/2012] [Indexed: 11/21/2022]
Abstract
OBJECTIVE The precise pathophysiology of fibromyalgia, a syndrome characterized by chronic widespread pain, remains to be clarified. When subjected to the same amount of stimulation, patients show enhanced brain responses as compared to controls, providing evidence of central pain augmentation in this syndrome. We aimed to characterize brain response differences when stimulation is adjusted to elicit similar subjective levels of pain in both groups. METHODS Magnetoencephalography (MEG) was used to investigate the brain responses to pressure stimulation applied both above and below the pain threshold in nine patients and nine control subjects. A device was developed to deliver pressure pulses in a quantifiable and precise manner. The amount of pressure was adjusted to produce similar subjective pain in both groups. RESULTS A between-group comparison of differences between responses evoked by stimulation above and below the pain threshold was performed using cluster-based permutation testing. Increases in signal amplitude in somatosensory, temporal and parietal areas at short latencies, and in prefrontal areas at both short and long latencies, were found to be larger for patients than for control subjects. CONCLUSION Fibromyalgia patients show enhanced brain responses after reducing the amount of pressure to produce similar subjective levels of pain than to the control subjects. SIGNIFICANCE The present results suggest that central pain augmentation is present in fibromyalgia, not only when the objective level of stimulation is kept the same as for control subjects, but also when stimulation is adjusted to produce similar levels of pain in patients and controls.
Collapse
|
46
|
Garcia-Larrea L. The posterior insular-opercular region and the search of a primary cortex for pain. Neurophysiol Clin 2012; 42:299-313. [DOI: 10.1016/j.neucli.2012.06.001] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 06/01/2012] [Accepted: 06/10/2012] [Indexed: 01/15/2023] Open
|
47
|
Perchet C, Frot M, Charmarty A, Flores C, Mazza S, Magnin M, Garcia-Larrea L. Do we activate specifically somatosensory thin fibres with the concentric planar electrode? A scalp and intracranial EEG study. Pain 2012; 153:1244-1252. [DOI: 10.1016/j.pain.2012.03.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Revised: 02/20/2012] [Accepted: 03/05/2012] [Indexed: 10/28/2022]
|
48
|
Rosen SD. From heart to brain: the genesis and processing of cardiac pain. Can J Cardiol 2012; 28:S7-19. [PMID: 22424286 DOI: 10.1016/j.cjca.2011.09.010] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 09/15/2011] [Accepted: 09/15/2011] [Indexed: 01/12/2023] Open
Abstract
Angina pectoris is important because of its association with heart disease and risk of death. Historically after Heberden's account of angina in 1772, the association of pain with coronary artery disease quickly followed. Within a few years, Burns suggested an etiological role for ischemia. Subsequently, theories of differential myocardial stretch dominated thinking until Lewis' chemical hypothesis in 1932, in which the local release of chemical substances during ischemia was seen as the cause of pain. This review considers how ischemia at the tissue level triggers activation of afferent nociceptive pain fibres. The afferent projections of sympathetic and vagal afferent fibres are described, with a number of methodologies cited (eg, injection of pseudorabies virus into the heart with mapping of the retrograde viral transport pathways; and elevation of neuronal c-fos synthesis in brain regions activated by capsaicin application to the heart). Our own functional neuroimaging studies of angina are also reviewed. There are 2 intriguing features of angina. The first is the poor correlation between symptoms and extent of coronary disease. The spectrum ranges from entirely silent myocardial ischemia to that of a functional pain syndrome--the 'sensitive heart'--of cardiac syndrome X. An even more difficult aspect is the wide variability in symptoms experienced by an individual patient. A new paradigm is presented which, besides considering myocardial oxygen supply/demand imbalance, also draws insights from the broader field of pain research. Neuromodulation applies at multiple levels of the neuraxis--peripheral nerves, spinal cord, and brain--and it invites exploitation, whether pharmacological or electrical, for the benefit of the cardiac patient in pain.
Collapse
Affiliation(s)
- Stuart D Rosen
- National Heart and Lung Institute, Imperial College, London, United Kingdom.
| |
Collapse
|
49
|
Wu JJS, Shih HC, Yen CT, Shyu BC. Network dynamics in nociceptive pathways assessed by the neuronal avalanche model. Mol Pain 2012; 8:33. [PMID: 22537828 PMCID: PMC3478175 DOI: 10.1186/1744-8069-8-33] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 04/26/2012] [Indexed: 01/04/2023] Open
Abstract
Background Traditional electroencephalography provides a critical assessment of pain responses. The perception of pain, however, may involve a series of signal transmission pathways in higher cortical function. Recent studies have shown that a mathematical method, the neuronal avalanche model, may be applied to evaluate higher-order network dynamics. The neuronal avalanche is a cascade of neuronal activity, the size distribution of which can be approximated by a power law relationship manifested by the slope of a straight line (i.e., the α value). We investigated whether the neuronal avalanche could be a useful index for nociceptive assessment. Findings Neuronal activity was recorded with a 4 × 8 multichannel electrode array in the primary somatosensory cortex (S1) and anterior cingulate cortex (ACC). Under light anesthesia, peripheral pinch stimulation increased the slope of the α value in both the ACC and S1, whereas brush stimulation increased the α value only in the S1. The increase in α values was blocked in both regions under deep anesthesia. The increase in α values in the ACC induced by peripheral pinch stimulation was blocked by medial thalamic lesion, but the increase in α values in the S1 induced by brush and pinch stimulation was not affected. Conclusions The neuronal avalanche model shows a critical state in the cortical network for noxious-related signal processing. The α value may provide an index of brain network activity that distinguishes the responses to somatic stimuli from the control state. These network dynamics may be valuable for the evaluation of acute nociceptive processes and may be applied to chronic pathological pain conditions.
Collapse
Affiliation(s)
- José Jiun-Shian Wu
- Institute of Biomedical Science, Academia Sinica, Taipei, Republic of China
| | | | | | | |
Collapse
|
50
|
Tiemann L, Schulz E, Winkelmann A, Ronel J, Henningsen P, Ploner M. Behavioral and neuronal investigations of hypervigilance in patients with fibromyalgia syndrome. PLoS One 2012; 7:e35068. [PMID: 22509383 PMCID: PMC3324411 DOI: 10.1371/journal.pone.0035068] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 03/08/2012] [Indexed: 11/18/2022] Open
Abstract
Painful stimuli are of utmost behavioral relevance and thereby affect attentional resources. In health, variable effects of pain on attention have been observed, indicating alerting as well as distracting effects of pain. In the human brain, these effects are closely related to modulations of neuronal gamma oscillations. As hypervigilance as an abnormal increase of attention to external stimuli has been implicated in chronic pain states, we assumed both attentional performance and pain-induced gamma oscillations to be altered in patients with fibromyalgia syndrome (FMS). We recorded electroencephalography from healthy subjects (n = 22) and patients with FMS (n = 19) during an attention demanding visual reaction time task. In 50% of the trials we applied painful laser stimuli. The results of self-assessment questionnaires confirm that patients with FMS consider themselves hypervigilant towards pain as compared to healthy controls. However, the experimental findings indicate that the effects of painful stimuli on attentional performance and neuronal gamma oscillations do not differ between patients and healthy subjects. We further found a significant correlation between the pain-induced modulation of visual gamma oscillations and the pain-induced modulation of reaction times. This relationship did not differ between groups either. These findings confirm a close relationship between gamma oscillations and the variable attentional effects of pain, which appear to be comparable in health and disease. Thus, our results do not provide evidence for a behavioral or neuronal manifestation of hypervigilance in patients with FMS.
Collapse
Affiliation(s)
- Laura Tiemann
- Department of Neurology, Technische Universität München, Munich, Germany.
| | | | | | | | | | | |
Collapse
|