1
|
Peng K, Karunakaran KD, Green S, Borsook D. Machines, mathematics, and modules: the potential to provide real-time metrics for pain under anesthesia. NEUROPHOTONICS 2024; 11:010701. [PMID: 38389718 PMCID: PMC10883389 DOI: 10.1117/1.nph.11.1.010701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 01/08/2024] [Accepted: 01/16/2024] [Indexed: 02/24/2024]
Abstract
The brain-based assessments under anesthesia have provided the ability to evaluate pain/nociception during surgery and the potential to prevent long-term evolution of chronic pain. Prior studies have shown that the functional near-infrared spectroscopy (fNIRS)-measured changes in cortical regions such as the primary somatosensory and the polar frontal cortices show consistent response to evoked and ongoing pain in awake, sedated, and anesthetized patients. We take this basic approach and integrate it into a potential framework that could provide real-time measures of pain/nociception during the peri-surgical period. This application could have significant implications for providing analgesia during surgery, a practice that currently lacks quantitative evidence to guide patient tailored pain management. Through a simple readout of "pain" or "no pain," the proposed system could diminish or eliminate levels of intraoperative, early post-operative, and potentially, the transition to chronic post-surgical pain. The system, when validated, could also be applied to measures of analgesic efficacy in the clinic.
Collapse
Affiliation(s)
- Ke Peng
- University of Manitoba, Department of Electrical and Computer Engineering, Price Faculty of Engineering, Winnipeg, Manitoba, Canada
| | - Keerthana Deepti Karunakaran
- Massachusetts General Hospital, Harvard Medical School, Department of Psychiatry, Boston, Massachusetts, United States
| | - Stephen Green
- Massachusetts Institute of Technology, Department of Mechanical Engineering, Boston, Massachusetts, United States
| | - David Borsook
- Massachusetts General Hospital, Harvard Medical School, Department of Psychiatry, Boston, Massachusetts, United States
- Massachusetts General Hospital, Harvard Medical School, Department of Radiology, Boston, Massachusetts, United States
| |
Collapse
|
2
|
Robayo LE, Govind V, Vastano R, Felix ER, Fleming L, Cherup NP, Widerström-Noga E. Multidimensional pain phenotypes after Traumatic Brain Injury. FRONTIERS IN PAIN RESEARCH 2022; 3:947562. [PMID: 36061413 PMCID: PMC9437424 DOI: 10.3389/fpain.2022.947562] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 08/02/2022] [Indexed: 12/04/2022] Open
Abstract
More than 50% of individuals develop chronic pain following traumatic brain injury (TBI). Research suggests that a significant portion of post-TBI chronic pain conditions is neuropathic in nature, yet the relationship between neuropathic pain, psychological distress, and somatosensory function following TBI is not fully understood. This study evaluated neuropathic pain symptoms, psychological and somatosensory function, and psychosocial factors in individuals with TBI (TBI, N = 38). A two-step cluster analysis was used to identify phenotypes based on the Neuropathic Pain Symptom Inventory and Beck's Anxiety Inventory scores. Phenotypes were then compared on pain characteristics, psychological and somatosensory function, and psychosocial factors. Our analyses resulted in two different neuropathic pain phenotypes: (1) Moderate neuropathic pain severity and anxiety scores (MNP-AS, N = 11); and (2) mild or no neuropathic pain symptoms and anxiety scores (LNP-AS, N = 27). Furthermore, the MNP-AS group exhibited greater depression, PTSD, pain severity, and affective distress scores than the LNP-AS group. In addition, thermal somatosensory function (difference between thermal pain and perception thresholds) was significantly lower in the MNP-AS compared to the LNP-AS group. Our findings suggest that neuropathic pain symptoms are relatively common after TBI and are not only associated with greater psychosocial distress but also with abnormal function of central pain processing pathways.
Collapse
Affiliation(s)
- Linda E. Robayo
- Neuroscience Graduate Program, University of Miami Miller School of Medicine, Miami, FL, United States
- Christine E. Lynn Rehabilitation Center, Miami Project to Cure Paralysis at UHealth/Jackson Memorial, Miami, FL, United States
| | - Varan Govind
- Department of Radiology, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Roberta Vastano
- Christine E. Lynn Rehabilitation Center, Miami Project to Cure Paralysis at UHealth/Jackson Memorial, Miami, FL, United States
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Elizabeth R. Felix
- Department of Physical Medicine and Rehabilitation, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Loriann Fleming
- Christine E. Lynn Rehabilitation Center, Miami Project to Cure Paralysis at UHealth/Jackson Memorial, Miami, FL, United States
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Nicholas P. Cherup
- Christine E. Lynn Rehabilitation Center, Miami Project to Cure Paralysis at UHealth/Jackson Memorial, Miami, FL, United States
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Eva Widerström-Noga
- Neuroscience Graduate Program, University of Miami Miller School of Medicine, Miami, FL, United States
- Christine E. Lynn Rehabilitation Center, Miami Project to Cure Paralysis at UHealth/Jackson Memorial, Miami, FL, United States
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, United States
- *Correspondence: Eva Widerström-Noga
| |
Collapse
|
3
|
He J, Dun W, Han F, Wang K, Yang J, Ma S, Zhang M, Liu J, Liu H. Abnormal white matter microstructure along the thalamus fiber pathways in women with primary dysmenorrhea. Brain Imaging Behav 2020; 15:2061-2068. [PMID: 33033985 DOI: 10.1007/s11682-020-00400-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/07/2020] [Indexed: 12/19/2022]
Abstract
Primary dysmenorrhea (PDM) is a cyclic menstrual pain in the absence of pelvic anomalies, and women with PDM have an increased sensitivity to pain than the internal and external areas associated with menstrual pain. However, the brain abnormality in the ascending pain pathways in dysmenorrhea remains largely unclear. As the thalamus plays a significant role in transmission of nociceptive input, we examined whether white matter microstructure of the thalamus-related fiber tracts obtained by DTI in women with PDM (n = 47) differs from healthy controls. A novel tractography atlas-based analysis method that detects tract integrity and altered microstructural properties along selected fibers was employed. The fiber bundles of interest contained the thalamus- primary somatosensory cortex (SI), thalamus- dorsal anterior cingulate cortex (dACC)/supplementary motor area (SMA), thalamus-insula, and thalamus-ACC. As compared with controls, abnormal white matter microstructures were found along the thalamus-related white matter fiber tracts. Additionally, the intensity of menstrual pain was significantly associated with diffusion measures of thalamus-SI fiber connections. Our study suggested that the thalamus-related pain processing pathways had altered white matter integrity that persisted beyond the time of menstruation, and the white matter microstructure of the thalamus-SI pathways was closely related to menstrual pain in the intensity by women with PDM.
Collapse
Affiliation(s)
- Juan He
- Department of Rehabilitation Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Wanghuan Dun
- Department of Rehabilitation Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Fang Han
- Department of Medical Imaging, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Ke Wang
- Department of Medical Imaging, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Jing Yang
- Department of Medical Imaging, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Shaohui Ma
- Department of Medical Imaging, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Ming Zhang
- Department of Rehabilitation Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.,Department of Medical Imaging, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Jixin Liu
- School of Life Science and Technology, Xidian University, Xi'an, China.
| | - Hongjuan Liu
- Department of Intensive Care Unit, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
| |
Collapse
|
4
|
Kim YR, Kim CE, Yoon H, Kim SK, Kim SJ. S1 Employs Feature-Dependent Differential Selectivity of Single Cells and Distributed Patterns of Populations to Encode Mechanosensations. Front Cell Neurosci 2019; 13:132. [PMID: 31024261 PMCID: PMC6460949 DOI: 10.3389/fncel.2019.00132] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 03/18/2019] [Indexed: 11/23/2022] Open
Abstract
The primary somatosensory (S1) cortex plays an important role in the perception and discrimination of touch and pain mechanosensations. Conventionally, neurons in the somatosensory system including S1 cortex have been classified into low/high threshold (HT; non-nociceptive/nociceptive) or wide dynamic range (WDR; convergent) neurons by their electrophysiological responses to innocuous brush-stroke and noxious forceps-pinch stimuli. Besides this “noxiousness” (innocuous/noxious) feature, each stimulus also includes other stimulus features: “texture” (brush hairs/forceps-steel arm), “dynamics” (dynamic stroke/static press) and “intensity” (weak/strong). However, it remains unknown how S1 neurons inclusively process such diverse features of brushing and pinch at the single-cell and population levels. Using in vivo two-photon Ca2+ imaging in the layer 2/3 neurons of the mouse S1 cortex, we identified clearly separated response patterns of the S1 neural population with distinct tuning properties of individual cells to texture, dynamics and noxiousness features of cutaneous mechanical stimuli. Among cells other than broadly tuned neurons, the majority of the cells showed a highly selective response to the difference in texture, but low selectivity to the difference in dynamics or noxiousness. Between the two low selectivity features, the difference in dynamics was slightly more specific, yet both could be decoded using the response patterns of neural populations. In addition, more neurons are recruited and stronger Ca2+ responses are evoked as the intensity of forceps-pinch is gradually increased. Our results suggest that S1 neurons encode various features of mechanosensations with feature-dependent differential selectivity of single cells and distributed response patterns of populations. Moreover, we raise a caution about describing neurons by a single stimulus feature ignoring other aspects of the sensory stimuli.
Collapse
Affiliation(s)
- Yoo Rim Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul, South Korea.,Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea
| | - Chang-Eop Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul, South Korea.,Department of Physiology, College of Korean Medicine, Gachon University, Gyeonggi-do, South Korea
| | - Heera Yoon
- Department of Science in Korean Medicine, Graduate School, Kyung Hee University, Seoul, South Korea
| | - Sun Kwang Kim
- Department of Science in Korean Medicine, Graduate School, Kyung Hee University, Seoul, South Korea.,Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul, South Korea
| | - Sang Jeong Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul, South Korea.,Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea.,Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, South Korea
| |
Collapse
|
5
|
Whitsel BL, Vierck CJ, Waters RS, Tommerdahl M, Favorov OV. Contributions of Nociresponsive Area 3a to Normal and Abnormal Somatosensory Perception. THE JOURNAL OF PAIN 2019; 20:405-419. [PMID: 30227224 PMCID: PMC6420406 DOI: 10.1016/j.jpain.2018.08.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 07/12/2018] [Accepted: 08/11/2018] [Indexed: 12/29/2022]
Abstract
Traditionally, cytoarchitectonic area 3a of primary somatosensory cortex (SI) has been regarded as a proprioceptive relay to motor cortex. However, neuronal spike-train recordings and optical intrinsic signal imaging, obtained from nonhuman sensorimotor cortex, show that neuronal activity in some of the cortical columns in area 3a can be readily triggered by a C-nociceptor afferent drive. These findings indicate that area 3a is a critical link in cerebral cortical encoding of secondary/slow pain. Also, area 3a contributes to abnormal pain processing in the presence of activity-dependent reversal of gamma-aminobutyric acid A receptor-mediated inhibition. Accordingly, abnormal processing within area 3a may contribute mechanistically to generation of clinical pain conditions. PERSPECTIVE: Optical imaging and neurophysiological mapping of area 3a of SI has revealed substantial driving from unmyelinated cutaneous nociceptors, complementing input to areas 3b and 1 of SI from myelinated nociceptors and non-nociceptors. These and related findings force a reconsideration of mechanisms for SI processing of pain.
Collapse
Affiliation(s)
- Barry L Whitsel
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina
| | - Charles J Vierck
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, Florida
| | - Robert S Waters
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, College of Medicine, Memphis, Tennessee
| | - Mark Tommerdahl
- Department of Biomedical Engineering, University of North Carolina, Chapel Hill, North Carolina
| | - Oleg V Favorov
- Department of Biomedical Engineering, University of North Carolina, Chapel Hill, North Carolina.
| |
Collapse
|
6
|
Lee J, Favorov OV, Tommerdahl M, Lee CJ, Whitsel BL. Attenuated Glial K(+) Clearance Contributes to Long-Term Synaptic Potentiation Via Depolarizing GABA in Dorsal Horn Neurons of Rat Spinal Cord. Exp Neurobiol 2014; 23:53-64. [PMID: 24737940 PMCID: PMC3984957 DOI: 10.5607/en.2014.23.1.53] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Revised: 03/05/2014] [Accepted: 03/05/2014] [Indexed: 11/19/2022] Open
Abstract
It has been reported that long-term enhancement of superficial dorsal horn (DHs) excitatory synaptic transmission underlies central sensitization, secondary hyperalgesia, and persistent pain. We tested whether impaired clearance of K(+) and glutamate by glia in DHs may contribute to initiation and maintenance of the CNS pain circuit and sensorimotor abnormalities. Transient exposure of the spinal cord slice to fluorocitrate (FC) is shown to be accompanied by a protracted decrease of the DHs optical response to repetitive electrical stimulation of the ipsilateral dorsal root, and by a similarly protracted increase in the postsynaptic response of the DHs like LTP. It also is shown that LTPFC does not occur in the presence of APV, and becomes progressively smaller as [K(+)]o in the perfusion solution decreased from 3.0 mM to 0.0 mM. Interestingly LTPFC is reduced by bath application of Bic. Whole-cell patch recordings were carried out to evaluate the effects of FC on the response of DHs neurons to puffer-applied GABA. The observations reveal that transient exposure to FC is reliably accompanied by a prolonged (>1 hr) depolarizing shift of the equilibrium potential for the DHs neuron transmembrane ionic currents evoked by GABA. Considered collectively, the findings demonstrate that LTPFC involves (1) elevation of [K(+)]o in the DHs, (2) NMDAR activation, and (3) conversion of the effect of GABA on DHs neurons from inhibition to excitation. It is proposed that a transient impairment of astrocyte energy production can trigger the cascade of dorsal horn mechanisms that underlies hyperalgesia and persistent pain.
Collapse
Affiliation(s)
- Jaekwang Lee
- Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. ; WCI Center for Functional Connectomics, Institute of Science and Technology (KIST), Seoul, Korea
| | - Oleg V Favorov
- Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Mark Tommerdahl
- Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - C Justin Lee
- WCI Center for Functional Connectomics, Institute of Science and Technology (KIST), Seoul, Korea. ; KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, Korea
| | - Barry L Whitsel
- Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. ; Department of Cell and Molecular Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| |
Collapse
|
7
|
Vierck CJ, Whitsel BL, Favorov OV, Brown AW, Tommerdahl M. Role of primary somatosensory cortex in the coding of pain. Pain 2013; 154:334-344. [PMID: 23245864 PMCID: PMC4501501 DOI: 10.1016/j.pain.2012.10.021] [Citation(s) in RCA: 148] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 09/15/2012] [Accepted: 10/29/2012] [Indexed: 02/04/2023]
Abstract
The intensity and submodality of pain are widely attributed to stimulus encoding by peripheral and subcortical spinal/trigeminal portions of the somatosensory nervous system. Consistent with this interpretation are studies of surgically anesthetized animals, demonstrating that relationships between nociceptive stimulation and activation of neurons are similar at subcortical levels of somatosensory projection and within the primary somatosensory cortex (in cytoarchitectural areas 3b and 1 of somatosensory cortex, SI). Such findings have led to characterizations of SI as a network that preserves, rather than transforms, the excitatory drive it receives from subcortical levels. Inconsistent with this perspective are images and neurophysiological recordings of SI neurons in lightly anesthetized primates. These studies demonstrate that an extreme anterior position within SI (area 3a) receives input originating predominantly from unmyelinated nociceptors, distinguishing it from posterior SI (areas 3b and 1), long recognized as receiving input predominantly from myelinated afferents, including nociceptors. Of particular importance, interactions between these subregions during maintained nociceptive stimulation are accompanied by an altered SI response to myelinated and unmyelinated nociceptors. A revised view of pain coding within SI cortex is discussed, and potentially significant clinical implications are emphasized.
Collapse
Affiliation(s)
- Charles J Vierck
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, FL 32610-0244, USA Department of Physiology, University of North Carolina School of Medicine, Chapel Hill, NC, USA Department of Computer Sciences, University of North Carolina School of Medicine, Chapel Hill, NC, USA Senior School, Shadyside Academy, Pittsburgh, PA, USA
| | | | | | | | | |
Collapse
|
8
|
Lee J, Woo J, Favorov OV, Tommerdahl M, Lee CJ, Whitsel BL. Columnar distribution of activity dependent gabaergic depolarization in sensorimotor cortical neurons. Mol Brain 2012; 5:33. [PMID: 23006518 PMCID: PMC3520830 DOI: 10.1186/1756-6606-5-33] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 09/11/2012] [Indexed: 11/10/2022] Open
Abstract
Background GABA, the major inhibitory neurotransmitter in CNS, has been demonstrated to paradoxically produce excitation even in mature brain. However activity-dependent form of GABA excitation in cortical neurons has not been observed. Here we report that after an intense electrical stimulation adult cortical neurons displayed a transient GABA excitation that lasted for about 30s. Results Whole-cell patch recordings were performed to evaluate the effects of briefly applied GABA on pyramidal neurons in adult rodent sensorimotor cortical slice before and after 1 s, 20 Hz suprathreshold electrical stimulation of the junction between layer 6 and the underlying white matter (L6/WM stimulation). Immediately after L6/WM stimulation, GABA puffs produced neuronal depolarization in the center of the column-shaped region. However, both prior to or 30s after stimulation GABA puffs produced hyperpolarization of neurons. 2-photon imaging in neurons infected with adenovirus carrying a chloride sensor Clomeleon revealed that GABA induced depolarization is due to an increase in [Cl-]i after stimulation. To reveal the spatial extent of excitatory action of GABA, isoguvacine, a GABAA receptors agonist, was applied right after stimulation while monitoring the intracellular Ca2+ concentration in pyramidal neurons. Isoguvacine induced an increase in [Ca2+]i in pyramidal neurons especially in the center of the column but not in the peripheral regions of the column. The global pattern of the Ca2+ signal showed a column-shaped distribution along the stimulation site. Conclusion These results demonstrate that the well-known inhibitory transmitter GABA rapidly switches from hyperpolarization to depolarization upon synaptic activity in adult somatosensory cortical neurons.
Collapse
Affiliation(s)
- Jaekwang Lee
- Department of Biomedical Engineering, University of North Carolina at Chapel Hill, CB#7575, Chapel Hill, NC, USA
| | | | | | | | | | | |
Collapse
|
9
|
Cruz-Almeida Y, Felix ER, Martinez-Arizala A, Widerström-Noga EG. Decreased spinothalamic and dorsal column medial lemniscus-mediated function is associated with neuropathic pain after spinal cord injury. J Neurotrauma 2012; 29:2706-15. [PMID: 22845918 DOI: 10.1089/neu.2012.2343] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Neuropathic pain (NP) after spinal cord injury (SCI) can significantly and negatively affect quality of life and is often refractory to currently available treatments. In order to find more effective therapeutic avenues, it would be helpful to identify the primary underlying pathophysiological mechanisms in each individual. The aim of the present study was to assess the relationship between the presence and severity of NP after SCI and measures of somatosensory function mediated via the dorsal column medial lemniscal (DCML) pathway and the spinothalamic tract (STT). Vibratory, mechanical, thermal, and pain thresholds measured in areas at and below the neurological level of injury (LOI) in persons with SCI and NP (SCI-NP, n=47) and in persons with SCI without NP (SCI-noNP, n=18) were normalized to data obtained from able-bodied pain-free control subjects (A-B, n=30). STT-mediated function at and below the LOI was significantly impaired in both SCI groups compared with A-B controls (p<0.001), but not significantly different between the two SCI groups (NP vs. no-NP). In contrast, the SCI-NP group had significantly greater impairment of DCML-mediated function at the LOI, as reflected by greater vibratory detection deficits (z=-3.89±0.5), compared with the SCI-noNP group (z=-1.95±0.7, p=0.034). Within the SCI-NP group, NP severity was significantly associated with increased thermal sensitivity below the LOI (r=0.50, p=0.038). Our results suggest that both impaired STT and DCML-mediated function are necessary for the development of NP after SCI. However, within the SCI-NP group, greater NP severity was associated with greater sensitivity to thermal stimuli below the LOI. This finding concurs with other studies suggesting that STT damage with some sparing is associated with NP.
Collapse
Affiliation(s)
- Yenisel Cruz-Almeida
- Research Service, Department of Veterans Affairs Medical Center, Miami, Florida, USA
| | | | | | | |
Collapse
|
10
|
Harper DE, Hollins M. Is touch gating due to sensory or cognitive interference? Pain 2012; 153:1082-1090. [PMID: 22421428 DOI: 10.1016/j.pain.2012.02.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 02/07/2012] [Accepted: 02/13/2012] [Indexed: 11/19/2022]
Abstract
Touch gating, the attenuation of tactile sensitivity in the presence of pain, is a well-documented phenomenon, but its mechanism is unknown. The ability of pain to capture attention suggests that touch gating may be an example of distraction, but the fact that pain raises tactile but not auditory thresholds argues that touch gating is a form of somatosensory interaction. Therefore, the present study was carried out to determine whether touch gating is the result of sensory or cognitive interference. Touch gating was repeatedly produced by delivering a colocalized painful heat stimulus (45°C) during forced-choice measurements of vibration threshold on the palm. Noxious heat significantly increased thresholds compared with those measured at normal skin temperature, and this interference did not decline over the course of an extended series of experiments during which pain intensity significantly habituated. Touch gating was thus related to the constant physical intensity, rather than to the changing subjective intensity, of the noxious stimulus. For comparison, a form of unambiguously cognitive interference, the Stroop effect, was also measured repeatedly; it declined significantly across sessions, unlike touch gating interference. Finally, touch gating was not correlated with measures of participants' distractibility, fear of pain, hypervigilance, or anxiety, variables previously found to influence pain on a cognitive level. Taken together, the results suggest that touch gating is a robust, stimulus-locked form of sensory interaction, rather than a transitory result of distraction or other cognitive processes.
Collapse
Affiliation(s)
- Daniel E Harper
- Department of Psychology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA Department of Endodontics, School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | | |
Collapse
|
11
|
Lewis J, Schweinhardt P. Perceptions of the painful body: The relationship between body perception disturbance, pain and tactile discrimination in complex regional pain syndrome. Eur J Pain 2012; 16:1320-30. [DOI: 10.1002/j.1532-2149.2012.00120.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/19/2012] [Indexed: 01/22/2023]
|