1
|
Rosner J, de Andrade DC, Davis KD, Gustin SM, Kramer JLK, Seal RP, Finnerup NB. Central neuropathic pain. Nat Rev Dis Primers 2023; 9:73. [PMID: 38129427 DOI: 10.1038/s41572-023-00484-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/21/2023] [Indexed: 12/23/2023]
Abstract
Central neuropathic pain arises from a lesion or disease of the central somatosensory nervous system such as brain injury, spinal cord injury, stroke, multiple sclerosis or related neuroinflammatory conditions. The incidence of central neuropathic pain differs based on its underlying cause. Individuals with spinal cord injury are at the highest risk; however, central post-stroke pain is the most prevalent form of central neuropathic pain worldwide. The mechanisms that underlie central neuropathic pain are not fully understood, but the pathophysiology likely involves intricate interactions and maladaptive plasticity within spinal circuits and brain circuits associated with nociception and antinociception coupled with neuronal hyperexcitability. Modulation of neuronal activity, neuron-glia and neuro-immune interactions and targeting pain-related alterations in brain connectivity, represent potential therapeutic approaches. Current evidence-based pharmacological treatments include antidepressants and gabapentinoids as first-line options. Non-pharmacological pain management options include self-management strategies, exercise and neuromodulation. A comprehensive pain history and clinical examination form the foundation of central neuropathic pain classification, identification of potential risk factors and stratification of patients for clinical trials. Advanced neurophysiological and neuroimaging techniques hold promise to improve the understanding of mechanisms that underlie central neuropathic pain and as predictive biomarkers of treatment outcome.
Collapse
Affiliation(s)
- Jan Rosner
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Spinal Cord Injury Center, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
- Department of Neurology, University Hospital Bern, Inselspital, University of Bern, Bern, Switzerland
| | - Daniel C de Andrade
- Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Aalborg, Denmark
| | - Karen D Davis
- Division of Brain, Imaging and Behaviour, Krembil Brain Institute, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
- Department of Surgery and Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Sylvia M Gustin
- Centre for Pain IMPACT, Neuroscience Research Australia, Sydney, New South Wales, Australia
- NeuroRecovery Research Hub, School of Psychology, University of New South Wales, Sydney, New South Wales, Australia
| | - John L K Kramer
- International Collaboration on Repair Discoveries, ICORD, University of British Columbia, Vancouver, Canada
- Department of Anaesthesiology, Pharmacology & Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Rebecca P Seal
- Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Departments of Neurobiology and Otolaryngology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Nanna B Finnerup
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
- Department of Neurology, Aarhus University Hospital, Aarhus, Denmark.
| |
Collapse
|
2
|
Rodrigues P, da Silva B, Trevisan G. A systematic review and meta-analysis of neuropathic pain in multiple sclerosis: Prevalence, clinical types, sex dimorphism, and increased depression and anxiety symptoms. Neurosci Biobehav Rev 2023; 154:105401. [PMID: 37777076 DOI: 10.1016/j.neubiorev.2023.105401] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 09/04/2023] [Accepted: 09/20/2023] [Indexed: 10/02/2023]
Abstract
Chronic pain is the most disability symptom related to multiple sclerosis (MS) brain lesions and can also generate anxiety and depression. There are no updated reports of the general prevalence of neuropathic pain, MS clinical types, sex dimorphism, and its association with depression and anxiety. The protocol was listed in PROSPERO (CRD42022303571). The article selection resulted in 24 studies with a low risk of bias. The prevalence of neuropathic pain in MS patients was 26.8% with higher levels of depression and anxiety. We also observed that female patients (74.2%) have a higher prevalence of neuropathic pain than males (28.9%). We showed the enhanced prevalence of neuropathic pain using the female and male data (58.9%) compared to the total prevalence (26.8%). In addition, the SPMS (40.3%) presented an increased prevalence of neuropathic pain compared to PPMS (15.6%). Thus, we demonstrated the association between neuropathic pain, depression and anxiety symptoms and the influence of diagnosis, age, disease score, and disease duration in the increased prevalence of neuropathic pain in MS patients.
Collapse
Affiliation(s)
- Patrícia Rodrigues
- Graduated Program in Pharmacology, Federal University of Santa Maria (UFSM), 97105-900 Santa Maria, RS, Brazil
| | - Brenda da Silva
- Graduated Program in Pharmacology, Federal University of Santa Maria (UFSM), 97105-900 Santa Maria, RS, Brazil
| | - Gabriela Trevisan
- Graduated Program in Pharmacology, Federal University of Santa Maria (UFSM), 97105-900 Santa Maria, RS, Brazil.
| |
Collapse
|
3
|
Zebhauser PT, Hohn VD, Ploner M. Resting-state electroencephalography and magnetoencephalography as biomarkers of chronic pain: a systematic review. Pain 2023; 164:1200-1221. [PMID: 36409624 PMCID: PMC10184564 DOI: 10.1097/j.pain.0000000000002825] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 10/28/2022] [Accepted: 11/04/2022] [Indexed: 11/22/2022]
Abstract
ABSTRACT Reliable and objective biomarkers promise to improve the assessment and treatment of chronic pain. Resting-state electroencephalography (EEG) is broadly available, easy to use, and cost efficient and, therefore, appealing as a potential biomarker of chronic pain. However, results of EEG studies are heterogeneous. Therefore, we conducted a systematic review (PROSPERO CRD42021272622) of quantitative resting-state EEG and magnetoencephalography (MEG) studies in adult patients with different types of chronic pain. We excluded populations with severe psychiatric or neurologic comorbidity. Risk of bias was assessed using a modified Newcastle-Ottawa Scale. Semiquantitative data synthesis was conducted using modified albatross plots. We included 76 studies after searching MEDLINE, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, and EMBASE. For cross-sectional studies that can serve to develop diagnostic biomarkers, we found higher theta and beta power in patients with chronic pain than in healthy participants. For longitudinal studies, which can yield monitoring and/or predictive biomarkers, we found no clear associations of pain relief with M/EEG measures. Similarly, descriptive studies that can yield diagnostic or monitoring biomarkers showed no clear correlations of pain intensity with M/EEG measures. Risk of bias was high in many studies and domains. Together, this systematic review synthesizes evidence on how resting-state M/EEG might serve as a diagnostic biomarker of chronic pain. Beyond, this review might help to guide future M/EEG studies on the development of pain biomarkers.
Collapse
Affiliation(s)
- Paul Theo Zebhauser
- Department of Neurology, School of Medicine, Technical University of Munich (TUM), Munich, Germany
| | - Vanessa D. Hohn
- Department of Neurology, School of Medicine, Technical University of Munich (TUM), Munich, Germany
| | - Markus Ploner
- Department of Neurology, School of Medicine, Technical University of Munich (TUM), Munich, Germany
| |
Collapse
|
4
|
Wen J, Gao Y, Li M, Hu S, Zhao M, Su C, Wang Q, Xi H, Zhan L, Lv Y, Antwi CO, Ren J, Jia X. Regional abnormalities of spontaneous brain activity in migraine: A coordinate‐based meta‐analysis. J Neurosci Res 2023. [DOI: 10.1002/jnr.25191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 02/17/2023] [Accepted: 03/13/2023] [Indexed: 04/03/2023]
|
5
|
Takeuchi N. Pain control based on oscillatory brain activity using transcranial alternating current stimulation: An integrative review. Front Hum Neurosci 2023; 17:941979. [PMID: 36742359 PMCID: PMC9892942 DOI: 10.3389/fnhum.2023.941979] [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: 05/12/2022] [Accepted: 01/04/2023] [Indexed: 01/20/2023] Open
Abstract
Developing effective tools and strategies to relieve chronic pain is a high-priority scientific and clinical goal. In particular, the brain regions related to pain processing have been investigated as potential targets to relieve pain by non-invasive brain stimulation (NIBS). In addition to elucidating the relationship between pain and oscillatory brain activity, transcranial alternating current stimulation (tACS), which can non-invasively entrain oscillatory brain activity and modulate oscillatory brain communication, has attracted scientific attention as a possible technique to control pain. This review focuses on the use of tACS to relieve pain through the manipulation of oscillatory brain activity and its potential clinical applications. Several studies have reported that tACS on a single brain reduces pain by normalizing abnormal oscillatory brain activity in patients with chronic pain. Interpersonal tACS approaches based on inter-brain synchrony to manipulate inter-brain communication may result in pain relief via prosocial effects. Pain is encoded by the spatiotemporal neural communication that represents the integration of cognitive, emotional-affective, and sensorimotor aspects of pain. Therefore, future studies should seek to identify the pathological oscillatory brain communication in chronic pain as a therapeutic target for tACS. In conclusion, tACS could be effective for re-establishing oscillatory brain activity and assisting social interaction, and it might help develop novel approaches for pain control.
Collapse
|
6
|
Electroencephalographic characteristics of children and adolescents with chronic musculoskeletal pain. Pain Rep 2022; 7:e1054. [PMID: 36601627 PMCID: PMC9788982 DOI: 10.1097/pr9.0000000000001054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 10/11/2022] [Accepted: 10/25/2022] [Indexed: 01/06/2023] Open
Abstract
Introduction The pathophysiology of pediatric musculoskeletal (MSK) pain is unclear, contributing to persistent challenges to its management. Objectives This study hypothesizes that children and adolescents with chronic MSK pain (CPs) will show differences in electroencephalography (EEG) features at rest and during thermal pain modalities when compared with age-matched controls. Methods One hundred forty-two CP patients and 45 age-matched healthy controls (HCs) underwent a standardized thermal tonic heat and cold stimulations, while a 21-electrode headset collected EEG data. Cohorts were compared with respect to their EEG features of spectral power, peak frequency, permutation entropy, weight phase-lag index, directed phase-lag index, and node degree at 4 frequency bands, namely, delta (1-4 Hz), theta (4-8 Hz), alpha (8-13 Hz), and beta (13-30 Hz), at rest and during the thermal conditions. Results At rest, CPs showed increased global delta (P = 0.0493) and beta (P = 0.0002) power in comparison with HCs. These findings provide further impetus for the investigation and prevention of long-lasting developmental sequalae of early life chronic pain processes. Although no cohort differences in pain intensity scores were found during the thermal pain modalities, CPs and HCs showed significant difference in changes in EEG spectral power, peak frequency, permutation entropy, and network functional connectivity at specific frequency bands (P < 0.05) during the tonic heat and cold stimulations. Conclusion This suggests that EEG can characterize subtle differences in heat and cold pain sensitivity in CPs. The complementation of EEG and evoked pain in the clinical assessment of pediatric chronic MSK pain can better detect underlying pain mechanisms and changes in pain sensitivity.
Collapse
|
7
|
Fauchon C, Kim JA, El-Sayed R, Osborne NR, Rogachov A, Cheng JC, Hemington KS, Bosma RL, Dunkley BT, Oh J, Bhatia A, Inman RD, Davis KD. A Hidden Markov Model reveals magnetoencephalography spectral frequency-specific abnormalities of brain state power and phase-coupling in neuropathic pain. Commun Biol 2022; 5:1000. [PMID: 36131088 PMCID: PMC9492713 DOI: 10.1038/s42003-022-03967-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 09/08/2022] [Indexed: 11/09/2022] Open
Abstract
Neuronal populations in the brain are engaged in a temporally coordinated manner at rest. Here we show that spontaneous transitions between large-scale resting-state networks are altered in chronic neuropathic pain. We applied an approach based on the Hidden Markov Model to magnetoencephalography data to describe how the brain moves from one activity state to another. This identified 12 fast transient (~80 ms) brain states including the sensorimotor, ascending nociceptive pathway, salience, visual, and default mode networks. Compared to healthy controls, we found that people with neuropathic pain exhibited abnormal alpha power in the right ascending nociceptive pathway state, but higher power and coherence in the sensorimotor network state in the beta band, and shorter time intervals between visits of the sensorimotor network, indicating more active time in this state. Conversely, the neuropathic pain group showed lower coherence and spent less time in the frontal attentional state. Therefore, this study reveals a temporal imbalance and dysregulation of spectral frequency-specific brain microstates in patients with neuropathic pain. These findings can potentially impact the development of a mechanism-based therapeutic approach by identifying brain targets to stimulate using neuromodulation to modify abnormal activity and to restore effective neuronal synchrony between brain states.
Collapse
Affiliation(s)
- Camille Fauchon
- Division of Brain, Imaging, and Behaviour, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 2S8, Canada
| | - Junseok A Kim
- Division of Brain, Imaging, and Behaviour, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 2S8, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Rima El-Sayed
- Division of Brain, Imaging, and Behaviour, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 2S8, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Natalie R Osborne
- Division of Brain, Imaging, and Behaviour, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 2S8, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Anton Rogachov
- Division of Brain, Imaging, and Behaviour, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 2S8, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Joshua C Cheng
- Division of Brain, Imaging, and Behaviour, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 2S8, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Kasey S Hemington
- Division of Brain, Imaging, and Behaviour, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 2S8, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Rachael L Bosma
- Division of Brain, Imaging, and Behaviour, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 2S8, Canada
| | - Benjamin T Dunkley
- Neurosciences & Mental Health Program, The Hospital for Sick Children Research Institute, Toronto, ON, M5G 0A4, Canada.,Diagnostic Imaging, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada.,Department of Medical Imaging, University of Toronto, Toronto, ON, M5T 1W7, Canada
| | - Jiwon Oh
- Div of Neurology, Dept of Medicine, St. Michael's Hospital, Toronto, ON, M5B 1W8, Canada
| | - Anuj Bhatia
- Division of Brain, Imaging, and Behaviour, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 2S8, Canada.,Department of Anesthesia and Pain Medicine, Toronto Western Hospital, and University of Toronto, Toronto, ON, M5T 2S8, Canada
| | - Robert D Inman
- Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A8, Canada.,Division of Immunology, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Karen Deborah Davis
- Division of Brain, Imaging, and Behaviour, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 2S8, Canada. .,Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A8, Canada. .,Department of Surgery, University of Toronto, Toronto, ON, M5T 1P5, Canada.
| |
Collapse
|
8
|
Exploring sex differences in alpha brain activity as a potential neuromarker associated with neuropathic pain. Pain 2022; 163:1291-1302. [PMID: 34711764 DOI: 10.1097/j.pain.0000000000002491] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 09/09/2021] [Indexed: 12/31/2022]
Abstract
ABSTRACT Alpha oscillatory activity (8-13 Hz) is the dominant rhythm in the awake brain and is known to play an important role in pain states. Previous studies have identified alpha band slowing and increased power in the dynamic pain connectome (DPC) of people with chronic neuropathic pain. However, a link between alpha-band abnormalities and sex differences in brain organization in healthy individuals and those with chronic pain is not known. Here, we used resting-state magnetoencephalography to test the hypothesis that peak alpha frequency (PAF) abnormalities are general features across chronic central and peripheral conditions causing neuropathic pain but exhibit sex-specific differences in networks of the DPC (ascending nociceptive pathway [ANP], default mode network, salience network [SN], and subgenual anterior cingulate cortex). We found that neuropathic pain (N = 25 men and 25 women) was associated with increased PAF power in the DPC compared with 50 age- and sex-matched healthy controls, whereas slower PAF in nodes of the SN (temporoparietal junction) and the ANP (posterior insula) was associated with higher trait pain intensity. In the neuropathic pain group, women exhibited lower PAF power in the subgenual anterior cingulate cortex and faster PAF in the ANP and SN than men. The within-sex analyses indicated that women had neuropathic pain-related increased PAF power in the ANP, SN, and default mode network, whereas men with neuropathic pain had increased PAF power restricted to the ANP. These findings highlight neuropathic pain-related and sex-specific abnormalities in alpha oscillations across the DPC that could underlie aberrant neuronal communication in nociceptive processing and modulation.
Collapse
|
9
|
Mussigmann T, Bardel B, Lefaucheur JP. Resting-state electroencephalography (EEG) biomarkers of chronic neuropathic pain. A systematic review. Neuroimage 2022; 258:119351. [PMID: 35659993 DOI: 10.1016/j.neuroimage.2022.119351] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 05/09/2022] [Accepted: 05/31/2022] [Indexed: 10/18/2022] Open
Abstract
Diagnosis and management of chronic neuropathic pain are challenging, leading to current efforts to characterize 'objective' biomarkers of pain using imaging or neurophysiological techniques, such as electroencephalography (EEG). A systematic literature review was conducted in PubMed-Medline and Web-of-Science until October 2021 to identify EEG biomarkers of chronic neuropathic pain in humans. The risk of bias was assessed by the Newcastle-Ottawa-Scale. Experimental, provoked, or chronic non-neuropathic pain studies were excluded. We identified 14 studies, in which resting-state EEG spectral analysis was compared between patients with pain related to a neurological disease and patients with the same disease but without pain or healthy controls. From these heterogeneous exploratory studies, some conclusions can be drawn, even if they must be weighted by the fact that confounding factors, such as medication and association with anxio-depressive disorders, are generally not taken into account. Overall, EEG signal power was increased in the θ band (4-7Hz) and possibly in the high-β band (20-30Hz), but decreased in the high-α-low-β band (10-20Hz) in the presence of ongoing neuropathic pain, while increased γ band oscillations were not evidenced, unlike in experimental pain. Consequently, the dominant peak frequency was decreased in the θ-α band and increased in the whole-β band in neuropathic pain patients. Disappointingly, pain intensity correlated with various EEG changes across studies, with no consistent trend. This review also discusses the location of regional pain-related EEG changes in the pain connectome, as the perspectives offered by advanced techniques of EEG signal analysis (source location, connectivity, or classification methods based on artificial intelligence). The biomarkers provided by resting-state EEG are of particular interest for optimizing the treatment of chronic neuropathic pain by neuromodulation techniques, such as transcranial alternating current stimulation or neurofeedback procedures.
Collapse
Affiliation(s)
- Thibaut Mussigmann
- Univ Paris Est Creteil, EA4391, ENT, Créteil, France; Clinical Neurophysiology Unit, Henri Mondor Hospital, AP-HP, Créteil, France
| | - Benjamin Bardel
- Univ Paris Est Creteil, EA4391, ENT, Créteil, France; Clinical Neurophysiology Unit, Henri Mondor Hospital, AP-HP, Créteil, France
| | - Jean-Pascal Lefaucheur
- Univ Paris Est Creteil, EA4391, ENT, Créteil, France; Clinical Neurophysiology Unit, Henri Mondor Hospital, AP-HP, Créteil, France.
| |
Collapse
|
10
|
Pei Y, Peng J, Zhang Y, Huang M, Zhou F. Aberrant functional connectivity and temporal variability of the dynamic pain connectome in patients with low back related leg pain. Sci Rep 2022; 12:6324. [PMID: 35428850 PMCID: PMC9012841 DOI: 10.1038/s41598-022-10238-4] [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: 08/09/2021] [Accepted: 03/23/2022] [Indexed: 11/17/2022] Open
Abstract
Neuroimaging studies have suggested a link between the intensity of chronic low back pain intensity and structural and functional brain alterations. However, chronic pain results from the coordination and dynamics among several brain networks that comprise the dynamic pain connectome. Here, we use resting-state functional magnetic resonance imaging and measures of static (sFC) and dynamic functional connectivity (dFC) variability in the typical (0.01–0.1 Hz) and five specific (slow-6 to slow-2) frequency bands to test hypotheses regarding disruption in this variability in low back-related leg pain (LBLP) patients who experience chronic pain and numbness. Twenty-four LBLP patients and 23 healthy controls completed clinical assessments, and partial correlational analyses between altered sFC and dFC variability and clinical measures were conducted. We found a lower within-network sFC in the ascending nociceptive pathway (Asc) and a lower cross-network sFC between nodes of the salience network and the Asc in the typical frequency band. In the slow-5 frequency band, a lower within-network sFC was found in the Asc. Abnormal cross-network sFC was found between nodes of the salience network-Asc (slow-5 and slow-6) and the default mode network-Asc (slow-4 and slow-6). Furthermore, cross-network abnormalities in the typical and certain specific frequency bands were linked to clinical assessments. These findings indicate that frequency-related within- and cross-network communication among the nodes in the dynamic pain connectome is dysfunctional in LBLP patients and that selecting specific frequencies may be potentially useful for detecting LBLP-related brain activity.
Collapse
Affiliation(s)
- Yixiu Pei
- Department of Radiology, The First Affiliated Hospital, Nanchang University, 17 Yongwaizheng Street, Nanchang, Jiangxi, 330006, People's Republic of China.,Neuroradiology Laboratory, Jiangxi Province Medical Imaging Research Institute, Nanchang, 330006, People's Republic of China.,Department of Medical Imaging, The Affiliated Ganzhou Hospital of Nanchang University, Ganzhou, Jiangxi, 341000, People's Republic of China
| | - Jidong Peng
- Department of Medical Imaging, The Affiliated Ganzhou Hospital of Nanchang University, Ganzhou, Jiangxi, 341000, People's Republic of China
| | - Yong Zhang
- Department of Pain Clinic, The First Affiliated Hospital, Nanchang University, Nanchang, Jiangxi, 330006, People's Republic of China
| | - Muhua Huang
- Department of Radiology, The First Affiliated Hospital, Nanchang University, 17 Yongwaizheng Street, Nanchang, Jiangxi, 330006, People's Republic of China.,Neuroradiology Laboratory, Jiangxi Province Medical Imaging Research Institute, Nanchang, 330006, People's Republic of China
| | - Fuqing Zhou
- Department of Radiology, The First Affiliated Hospital, Nanchang University, 17 Yongwaizheng Street, Nanchang, Jiangxi, 330006, People's Republic of China. .,Neuroradiology Laboratory, Jiangxi Province Medical Imaging Research Institute, Nanchang, 330006, People's Republic of China.
| |
Collapse
|
11
|
Disrupted Dynamic Functional Connectivity of the Visual Network in Episodic Patients with Migraine without Aura. Neural Plast 2022; 2022:9941832. [PMID: 35035474 PMCID: PMC8754605 DOI: 10.1155/2022/9941832] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 12/01/2021] [Accepted: 12/16/2021] [Indexed: 12/28/2022] Open
Abstract
Background Visual symptoms are common in patients with migraine, even in interictal periods. The purpose was to assess the association between dynamic functional connectivity (dFC) of the visual cortex and clinical characteristics in migraine without aura (MwoA) patients. Methods We enrolled fifty-five MwoA patients as well as fifty gender- and age-matched healthy controls. Regional visual cortex alterations were investigated using regional homogeneity (ReHo) and amplitude of low-frequency fluctuation (ALFF). Then, significant regions were selected as seeds for conducting dFC between the visual cortex and the whole brain. Results Relative to healthy controls, MwoA patients exhibited decreased ReHo and ALFF values in the right lingual gyrus (LG) and increased ALFF values in the prefrontal cortex. The right LG showed abnormal dFC within the visual cortex and with other core brain networks. Additionally, ReHo values for the right LG were correlated with duration of disease and ALFF values of the right inferior frontal gyrus and middle frontal gyrus were correlated with headache frequency and anxiety scores, respectively. Moreover, the abnormal dFC of the right LG with bilateral cuneus was positively correlated with anxiety scores. Conclusions The dFC abnormalities of the visual cortex may be involved in pain integration with multinetworks and associated with anxiety disorder in episodic MwoA patients.
Collapse
|
12
|
Foley P, Kong Y, Dirvanskiene R, Valdes-Hernandez M, Bastiani M, Murnane J, Sellar R, Roberts N, Pernet C, Weir C, Bak T, Colvin L, Chandran S, Fallon M, Tracey I. Coupling cognitive and brainstem dysfunction in multiple sclerosis-related chronic neuropathic limb pain. Brain Commun 2022; 4:fcac124. [PMID: 35663383 PMCID: PMC9155950 DOI: 10.1093/braincomms/fcac124] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 04/01/2022] [Accepted: 05/13/2022] [Indexed: 11/12/2022] Open
Abstract
Chronic pain in multiple sclerosis is common and difficult to treat. Its mechanisms remain incompletely understood. Dysfunction of the descending pain modulatory system is known to contribute to human chronic pain conditions. However, it is not clear how alterations in executive function influence this network, despite healthy volunteer studies linking function of the descending pain modulatory system, to cognition. In adults with multiple sclerosis-associated chronic neuropathic limb pain, compared to those without pain, we hypothesized altered functional connectivity of the descending pain modulatory system, coupled to executive dysfunction. Specifically we hypothesized reduced mental flexibility, because of potential importance in stimulus reappraisal. To investigate these hypotheses, we conducted a case-control cross-sectional study of 47 adults with relapsing remitting multiple sclerosis (31 with chronic neuropathic limb pain, 16 without pain), employing clinical, neuropsychological, structural, and functional MRI measures. We measured brain lesions and atrophy affecting descending pain modulatory system structures. Both cognitive and affective dysfunctions were confirmed in the chronic neuropathic limb pain group, including reduced mental flexibility (Delis Kaplan Executive Function System card sorting tests P < 0.001). Functional connectivity of rostral anterior cingulate and ventrolateral periaqueductal gray, key structures of the descending pain modulatory system, was significantly lower in the group experiencing chronic neuropathic pain. There was no significant between-group difference in whole-brain grey matter or lesion volumes, nor lesion volume affecting white matter tracts between rostral anterior cingulate and periaqueductal gray. Brainstem-specific lesion volume was higher in the chronic neuropathic limb pain group (P = 0.0017). Differential functional connectivity remained after correction for brainstem-specific lesion volume. Gabapentinoid medications were more frequently used in the chronic pain group. We describe executive dysfunction in people with multiple sclerosis affected by chronic neuropathic pain, along with functional and structural MRI evidence compatible with dysfunction of the descending pain modulatory system. These findings extend understanding of close inter-relationships between cognition, function of the descending pain modulatory system, and chronic pain, both in multiple sclerosis and more generally in human chronic pain conditions. These findings could support application of pharmacological and cognitive interventions in chronic neuropathic pain associated with multiple sclerosis.
Collapse
Affiliation(s)
- Peter Foley
- Anne Rowling Regenerative Neurology Clinic, University of Edinburgh, 49 Little France Crescent, Edinburgh EH16 4SB, UK
| | - Yazhuo Kong
- CAS Key Laboratory of Behavioural Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.,Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Ramune Dirvanskiene
- Anne Rowling Regenerative Neurology Clinic, University of Edinburgh, 49 Little France Crescent, Edinburgh EH16 4SB, UK
| | - Maria Valdes-Hernandez
- Dementia Research Institute, University of Edinburgh, Edinburgh, UK.,Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Matteo Bastiani
- Sir Peter Mansfield Imaging Centre, School of Medicine, University of Nottingham, Nottingham, UK.,NIHR Biomedical Research Centre, University of Nottingham, Nottingham, UK.,Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
| | - Jonathan Murnane
- Clinical Research Imaging Centre, Edinburgh University, Edinburgh, UK
| | - Robin Sellar
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Neil Roberts
- Clinical Research Imaging Centre, Edinburgh University, Edinburgh, UK
| | - Cyril Pernet
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Christopher Weir
- Edinburgh Clinical Trials Unit, Usher Institute, University of Edinburgh, Edinburgh, UK
| | - Thomas Bak
- School of Philosophy, Psychology and Language Sciences, University of Edinburgh, Edinburgh, UK
| | - Lesley Colvin
- Division of Population Health and Genomics, University of Dundee, Dundee, UK
| | - Siddharthan Chandran
- Anne Rowling Regenerative Neurology Clinic, University of Edinburgh, 49 Little France Crescent, Edinburgh EH16 4SB, UK.,Dementia Research Institute, University of Edinburgh, Edinburgh, UK.,Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Marie Fallon
- Department of Palliative Medicine, University of Edinburgh, Edinburgh, UK
| | - Irene Tracey
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK.,Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
| |
Collapse
|
13
|
Khan H, Sami MB, Litvak V. The utility of Magnetoencephalography in multiple sclerosis - A systematic review. NEUROIMAGE-CLINICAL 2021; 32:102814. [PMID: 34537682 PMCID: PMC8455859 DOI: 10.1016/j.nicl.2021.102814] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 08/28/2021] [Accepted: 08/30/2021] [Indexed: 01/29/2023]
Abstract
We conducted a Systematic Review of studies, looking at 30 studies from 13 centres. MS patients had reduced power in some induced responses (motor beta, visual gamma). Increased latency and reduced connectivity were seen for somatosensory evoked fields. There was an association between upper alpha connectivity and cognitive function. MEG shows promise, although work is too preliminary to recommend current clinical use.
Introduction Magnetoencephalography (MEG), allows for a high degree temporal and spatial accuracy in recording cortical oscillatory activity and evoked fields. To date, no review has been undertaken to synthesise all MEG studies in Multiple Sclerosis (MS). We undertook a Systematic Review of the utility of MEG in MS. Methods We identified MEG studies carried out in MS using EMBASE, Medline, Cochrane, TRIP and Psychinfo databases. We included original research articles with a cohort of minimum of five multiple sclerosis patients and quantifying of at least one MEG parameter. We used a modified version of the JBI (mJBI) for case-control studies to assess for risk of bias. Results We identified 30 studies from 13 centres involving at least 433 MS patients and 347 controls. We found evidence that MEG shows perturbed activity (most commonly reduced power modulations), reduced connectivity and association with altered clinical function in Multiple Sclerosis. Specific replicated findings were decreased motor induced responses in the beta band, diminished increase of gamma power after visual stimulation, increased latency and reduced connectivity for somatosensory evoked fields. There was an association between upper alpha connectivity and cognitive measures in people with MS. Overall studies were of moderate quality (mean mJBI score 6.7). Discussion We find evidence for the utility of MEG in Multiple Sclerosis. Event-related designs are of particular value and show replicability between centres. At this stage, it is not clear whether these changes are specific to Multiple Sclerosis or are also observable in other diseases. Further studies should look to explore cognitive control in more depth using in-task designs and undertake longitudinal studies to determine whether these changes have prognostic value.
Collapse
Affiliation(s)
- H Khan
- UCL Queen's Square Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom; Queen's Medical Centre Nottingham, Clifton Boulevard, Derby Rd, Nottingham NG7 2UH, United Kingdom.
| | - M B Sami
- Institute of Mental Health, Jubilee Campus, University of Nottingham Innovation Park, Triumph Road, Nottingham NG7 2TU, United Kingdom
| | - V Litvak
- UCL Queen's Square Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom
| |
Collapse
|
14
|
Osborne NR, Anastakis DJ, Kim JA, El-Sayed R, Cheng JC, Rogachov A, Hemington KS, Bosma RL, Fauchon C, Davis KD. Sex-Specific Abnormalities and Treatment-Related Plasticity of Subgenual Anterior Cingulate Cortex Functional Connectivity in Chronic Pain. FRONTIERS IN PAIN RESEARCH 2021; 2:673538. [PMID: 35295450 PMCID: PMC8915549 DOI: 10.3389/fpain.2021.673538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 04/28/2021] [Indexed: 11/17/2022] Open
Abstract
The subgenual anterior cingulate cortex (sgACC) is a key node of the descending antinociceptive system with sex differences in its functional connectivity (FC). We previously reported that, in a male-prevalent chronic pain condition, sgACC FC is abnormal in women but not in men. This raises the possibility that, within a sex, sgACC FC may be either protective or represent a vulnerability to develop a sex-dominant chronic pain condition. The aim of this study was to characterize sgACC FC in a female-dominant chronic pain condition, carpal tunnel syndrome (CTS), to investigate whether sgACC abnormalities are a common feature in women with chronic pain or unique to individuals with pain conditions that are more prevalent in the opposite sex. We used fMRI to determine the resting state FC of the sgACC in healthy controls (HCs, n = 25, 18 women; 7 men) and people with CTS before (n = 25, 18 women; 7 men) and after (n = 17, 13 women; 4 men) successful surgical treatment. We found reduced sgACC FC with the medial pre-frontal cortex (mPFC) and temporal lobe in CTS compared with HCs. The group-level sgACC-mPFC FC abnormality was driven by men with CTS, while women with CTS did not have sgACC FC abnormalities compared with healthy women. We also found that age and sex influenced sgACC FC in both CTS and HCs, with women showing greater FC with bilateral frontal poles and men showing greater FC with the parietal operculum. After surgery, there was reduced sgACC FC with the orbitofrontal cortex, striatum, and premotor areas and increased FC with the posterior insula and precuneus compared with pre-op scans. Abnormally reduced sgACC-mPFC FC in men but not women with a female-prevalent chronic pain condition suggests pain-related sgACC abnormalities may not be specific to women but rather to individuals who develop chronic pain conditions that are more dominant in the opposite sex. Our data suggest the sgACC plays a role in chronic pain in a sex-specific manner, and its communication with other regions of the dynamic pain connectome undergoes plasticity following pain-relieving treatment, supporting it as a potential therapeutic target for neuromodulation in chronic pain.
Collapse
Affiliation(s)
- Natalie R. Osborne
- Krembil Research Institute, Krembil Brain Institute, University Health Network, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Dimitri J. Anastakis
- Krembil Research Institute, Krembil Brain Institute, University Health Network, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
- Toronto Western Hospital, University Health Network, Toronto, ON, Canada
- Department of Surgery, University of Toronto, Toronto, ON, Canada
| | - Junseok Andrew Kim
- Krembil Research Institute, Krembil Brain Institute, University Health Network, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Rima El-Sayed
- Krembil Research Institute, Krembil Brain Institute, University Health Network, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Joshua C. Cheng
- Krembil Research Institute, Krembil Brain Institute, University Health Network, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Anton Rogachov
- Krembil Research Institute, Krembil Brain Institute, University Health Network, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Kasey S. Hemington
- Krembil Research Institute, Krembil Brain Institute, University Health Network, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Rachael L. Bosma
- Krembil Research Institute, Krembil Brain Institute, University Health Network, Toronto, ON, Canada
| | - Camille Fauchon
- Krembil Research Institute, Krembil Brain Institute, University Health Network, Toronto, ON, Canada
| | - Karen D. Davis
- Krembil Research Institute, Krembil Brain Institute, University Health Network, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
- Toronto Western Hospital, University Health Network, Toronto, ON, Canada
- Department of Surgery, University of Toronto, Toronto, ON, Canada
- *Correspondence: Karen D. Davis
| |
Collapse
|
15
|
Sex differences in brain modular organization in chronic pain. Pain 2021; 162:1188-1200. [PMID: 33044396 DOI: 10.1097/j.pain.0000000000002104] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 10/01/2020] [Indexed: 11/26/2022]
Abstract
ABSTRACT Men and women can exhibit different pain sensitivities, and many chronic pain conditions are more prevalent in one sex. Although there is evidence of sex differences in the brain, it is not known whether there are sex differences in the organization of large-scale functional brain networks in chronic pain. Here, we used graph theory with modular analysis and machine-learning of resting-state-functional magnetic resonance imaging data from 220 participants: 155 healthy controls and 65 individuals with chronic low back pain due to ankylosing spondylitis, a form of arthritis. We found an extensive overlap in the graph partitions with the major brain intrinsic systems (ie, default mode, central, visual, and sensorimotor modules), but also sex-specific network topological characteristics in healthy people and those with chronic pain. People with chronic pain exhibited higher cross-network connectivity, and sex-specific nodal graph properties changes (ie, hub disruption), some of which were associated with the severity of the chronic pain condition. Females exhibited atypically higher functional segregation in the mid cingulate cortex and subgenual anterior cingulate cortex and lower connectivity in the network with the default mode and frontoparietal modules, whereas males exhibited stronger connectivity with the sensorimotor module. Classification models on nodal graph metrics could classify an individual's sex and whether they have chronic pain with high accuracies (77%-92%). These findings highlight the organizational abnormalities of resting-state-brain networks in people with chronic pain and provide a framework to consider sex-specific pain therapeutics.
Collapse
|
16
|
Tu Y, Pantazis D, Wilson G, Khan S, Ahlfors S, Kong J. How expectations of pain elicited by consciously and unconsciously perceived cues unfold over time. Neuroimage 2021; 235:117985. [PMID: 33762214 PMCID: PMC8248481 DOI: 10.1016/j.neuroimage.2021.117985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 03/10/2021] [Accepted: 03/14/2021] [Indexed: 11/30/2022] Open
Abstract
Expectation can shape the perception of pain within a fraction of time, but little is known about how perceived expectation unfolds over time and modulates pain perception. Here, we combine magnetoencephalography (MEG) and machine learning approaches to track the neural dynamics of expectations of pain in healthy participants with both sexes. We found that the expectation of pain, as conditioned by facial cues, can be decoded from MEG as early as 150 ms and up to 1100 ms after cue onset, but decoding expectation elicited by unconsciously perceived cues requires more time and decays faster compared to consciously perceived ones. Also, results from temporal generalization suggest that neural dynamics of decoding cue-based expectation were predominately sustained during cue presentation but transient after cue presentation. Finally, although decoding expectation elicited by consciously perceived cues were based on a series of time-restricted brain regions during cue presentation, decoding relied on the medial prefrontal cortex and anterior cingulate cortex after cue presentation for both consciously and unconsciously perceived cues. These findings reveal the conscious and unconscious processing of expectation during pain anticipation and may shed light on enhancing clinical care by demonstrating the impact of expectation cues.
Collapse
Affiliation(s)
- Yiheng Tu
- Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA; Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Dimitrios Pantazis
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA; McGovern Institute of Brain Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Georgia Wilson
- Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Sheraz Khan
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Seppo Ahlfors
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Jian Kong
- Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA; Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.
| |
Collapse
|
17
|
Kim JA, Davis KD. Magnetoencephalography: physics, techniques, and applications in the basic and clinical neurosciences. J Neurophysiol 2021; 125:938-956. [PMID: 33567968 DOI: 10.1152/jn.00530.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Magnetoencephalography (MEG) is a technique used to measure the magnetic fields generated from neuronal activity in the brain. MEG has a high temporal resolution on the order of milliseconds and provides a more direct measure of brain activity when compared with hemodynamic-based neuroimaging methods such as magnetic resonance imaging and positron emission tomography. The current review focuses on basic features of MEG such as the instrumentation and the physics that are integral to the signals that can be measured, and the principles of source localization techniques, particularly the physics of beamforming and the techniques that are used to localize the signal of interest. In addition, we review several metrics that can be used to assess functional coupling in MEG and describe the advantages and disadvantages of each approach. Lastly, we discuss the current and future applications of MEG.
Collapse
Affiliation(s)
- Junseok A Kim
- Division of Brain, Imaging and Behaviour, Krembil Brain Institute, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Karen D Davis
- Division of Brain, Imaging and Behaviour, Krembil Brain Institute, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Department of Surgery, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
18
|
Abstract
Neural oscillations play an important role in the integration and segregation of brain regions that are important for brain functions, including pain. Disturbances in oscillatory activity are associated with several disease states, including chronic pain. Studies of neural oscillations related to pain have identified several functional bands, especially alpha, beta, and gamma bands, implicated in nociceptive processing. In this review, we introduce several properties of neural oscillations that are important to understand the role of brain oscillations in nociceptive processing. We also discuss the role of neural oscillations in the maintenance of efficient communication in the brain. Finally, we discuss the role of neural oscillations in healthy and chronic pain nociceptive processing. These data and concepts illustrate the key role of regional and interregional neural oscillations in nociceptive processing underlying acute and chronic pains.
Collapse
Affiliation(s)
- Junseok A. Kim
- Division of Brain, Imaging and Behaviour, Krembil Brain Institute, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada
- Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Karen D. Davis
- Division of Brain, Imaging and Behaviour, Krembil Brain Institute, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada
- Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
- Department of Surgery, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|