scholarly journals Association between Neuropathic Pain Characteristics and DNA Methylation of TRPA1 in Human Peripheral Blood

2019 ◽  
Author(s):  
Shiho Takenaka ◽  
Norihiko Sukenaga ◽  
Mai Imasaka ◽  
Masaki Ohmuraya ◽  
Yuka Matsuki ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Chronic Pain ◽  
Neuropathic Pain ◽  
Peripheral Blood ◽  
Transient Receptor Potential ◽  
Cpg Island ◽  
Human Peripheral Blood ◽  
Chronic Pain Patients ◽  
Pain Characteristics ◽  
Pain Patients

Background: Elucidation of epigenetic mechanisms correlating with neuropathic pain in humans is crucial for the prevention and treatment of this treatment-resistant pain state. In the present study, associations between neuropathic pain characteristics and DNA methylation of the transient receptor potential ankyrin 1(TRPA1) gene were evaluated in chronic pain patients and preoperative patients. Methods: Pain and psychological states were prospectively assessed in patients who suffered chronic pain or were scheduled for thoracic surgery. Neuropathic characteristics were assessed using the Douleur Neuropathique 4 (DN4) questionnaire. DNA methylation levels of the CpG island in the TRPA1 gene were examined using whole blood. Results: Forty-eight adult patients were enrolled in this study. Increases in DNA methylation rates at CpG -51 showed positive correlations with increases in the DN4 score both in preoperative and chronic pain patients. Combined methylation rates at CpG -51 also significantly increased together with increase in DN4 scores. Conclusions: Neuropathic pain characteristics are likely associated with methylation rates at the promoter region of the TRPA1 gene in human peripheral blood.

Electroencephalography During Nociceptive Stimulation in Chronic Pain Patients: A Systematic Review

Pain Medicine ◽  
2020 ◽  
Vol 21 (12) ◽  
pp. 3413-3427
Author(s):  
Dorine Lenoir ◽  
Ward Willaert ◽  
Iris Coppieters ◽  
Anneleen Malfliet ◽  
Kelly Ickmans ◽  
...  
Keyword(s):  
Systematic Review ◽  
Chronic Pain ◽  
Neuropathic Pain ◽  
Subjective Experience ◽  
Event Related Potential ◽  
High Temporal Resolution ◽  
Healthy Controls ◽  
Somatosensory Processing ◽  
Chronic Pain Patients ◽  
Pain Patients

Abstract Background With its high temporal resolution, electroencephalography (EEG), a technique that records electrical activity of cortical neuronal cells, is a potentially suitable technique to investigate human somatosensory processing. By using EEG, the processing of (nociceptive) stimuli can be investigated, along with the functionality of the nociceptive pathway. Therefore, it can be applied in chronic pain patients to objectify whether changes have occurred in nociceptive processing. Typically, so-called event-related potential (ERP) recordings are used, where EEG signals are recorded in response to specific stimuli and characterized by latency and amplitude. Objective To summarize whether differences in somatosensory processing occur between chronic pain patients and healthy controls, measured with ERPs, and determine whether this response is related to the subjective pain intensity. Design Systematic review. Setting and Methods PubMed, Web of Science, and Embase were consulted, and 18 case–control studies were finally included. Subjects The chronic pain patients suffered from tension-type headache, back pain, migraine, fibromyalgia, carpal tunnel syndrome, prostatitis, or complex regional pain syndrome. Results Chronic neuropathic pain patients showed increased latencies of the N2 and P2 components, along with a decreased amplitude of the N2-P2 complex, which was also obtained in FM patients with small fiber dysfunction. The latter also showed a decreased amplitude of the N2-P3 and N1-P1 complex. For the other chronic pain patients, the latencies and the amplitudes of the ERP components did not seem to differ from healthy controls. One paper indicated that the N2-P3 peak-to-peak amplitude correlates with the subjective experience of the stimulus. Conclusions Differences in ERPs with healthy controls can mostly be found in chronic pain populations that suffer from neuropathic pain or where fiber dysfunction is present. In chronic pain populations with other etiological mechanisms, limited differences were found or agreed upon across studies.

Chronic Pain Patients with and without Alexithymia*

1988 ◽  
Vol 33 (9) ◽  
pp. 830-833 ◽  
Author(s):  
Santosh K. Chaturvedi
Keyword(s):  
Chronic Pain ◽  
Psychiatric Diagnosis ◽  
Demographic Variables ◽  
Physical Illness ◽  
Study Group ◽  
Control Groups ◽  
Chronic Pain Patients ◽  
Pain Characteristics ◽  
Pain Patients

Chronic pain patients with and without alexithymia have been compared, but no differences were observed as regards demographic variables or pain characteristics. More alexithymic patients had associated physical illness and this was significantly (P < 0.05) different from the control groups. Psychiatric diagnosis was ascribed to only three alexithymic pain patients. It is likely that verbal inexpressivity interferes with the emergence of psychopathology. Lower level of psychopathology could be due to the marked alexithymia in the pain patients of the study group.

scholarly journals Classification of circadian pain rhythms and pain characteristics in chronic pain patients

Medicine ◽  
2021 ◽  
Vol 100 (25) ◽  
pp. e26500
Author(s):  
Yoichi Tanaka ◽  
Hayato Shigetoh ◽  
Gosuke Sato ◽  
Ren Fujii ◽  
Ryota Imai ◽  
...  
Keyword(s):  
Chronic Pain ◽  
Chronic Pain Patients ◽  
Pain Characteristics ◽  
Pain Patients

scholarly journals Cortico-autonomic local arousals and heightened somatosensory arousability during NREM sleep of mice in neuropathic pain

2021 ◽  
Author(s):  
Anita Lüthi ◽  
Romain Cardis ◽  
Sandro Lecci ◽  
Laura MJ Fernandez ◽  
Alejandro Osorio-Forero ◽  
...  
Keyword(s):  
Chronic Pain ◽  
Neuropathic Pain ◽  
Sleep Disturbances ◽  
Low Frequency ◽  
Nrem Sleep ◽  
Rapid Eye Movement Sleep ◽  
Sleep Complaints ◽  
Chronic Pain Patients ◽  
Neurophysiological Mechanisms ◽  
Pain Patients

Chronic pain patients frequently suffer from sleep disturbances. Improvement of sleep quality alleviates pain, but neurophysiological mechanisms underlying sleep disturbances require clarification to advance therapeutic strategies. Chronic pain causes high-frequency electrical activity in pain-processing cortical areas that could disrupt the normal process of low-frequency sleep rhythm generation. We found that the spared-nerve-injury (SNI) mouse model, mimicking human neuropathic pain, had preserved sleep-wake behavior. However, when we probed spontaneous arousability based on infraslow continuity-fragility dynamics of non-rapid-eye-movement sleep (NREMS), we found more numerous local cortical arousals accompanied by heart rate increases in hindlimb primary somatosensory, but not in prelimbic, cortices of SNI mice. Closed-loop mechanovibrational stimulation revealed higher sensory arousability in SNI. Sleep in chronic pain thus looked preserved in conventional measures but showed elevated spontaneous and evoked arousability. Our findings develop a novel moment-to-moment probing of NREMS fragility and propose that chronic pain-induced sleep complaints arise from perturbed arousability.

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