25 results on '"Deldar Z"'
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2. Cortical interaction of bilateral inputs is similar for noxious and innocuous stimuli but leads to different perceptual effects
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Northon, S., Deldar, Z., Piché, M., Northon, S., Deldar, Z., and Piché, M.
- Abstract
The cerebral integration of somatosensory inputs from multiple sources is essential to produce adapted behaviors. Previous studies suggest that bilateral somatosensory inputs interact differently depending on stimulus characteristics, including their noxious nature. The aim of this study was to clarify how bilateral inputs evoked by noxious laser stimuli, noxious shocks, and innocuous shocks interact in terms of perception and brain responses. The experiment comprised two conditions (right-hand stimulation and concurrent stimulation of both hands) in which painful laser stimuli, painful shocks and non-painful shocks were delivered. Perception, somatosensory-evoked potentials (P45, N100, P260), laser-evoked potentials (N1, N2 and P2) and event-related spectral perturbations (delta to gamma oscillation power) were compared between conditions and stimulus modalities. The amplitude of negative vertex potentials (N2 or N100) and the power of delta/theta oscillations were increased in the bilateral compared with unilateral condition, regardless of the stimulus type (P < 0.01). However, gamma oscillation power increased for painful and non-painful shocks (P < 0.01), but not for painful laser stimuli (P = 0.08). Despite the similarities in terms of brain activity, bilateral inputs interacted differently for painful stimuli, for which perception remained unchanged, and non-painful stimuli, for which perception increased. This may reflect a ceiling effect for the attentional capture by noxious stimuli and warrants further investigations to examine the regulation of such interactions by bottom–up and top–down processes.
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- 2021
3. Disruption of working memory and contralateral delay activity by nociceptive stimuli is modulated by task demands
- Author
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Wagenaar-Tison, A., Deldar, Z., Northon, S., Brisson, B., Blanchette, I., Piché, M., Wagenaar-Tison, A., Deldar, Z., Northon, S., Brisson, B., Blanchette, I., and Piché, M.
- Abstract
Top–down processes allow the selection and prioritization of information by limiting attentional capture by distractors, and these mechanisms depend on task demands such as working memory (WM) load. However, bottom–up processes give salient stimuli a stronger neuronal representation and provoke attentional capture. The aim of this study was to examine the effect of salient nociceptive stimuli on WM while manipulating task demands. Twenty-one healthy participants performed a change detection task during which they had to determine whether 2 successive visual arrays were different or the same. Task demands were modulated by manipulating the WM load (set size included 2 or 4 objects to recall) and by the correspondence between the 2 successive visual arrays (change vs no change). Innocuous stimuli (control) or nociceptive stimuli (distractors) were delivered during the delay period between the 2 visual arrays. Contralateral delay activity and laser-evoked potentials were recorded to examine neural markers of visual WM and nociceptive processes. Nociceptive stimuli decreased WM performance depending on task demands (all P < 0.05). Moreover, compared with control stimuli, nociceptive stimuli abolished the increase in contralateral delay activity amplitude for set size 4 vs set size 2 (P = 0.04). Consistent with these results, laser-evoked potential amplitude was not decreased when task demands were high (P = 0.5). These findings indicate that WM may shield cognition from nociceptive stimuli, but nociceptive stimuli disrupt WM and alter task performance when cognitive resources become insufficient to process all task-relevant information. Corresponding author. Address: Department of Anatomy, Université du Québec à Trois-Rivières, 3351 Blvd des Forges, C.P. 500, Trois-Rivières, QC, Canada G9A 5H7. Tel.: 819-376-5011, Ext.: 3998; fax: 819-376-5204. E-mail address: mathieu.piche@uqtr.ca (M. Piché). Sponsorships or competing interests that may be relevant to content are discl
- Published
- 2021
4. Reduction of pain and spinal nociceptive transmission by working memory is load dependant
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Deldar, Z., Blanchette, I., Piché, M., Deldar, Z., Blanchette, I., and Piché, M.
- Abstract
Working memory (WM) engagement produces pain inhibition. However, it remains unclear whether higher WM load increases this effect. The aim of this study was to investigate the interaction between WM load and pain inhibition by WM and examine the contribution of cerebrospinal mechanism. Thirty-eight healthy volunteers were assigned to one of 2 n-back groups for which WM load was different (2-back or 3-back). The experimental protocol comprised 5 counterbalanced conditions (0-back, n-back, pain, 0-back with pain, and n-back with pain). Pain and the nociceptive flexion reflex (NFR) were evoked by transcutaneous electrical stimulation of the sural nerve. Pain was significantly different between conditions, but not between n-back groups. Both the 0-back and n-back tasks reduced pain compared with pain alone, but the n-back task produced stronger pain inhibition compared with the 0-back task. NFR amplitude was significantly different between conditions but not between n-back groups. NFR was inhibited by the 0-back and n-back tasks, with no difference between the 2 tasks. These findings indicate that pain inhibition by WM is increased by WM load, but only to a certain point. NFR inhibition by WM suggests that inhibition of pain by WM depends, at least in part, on cerebrospinal mechanism. Perspective: This behavioral and electrophysiological study shows that engaging in a cognitive task reduces pain by decreasing spinal nociceptive transmission, depending on task difficulty. These findings may yield better nonpharmacological pain therapies based on individual differences in working memory performance and capacity as well as several factors that regulate working memory. © 2021 United States Association for the Study of Pain, Inc.
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- 2021
5. Improving working memory and pain inhibition in older persons using transcranial direct current stimulation
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Deldar, Z., Rustamov, N., Blanchette, I., Piché, M., Deldar, Z., Rustamov, N., Blanchette, I., and Piché, M.
- Abstract
The aim of the present study was to examine whether transcranial Direct Current Stimulation (tDCS) could enhance working memory and pain inhibition in older persons. Fifteen volunteers (7 women, 8 men; mean ± SD: 64 ± 4.4 y.o.) participated in two tDCS sessions during which an n-back task was performed with two levels of working memory load, while painful stimulation was delivered at the ankle. The experiment included five within-subject counterbalanced conditions (pain alone and 0-back or 2-back with or without pain) performed twice during each session. Compared with the pre-tDCS baseline, anodal tDCS decreased response times and improved pain inhibition by working memory in the 2-back condition (p < 0.01), but not in the 0-back or pain alone conditions, while sham tDCS produced no effect (all p > 0.3). These results indicate that working memory and pain inhibition can be improved by tDCS in older persons. © 2019 Elsevier B.V. and Japan Neuroscience Society
- Published
- 2019
6. Enhancement of pain inhibition by working memory with anodal transcranial direct current stimulation of the left dorsolateral prefrontal cortex
- Author
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Deldar, Z., Rustamov, N., Bois, S., Blanchette, I., Piché, M., Deldar, Z., Rustamov, N., Bois, S., Blanchette, I., and Piché, M.
- Abstract
The aim of this study was to examine whether transcranial direct current stimulation (tDCS) of the dorsolateral prefrontal cortex (DLPFC) enhances pain inhibition by improving working memory (WM). Forty healthy volunteers participated in two tDCS sessions. Pain was evoked by electrical stimulation at the ankle. Participants performed an n-back task (0-back and 2-back). The experimental protocol comprised five counterbalanced conditions (0-back, 2-back, pain, 0-back with pain and 2-back with pain) that were performed twice (pre-tDCS baseline and during tDCS). Compared with the pre-tDCS baseline values, anodal tDCS decreased response times for the 2-back condition (p < 0.01) but not for the 0-back condition (p > 0.5). Anodal tDCS also decreased pain ratings marginally in the 2-back with pain condition, but not the 0-back with pain condition (p = 0.052 and p > 0.2, respectively). No effect was produced by sham tDCS for any condition (p > 0.2). These results indicate that tDCS of the left DLPFC may enhance pain inhibition by improving WM. © 2018, The Physiological Society of Japan and Springer Japan KK, part of Springer Nature.
- Published
- 2018
7. Regional Sensorimotor Effects of Chiropractic Spinal Manipulation: Preliminary Results From an Experimental Study.
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Gevers-Montoro C, Deldar Z, and Mues AO
- Abstract
Objective: The purpose of this study was to assess the effects of different spinal manipulation (SM) techniques and target segments on a specific dermatome and myotome, when compared with a remote spinal cord segment that served as a control location., Methods: Twenty-nine healthy volunteers were randomized to receive instrumental (Activator IV, Activator Methods International Ltd) or manual SM at the C6, C1, and T4 vertebral segments in 3 independent sessions. Pressure pain thresholds (PPTs) and muscle strength were examined at the C6 (test) and L4 (control) dermatomes and myotomes, at baseline and after intervention. Linear mixed-effects models were used to analyze changes over time and interindividual variability., Results: Pressure pain thresholds significantly increased at both proximal and distal C6 dermatome locations (P < .05), irrespective of the technique and segment of application (P > .2). No significant changes were observed at the L4 dermatome. Muscle strength remained unchanged throughout the study. Multilevel modeling revealed significant associations between increased PPTs along the C6 dermatome (P < .001), whereas the combination of technique and target segment predicted PPT increases at the proximal C6 dermatome., Conclusion: These findings support regional, rather than segmental mechanisms underlying the sensory effects of SM. Specifically, significant increases in PPTs along the C6 dermatome suggest localized effects on pain sensitivity, which may depend on the target spinal region. Further investigation is needed to better understand these regional changes of SM and their potential clinical implications., (Copyright © 2024. Published by Elsevier Inc.)
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- 2024
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8. Second language learning in older adults modulates Stroop task performance and brain activation.
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Schultz DH, Gansemer A, Allgood K, Gentz M, Secilmis L, Deldar Z, Savage CR, and Ghazi Saidi L
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Introduction: Numerous studies have highlighted cognitive benefits in lifelong bilinguals during aging, manifesting as superior performance on cognitive tasks compared to monolingual counterparts. Yet, the cognitive impacts of acquiring a new language in older adulthood remain unexplored. In this study, we assessed both behavioral and fMRI responses during a Stroop task in older adults, pre- and post language-learning intervention., Methods: A group of 41 participants (age:60-80) from a predominantly monolingual environment underwent a four-month online language course, selecting a new language of their preference. This intervention mandated engagement for 90 minutes a day, five days a week. Daily tracking was employed to monitor progress and retention. All participants completed a color-word Stroop task inside the scanner before and after the language instruction period., Results: We found that performance on the Stroop task, as evidenced by accuracy and reaction time, improved following the language learning intervention. With the neuroimaging data, we observed significant differences in activity between congruent and incongruent trials in key regions in the prefrontal and parietal cortex. These results are consistent with previous reports using the Stroop paradigm. We also found that the amount of time participants spent with the language learning program was related to differential activity in these brain areas. Specifically, we found that people who spent more time with the language learning program showed a greater increase in differential activity between congruent and incongruent trials after the intervention relative to before., Discussion: Future research is needed to determine the optimal parameters for language learning as an effective cognitive intervention for aging populations. We propose that with sufficient engagement, language learning can enhance specific domains of cognition such as the executive functions. These results extend the understanding of cognitive reserve and its augmentation through targeted interventions, setting a foundation for future investigations., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Schultz, Gansemer, Allgood, Gentz, Secilmis, Deldar, Savage and Ghazi Saidi.)
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- 2024
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9. Characteristics, outcome, duration of hospitalization, and cycle threshold of patients with COVID-19 referred to four hospitals in Babol City: a multicenter retrospective observational study on the fourth, fifth, and sixth waves.
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Sadeghi F, Halaji M, Shirafkan H, Pournajaf A, Ghorbani H, Babazadeh S, Ezami N, Fallhpour K, Fakhraie F, Gorjinejad S, Amoli SS, Amiri FH, Baghershiroodi M, Ahmadnia Z, Salehi M, Tourani M, Jafarzadeh J, Tabari FS, Ahmadian SR, Mohammadi Abandansari R, Jafarian F, Rouhi S, Zabihollahi A, Mostafanezhad S, Saeedi F, Ebrahimian A, Deldar Z, Zavareh MSH, Bayani M, Broun MB, Shirzad M, Sabbaghi S, Mohammadi M, Rahmani R, and Yahyapour Y
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- Humans, RNA, Viral, Hospitalization, Hospitals, SARS-CoV-2, COVID-19 epidemiology
- Abstract
Background: The aim of the present study was to compare the epidemiological patterns of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infections, hospitalizations, deaths, and duration of hospitalization during the fourth, fifth and sixth epidemic waves of coronavirus disease 2019 (COVID-19) in Iran., Methods: A multicenter retrospective observational study was conducted on hospitalized patients in four hospitals in the Babol district of northern Iran. The study periods were during the fourth, fifth, and sixth waves of the epidemic in Iran, (March 2021 to March 2022). A total of 13,312 patients with suspected COVID-19 were included. Patient demographics, medical history, length of hospital stay, and clinical outcomes were obtained from the hospital information system. Data on the cycle threshold (Ct) and SARS-CoV2 variant were collected for SARS-CoV2-positive cases., Results: The highest number of hospitalized patients was reported during the fifth (Delta) wave (5231; 39.3%), while the lowest number of hospitalized patients was reported during the sixth (Omicron) wave (2143; 16.1%). In total, 6459 (48.5%) out of 13,312 hospitalized patients with suspected COVID-19 had a positive rRT-PCR result. The fifth (Delta) wave had the highest number of SARS-CoV2 rRT-PCR-positive hospitalized patients (3573, 55.3%), while the sixth (Omicron) wave had the lowest number (835, 12.9%). Moreover, 238 (3.7%) patients with laboratory-confirmed COVID-19 died. The hospital mortality rate was 6.8% in the fourth (Alpha) wave, which reduced to 2.7 and 3.5% in the fifth (Delta) and sixth (Omicron) waves, respectively (p < 0.001)., Conclusions: This is the most comprehensive study evaluating the epidemiologic characteristics of laboratory-confirmed SARS-CoV2 cases in Iran during the Alpha, Delta, and Omicron waves. The highest number of SARS-CoV2-positive hospitalized patients was in the fifth wave of COVID-19 (dominance of the Delta variant), while the sixth wave (dominance of the Omicron variant) had the lowest number. Comorbidities were similar, and cardiovascular disease, diabetes, kidney disease, and hypertension were the main risk factors in all waves., (© 2024. The Author(s).)
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- 2024
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10. A network analysis on biopsychosocial factors and pain-related outcomes assessed during a COVID-19 lockdown.
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Gevers-Montoro C, Liew BXW, Deldar Z, Conesa-Buendia FM, Ortega-De Mues A, Falla D, and Khatibi A
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- Humans, Cross-Sectional Studies, Pandemics, Communicable Disease Control, COVID-19 epidemiology, Acute Pain
- Abstract
Psychological stress, social isolation, physical inactivity, and reduced access to care during lockdowns throughout a pandemic negatively impact pain and function. In the context of the first COVID-19 lockdown in Spain, we aimed to investigate how different biopsychosocial factors influence chiropractic patients' pain-related outcomes and vice-versa. A total of 648 chiropractic patients completed online questionnaires including variables from the following categories: demographics, pain outcomes, pain beliefs, impact of the COVID-19 pandemic, stress/anxiety and self-efficacy. Twenty-eight variables were considered in a cross-sectional network analysis to examine bidirectional associations between biopsychosocial factors and pain outcomes. Subgroup analyses were conducted to estimate differences according to gender and symptom duration. The greatest associations were observed between pain duration and pain evolution during lockdown. Participants' age, pain symptoms' evolution during lockdown, and generalized anxiety were the variables with the strongest influence over the whole network. Negative emotions evoked by the pandemic were indirectly associated with pain outcomes, possibly via pain catastrophizing. The network structure of patients reporting acute pain showed important differences when compared to patients with chronic pain. These findings will contribute to identify which factors explain the deleterious effects of both the pandemic and the restrictions on patients living with pain., (© 2023. The Author(s).)
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- 2023
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11. Emotion regulation mediates the relationship between family caregivers' pain-related beliefs and patients' coping strategies.
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Alinajimi F, Deldar Z, Dehghani M, and Khatibi A
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Background: In order to tailor more effective interventions and minimize the burden of chronic pain, it is critical to identify the interaction and contribution of social and psychological factors in pain. One of the important psychological factors in pain management is related to the choice of pain coping strategies in chronic pain patients. Social resources, including family caregivers' pain attitudes-beliefs, can influence pain coping strategies in chronic pain patients. Moreover, one key factor that may intervene in the relationship between caregivers' pain attitudes-beliefs and the patients' coping strategies is the emotion regulation strategies. Therefore, the present study aimed to investigate the mediating role of emotion regulation strategies of chronic pain patients and their family caregivers on the association between caregivers' pain attitudes-beliefs and pain coping strategies of chronic pain patients. Methods: We recruited 200 chronic musculoskeletal pain patients and their family caregivers. Chronic pain patients responded to measures of pain coping and emotion regulation strategies while family caregivers completed questionnaires related to their attitude toward pain and emotion regulation of themselves. Results: There is an association between caregivers' pain attitudes-beliefs and pain coping strategies in patients with chronic musculoskeletal. Moreover, the structural equation modeling revealed that the emotion regulation of both patients and family caregivers mediate the relationship between the caregivers' pain attitudes-beliefs and pain coping strategies of patients with chronic musculoskeletal. Conclusions: The social context of pain, including the effect of family caregivers' responses to the patient's pain, is a critical pain source that is suggested to affect coping strategies in patients. These findings suggest an association between pain attitudes-beliefs in family caregivers and pain coping strategies in patients. Moreover, these results showed that the emotion regulation of both patients and their family caregivers mediates this association., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Alinajimi, Deldar, Dehghani and Khatibi.)
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- 2023
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12. From hands-on to remote: Moderators of response to a novel self-management telehealth programme during the COVID-19 pandemic.
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Gevers-Montoro C, Deldar Z, Furlan A, Lazar EA, Ghalibaf E, Ortega-De Mues A, and Khatibi A
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- Communicable Disease Control, Humans, Pain psychology, Pandemics, COVID-19, Self-Management, Telemedicine
- Abstract
Background: In March 2020, state-wide lockdowns were declared in many countries, including Spain. Citizens were confined to their homes and remotely supported activities were prioritized as an alternative to in-person interactions. Previous data suggest that remote and self-management interventions may be successful at reducing pain and related psychological variables. However, individual factors influencing the effectiveness of these interventions remain to be identified. We aimed to investigate the psychological and motivational factors moderating changes in pain observed in chiropractic patients undertaking a novel telehealth self-management programme., Methods: A cohort of 208 patients from a chiropractic teaching clinic was recruited to participate in the study. Patients received telehealth consultations and individualized self-management strategies tailored for their current complaint. They were encouraged to make use of these strategies daily for 2-4 weeks, whilst rating their pain intensity, motivation and adherence. Validated questionnaires were completed online to assess catastrophizing, kinesiophobia and anxiety., Results: A total of 168 patients completed the first 2 weeks of the programme, experiencing significant reductions in all variables. Kinesiophobia emerged as a key factor influencing pain reduction and moderating the association between motivation and pain relief. In turn, adherence to the programme was associated with lower pain intensity, although moderated by the degree of motivation., Conclusions: In the context of COVID-19, when introducing remote and self-management strategies, pain cognitions and motivational factors should be taken into consideration to foster adherence and yield better pain outcomes., (© 2022 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation - EFIC®.)
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- 2022
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13. Disruption of working memory and contralateral delay activity by nociceptive stimuli is modulated by task demands.
- Author
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Wagenaar-Tison A, Deldar Z, Northon S, Brisson B, Blanchette I, and Piché M
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- Attention physiology, Cognition physiology, Electroencephalography methods, Humans, Memory, Short-Term physiology, Nociception physiology
- Abstract
Abstract: Top-down processes allow the selection and prioritization of information by limiting attentional capture by distractors, and these mechanisms depend on task demands such as working memory (WM) load. However, bottom-up processes give salient stimuli a stronger neuronal representation and provoke attentional capture. The aim of this study was to examine the effect of salient nociceptive stimuli on WM while manipulating task demands. Twenty-one healthy participants performed a change detection task during which they had to determine whether 2 successive visual arrays were different or the same. Task demands were modulated by manipulating the WM load (set size included 2 or 4 objects to recall) and by the correspondence between the 2 successive visual arrays (change vs no change). Innocuous stimuli (control) or nociceptive stimuli (distractors) were delivered during the delay period between the 2 visual arrays. Contralateral delay activity and laser-evoked potentials were recorded to examine neural markers of visual WM and nociceptive processes. Nociceptive stimuli decreased WM performance depending on task demands (all P < 0.05). Moreover, compared with control stimuli, nociceptive stimuli abolished the increase in contralateral delay activity amplitude for set size 4 vs set size 2 (P = 0.04). Consistent with these results, laser-evoked potential amplitude was not decreased when task demands were high (P = 0.5). These findings indicate that WM may shield cognition from nociceptive stimuli, but nociceptive stimuli disrupt WM and alter task performance when cognitive resources become insufficient to process all task-relevant information., (Copyright © 2021 International Association for the Study of Pain.)
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- 2022
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14. Effects of spatial attention and limb position on the cortical interaction of bilateral noxious inputs.
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Northon S, Deldar Z, and Piché M
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- Adult, Electroencephalography, Female, Humans, Male, Young Adult, Attention physiology, Cerebral Cortex physiology, Hand physiology, Laser-Evoked Potentials physiology, Pain Perception physiology, Space Perception physiology
- Abstract
Bilateral noxious inputs interact in the brain to provide a better representation of physical threat. In the present study, we investigated the effects of spatial attention and limb position on this interaction. Painful laser stimuli were applied randomly on the right hand or on both hands, while varying spatial attention (focal or overall) and limb position (hands near or far from each other). Pain perception and laser-evoked potentials (N1, N2, P2) were compared between conditions in 27 healthy volunteers. Compared with unilateral stimulation, bilateral stimulation increased pain (p = .004), the N2 (p = .0015) and P2 (p < .001) amplitude. The effects on pain and the P2 were greater when hands were in the near compared with the far position (p < .05). The effect on pain was also greater for overall compared with focal pain rating (p = .003). In addition, the N1 amplitude was greater for bilateral stimulation when hands were in the far compared with the near position (p = .01). These results show that increased brain responses and pain for bilateral compared with unilateral noxious stimulation are modulated differentially by spatial attention and limb position. This suggests that the integration of noxious inputs occurs through partially independent pain-related processes, that it is modulated by limb position, and that it is partially independent of pain perception. We propose that this is necessary to produce coordinated, flexible and adapted defensive responses., (© 2021 Society for Psychophysiological Research.)
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- 2022
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15. Pain catastrophizing mediates rapid benefits of accessing in-person chiropractic care during the COVID-19 lockdown.
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Gevers-Montoro C, Deldar Z, Conesa-Buendía FM, Lazar EA, Mahillo-Fernandez I, Khatibi A, and Ortega de Mues A
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- Catastrophization, Communicable Disease Control, Humans, Pandemics, SARS-CoV-2, COVID-19, Chiropractic
- Abstract
Background: In March 2020, the COVID-19 pandemic forced the Spanish government to declare a state of emergency. A stringent lockdown was enforced, restricting access to healthcare services, including chiropractic. Reduced access to care provision in combination with psychological stress, social isolation and physical inactivity during the lockdown were shown to negatively influence pain conditions. However, data on strategies to mitigate the impact of the pandemic on these conditions are lacking., Methods: Upon easing of restrictions in May 2020, 51 chiropractic clinics throughout Spain pseudo-randomly invited patients, recruiting a total of 385 participants. During a 14-day period, participants were exposed to in-person chiropractic care in either one (n = 177) or multiple encounters (n = 109) or to no care (n = 99). The effects of access to chiropractic care on patients' pain-related and psychological outcomes were assessed online through validated self-reported questionnaires before and after the period of care. Coprimary outcomes included pain intensity, pain interference and pain cognitions., Results: When comparing to participants without access to care, pain intensity and interference were significantly decreased at follow-up, irrespective of the number of encounters. Kinesiophobia was also significantly reduced at follow-up, though only after multiple encounters. The relationship between fear of movement, changes in pain intensity and interference was mediated by catastrophizing., Conclusion: Access to in-person chiropractic care may provide pain relief, associated with reductions in interference and pain cognitions. Prioritizing in-person care for patients with maladaptive pain cognitions may help dampen the detrimental consequences of the pandemic on physical and psychological well-being., (© 2021 European Pain Federation - EFIC®.)
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- 2022
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16. Suppression May Improve Adaptation to Worry When Facing Uncertainty: Studying COVID-19 Pandemic.
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Khatibi A, Sharpe L, Dehghani M, Ghalibaf E, Hosseinchi P, Mazidi M, Ranjbar S, Deldar Z, Gevers-Montoro C, Alizadeh P, Alidoust S, Babaei A, Telkabadi F, and Ghadiri T
- Abstract
The COVID-19 pandemic has been associated with increased uncertainty, fear and worry in everyone's life. The effect of changes in daily life has been studied widely, but we do not know how emotion-regulation strategies influence adaptation to a new situation to help them overcome worry in the face of uncertainty. Here, 1,064 self-selected Farsi speaking participants completed an online battery of questionnaires that measured fear of virus and illness, worry, intolerance of uncertainty, and emotion regulation (two subscales: reappraisal, suppression). We also documented the number of daily COVID-19 cases and deaths due to COVID-19 on the day in which participants completed the questionnaire. Our findings suggest a correlation between contamination fear and the number of daily-confirmed cases (r = 0.11), and the number of reported deaths due to COVID-19 (r = 0.09). Worry mediated the relationship between intolerance of uncertainty and fear of virus and illness (b = 0.16, 0.1141 < CI < 0.2113). In addition, suppression moderated the relationship between intolerance of uncertainty and worry ( p < 0.01). Our results suggest that suppression (at least in the short term) can be an adaptive response to the worry associated with uncertainty. Suppression can reduce worry, which in turn can decrease fear of contamination and improve adaptation to social distancing requirements. Although, the observed correlations were significant, but considering the sample size, they are not strong, and they should be interpreted cautiously., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Khatibi, Sharpe, Dehghani, Ghalibaf, Hosseinchi, Mazidi, Ranjbar, Deldar, Gevers-Montoro, Alizadeh, Alidoust, Babaei, Telkabadi and Ghadiri.)
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- 2021
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17. An Analysis of the #CovidPain Tweet Chat During the First Wave of the COVID-19 Pandemic in 2020.
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Furlan AD, Deldar Z, Berezin L, Clarke H, Bogden BJ, and Buchman DZ
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Introduction: In March 2020, we organized two tweet chats to discuss the COVID-19 pandemic and its impact on people affected by chronic pain. The objective of this study is to evaluate the #CovidPain tweet chat activities that took place at the early stages of the COVID-19 pandemic., Methods: We performed a quantitative analysis of the magnitude, range, engagement, and sentiment of each tweet chat. The data was extracted from Twitter and analyzed in Twitter Analytics and Symplur Signals using frequency and distributions. Then, we conducted a qualitative content analysis of the narrative tweets generated in response to the questions posted during the tweet chats., Results: The two tweet chats attracted 2305 participants, which generated 4351 tweets. The participants were healthcare providers, patient advocates, researchers/academics, and caregivers. COVID-19 had both negative and positive impacts. The negative consequences of COVID-19 included the reduction of physical activity, canceled appointments and treatments, more isolation, deterioration of preexisting mental health problems, and economic consequences. The positive consequences included efficient use of telemedicine, innovative methods for self-management, and at-home interventions., Conclusion: Twitter and tweet chats are useful in involving a diverse group of stakeholders for taking a deep dive into the topical issues relevant to a community that might be disproportionately affected by a public health crisis., Competing Interests: The authors have declared financial relationships, which are detailed in the next section., (Copyright © 2021, Furlan et al.)
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- 2021
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18. Cortical interaction of bilateral inputs is similar for noxious and innocuous stimuli but leads to different perceptual effects.
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Northon S, Deldar Z, and Piché M
- Subjects
- Brain, Brain Mapping, Electroencephalography, Hand, Humans, Evoked Potentials, Somatosensory, Laser-Evoked Potentials
- Abstract
The cerebral integration of somatosensory inputs from multiple sources is essential to produce adapted behaviors. Previous studies suggest that bilateral somatosensory inputs interact differently depending on stimulus characteristics, including their noxious nature. The aim of this study was to clarify how bilateral inputs evoked by noxious laser stimuli, noxious shocks, and innocuous shocks interact in terms of perception and brain responses. The experiment comprised two conditions (right-hand stimulation and concurrent stimulation of both hands) in which painful laser stimuli, painful shocks and non-painful shocks were delivered. Perception, somatosensory-evoked potentials (P45, N100, P260), laser-evoked potentials (N1, N2 and P2) and event-related spectral perturbations (delta to gamma oscillation power) were compared between conditions and stimulus modalities. The amplitude of negative vertex potentials (N2 or N100) and the power of delta/theta oscillations were increased in the bilateral compared with unilateral condition, regardless of the stimulus type (P < 0.01). However, gamma oscillation power increased for painful and non-painful shocks (P < 0.01), but not for painful laser stimuli (P = 0.08). Despite the similarities in terms of brain activity, bilateral inputs interacted differently for painful stimuli, for which perception remained unchanged, and non-painful stimuli, for which perception increased. This may reflect a ceiling effect for the attentional capture by noxious stimuli and warrants further investigations to examine the regulation of such interactions by bottom-up and top-down processes., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
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- 2021
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19. Spinal and Cerebral Integration of Noxious Inputs in Left-handed Individuals.
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Northon S, Deldar Z, and Piché M
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- Evoked Potentials, Functional Laterality, Humans, Hand, Pain
- Abstract
Some pain-related information is processed preferentially in the right cerebral hemisphere. Considering that functional lateralization can be affected by handedness, spinal and cerebral pain-related responses may be different between right- and left-handed individuals. Therefore, this study aimed to investigate the cortical and spinal mechanisms of nociceptive integration when nociceptive stimuli are applied to right -handed vs. left -handed individuals. The NFR, evoked potentials (ERP: P45, N100, P260), and event-related spectral perturbations (ERSP: theta, alpha, beta and gamma band oscillations) were compared between ten right-handed and ten left-handed participants. Pain was induced by transcutaneous electrical stimulation of the lower limbs and left upper limb. Stimulation intensity was adjusted individually in five counterbalanced conditions of 21 stimuli each: three unilateral (right lower limb, left lower limb, and left upper limb stimulation) and two bilateral conditions (right and left lower limbs, and the right lower limb and left upper limb stimulation). The amplitude of the NFR, ERP, ERSP, and pain ratings were compared between groups and conditions using a mixed ANOVA. A significant increase of responses was observed in bilateral compared with unilateral conditions for pain intensity, NFR amplitude, N100, theta oscillations, and gamma oscillations. However, these effects were not significantly different between right- and left-handed individuals. These results suggest that spinal and cerebral integration of bilateral nociceptive inputs is similar between right- and left-handed individuals. They also imply that pain-related responses measured in this study may be examined independently of handedness., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)
- Published
- 2021
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20. Reduction of Pain and Spinal Nociceptive Transmission by Working Memory is Load Dependant.
- Author
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Deldar Z, Blanchette I, and Piché M
- Subjects
- Adolescent, Adult, Female, Humans, Male, Pain etiology, Pain psychology, Reaction Time, Sural Nerve, Task Performance and Analysis, Transcutaneous Electric Nerve Stimulation, Young Adult, Memory, Short-Term physiology, Nociception physiology, Pain prevention & control
- Abstract
Working memory (WM) engagement produces pain inhibition. However, it remains unclear whether higher WM load increases this effect. The aim of this study was to investigate the interaction between WM load and pain inhibition by WM and examine the contribution of cerebrospinal mechanism. Thirty-eight healthy volunteers were assigned to one of 2 n-back groups for which WM load was different (2-back or 3-back). The experimental protocol comprised 5 counterbalanced conditions (0-back, n-back, pain, 0-back with pain, and n-back with pain). Pain and the nociceptive flexion reflex (NFR) were evoked by transcutaneous electrical stimulation of the sural nerve. Pain was significantly different between conditions, but not between n-back groups. Both the 0-back and n-back tasks reduced pain compared with pain alone, but the n-back task produced stronger pain inhibition compared with the 0-back task. NFR amplitude was significantly different between conditions but not between n-back groups. NFR was inhibited by the 0-back and n-back tasks, with no difference between the 2 tasks. These findings indicate that pain inhibition by WM is increased by WM load, but only to a certain point. NFR inhibition by WM suggests that inhibition of pain by WM depends, at least in part, on cerebrospinal mechanism. PERSPECTIVE: This behavioral and electrophysiological study shows that engaging in a cognitive task reduces pain by decreasing spinal nociceptive transmission, depending on task difficulty. These findings may yield better nonpharmacological pain therapies based on individual differences in working memory performance and capacity as well as several factors that regulate working memory., (Copyright © 2021 United States Association for the Study of Pain, Inc. Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
- Full Text
- View/download PDF
21. The interaction between language and working memory: a systematic review of fMRI studies in the past two decades.
- Author
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Deldar Z, Gevers-Montoro C, Khatibi A, and Ghazi-Saidi L
- Abstract
Language processing involves other cognitive domains, including Working Memory (WM). Much detail about the neural correlates of language and WM interaction remains unclear. This review summarizes the evidence for the interaction between WM and language obtained via functional Magnetic Resonance Imaging (fMRI) in the past two decades. The search was limited to PubMed, Google Scholar, Science direct and Neurosynth for working memory, language, fMRI, neuroimaging, cognition, attention, network, connectome keywords. The exclusion criteria consisted of studies including children, older adults, bilingual or multilingual population, clinical cases, music, sign language, speech, motor processing, review papers, meta-analyses, electroencephalography/event-related potential, and positron emission tomography. A total of 20 articles were included and discussed in four categories: language comprehension, language production, syntax, and networks. Studies on neural correlates of WM and language interaction are rare. Language tasks that involve WM activate common neural systems. Activated areas can be associated with cognitive concepts proposed by Baddeley and Hitch (1974), including the phonological loop of WM (mainly Broca and Wernicke's areas), other prefrontal cortex and right hemispheric regions linked to the visuospatial sketchpad. There is a clear, dynamic interaction between language and WM, reflected in the involvement of subcortical structures, particularly the basal ganglia (caudate), and of widespread right hemispheric regions. WM involvement is levered by cognitive demand in response to task complexity. High WM capacity readers draw upon buffer memory systems in midline cortical areas to decrease the WM demands for efficiency. Different dynamic networks are involved in WM and language interaction in response to the task in hand for an ultimate brain function efficiency, modulated by language modality and attention., Competing Interests: Conflicts of interest: The authors declare no competing interests and no relationship that may lead to any conflict of interest., (© 2021 the Author(s), licensee AIMS Press.)
- Published
- 2020
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22. Improving working memory and pain inhibition in older persons using transcranial direct current stimulation.
- Author
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Deldar Z, Rustamov N, Blanchette I, and Piché M
- Subjects
- Adult, Aged, Aged, 80 and over, Female, Humans, Inhibition, Psychological, Male, Memory, Short-Term physiology, Middle Aged, Prefrontal Cortex physiology, Memory, Short-Term radiation effects, Nociceptive Pain radiotherapy, Pain Management, Prefrontal Cortex radiation effects, Transcranial Direct Current Stimulation psychology
- Abstract
The aim of the present study was to examine whether transcranial Direct Current Stimulation (tDCS) could enhance working memory and pain inhibition in older persons. Fifteen volunteers (7 women, 8 men; mean ± SD: 64 ± 4.4 y.o.) participated in two tDCS sessions during which an n-back task was performed with two levels of working memory load, while painful stimulation was delivered at the ankle. The experiment included five within-subject counterbalanced conditions (pain alone and 0-back or 2-back with or without pain) performed twice during each session. Compared with the pre-tDCS baseline, anodal tDCS decreased response times and improved pain inhibition by working memory in the 2-back condition (p < 0.01), but not in the 0-back or pain alone conditions, while sham tDCS produced no effect (all p > 0.3). These results indicate that working memory and pain inhibition can be improved by tDCS in older persons., (Copyright © 2019 Elsevier B.V. and Japan Neuroscience Society. All rights reserved.)
- Published
- 2019
- Full Text
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23. Bias Toward Drug-Related Stimuli Is Affected by Loading Working Memory in Abstinent Ex-Methamphetamine Users.
- Author
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Deldar Z, Ekhtiari H, Pouretemad HR, and Khatibi A
- Abstract
Background: There is a trade-off between drug-related impulsive process and cognitive reflective process among ex-drug abusers. The present study aimed to investigate the impulsive effects of methamphetamine-related stimuli on working memory (WM) performance by manipulating WM load in abstinent ex-methamphetamine users. Methods: Thirty abstinent ex-methamphetamine users and 30 nonaddict matched control participants were recruited in this study. We used a modified Sternberg task in which participants were instructed to memorize three different sets of methamphetamine-related and non-drug-related words (three, five, or seven words) while performing a secondary attention-demanding task as an interference. Results: Repeated-measures ANOVA revealed that reaction times of abstinent ex-methamphetamine users increased during low WM load (three words) compared to the control group ( p = 0.01). No significant differences were observed during high WM loads (five or seven words) (both p 's > 0.1). Besides, reaction times of the experimental group during trials with high interference (three, five, or seven words) were not significantly different compared to the control group ( p > 0.2). Conclusion: These findings imply that increasing WM load may provide an efficient buffer against attentional capture by salient stimuli (i.e., methamphetamine-related words). This buffer might modify the effect of interference bias. Besides, presenting methamphetamine-related stimuli might facilitate the encoding phase due to bias toward task-relevant stimuli. This finding has an important implication, suggesting that performing concurrent demanding tasks may reduce the power of salient stimuli and thus improve the efficiency of emotional regulation strategies., (Copyright © 2019 Deldar, Ekhtiari, Pouretemad and Khatibi.)
- Published
- 2019
- Full Text
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24. Enhancement of pain inhibition by working memory with anodal transcranial direct current stimulation of the left dorsolateral prefrontal cortex.
- Author
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Deldar Z, Rustamov N, Bois S, Blanchette I, and Piché M
- Subjects
- Adult, Electric Stimulation, Female, Healthy Volunteers, Humans, Male, Pain psychology, Transcranial Direct Current Stimulation, Young Adult, Memory, Short-Term physiology, Nociception physiology, Pain physiopathology, Prefrontal Cortex physiopathology
- Abstract
The aim of this study was to examine whether transcranial direct current stimulation (tDCS) of the dorsolateral prefrontal cortex (DLPFC) enhances pain inhibition by improving working memory (WM). Forty healthy volunteers participated in two tDCS sessions. Pain was evoked by electrical stimulation at the ankle. Participants performed an n-back task (0-back and 2-back). The experimental protocol comprised five counterbalanced conditions (0-back, 2-back, pain, 0-back with pain and 2-back with pain) that were performed twice (pre-tDCS baseline and during tDCS). Compared with the pre-tDCS baseline values, anodal tDCS decreased response times for the 2-back condition (p < 0.01) but not for the 0-back condition (p > 0.5). Anodal tDCS also decreased pain ratings marginally in the 2-back with pain condition, but not the 0-back with pain condition (p = 0.052 and p > 0.2, respectively). No effect was produced by sham tDCS for any condition (p > 0.2). These results indicate that tDCS of the left DLPFC may enhance pain inhibition by improving WM.
- Published
- 2018
- Full Text
- View/download PDF
25. Evaluation of HPV DNA positivity in colorectal cancer patients in Kerman, Southeast Iran
- Author
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Malekpour Afshar R, Deldar Z, Mollaei HR, Arabzadeh SA, and Iranpour M
- Abstract
Background: The HPV virus is known to be oncogenic and associations with many cancers has been proven. Although many studies have been conducted on the possible relationship with colorectal cancer (CRC), a definitive role of the virus has yet to be identified. Method: In this cross-sectional study, the frequency of HPV positivity in CRC samples in Kerman was assessed in 84 cases with a mean age of 47.7 ± 12.5 years over two years. Qualitative real time PCR was performed using general primers for the L1 region of HPV DNA. Results: Out of 84 CRC samples, 19 (22.6%), proved positive for HPV DNA. Genotyping of positive samples showed all of these to be of high risk HPV type. Prevalence of HPV infection appears to depend geographic region, life style, diet and other factors. Conclusion: In our location frequency of CRC is low, and this limited the sample size for evaluation of HPV DNA. The most prevalent types were HPV types 51 and 56. While HPV infection may play an important role in colorectal carcinogenesis, this needs to be assessed in future studies., (Creative Commons Attribution License)
- Published
- 2018
- Full Text
- View/download PDF
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