Faculty Opinions recommendation of Dopamine transporter genotype dependent effects of apomorphine on cold pain tolerance in healthy volunteers.

AbstractAimsNovel quantitative thermal stimulator devices (QTSDs) have been developed to deliver thermal pulse stimulation with regulated constant temperatures (0–45°C) with a Peltier element probe (16 cm2). The aim of this study was to investigate subjective sensation induced by the interaction between simultaneously applied painful cold and heat stimuli in various sites.MethodsTwenty healthy subjects (12 men and 8 women, age range: 25–45 years) participated. The intensity of cold pain (CP) and heat pain (HP) stimuli were assessed by visual analogue scale (VAS) and adjusted to elicit approximately 70/100 mm. Alternately pulse stimulations (pulse duration of 40 s; 0.025 Hz) which consisted of CP, HP, or neutral temperature (32°C) were applied. Four conditions were tested and subjective sensations were assessed: (1) one QTSD was applied to non-dominant forearm and cold-heat pulse stimulation was applied.Two QTSDs were applied to (2) non-dominant ipsilateral forearm with 5 cm apart, (3) non-dominant and contralateral forearms, (4) non-dominant forearm and ipsilateral thigh, respectively. In conditions of (2)–(4), CP-neutral pulse stimulation (C-Neutral) and neutral-HP pulse stimulation (Neutral-H) were applied simultaneously with opposite phase, respectively.ResultsCP and HP were 3.9±1.0°C (mean±SD) and 43.6±0.9°C (mean±SD), respectively. The VAS values for CP and HP were 73.4±2.0 mm (mean±SD) and 76.4 ±4.8 mm (mean±SD), respectively. Some subjects could not discriminate cold or heat sensation and some felt cold as heat (paradoxical sensation). The number of subjects with such paradoxical sensation in (1), (2), (3), (4) were 9 (45%), 2 (10%), 0 (0%) and 3 (15%), respectively.ConclusionsIn healthy volunteers, simultaneous alternately cold-heat pulse stimulation on one site triggered paradoxical thermal sensation, which to a much less degree is triggered when C-Neutral and Neutral-H were applied to different dermatomes. This suggests that the mechanism is primarily triggered peripherally.

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Static mechanical allodynia in post-surgical neuropathic pain after breast cancer treatments

Scandinavian Journal of Pain ◽

10.1515/sjpain-2020-0013 ◽

2020 ◽

Vol 20 (4) ◽

pp. 683-691

Author(s):

Laura Mustonen ◽

Tommi Aho ◽

Hanna Harno ◽

Eija Kalso

Keyword(s):

Breast Cancer ◽

Neuropathic Pain ◽

Psychological Factors ◽

Mechanical Allodynia ◽

Cold Pressor Test ◽

Pain Tolerance ◽

Cancer Surgery ◽

Breast Cancer Surgery ◽

Cold Pain ◽

Static Mechanical

AbstractObjectivesStatic mechanical allodynia (SMA), i. e., pain caused by normally non-painful static pressure, is a prevalent manifestation of neuropathic pain (NP). Although SMA may significantly affect the patient’s daily life, it is less well studied in the clinical context. We aimed to characterize SMA in women with chronic post-surgical NP (CPSNP) after breast cancer surgery. Our objective was to improve understanding of the clinical picture of this prevalent pain condition. This is a substudy of a previously published larger cohort of patients with intercostobrachial nerve injury after breast cancer surgery (Mustonen et al. Pain. 2019;160:246–56).MethodsWe studied SMA in 132 patients with CPSNP after breast cancer surgery. The presence, location, and intensity of SMA were assessed at clinical sensory examination. The patients gave self-reports of pain with the Brief Pain Inventory (BPI). We studied the association of SMA to type of surgery, oncological treatments, BMI, other pains, and psychological factors. General pain sensitivity was assessed by the cold pressor test.ResultsSMA was prevalent (84%) in this cohort whereas other forms of allodynia were scarce (6%). Moderate-to-severe SMA was frequently observed even in patients who reported mild pain in BPI. Breast and the side of chest were the most common locations of SMA. SMA was associated with breast surgery type, but not with psychological factors. Severe SMA, but not self-reported pain, was associated with lower cold pain tolerance.ConclusionsSMA is prevalent in post-surgical NP after breast cancer surgery and it may represent a distinct NP phenotype. High intensities of SMA may signal the presence of central sensitization.ImplicationsSMA should be considered when examining and treating patients with post-surgical NP after breast cancer surgery.

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Laboratory Personnel Gender and Cold Pressor Apparatus Affect Subjective Pain Reports

Pain Research and Management ◽

10.1155/2014/213950 ◽

2014 ◽

Vol 19 (1) ◽

pp. e13-e18 ◽

Cited By ~ 18

Author(s):

Jacob M Vigil ◽

Lauren N Rowell ◽

Joe Alcock ◽

Randy Maestes

Keyword(s):

Pain Sensitivity ◽

Experimental Pain ◽

Cold Pressor ◽

Pain Tolerance ◽

Cold Pain ◽

Laboratory Personnel ◽

Subjective Pain ◽

Lower Pain ◽

Pain Reporting ◽

Pain Reports

BACKGROUND: There is no standardized method for cold pressor pain tasks across experiments. Temperature, apparatus and aspects of experimenters vary widely among studies. It is well known that experimental pain tolerance is influenced by setting as well as the sex of the experimenter. It is not known whether other contextual factors influence experimental pain reporting.OBJECTIVES: The present two-part experiment examines whether minimizing and standardizing interactions with laboratory personnel (eg, limiting interaction with participants to consenting and questions and not during the actual pain task) eliminates the influence of examiner characteristics on subjective pain reports and whether using different cold pain apparatus (cooler versus machine) influences reports.METHODS:The present experiment manipulated the gender of the experimenter (male, female and transgender) and the type of cold pressor task (CPT) apparatus (ice cooler versus refrigerated bath circulator). Participants conducted the CPT at one of two pain levels (5°C or 16°C) without an experimenter present.RESULTS:Men and women showed lower pain sensitivity when they were processed by biological male personnel than by biological female personnel before the CPT. Women who interacted with a transgendered researcher likewise reported higher pain sensitivity than women processed by biological male or female researchers. The type of CPT apparatus, despite operating at equivalent temperatures, also influenced subjective pain reports.DISCUSSION: The findings show that even minimal interactions with laboratory personnel who differ in gender, and differences in laboratory materials impact the reliable measurement of pain.CONCLUSION: More standardized protocols for measuring pain across varying research and clinical settings should be developed.

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Effects of C825T polymorphism of the GNB3 gene on availability of dopamine transporter in healthy volunteers — A SPECT study

NeuroImage ◽

10.1016/j.neuroimage.2010.10.082 ◽

2011 ◽

Vol 56 (3) ◽

pp. 1526-1530 ◽

Cited By ~ 17

Author(s):

Po See Chen ◽

Tzung Lieh Yeh ◽

I Hui Lee ◽

Cheng Bill Lin ◽

Hsin Chun Tsai ◽

...

Keyword(s):

Healthy Volunteers ◽

Dopamine Transporter ◽

C825t Polymorphism

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Reduced Cold Pain Tolerance in Chronic Pain Patients Following Opioid Detoxification

Pain Medicine ◽

10.1111/j.1526-4637.2008.00475.x ◽

2008 ◽

Vol 9 (8) ◽

pp. 1158-1163 ◽

Cited By ~ 15

Author(s):

Jarred Younger ◽

Peter Barelka ◽

Ian Carroll ◽

Kim Kaplan ◽

Larry Chu ◽

...

Keyword(s):

Chronic Pain ◽

Pain Tolerance ◽

Cold Pain ◽

Chronic Pain Patients ◽

Pain Patients ◽

Opioid Detoxification

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No correlation between body mass index and striatal dopamine transporter availability in healthy volunteers using SPECT and [123 I]PE2I

Obesity ◽

10.1002/oby.20225 ◽

2013 ◽

Vol 21 (9) ◽

pp. 1803-1806 ◽

Cited By ~ 25

Author(s):

G. Thomsen ◽

M. Ziebell ◽

P. S. Jensen ◽

S. da Cuhna-Bang ◽

G. M. Knudsen ◽

...

Keyword(s):

Body Mass Index ◽

Healthy Volunteers ◽

Dopamine Transporter ◽

Body Mass ◽

Striatal Dopamine

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Experimental Pain Responses in Children with Chronic Pain and in Healthy Children: How Do They Differ?

Pain Research and Management ◽

10.1155/2012/592108 ◽

2012 ◽

Vol 17 (2) ◽

pp. 103-109 ◽

Cited By ~ 18

Author(s):

Jennie CI Tsao ◽

Subhadra Evans ◽

Laura C Seidman ◽

Lonnie K Zeltzer

Keyword(s):

Heart Rate ◽

Chronic Pain ◽

Experimental Pain ◽

Cold Pressor ◽

Pain Tolerance ◽

Depression Symptoms ◽

Healthy Children ◽

Cold Pain ◽

Lower Pain ◽

Pain Responses

BACKGROUND: Extant research comparing laboratory pain responses of children with chronic pain with healthy controls is mixed, with some studies indicating lower pain responsivity for controls and others showing no differences. Few studies have included different pain modalities or assessment protocols.OBJECTIVES: To compare pain responses among 26 children (18 girls) with chronic pain and matched controls (mean age 14.8 years), to laboratory tasks involving thermal heat, pressure and cold pain. Responses to cold pain were assessed using two different protocols: an initial trial of unspecified duration and a second trial of specified duration.METHODS: Four trials of pressure pain and of thermal heat pain stimuli, all of unspecified duration, were administered, as well as the two cold pain trials. Heart rate and blood pressure were assessed at baseline and after completion of the pain tasks.RESULTS: Pain tolerance and pain intensity did not differ between children with chronic pain and controls for the unspecified trials. For the specified cold pressor trial, 92% of children with chronic pain completed the entire trial compared with only 61.5% of controls. Children with chronic pain exhibited a trend toward higher baseline and postsession heart rate and reported more anxiety and depression symptoms compared with control children.CONCLUSIONS: Contextual factors related to the fixed trial may have exerted a greater influence on pain tolerance in children with chronic pain relative to controls. Children with chronic pain demonstrated a tendency toward increased arousal in anticipation of and following pain induction compared with controls.

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Pain sensitivity in men who have never experienced a headache: an observer blinded case control study

The Journal of Headache and Pain ◽

10.1186/s10194-021-01345-0 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Isa Amalie Olofsson ◽

Jeppe Hvedstrup ◽

Katrine Falkenberg ◽

Mona Ameri Chalmer ◽

Henrik Winther Schytz ◽

...

Keyword(s):

Pain Sensitivity ◽

Pain Threshold ◽

Case Control Study ◽

Cold Pressor Test ◽

Case Control ◽

Pain Tolerance ◽

Cold Pain ◽

Primary Headache Disorders ◽

Heat Pain Threshold ◽

Control Study

Abstract Background Headache affects 90–99% of the population. Based on the question “Do you think that you never ever in your whole life have had a headache?” 4% of the population say that they have never experienced a headache. The rarity of never having had a headache suggests that distinct biological and environmental factors may be at play. We hypothesized that people who have never experienced a headache had a lower general pain sensitivity than controls. Methods We included 99 male participants, 47 headache free participants and 52 controls, in an observer blinded nested case-control study. We investigated cold pain threshold and heat pain threshold using a standardized quantitative sensory testing protocol, pericranial tenderness with total tenderness score and pain tolerance with the cold pressor test. Differences between the two groups were assessed with the unpaired Student’s t-test or Mann-Whitney U test as appropriate. Results There was no difference in age, weight or mean arterial pressure between headache free participants and controls. We found no difference in pain detection threshold, pericranial tenderness or pain tolerance between headache free participants and controls. Conclusion Our study clearly shows that freedom from headache is not caused by a lower general pain sensitivity. The results support the hypothesis that headache is caused by specific mechanisms, which are present in the primary headache disorders, rather than by a decreased general sensitivity to painful stimuli. Trial registration Registered at ClinicalTrials.gov (NCT04217616), 3rd January 2020, retrospectively registered.

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The Added Value of Sensitivity to Nonnoxious Stimuli to Predict an Individual’s Sensitivity to Pain

January 2018 - Pain Physician ◽

10.36076/ppj.2021.24.e783 ◽

2021 ◽

Vol 24 (6) ◽

pp. E783-E794

Keyword(s):

Postoperative Pain ◽

Healthy Volunteers ◽

Pain Score ◽

Pain Sensitivity ◽

Pain Catastrophizing ◽

Light Sensitivity ◽

Heat Pain ◽

Cold Pain ◽

Eye Color ◽

Anxiety Depression

BACKGROUND: Simple tools are needed to predict postoperative pain. Questionnaire-based tools such as the Pain Sensitivity Questionnaire (PSQ) are validated for this purpose, but prediction could be improved by incorporating other parameters. OBJECTIVES: To explore the potency of sensitivity to nonpainful stimuli and biometric data to improve prediction of pain. STUDY DESIGN: Transversal exploratory study. SETTING: Single clinical investigation center. METHODS. Eighty-five healthy volunteers of both genders underwent a multimodal exploration including biometry, questionnaire-based assessment of anxiety, depression, pain catastrophizing, sensitivity to smell, and the PSQ, followed by a psychophysical assessment of unpleasantness thresholds for light and sound, and sensitivity to mechanical, heat, and cold pain. These last 3 parameters were used to calculate a composite pain score. After a multi-step selection, multivariable analyses identified the explanative factors of experimental pain sensitivity, by including biometric, questionnaire-based, and psychophysical nonnociceptive sensitivity parameters, with the aim of having each domain represented. RESULTS: Female gender predicted mechanical pain, a younger age and dark eyes predicted cold pain, and the PSQ predicted heat pain. Sensitivity to unpleasantness of sound predicted mechanical and heat pain, and sensitivity to unpleasantness of light predicted cold pain. Sensitivity to smell was unrelated. The predictors of the composite pain score were the PSQ, the light unpleasantness threshold, and an interaction between gender and eye color, the score being lower in light-eyed men and higher in all women. The final multivariable multi-domain model was more predictive of pain than the PSQ alone (R2 = 0.301 vs 0.122, respectively). LIMITATIONS: Sensitivity to smell was only assessed by a short questionnaire and could lack relevance. Healthy volunteers were unlikely to elicit psychological risk factors such as anxiety, depression, or catastrophizing. These results have not been validated in a clinical setting (e.g., perioperative). CONCLUSION: The predictive potential of the PSQ can be improved by including information about gender, eye color, and light sensitivity. However, there is still a need for a technique suitable for routine clinical use to assess light sensitivity. KEY WORDS: Personalized medicine, postoperative pain, senses, prediction, photophobia, hyperacusis, eye color, hypervigilance, sensory over-responsivity

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