Mechanisms of Affective Touch in Chronic Pain

Not Applicable

Completed

Conditions: Fibromyalgia

Registration Number: NCT04206397

Lead Sponsor: Laura Case

Brief Summary: This study compares how different types of touch found in massage therapies impact pain perception, and whether these effects differ in individuals with and without chronic pain. This study also examines psychological factors that may predict differences in touch perception in individuals with chronic pain. This research will improve our understanding of whether and how massage therapies can benefit pain and health, and whether this differs in people who suffer from chronic pain.

Detailed Description: Not available

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 80

Inclusion Criteria

ages 18-65
fluent in English
physician diagnosis of Fibromyalgia but no other chronic pain conditions (patients) or no evidence of chronic pain (healthy volunteers)

Exclusion Criteria

Sensory, motor, or anatomic differences or injuries relevant to study procedures
Known anomalies of the central nervous system (including stroke, dementia, aneurysm, or personal history of psychosis)
Pregnancy
Inability to rate pain or sensations
Major medical conditions such as kidney, liver, cardiovascular (hypertension, preexisting cardiac arrhythmia), autonomic, pulmonary, or neurological problems (e.g., seizure disorder) or a chronic systemic disease (e.g., diabetes).
History of blood clots or first-degree family members with clotting disorders
Current use of opiate medication(s)
Contraindications to MRI if participating in pilot MRI study
Unable to identify a heat stimulus 50C or lower that generates a rating of a 7 on our VAS scale
History of fainting or seizures
History of frostbite
Open cut or sore on hand to be immersed in cold water bath
Fracture of limb to be immersed
History of Reynaud's phenomenon (hands get white, then blue on exposure to cold, then red on warming)

Study & Design

Study Type: INTERVENTIONAL

Study Design: SINGLE_GROUP

Primary Outcome Measures

Name	Time	Method
Ratings of Affective Touch	Day 1	Touch pleasantness/unpleasantness ratings will be assessed in response to each sensory stimulus (brushing, tapping, and pressure) using a Visual Analog Scale. Anchors were defined as far left = 'extremely unpleasant' (coded as -100), midpoint = 'neutral' (coded as 0), and far right = 'extremely pleasant' (coded as 100). Affective touch perception is defined as the difference in ratings between the affective and neutral touch conditions (rating of brushing minus rating of tapping) during the Day 1 baseline and will be compared between individuals with and without chronic pain. This value ranged from 200 (brushing extremely pleasant and tapping extremely unpleasant) to -200 (tapping extremely pleasant and brushing extremely unpleasant). These values are not inherently 'better' or 'worse' but represent individual differences in preference for affective touch.
Change in Heat Pain Intensity From Before to After the Cold Water Bath	Day 1	Pain intensity will be measured before and after the left hand is submerged in cold water (conditioned pain modulation task). Pain intensity will be assessed with a Visual Analog Scale. Anchors are defined as far left = 'no sensation' (coded as -100), midpoint = 'pain threshold' (coded as 0), and far right = 'intolerable pain' (coded as 100). Change in heat pain ratings after cold water bath ranges from -200 to 200 where higher scores indicate pain increases after cold water bath (worse) and lower scores indicate pain reduction (better).
Change in Heat Pain Intensity From Before to After Gentle Brushing	Day 2	Pain intensity will be measured before and after gentle brushing (affective-touch-pain task) on a Visual Analog Scale. Anchors are defined as far left = 'no sensation' (coded as -100), midpoint = 'pain threshold' (coded as 0), and far right = 'intolerable pain' (coded as 100). Change in heat pain ratings after brushing ranges from -200 to 200 where higher scores indicate pain increases (worse) and lower scores indicate pain reduction (better).
Chronic Pain Intensity Using the Chronic Pain Grade Questionnaire	Day 1	The investigators will measure chronic pain levels using the Characteristic Pain Intensity score, a subscale of the Chronic Pain Grade Questionnaire (CPGQ). The questions that contribute to the subscale each use a scale from 0-10 where 0 is 'no pain' and 10 is 'pain as bad could be', and their mean is multiplied by 10. The intensity subscale score thus ranges from 0 to 100, where 0 would be least pain reported and 100 would be the most pain reported. This measure will be included in a linear regression model to determine whether this measure significantly predicts differences in ratings of touch pleasantness.
Trauma History Using the Childhood Trauma Questionnaire	Day 1	The investigators will measure trauma history using the Childhood Trauma Questionnaire. The total score ranges from 25-125, where 25 is the least childhood trauma (better) and 125 is the greatest childhood trauma (worse). This measure will be included in a linear regression model to determine whether this measure significantly predicts differences in ratings of touch pleasantness.
Current Depression Using the Hospital Anxiety and Depression Scale Without Chronic Pain	Day 1	The investigators will measure current depression using the Hospital Anxiety and Depression Scale (HADS). The HADS consists of two sub scales for depression and anxiety. The depression sub scale ranges from 0 - 21 where 0 indicates no depression (better) and 21 indicates highest depression levels (worse). This measure will be included in a linear regression model to determine whether this measure significantly predicts differences in ratings of touch pleasantness.