Central Sensitisation, Pain
Conditions
Brief summary
The goal of this clinical trial is to investigate the effect of breathing on the processing of experimental pain in healthy participants. The main questions are: 1. Does breathing rate influence the spatial extent of thermally induced secondary hyperalgesia, a proxy of central sensitization? 2. Does resonance frequency breathing influence the autonomic nervous system, compared to baseline and compared to paced breathing at a natural frequency? 3. Is spinal excitability, measured using the magnitude of the nociception withdrawal reflex (NWR), affected by resonance frequency breathing, compared to paced breathing at a natural frequency? Participants: * will receive heat stimuli * 's skin's sensitivity will be tested using quantitative sensory testing tools. * will receive various instructions on the speed of their breathing * 's heart rate, respiratory rate and sweat response will be measured * will fill in questionnaires Researchers will compare the spatial extent of sensitivity resulting from application of heat stimuli during paced resonance frequency breathing compared to paced breathing at a natural frequency to see if the breathing rhythm influences central sensitization processes.
Interventions
BEHAVIORALPaced Resonance Frequency Breathing
Participants are required to pace their breathing to their pre-determined individual resonance frequency.
BEHAVIORALPaced Breathing at Natural Frequency
Participants are required to pace their breathing to their pre-determined individual breathing frequency at rest.
OTHERHeat Stimulations
Participants will undergo a heat stimulation procedure on their left and right foot (the order of which is counterbalanced across participants). During this procedure, there are 10 blocks, with an inter-stimulus interval of 30 seconds between two blocks. During a block, six 6-second heat stimulations (48 degrees) are given. Between the stimulations, the temperature quickly returns to baseline (32 degrees).
Sponsors
Balgrist University Hospital
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
1. over 18 and below 40 years of age 2. good general health 3. able to give informed consent
Exclusion criteria
1. any major medical or psychiatric condition (e.g. heart disease, diabetes, autoimmune disorders, infectious diseases, major depressive disorder), any chronic pain condition, any respiratory problems, any current acute pain at time of study 2. inability to follow study instructions, e.g. due to language problems 3. Consumption of alcohol, drugs, analgesics within the last 24 h 4. Consumption of no more than 100 mg of caffeine within the last 8 h 5. Scar tissue or generally reduced sensitivity in the designated testing site areas Additional
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Area of Hypersensitivity surrounding the primary stimulation site | 40 minutes | Before and after thermal stimulations, the sensitivity of the skin is tested using a von Frey Filament, a Pin Prick and a brush. Thermal stimulations cause hypersensitivity of the skin, resulting in an area of hypersensitivity surrounding the stimulation site. The primary outcome measure is the amount of change in the area of hypersensitivity from before to after the thermal stimulations. The measuring unit of this outcome is square centimetres. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Power in the Low-frequency Range of the Heart Rate Variability | 25 minutes | Power is measured in units of milliseconds squared (ms 2) for a the low frequency band (Hz), ranging from 0.04 - 0.15Hz |
| Root Mean Square of Successive Differences of the Heart Rate Variability | 25 minutes | The measuring unit to measure heart rate variability is the root mean square of successive differences between normal heartbeats. |
| Galvanic Skin Potential | 25 minutes | Galvanic Skin potential is taken as a reflection of electrodermal activity. The measuring unit of this outcome is microsiemens |
| Threshold and Magnitude of the Nociceptive Withdrawal Reflex | 25 minutes | The nociceptive withdrawal reflex is triggered using an supratheshold electrical stimulation at the nervus suralis leading muscle contraction in the ipsilateral biceps femoris, rectus femoris and tibialis anterior. Muscle contraction is measures in millivolt using electromyogram with recording electrodes attached to the respective muscles |
Countries
Switzerland
Contacts
Primary ContactPetra Schweinhardt, Prof. Dr. med
Outcome results
None listed