Non-invasive Investigation of Excitability Changes in the Human Spinal Cord: the Effect of Transcutaneous Spinal Direct Current Stimulation (tsDCS) on Nociceptive Flexion Reflexes
Overview
- Phase
- N/A
- Intervention
- Not specified
- Conditions
- Pain
- Sponsor
- Max Planck Research Group Pain Perception
- Enrollment
- 40
- Locations
- 1
- Primary Endpoint
- Change in pain intensity rating
- Status
- Enrolling by Invitation
- Last Updated
- 3 years ago
Overview
Brief Summary
The aims of this study are threefold. First, to investigate whether spinal nociceptive processing - represented here by the nociceptive flexion reflex (NFR) - is influenced by thoracic transcutaneous spinal direct current stimulation (tsDCS) in a spatially selective manner, i.e., whether effects are only observed for lower limb NFRs, but not for upper limb NFRs. Second, to investigate - in a double-blind, sham-controlled, within-participant design - whether anodal and cathodal tsDCS do affect the NFR in a polarity-dependent manner. Third, to investigate whether tsDCS effects observed on a spinal measure (NFR) are also observed in responses that are mediated supra-spinally, namely autonomic parameters and pain intensity ratings.
Investigators
Eligibility Criteria
Inclusion Criteria
- •Healthy volunteers between the ages of 18 and 40 years
- •Having participated in the MRI medical assessment session and consented to taking part in 3T MRI measurements in written form
- •Having participated in the magnetic/electric neurostimulation medical assessment session and consented to taking part in magnetic/electric neurostimulation experiments in written form
- •Voluntary participation and signing of the study-specific consent form
Exclusion Criteria
- •Existence of any contraindications for MRI measurements and magnetic/electric neurostimulation experiments
- •Pregnancy or breastfeeding
- •Very dry or sensitive skin (e.g., intolerance to creams/shampoos)
- •Chronic skin diseases - such as eczema or neurodermatitis - in the area of somatosensory / nociceptive stimulation (arm or hand, leg or foot) or electrophysiological data recording (upper body, arm, leg)
- •Scar tissue in the area of somatosensory / nociceptive stimulation (arm or hand, leg or foot) or electrophysiological data recording (upper body, arm, leg)
- •Acute sunburn in the area of somatosensory / nociceptive stimulation (arm or hand, leg or foot) or electrophysiological data recording (upper body, arm, leg)
- •Current or recurring pain
- •Injuries to the nervous system
- •History of or current neurological or psychiatric disorders
- •Chronic diseases that require permanent medication (e.g., asthma, diabetes mellitus, etc.)
Outcomes
Primary Outcomes
Change in pain intensity rating
Time Frame: Baseline and immediately after the intervention
One rating per trial on a standard visual analogue scale (VAS); internally numbered from 0 (no sensation) to 100 (unbearable pain)
Change in skin conductance response
Time Frame: Baseline and immediately after the intervention
Amplitude maximum before onset of pain rating
Change in NFR amplitude
Time Frame: Baseline and immediately after the intervention
90-150ms for lower limb, 60-200ms for upper limb
Change in heart period acceleration
Time Frame: Baseline and immediately after the intervention
Amplitude maximum before onset of pain rating
Secondary Outcomes
- Change in NFR area(Baseline and immediately after the intervention)