Healthy Subjects, Non-inflammatory Neuropathic Pain
Conditions
Keywords
Use of NGF injection as a model of non-inflammatory neuropathic pain in healthy subjects
Brief summary
Intraepidermal injection of nerve growth factor results in a non-inflammatory hyperalgesia for thermal and mechanical stimuli. This hyperalgesia is similar to the pathological ailments of patients with neuropathic pain. The mechanisms of the cognitive modulation of pain and hyperalgesia are not yet understood in this group of patients. The investigators plan to use NGF injection as a model of non-inflammatory neuropathic pain in healthy subjects to investigate the underlying neuronal mechanisms of this hyperalgesia using functional magnetic resonance imaging and resting state network analysis.
Interventions
BIOLOGICALNGF injection
single injection of NGF into the volar forearm / single injection of NaCl into the volar forearm
Sponsors
Heidelberg University
Prof Herta Flor
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
MALE
Age
18 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
* no acute or chronic disease * no acute or chronic pain * age: 18-60 years * male * no medication use
Exclusion criteria
* metallic parts in the body * claustrophobia * drug or substance abuse
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Changes in activation of the pain processing and resting state networks | baseline to one week | Activation of the resting state network (using functional magnetic resonance imaging (fMRI) and a standard echo planar imaging (EPI) sequence) as well as acitvation of the pain processing network (using fMRI and a standard EPI sequence) in response to painful stimulation, will be measured before and after injection of NGF into the volar forearm of the participant. Particants are measured 0-4 days before injection (baseline) and then again 4-7 days after injection (to measure changes due to NGF injection). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Changes in pain intensity, unpleasentness and suffering ratings | baseline to one week | Pain will be applied by using impact stimulation to the side where NGF was injected as well as a control side. Pain and tolerance thresholds as well as 3 ratings of intensity/unpleasantness and suffering will be obtained immediately after stimulation. This will take place before NGF injection (baseline, 0-4 days) and after NGF injection (4-7 days). Ratings will be conducted on visual analog scale from 0 (no pain/unpleasantess/suffering) to 100 (worst pain/unpleasantness/suffering imaginable). |
Countries
Germany
Outcome results
None listed