Ipsi- and Contralateral Hypoesthesia
Conditions
Brief summary
Main of the present study was to develop a model of concomitant C-fibre block and sensitization eliciting spontaneous pain as well applying topical capsaicin and local anesthetics (LA) to examine the sensory alterations after combined C-fiber block and sensitization in both different application orders (sensitization of blocked C-fibers and block of sensitized C-fibers), compared to each of both mechanisms alone. Thereby, we expect stronger sensory changes during the combined substance application than during the monoapplication. We expect also contralateral sensory alterations mirroring the changes on the intervention site after the combined capsaicin and LA application, being stronger than after sensitization alone absent after C-fiber block alone.
Interventions
PROCEDUREApplication of capsaicin 0.6%
topical application of 0.6% capsaicin on the volar forearm
PROCEDUREApplication of local anesthetics (EMLA plaster)
topical application of EMLA on the volar forearm
PROCEDUREApplication of 1 capsaicin 0.6% and 2. EMLA
topical application of 1. 0.6% capsaicin and 2. EMLA on the volar forearm
PROCEDUREApplication of 1. EMLA and 2. capsaicin 0.6%
topical application of 1. EMLA and 2. 0.6% capsaicin on the volar forearm
Sponsors
Ruhr University of Bochum
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 90 Years
Healthy volunteers
Yes
Inclusion criteria
* healthy subject, older than 18 years, provided written informed consent
Exclusion criteria
* insufficient comprehension of the German language, history of severe internal, neurological or dermatological diseases, substance abuse, manifest psychiatric diseases, chronic and acute pain, any medication intake (except contraceptives in females) regularly or on demand during the last 14 days before study inclusion and during the study period, hypersensitivity to lidocaine or other amide-type anesthetics, hereditary or acquired methemoglobinemia, pregnancy, nursing, abnormal sensory profile in the quantitative sensory testing (QST) with side-to-side differences beyond the normal range at baseline and participation in clinical trials during the last month.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| grade of the ipsi- and contralateral hypoesthesia | 6 months |
Secondary
| Measure | Time frame |
|---|---|
| area of the ipsi- and contralateral hypoesthesia | 6 months |
Countries
Germany
Outcome results
None listed