Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT05440266 |
| Other study ID # |
2022-00682; am22Schneider2 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
May 20, 2022 |
| Est. completion date |
November 25, 2022 |
Study information
| Verified date |
November 2023 |
| Source |
University Hospital, Basel, Switzerland |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
This exploratory study is to improve an established pain model by a new stimulation profile
that allows preferential activation of C fibers that are of main clinical interest in chronic
pain and also to generate a stable secondary hyperalgesia, which is of particular interest in
the actual research of acute and chronic pain. It is to investigate if the specific
activation of afferent sensory fibers and expected lower current intensities makes it more
comfortable for the participant as motor neuron activation is much less pronounced at low
current intensities. Therefore it compares the area under the curve (AUC) of hyperalgesia
during electrical, intracutaneous 25 ms half-sine wave stimulation at a pain level of the
numeric rating scale (NRS) of 6 out of 10 for 65 minutes compared to 500 µs rectangular
pulses.
Description:
Nociceptors in the epidermis are responsible for peripheral pain perception. Mechanical,
thermal as well as chemical stimuli can trigger action potentials in nociceptors and thereby
pain. Regarding pain, polymodal and "silent" C-fibers are of special interest. Slower
depolarisation via sine and half-sine currents preferentially stimulate C-fibers compared to
rectangular shaped currents. This study is to compare the development of central
sensitization comparing the half-sine wave and the rectangular stimulation, hypothesizing
that preferential C fiber stimulation through half-sine currents facilitate the development
of secondary hyperalgesia.
This exploratory study is to improve an established pain model by a new stimulation profile
that allows preferential activation of C fibers that are of main clinical interest in chronic
pain and also to generate a stable secondary hyperalgesia, which is of particular interest in
the actual research of acute and chronic pain. It is to investigate if the specific
activation of afferent sensory fibers and expected lower current intensities makes it more
comfortable for the participant as motor neuron activation is much less pronounced at low
current intensities. Therefore it compares the area under the curve (AUC) of hyperalgesia
during electrical, intracutaneous 25 ms half-sine wave stimulation at a pain level of the
numeric rating scale (NRS) of 6 out of 10 for 65 minutes compared to 500 µs rectangular
pulses.
Every volunteer will have two appointments. There will be a "washout" period of at least two
weeks between the two appointments. On each day two microdialysis catheters containing
internally a stainless steel wire will be inserted intracutaneously on the volar surface of
the adominant forearm for a length of approximately 10 mm and at a distance of 5 mm. Before
insertion, the catheters are filled with 0.9% saline and after insertion a continuous flow of
0.4 μl/min will be ensured by a syringe pump (Perfusor®) to facilitate conduction and to
protect the tissue from potential local pH changes by the direct current. Alternating
polarity of the both pulses is used to ensure charge-balanced stimulation.
It is randomly assigned which current form is applied on the first and on the second trial.
Subsequently, the stainless steel wire serving as electrodes of the current generator (for 25
ms half-sine stimulation the Digitimer DS5; Digitimer Ltd, Hertfordshire, United Kingdom; and
for 500 µs rectangular stimulation the Digitimer DS7A; Digitimer Ltd, Hertfordshire, United
Kingdom) are connected. The rectangular pulses are generated by the Digitimer DS7A, which
works in combination with a pulse generator (PG 1, Rimkus Medizintechnik, Parsdorf, Germany)
