Preferential activation of small cutaneous fibers through small pin electrode also depends on the shape of a long duration electrical current

Rosa Hugosdottir, Carsten Dahl Mørch, Ole Kæseler Andersen, Thordur Helgason, Lars Arendt-Nielsen

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

7 Downloads (Pure)

Resumé

BACKGROUND: Electrical stimulation is widely used in experimental pain research but it lacks selectivity towards small nociceptive fibers. When using standard surface patch electrodes and rectangular pulses, large fibers are activated at a lower threshold than small fibers. Pin electrodes have been designed for overcoming this problem by providing a higher current density in the upper epidermis where the small nociceptive fibers mainly terminate. At perception threshold level, pin electrode stimuli are rather selectively activating small nerve fibers and are perceived as painful, but for high current intensity, which is usually needed to evoke sufficient pain levels, large fibers are likely co-activated. Long duration current has been shown to elevate the threshold of large fibers by the mechanism of accommodation. However, it remains unclear whether the mechanism of accommodation in large fibers can be utilized to activate small fibers even more selectively by combining pin electrode stimulation with a long duration pulse.

RESULTS: In this study, perception thresholds were determined for a patch- and a pin electrode for different pulse shapes of long duration. The perception threshold ratio between the two different electrodes was calculated to estimate the ability of the pulse shapes to preferentially activate small fibers. The perception threshold ratios were compared between stimulation pulses of 5- and 50 ms durations and shapes of: exponential increase, linear increase, bounded exponential, and rectangular. Qualitative pain perception was evaluated for all pulse shapes delivered at 10 times perception threshold. The results showed a higher perception threshold ratio for long duration 50 ms pulses than for 5 ms pulses. The highest perception threshold ratio was found for the 50 ms, bounded exponential pulse shape. Results furthermore revealed different strength-duration relation between the bounded exponential- and rectangular pulse shapes. Pin electrode stimulation at high intensity was mainly described as "stabbing", "shooting", and "sharp".

CONCLUSION: These results indicate that long duration pulses with a bounded exponential increase preferentially activate the small nociceptive fibers with a pin electrode and concurrently cause elevated threshold of large non-nociceptive fibers with patch electrodes.

OriginalsprogEngelsk
Artikelnummer48
TidsskriftBMC Neuroscience
Vol/bind20
Udgave nummer1
Antal sider11
ISSN1471-2202
DOI
StatusUdgivet - 14 sep. 2019

Fingerprint

Electrodes
Skin
Time Perception
Pain
Pain Perception
Aptitude
Nerve Fibers
Epidermis
Electric Stimulation
Research

Citer dette

@article{36ab15a8f90146099429dd555efa83fd,
title = "Preferential activation of small cutaneous fibers through small pin electrode also depends on the shape of a long duration electrical current",
abstract = "BACKGROUND: Electrical stimulation is widely used in experimental pain research but it lacks selectivity towards small nociceptive fibers. When using standard surface patch electrodes and rectangular pulses, large fibers are activated at a lower threshold than small fibers. Pin electrodes have been designed for overcoming this problem by providing a higher current density in the upper epidermis where the small nociceptive fibers mainly terminate. At perception threshold level, pin electrode stimuli are rather selectively activating small nerve fibers and are perceived as painful, but for high current intensity, which is usually needed to evoke sufficient pain levels, large fibers are likely co-activated. Long duration current has been shown to elevate the threshold of large fibers by the mechanism of accommodation. However, it remains unclear whether the mechanism of accommodation in large fibers can be utilized to activate small fibers even more selectively by combining pin electrode stimulation with a long duration pulse.RESULTS: In this study, perception thresholds were determined for a patch- and a pin electrode for different pulse shapes of long duration. The perception threshold ratio between the two different electrodes was calculated to estimate the ability of the pulse shapes to preferentially activate small fibers. The perception threshold ratios were compared between stimulation pulses of 5- and 50 ms durations and shapes of: exponential increase, linear increase, bounded exponential, and rectangular. Qualitative pain perception was evaluated for all pulse shapes delivered at 10 times perception threshold. The results showed a higher perception threshold ratio for long duration 50 ms pulses than for 5 ms pulses. The highest perception threshold ratio was found for the 50 ms, bounded exponential pulse shape. Results furthermore revealed different strength-duration relation between the bounded exponential- and rectangular pulse shapes. Pin electrode stimulation at high intensity was mainly described as {"}stabbing{"}, {"}shooting{"}, and {"}sharp{"}.CONCLUSION: These results indicate that long duration pulses with a bounded exponential increase preferentially activate the small nociceptive fibers with a pin electrode and concurrently cause elevated threshold of large non-nociceptive fibers with patch electrodes.",
keywords = "Electrical pulse shapes, Electrical stimulation, Large fiber accommodation, Patch electrode, Pin electrode, Small fiber activation",
author = "Rosa Hugosdottir and M{\o}rch, {Carsten Dahl} and Andersen, {Ole K{\ae}seler} and Thordur Helgason and Lars Arendt-Nielsen",
year = "2019",
month = "9",
day = "14",
doi = "10.1186/s12868-019-0530-8",
language = "English",
volume = "20",
journal = "B M C Neuroscience",
issn = "1471-2202",
publisher = "BioMed Central",
number = "1",

}

Preferential activation of small cutaneous fibers through small pin electrode also depends on the shape of a long duration electrical current. / Hugosdottir, Rosa; Mørch, Carsten Dahl; Andersen, Ole Kæseler; Helgason, Thordur; Arendt-Nielsen, Lars.

I: BMC Neuroscience, Bind 20, Nr. 1, 48, 14.09.2019.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Preferential activation of small cutaneous fibers through small pin electrode also depends on the shape of a long duration electrical current

AU - Hugosdottir, Rosa

AU - Mørch, Carsten Dahl

AU - Andersen, Ole Kæseler

AU - Helgason, Thordur

AU - Arendt-Nielsen, Lars

PY - 2019/9/14

Y1 - 2019/9/14

N2 - BACKGROUND: Electrical stimulation is widely used in experimental pain research but it lacks selectivity towards small nociceptive fibers. When using standard surface patch electrodes and rectangular pulses, large fibers are activated at a lower threshold than small fibers. Pin electrodes have been designed for overcoming this problem by providing a higher current density in the upper epidermis where the small nociceptive fibers mainly terminate. At perception threshold level, pin electrode stimuli are rather selectively activating small nerve fibers and are perceived as painful, but for high current intensity, which is usually needed to evoke sufficient pain levels, large fibers are likely co-activated. Long duration current has been shown to elevate the threshold of large fibers by the mechanism of accommodation. However, it remains unclear whether the mechanism of accommodation in large fibers can be utilized to activate small fibers even more selectively by combining pin electrode stimulation with a long duration pulse.RESULTS: In this study, perception thresholds were determined for a patch- and a pin electrode for different pulse shapes of long duration. The perception threshold ratio between the two different electrodes was calculated to estimate the ability of the pulse shapes to preferentially activate small fibers. The perception threshold ratios were compared between stimulation pulses of 5- and 50 ms durations and shapes of: exponential increase, linear increase, bounded exponential, and rectangular. Qualitative pain perception was evaluated for all pulse shapes delivered at 10 times perception threshold. The results showed a higher perception threshold ratio for long duration 50 ms pulses than for 5 ms pulses. The highest perception threshold ratio was found for the 50 ms, bounded exponential pulse shape. Results furthermore revealed different strength-duration relation between the bounded exponential- and rectangular pulse shapes. Pin electrode stimulation at high intensity was mainly described as "stabbing", "shooting", and "sharp".CONCLUSION: These results indicate that long duration pulses with a bounded exponential increase preferentially activate the small nociceptive fibers with a pin electrode and concurrently cause elevated threshold of large non-nociceptive fibers with patch electrodes.

AB - BACKGROUND: Electrical stimulation is widely used in experimental pain research but it lacks selectivity towards small nociceptive fibers. When using standard surface patch electrodes and rectangular pulses, large fibers are activated at a lower threshold than small fibers. Pin electrodes have been designed for overcoming this problem by providing a higher current density in the upper epidermis where the small nociceptive fibers mainly terminate. At perception threshold level, pin electrode stimuli are rather selectively activating small nerve fibers and are perceived as painful, but for high current intensity, which is usually needed to evoke sufficient pain levels, large fibers are likely co-activated. Long duration current has been shown to elevate the threshold of large fibers by the mechanism of accommodation. However, it remains unclear whether the mechanism of accommodation in large fibers can be utilized to activate small fibers even more selectively by combining pin electrode stimulation with a long duration pulse.RESULTS: In this study, perception thresholds were determined for a patch- and a pin electrode for different pulse shapes of long duration. The perception threshold ratio between the two different electrodes was calculated to estimate the ability of the pulse shapes to preferentially activate small fibers. The perception threshold ratios were compared between stimulation pulses of 5- and 50 ms durations and shapes of: exponential increase, linear increase, bounded exponential, and rectangular. Qualitative pain perception was evaluated for all pulse shapes delivered at 10 times perception threshold. The results showed a higher perception threshold ratio for long duration 50 ms pulses than for 5 ms pulses. The highest perception threshold ratio was found for the 50 ms, bounded exponential pulse shape. Results furthermore revealed different strength-duration relation between the bounded exponential- and rectangular pulse shapes. Pin electrode stimulation at high intensity was mainly described as "stabbing", "shooting", and "sharp".CONCLUSION: These results indicate that long duration pulses with a bounded exponential increase preferentially activate the small nociceptive fibers with a pin electrode and concurrently cause elevated threshold of large non-nociceptive fibers with patch electrodes.

KW - Electrical pulse shapes

KW - Electrical stimulation

KW - Large fiber accommodation

KW - Patch electrode

KW - Pin electrode

KW - Small fiber activation

UR - http://www.scopus.com/inward/record.url?scp=85072199844&partnerID=8YFLogxK

U2 - 10.1186/s12868-019-0530-8

DO - 10.1186/s12868-019-0530-8

M3 - Journal article

C2 - 31521103

VL - 20

JO - B M C Neuroscience

JF - B M C Neuroscience

SN - 1471-2202

IS - 1

M1 - 48

ER -