TY - JOUR
T1 - The test–retest reliability of large and small fiber nerve excitability testing with threshold tracking
AU - Pia, Hossein
AU - Nochi, Zahra
AU - Kristensen, Alexander Gramm
AU - Pelz, Bernhard
AU - Goetz, Marcus
AU - Hoeink, Jan Niclas
AU - Blockeel, Anthony James
AU - Mouraux, André
AU - Truini, Andrea
AU - Finnerup, Nanna Brix
AU - Phillips, Keith Geoffrey
AU - Treede, Rolf Detlef
AU - Tankisi, Hatice
N1 - Publisher Copyright:
© 2023 International Federation of Clinical Neurophysiology
PY - 2023
Y1 - 2023
N2 - Objective: Standard nerve excitability testing (NET) predominantly assesses Aα- and Aβ-fiber function, but a method examining small afferents would be of great interest in pain studies. Here, we examined the properties of a novel perception threshold tracking (PTT) method that preferentially activates Aδ-fibers using weak currents delivered by a novel multipin electrode and compared its reliability with NET. Methods: Eighteen healthy subjects (mean age:34.06 ± 2.0) were examined three times with motor and sensory NET and PTT in morning and afternoon sessions on the same day (intra-day reliability) and after a week (inter-day reliability). NET was performed on the median nerve, while PTT stimuli were delivered through a multipin electrode located on the forearm. During PTT, subjects indicated stimulus perception via a button press and the intensity of the current was automatically increased or decreased accordingly by Qtrac software. This allowed changes in the perception threshold to be tracked during strength-duration time constant (SDTC) and threshold electrotonus protocols. Results: The coefficient of variation (CoV) and interclass coefficient of variation (ICC) showed good–excellent reliability for most NET parameters. PTT showed poor reliability for both SDTC and threshold electrotonus parameters. There was a significant correlation between large (sensory NET) and small (PTT) fiber SDTC when all sessions were pooled (r = 0.29, p = 0.03). Conclusions: Threshold tracking technique can be applied directly to small fibers via a psychophysical readout, but with the current technique, the reliability is poor. Significance: Further studies are needed to examine whether Aβ-fiber SDTC may be a surrogate biomarker for peripheral nociceptive signalling.
AB - Objective: Standard nerve excitability testing (NET) predominantly assesses Aα- and Aβ-fiber function, but a method examining small afferents would be of great interest in pain studies. Here, we examined the properties of a novel perception threshold tracking (PTT) method that preferentially activates Aδ-fibers using weak currents delivered by a novel multipin electrode and compared its reliability with NET. Methods: Eighteen healthy subjects (mean age:34.06 ± 2.0) were examined three times with motor and sensory NET and PTT in morning and afternoon sessions on the same day (intra-day reliability) and after a week (inter-day reliability). NET was performed on the median nerve, while PTT stimuli were delivered through a multipin electrode located on the forearm. During PTT, subjects indicated stimulus perception via a button press and the intensity of the current was automatically increased or decreased accordingly by Qtrac software. This allowed changes in the perception threshold to be tracked during strength-duration time constant (SDTC) and threshold electrotonus protocols. Results: The coefficient of variation (CoV) and interclass coefficient of variation (ICC) showed good–excellent reliability for most NET parameters. PTT showed poor reliability for both SDTC and threshold electrotonus parameters. There was a significant correlation between large (sensory NET) and small (PTT) fiber SDTC when all sessions were pooled (r = 0.29, p = 0.03). Conclusions: Threshold tracking technique can be applied directly to small fibers via a psychophysical readout, but with the current technique, the reliability is poor. Significance: Further studies are needed to examine whether Aβ-fiber SDTC may be a surrogate biomarker for peripheral nociceptive signalling.
KW - Motor nerve excitability testing
KW - Pain biomarker
KW - Perception threshold tracking
KW - Sensory nerve excitability testing
KW - Test–retest reliability
UR - http://www.scopus.com/inward/record.url?scp=85153489100&partnerID=8YFLogxK
U2 - 10.1016/j.cnp.2023.03.003
DO - 10.1016/j.cnp.2023.03.003
M3 - Journal article
C2 - 37181417
AN - SCOPUS:85153489100
SN - 2467-981X
VL - 8
SP - 71
EP - 78
JO - Clinical Neurophysiology Practice
JF - Clinical Neurophysiology Practice
ER -