Abstract
Contact heat evoked potentials (CHEPs) have become an acknowledged research tool in the assessment of the integrity of the nociceptive system and gained importance in the diagnostic work-up of patients with suspected small fiber neuropathy. For the latter, normative values for CHEP amplitude and latency are indispensable for a clinically meaningful interpretation of the results gathered in patients. To this end, CHEPs were recorded in 100 healthy subjects over a wide age range (20–80 years) and from three different dermatomes of the lower extremities (L2, L5, and S2). A normal baseline (35–52 °C) and increased baseline stimulation (42–52 °C) were applied. Statistical analysis revealed significant effects of stimulation site, stimulation intensity, and sex on CHEP parameters (N2 latency, N2P2 amplitude, and NRS). Significant positive correlations of body height with N2 latency, and pain ratings with N2P2 amplitudes were observed. This is the first time that normative values have been obtained from multiple dermatomes of the lower extremities. The present dataset will facilitate the clinical application of CHEPs in the neurophysiological diagnosis of small fiber neuropathy and by discerning pathological findings help establish a proximal-distal gradient of nerve degeneration in polyneuropathies.
Highlights
Contact heat stimulation activates small diameter A-delta and C fiber nociceptors within the epidermis[1,2]
We demonstrated the superiority of the increased baseline (IB) protocol (42–52 °C) for the acquisition of Contact heat evoked potentials (CHEPs) from lower extremities with higher signal persistence[12]
As small fiber neuropathies often present in a distal-symmetrical fashion owing to a length-dependency of fiber degeneration[19], normative values from proximal and distal sites are needed in order to establish a neurophysiological gradient
Summary
Contact heat stimulation activates small diameter A-delta and C fiber nociceptors within the epidermis[1,2]. While several studies have reported normative values of CHEPs from the upper extremities[11,13,14,15], few have addressed the lower extremity[12]. The availability of such normative data may help close an important diagnostic gap in increasingly prevalent conditions, such as small fiber neuropathies[16]. The study protocol only included one site from the lower extremities, precluding its use for the assessment of length-dependency in polyneuropathies. As small fiber neuropathies often present in a distal-symmetrical fashion owing to a length-dependency of fiber degeneration[19], normative values from proximal and distal sites are needed in order to establish a neurophysiological gradient
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
