There has been a significant increase over recent years in the use of contact heat evoked potentials (CHEPs) for the evaluation of small nerve fiber function. Measuring CHEP amplitude and latency has clinical utility for the diagnosis and assessment of conditions with neuropathic pain. This international multicenter study aimed to provide reference values for CHEPs to stimuli at 5 commonly examined body sites. Contact heat evoked potentials were recorded from 226 subjects (114 females), distributed per age decade between 20 and 79 years. Temperature stimuli were delivered by a thermode (32°C-51°C at a rate of 70°C/s). In phase I of the study, we investigated side-to-side differences and reported the maximum normal side-to-side difference in Aδ CHEP peak latency and amplitude for leg, forearm, and face. In phase II, we obtained normative data for 3 CHEP parameters (N2P2 amplitude, N2 latency, and P2 latency), stratified for gender and age decades from face, upper and lower limbs, and overlying cervical and lumbar spine. In general, larger CHEP amplitudes were associated with higher evoked pain scores. Females had CHEPs of larger amplitude and shorter latency than males. This substantive data set of normative values will facilitate the clinical use of CHEPs as a rapid, noninvasive, and objective technique for the assessment of patients presenting with neuropathic pain.
Supplemental Digital Content is Available in the Text.We obtained reference data on contact heat evoked potentials (CHEPs) from healthy subjects aged 20 to 79 years from 5 centers distributed worldwide.
aClinical Neurophysiology Laboratory, Technion Medical School, Haifa, Israel
bDepartment of Neurology, Rambam Health Care Campus, Haifa, Israel
cDepartment of Neurology, Imperial College London, London, United Kingdom
dLaboratory of Brain-Immune Interaction, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan, Department of Anesthesiology and Intensive Care, Osaka, Japan
eDepartment of Neurology, Universidade Federal Fluminense, Rio de Janeiro, Brazil
fDepartment of Neurology, Mayo Clinic, Scottsdale, AZ, USA
gDepartment of Neurology, Hospital Clinic, Barcelona, Spain
Corresponding author. Address: EMG Unit, Neurology Department, Hospital Clínic, Villarroel, 170 Barcelona, 08036, Spain. Tel.: +34932275413; fax: +34932275783. E-mail address: firstname.lastname@example.org (J. Valls-Solé).
Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article.
Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Web site (www.painjournalonline.com).
Received July 26, 2015
Received in revised form January 06, 2016
Accepted January 11, 2016