Clinical Use of Cold and Contact Heat-evoked Potentials: Normative Values

Population sample of 80 healthy volunteers between 26 and 75 years old will be recruited and will be categorized into 5 age subgroups (26-35, 36-45, 46-55, 56-65, 66-75 years old). Upon arrival, participants will be reminded of the aims and of the content of the experiment. After informed consent (recorded in writing), healthy subjects will be screened with a baseline examination: 1. brief neurological examination 2. sensory nerve conduction study-related 3. quantitative sensory testing If the baseline examination screening is considered normal, CEPs and CHEPs will be performed. To avoid bias, the side and order of the tests will be randomized. All thermal stimuli for CEPs and CHEPs will be delivered delivered using a contact thermal stimulator (TCS model II.1, QST.Lab, Strasbourg, France). Only stimuli that are safe and acceptable for the subject will be used in the study, and all experimental procedures can be interrupted at any time by the participant, with no detrimental effect.