Effects of thermosensory aging well demonstrated by cold stimulations with high temporal resolution

Introduction: The method of limits (MLi) is the most commonly used paradigm to measure the threshold of thermal stimuli. However, the threshold measured by MLi is dependent on reaction time (RT). Because RT in adults increases with age, the inclusion of RT in the MLi paradigm may result in an overestimation of thermal threshold in the older individuals. Methods: A device with a very rapid cooling rate (300 degrees C/s) was employed to measure cool thresholds by using the method of levels (MLe), a method independent of RT, in 11 older patients and 14 younger adults. Results: Compared with the MLi, the MLe resulted in a greater than 2 degrees C gain in threshold measurement accuracy in older patients. Discussion: The MLe confirmed that cool perception threshold is dependent on age. The use of MLe provides new opportunities for the study of mechanisms underlying age-associated alterations in thermal perception. Muscle Nerve 60: 141-146, 2019