Thermal quantitative sensory testing: a study of 101 control subjects

Abstract

Quantitative sensory testing is useful for the diagnosis, confirmation and monitoring of small fibre neuropathies. Normative data have been reported but differences in methodology, lack of age-specific values and graphical presentation of data make much of these data difficult to apply in a clinical setting. We have collected normative age-specific thermal threshold data for use in a clinical setting and clarified other factors influencing reference values, including the individual machine or operator. Thermal threshold studies were performed on 101 healthy volunteers (21-70 years old) using one of two Medoc Thermal Sensory Analyser II machines (Medoc, Ramat Yishai, Israel) with a number of operators. A further study was performed on 10 healthy volunteers using both machines and one operator at least 3 weeks apart. Thermal threshold detection increases with age and is different for different body regions. There is no significant difference seen in results between machines of the same make and model; however, different operators may influence results. Normative data for thermal thresholds should be applied using only age- and region-specific values and all operators should be trained and strictly adhere to standard protocols. To our knowledge, this is the largest published collection of normal controls for thermal threshold testing presented with regression data which can easily be used in the clinical setting.

Keywords: Marstock method of limits; Quantitative sensory testing; Small fibre neuropathy; Thermal threshold; Variability.