Assessing thermal sensitivity using transient heat and cold stimuli combined with a Bayesian adaptive method in a clinical setting: A proof of concept study

Abstract

Background Quantitative sensory testing of thermal detection abilities is used as a clinical tool to assess the function of pain pathways. The most common procedure to assess thermal sensitivity, the ‘method of limits’, provides a quick but rough estimate of detection thresholds. Here, we investigate the potential of evaluating not only the threshold but also the slope of the psychometric functions for cold and warm detection. Method A convenience sample of 15 patients with diabetes mellitus (DM) and 15 age‐matched healthy controls (HC) was tested. Thirty brief (100 ms) stimuli of each modality were applied to the volar wrist and foot dorsum. Cold and warm stimuli were delivered with a Peltier thermode and a temperature‐controlled CO2 laser, respectively. Stimulus intensities were dynamically selected using an adaptive Bayesian algorithm (psi method) maximizing information gain for threshold and slope estimation. ROC analyses were used to assess the ability of slopes, thresholds and the combination of both to discriminate between groups. Results Assessment of the slope and threshold of the psychometric function for thermal detection took about 10 min. The ability to detect warmth was not reduced in DM patients as compared to HC. Cold detection performance assessed using slope or threshold parameters separated DM from HC with good discriminative power. Discrimination was further increased when both parameters were used together (93% sensitivity and 87% specificity), indicating that they provide complementary information on patient status. Conclusion The psi method may be an interesting alternative to the classical method of limits for thermal QST. Significance Current QST protocols provide an incomplete and potentially biased estimate of sensory detection performance. We propose a method that estimates the slope and the threshold of the psychometric function, defining heat and cold sensory detection performance, in only a few minutes. Furthermore, we provide preliminary evidence that combining slope and threshold parameters of cold detection performance leads to a better discriminative ability than relying solely on the threshold.

Adaptation to tonic heat in healthy subjects and patients with sensory polyneuropathy

“…To improve the evaluation of sensory function in the thermoalgesic system, researchers have developed alternatives to the classical methods of levels and limits (Dyck et al, 2005; Fruhstorfer et al, 1976). One such development is the online continuous recording of the perceived sensation during a relatively long‐lasting static or dynamic temperature stimuli, as in the so‐called dynamic thermotest (Medici et al, 2013), the tonic heat pain paradigms (Naert et al, 2008; Suzan et al, 2015) or the adaptive algorithm to assess the psychometric function of thermal sensitivity (Courtin et al, 2020). Subjects’ cooperation is equally needed for such tests, which require continuous attention focusing throughout the duration of the stimulus.…”

Observation of nociceptive detection thresholds and cortical evoked potentials: Go/no-go versus two-interval forced choice

“…The mechanical and thermal detection threshold are increased in patients with neuropathic pain and signs of central sensitization (Maier et al, 2010 ). Thermal heat and cold detection thresholds show a high sensitivity to potential peripheral nerve damage by diabetes (Courtin et al, 2020 ) as well as painfulness in diabetic neuropathies (Krämer et al, 2004 ). Intra-epidermal electric detection thresholds are increased following deafferentiation by capsaicin (Doll, van Amerongen, et al, 2016b ) and following diabetic neuropathy (Suzuki et al, 2016 ).…”

Influence of Response Criterion on Nociceptive Detection Thresholds and Evoked Potentials

“…The mechanical and thermal detection threshold are increased in patients with neuropathic pain and signs of central sensitization (Maier et al, 2010). Thermal heat and cold detection thresholds show a high sensitivity to potential peripheral nerve damage by diabetes (Courtin et al, 2020) as well as painfulness in diabetic neuropathies (Krämer, Rolke, Bickel, & Birklein, 2004). Intra-epidermal electric detection thresholds are increased following deafferentiation by capsaicin (Doll et al, 2016) and following diabetic neuropathy (Suzuki et al, 2016).…”