Psychophysical methods for improved observation of nociceptive processing

Combined Psychophysical and Neurophysiological Tools for Mechanism-Based Observation of Impaired Nociceptive Processing

“…Sensory and pain thresholds can be used to assess gain and loss of nociceptive function. Experimental techniques to allow simultaneous observation of multiple non-stationary psychophysical thresholds were developed by Doll (Doll, 2016). The method that was developed to measure time-dependent nociceptive detection thresholds in this earlier work , also referred to as threshold tracking, was used as one of the starting points for this thesis.…”

“…However, some of the underlying mechanisms might be observed by presenting selective nociceptive stimuli with various temporal properties (e.g., pulse-width, inter-pulse interval, number of pulses) and measuring multiple nociceptive detection thresholds. To address these concerns regarding the observation of nociceptive processing, Doll et al (Doll, 2016) developed a method to simultaneously estimate and track multiple nociceptive detection thresholds, referred to as threshold tracking.…”

“…As both thresholds are subjective and show a high inter-individual variability among healthy and especially clinical populations (most notably the pain threshold (Cathcart & Pritchard, 2006)), the potential calibration error reduced significance of effects on a group-level and would certainly impede interpretation of these results in an individual patient. This problem of selective activation was addressed by Doll (Doll, 2016) by tracking the nociceptive detection threshold and limiting stimulus intensity to less than twice the detection threshold, which was suggested in earlier validation studies as a rule of thumb for nociception selective intra-epidermal electric stimulation. In addition, this reduced the possible error in stimulus intensity calibration, as accurate estimates of the detection threshold remain available throughout the measurement.…”