Quantifying Pain Location and Intensity with Multimodal Pain Body Diagrams.

To quantify an individual's subjective pain severity, standardized pain rating scales such as the numeric rating scale (NRS), visual analog scale (VAS), or McGill pain questionnaire (MPQ) are commonly used to assess pain on a numerical scale. However, these scales are often biased and fail to capture the complexity of pain experiences. In contrast, clinical practice often requires patients to report areas of pain by drawing on a body diagram, which is an effective but qualitative tool. The method presented here extracts quantifiable metrics from pain body diagrams (PBDs) which are validated against the NRS, VAS, and MPQ pain scales. By using a novel pressure-hue transformation on a digital tablet, different drawing pressures applied with a digital stylus can be represented as different hues on a PBD. This produces a visually intuitive diagram of hues ranging from green to blue to red, representing mild to moderate to most painful regions, respectively. To quantify each PBD, novel pain metrics were defined: (1) PBD mean intensity, which equals the sum of each pixel's hue value divided by the number of colored pixels, (2) PBD coverage, which equals the number of colored pixels divided by the total number of pixels on the body, and (3) PBD sum intensity, which equals the sum of all pixels' hue values. Using correlation and information theory analyses, these PBD metrics were shown to have high concordance with standardized pain metrics, including NRS, VAS and MPQ. In conclusion, PBDs can provide novel spatial and quantitative information that can be repeatedly measured and tracked over time to comprehensively characterize a participant's pain experience.

Reduced sensorimotor beta dynamics could represent a "slowed movement state" in healthy individuals.

It is well established that the amplitude of beta oscillations (∼13-30 Hz)-recorded over the sensorimotor cortex-distinctly change throughout movement. Specifically, a movement-related beta decrease (MRBD) occurs before and during movement, and a post-movement beta rebound (PMBR) follows. We investigated how the magnitude of the MRBD and PMBR vary when participants are put in an experimentally induced slow versus fast movement state. Individuals performed a task with blocks that elicited longer reaction times (RTs) and shorter RTs (SLOW and FAST blocks, respectively) while scalp-electroencephalography (EEG) was recorded. The timing of an upcoming movement was also modulated to create blocks with certain and uncertain response timing (FIXED and VARIED blocks, respectively). We found that beta modulation was reduced in SLOW blocks compared to FAST blocks (i.e., a less negative MRBD and less positive PMBR). For the movement certainty manipulation, we saw mixed behavioral and EEG results. Our primary finding of reduced beta modulation during an experimentally induced "slowed movement state" aligns with previous work showing reduced movement-related beta activity in patients with Parkinson's disease.