Age Differences in Multimodal Quantitative Sensory Testing and Associations With Brain Volume

Abstract

Background and Objectives Somatosensory function is critical for successful aging. Prior studies have shown declines in somatosensory function with age; however, this may be affected by testing site, modality, and biobehavioral factors. While somatosensory function declines are associated with peripheral nervous system degradation, little is known regarding correlates with the central nervous system and brain structure in particular. The objectives of this study were to examine age-related declines in somatosensory function using innocuous and noxious stimuli, across 2 anatomical testing sites, with considerations for affect and cognitive function, and associations between somatosensory function and brain structure in older adults. Research Design and Methods A cross-sectional analysis included 84 “younger” (n = 22, age range: 19–24 years) and “older” (n = 62, age range: 60–94 years) healthy adults who participated in the Neuromodulatory Examination of Pain and Mobility Across the Lifespan study. Participants were assessed on measures of somatosensory function (quantitative sensory testing), at 2 sites (metatarsal and thenar) using standardized procedures, and completed cognitive and psychological function measures and structural magnetic resonance imaging. Results Significant age × test site interaction effects were observed for warmth detection (p = .018, ηp2= 0.10) and heat pain thresholds (p = .014, ηp2= 0.12). Main age effects were observed for mechanical, vibratory, cold, and warmth detection thresholds (ps < .05), with older adults displaying a loss of sensory function. Significant associations between somatosensory function and brain gray matter structure emerged in the right occipital region, the right temporal region, and the left pericallosum. Discussion and Implications Our findings indicate healthy older adults display alterations in sensory responses to innocuous and noxious stimuli compared to younger adults and, furthermore, these alterations are uniquely affected by anatomical site. These findings suggest a nonuniform decline in somatosensation in older adults, which may represent peripheral and central nervous system alterations part of aging processes.

Aging is associated with impaired triggering of TRPV3-mediated cutaneous vasodilation: a crucial process for local heat exposure

“…The temperature activation of TRPV1 being > 42°C, this may suggest that elderly are more able to detect painful/burning temperature, related to UV exposure, than moderate temperature of 33-39°C (TRPV3 range) [62][63][64]. In addition to the decrease of TRPV3 expression in aged keratinocytes, we also point out for the first time an impaired intrinsic activity of the TRPV3 channel.…”

Quantitative Sensory Testing Across Chronic Pain Conditions and Use in Special Populations

“…As highlighted in our descriptions of QST in TMD and placebo research, sex and racial effects regarding pain sensitivity, and racial effects regarding placebo efficiency have been observed, and thus need be accounted for when analyzing results ( 57 , 58 ). In addition, effects of age must be considered when incorporating QST, as loss of sensory function has been observed in older adults for cold, warmth, mechanical, and vibratory detection thresholds ( 90 ). Moreover, a recent systematic review with meta-analysis surrounding the use of QST in individuals with joint pain, reports an association between depression, pain catastrophizing, and physical activity level with several QST measures; therefore, such variables need be acknowledged when evaluating the relationship between pain and somatosensory function ( 91 ).…”

Experimental Pain Phenotype Profiles in Community-dwelling Older Adults

“…Participants were asked to rate their current pain on a 0=“no pain” to 100=“worst pain imaginable” numerical rating scale (NRS) before QST testing. To examine pain profiles, the following QST procedures were applied: pressure pain threshold, (PPT) thermal pain threshold, pinprick pain (PP), and punctate temporal summation (TS) 10,17,18,32,33…”

“…To examine pain profiles, the following QST procedures were applied: pressure pain threshold, (PPT) thermal pain threshold, pinprick pain (PP), and punctate temporal summation (TS). 10,17,18,32,33 PPT A handheld digital pressure algometer (AlgoMed, Medoc Ltd., Ramat Yishai, Israel) was applied with increasing pressure at a constant rate of 30 kPa/s up to a maximum pressure level of 1000 kPa until the participant indicated the pressure sensation "first became painful." PPT was applied to the quadriceps and trapezius in a counterbalanced order.…”