Examining somatosensory function by age, testing site, and modality

Abstract

The purpose of this study was to systematically examine somatosensory function by age and testing site across a variety of quantitative sensory testing (QST) modalities and determine if age differences were associated with brain gray matter volume and cortical thickness. Healthy younger (n=22; mean (SD) age = 21.31 (1.54) years) and older adults (n=62; mean (SD) age= 72.11 (6.69) years) were recruited as part of the Neuromodulatory Examination of Pain and Mobility Across the Lifespan study. Participants underwent mechanical and thermal detection as well as pain perception applied to two different anatomical sites (metatarsal and thenar). MRI data was collected on a 3-Tesla scanner with a 32-channel radiofrequency coil. A repeated measures ANOVA examined differences in QST by age and test site. Freesurfer examined associations between QST modalities and brain structure in older adults. Significant test site by age interaction effects were observed for warm detection threshold (p=0.018, partial eta2=0.10) and heat pain threshold (p=0.014, partial eta2=0.12). Main effects of age were observed for mechanical detection threshold, vibratory detection threshold, cold detection threshold, warm detection threshold, heat pain threshold, heat pain rating (p's