Beach Paul A, Cowan Ronald L, Dietrich Mary S, Bruehl Stephen P, Atalla Sebastian W, Monroe Todd B
Department of Neurology, Emory University School of Medicine, Atlanta, Georgia.
Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, Tennessee.
Pain Med. 2020 Sep 1;21(9):1779-1792. doi: 10.1093/pm/pnz281.
To examine psychophysical and brain activation patterns to innocuous and painful thermal stimulation along a continuum of healthy older adults.
Single center, cross-sectional, within-subjects design.
Thermal perceptual psychophysics (warmth, mild, and moderate pain) were tested in 37 healthy older adults (65-97 years, median = 73 years). Percept thresholds (oC) and unpleasantness ratings (0-20 scale) were obtained and then applied during functional magnetic resonance imaging scanning. General linear modeling assessed effects of age on psychophysical results. Multiple linear regressions were used to test the main and interaction effects of brain activation against age and psychophysical reports. Specifically, differential age effects were examined by comparing percent-signal change slopes between those above/below age 73 (a median split).
Advancing age was associated with greater thresholds for thermal perception (z = 2.09, P = 0.037), which was driven by age and warmth detection correlation (r = 0.33, P = 0.048). Greater warmth detection thresholds were associated with reduced hippocampal activation in "older" vs "younger" individuals (>/<73 years; beta < 0.40, P < 0.01). Advancing age, in general, was correlated with greater activation of the middle cingulate gyrus (beta > 0.44, P < 0.01) during mild pain. Differential age effects were found for prefrontal activation during moderate pain. In "older" individuals, higher moderate pain thresholds and greater degrees of moderate pain unpleasantness correlated with lesser prefrontal activation (anterolateral prefrontal cortex and middle-frontal operculum; beta < -0.39, P < 0.009); the opposite pattern was found in "younger" individuals.
Advancing age may lead to altered thermal sensation and (in some circumstances) altered pain perception secondary to age-related changes in attention/novelty detection and cognitive functions.
研究健康老年人连续体上对无害和疼痛性热刺激的心理物理学和大脑激活模式。
单中心、横断面、受试者内设计。
对37名健康老年人（65 - 97岁，中位数 = 73岁）进行热感觉心理物理学测试（温暖、轻度和中度疼痛）。获得感知阈值（℃）和不愉快评分（0 - 20量表），然后在功能磁共振成像扫描期间应用。通用线性模型评估年龄对心理物理学结果的影响。多元线性回归用于测试大脑激活对年龄和心理物理学报告的主要和交互作用。具体而言，通过比较73岁以上/以下（中位数分割）人群之间的百分比信号变化斜率来检查年龄差异效应。
年龄增长与热感觉阈值升高相关（z = 2.09，P = 0.037），这是由年龄与温暖检测相关性驱动的（r = 0.33，P = 0.048）。“老年”个体（> / < 73岁）与“年轻”个体相比，更高的温暖检测阈值与海马体激活减少相关（β < 0.40，P < 0.01）。一般而言，年龄增长与轻度疼痛期间扣带回中部的激活增加相关（β > 0.44，P < 0.01）。在中度疼痛期间，前额叶激活存在年龄差异效应。在“老年”个体中，较高的中度疼痛阈值和较高程度的中度疼痛不愉快与较少的前额叶激活相关（前额叶前外侧皮质和额中回盖部；β < -0.39，P < 0.009）；在“年轻”个体中发现相反的模式。
年龄增长可能导致热感觉改变，并且（在某些情况下）由于与年龄相关的注意力/新奇性检测和认知功能变化而导致疼痛感知改变。
