COOL, WARM, AND HEAT-PAIN DETECTION THRESHOLDS - TESTING METHODS AND INFERENCES ABOUT ANATOMIC DISTRIBUTION OF RECEPTORS
COOL, WARM, AND HEAT-PAIN DETECTION THRESHOLDS - TESTING METHODS AND INFERENCES ABOUT ANATOMIC DISTRIBUTION OF RECEPTORS
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DOI：
10.1212/wnl.43.8.1500
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发表时间：
1993-08-01
期刊：
影响因子：
9.9
通讯作者：
OBRIEN, PC
中科院分区：
文献类型：
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作者：
DYCK, PJ;ZIMMERMAN, I;OBRIEN, PC
我们最近发现振动检测阈值受测试算法的影响很大。在这里，我们研究了刺激特性和测试和估计阈值的算法对冷(CDT)、热(WDT)和热痛(HPDT)检测阈值的影响。我们发现，持续降低(对于CDT)或升高(对于WDT)热模式温度到通过按下响应键(“外观”阈值)来感知和通知冷却或变暖的点，高估了具有快速热变化速率的阈值。对于不敏感的部位和患者，出现和消失阈值的平均值也表现不佳。锥体(或平顶金字塔)刺激的大小范围为25步，从近皮温到9摄氏度10秒(对于CDT)，从近皮温到45摄氏度10秒(对于WDT)，以及从近皮温到49摄氏度10秒(对于HPDT)，为用于测试和估计阈值的几种算法提供了理想的刺激。在阈值附近，只感知皮肤温度的初始热变化方向，而不是返回到基线。刺激强度阶跃的使用允许受试者或患者花费所需的时间来决定刺激是否感觉到(在4、2和1步进算法中)，或者它是否发生在刺激间隔1或2中(在两种选择的强迫选择测试中)。温度模式大(10 Cm2)时的温度阈值通常显著低于小温度模式(2.7 cm2)时的温度阈值。CDT、WDT和HPDT具有地形学差异，面部和掌侧手臂阈值最低，腿部和脚阈值最高。在健康受试者中，热阈值在不同部位差异最大，其次是不舒服的热，最后是热痛阈值。尤其是在老年人，CDT可以在足背上确定，而WDT有时不能，第一感觉是热痛。低密度的温暖感受器，特别是在老年人的脚和腿上，可以解释后一种发现。
We recently found that vibratory detection threshold is greatly influenced by the algorithm of testing. Here, we study the influence of stimulus characteristics and algorithm of testing and estimating threshold on cool (CDT), warm (WDT), and heat-pain (HPDT) detection thresholds. We show that continuously decreasing (for CDT) or increasing (for WDT) thermode temperature to the point at which cooling or warming is perceived and signaled by depressing a response key (''appearance'' threshold) overestimates threshold with rapid rates of thermal change. The mean of the appearance and disappearance thresholds also does not perform well for insensitive sites and patients. Pyramidal (or flat-topped pyramidal) stimuli ranging in magnitude, in 25 steps, from near skin temperature to 9-degrees-C for 10 seconds (for CDT), from near skin temperature to 45-degrees-C for 10 seconds (for WDT), and from near skin temperature to 49-degrees-C for 10 seconds (for HPDT) provide ideal stimuli for use in several algorithms of testing and estimating threshold. Near threshold, only the initial direction of thermal change from skin temperature is perceived, and not its return to baseline. Use of steps of stimulus intensity allows the subject or patient to take the needed time to decide whether the stimulus was felt or not (in 4, 2, and 1 stepping algorithms), or whether it occurred in stimulus interval 1 or 2 (in two-alternative forced-choice testing). Thermal thresholds were generally significantly lower with a large (10 cm2) than with a small (2.7 cm2) thermode. A topographic difference of CDT, WDT, and HPDT was demonstrated, with the face and volar arms having the lowest threshold and legs and feet having the highest threshold. In healthy subjects, warm threshold varied most among different sites, followed by uncomfortably hot, and last by heat-pain threshold. Particularly in older subjects, CDT could be determined on the dorsum of the foot whereas WDT sometimes could not, the first sensation experienced being heat-pain. A low density of warm receptors, especially in the foot and leg of old people, would explain these latter findings.