定量温度觉检测在周围神经疾病中的临床价值

目的：了解定量温度觉检测(QTT)在周围神经疾病中的临床应用价值。方法：使用TSAⅡ型温度觉分析仪,以极限法对90例正常人和50例周围神经疾病患者行QTT。结果：在正常人,温度觉阈值在不同性别间无差异,有随年龄增大而增加的趋势；除小腿与足背的温度觉阈值差异无显著意义外,其余各不同部位的冷、热觉及热痛觉阈值不同；冷痛觉的变异度较大。与年龄、性别匹配的对照组比较,腕管综合征患者的温度觉阈值差异无显著意义(P＞0．05)；尺神经损伤者患侧小鱼际的冷、热觉及热痛觉阈值增高(P＜0．05),总异常率82%；多发性神经病患者食指和中指掌面、小鱼际、小腿前外侧以及足背皮肤4个部位的冷、热觉及热痛觉阈值增高(P＜0．05),总异常率50%。结论：QTT可作为周围神经疾病的客观评价指标应用于临床。     

定量感觉测定对有感觉异常的焦虑症患者的研究

目的：观察定量感觉测定（QST）在有感觉异常的焦虑症患者中的应用价值。方法：用QST检测有主观感觉障碍的20例焦虑症患者和20例正常对照组的感觉阈值,包括四肢的冷觉（CS）、温觉（WS）、冷痛觉（CP）、热痛觉（HP）的值进行分析,并作比较。结果：焦虑症组中的四肢的CP、HP异常较CS、WS更明显,焦虑症组中CS、WS、CP、WP的异常率分别是10％,15％,51％,53％。结论：焦虑组的QST的感觉阈值改变,说明焦虑症所产生的感觉障碍可能与周围和中枢神经敏感性增高有关。     

自动递增刺激记录大鱼际肌运动单位估数及其可重复性

目的 :建立自动递增刺激记录正中神经支配的大鱼际肌运动单位估数 (motorunitnumberestimation ,MUNE)正常值并研究其与年龄、性别的关系和该技术的重复性。方法 :用自动递增刺激记录技术估测正中神经支配的大鱼际肌运动单位数 ,检测无神经肌肉病变的正常人 6 0名 ,年龄 2 0～ 88岁 ,平均 5 0 33± 2 0 81岁。结果 :①正常人正中神经支配的大鱼际肌MUNE为 30 0± 83个 ,三个年龄组的MUNE分别为 35 3± 6 3个 (2 0～ 39岁 )、32 2± 5 4个 (4 0～ 5 9岁 )、2 16± 5 9个 (6 0～ 88岁 ) ;②正常人大鱼际肌MUNE与年龄呈负相关 ,与性别无关 ,6 0岁以上组大鱼际肌MUNE比 6 0岁以下各组明显减少 (P <0 0 0 1) ;③大鱼际肌MUNE重复性实验两次检查值相差不显著 (P =0 3)。结论 :自动递增刺激记录正中神经支配的大鱼际肌MUNE为 30 0± 83个 ,随年龄的增大持续性下降 ,特别在 6 0岁后运动单位数下降明显 ,运动单位估数应考虑年龄因素。大鱼际肌MUNE有良好的可靠性和重复性 ,与性别无关。     

X-连锁隐性遗传腓骨肌萎缩症一家系九例

先证者（Ⅲ7）男，72岁。32岁时发现双下肢小腿肌肉萎缩，足弓增高，并双手大鱼际肌、骨间肌萎缩，于劳累或激动时偶有书写震颤，数10年来病情稳定。20年前诊断为“腓骨肌萎缩症”。55岁后双下肢肌力有所减退，60岁后行走明显缓慢，68岁后无法站稳，70岁后行走也不稳，书写、持筷均感困难，但无大小便障碍。查体：智力正常，脑神经检查阴性，双手大鱼际、骨间肌明显萎缩，可见肌束震颤，左侧拇、食指勉强能持物，右侧者无功能，无爪形手或爪形趾，     

基于Anybody软件平台冷水刺激前后食指动力学的特性

背景：Anybody人体建模仿真系统是计算机辅助人类工效学和生物力学分析软件,并且是目前惟一可以分析完整骨骼肌肉系统的软件,利用它可以计算模型中骨骼、肌肉、关节的受力变形。 目的：实验旨在通过计算模型观察手指在冷水刺激环境下食指的灵活性。 方法：参照以往人食指运动实验结果,获得人食指弯曲的运动学参数,利用Anybody软件平台构建正常人手部握拳运动学模型,并进一步构建了包含两根外屈肌(指浅屈肌和指深屈肌)的骨骼肌肉模型,通过逆向动力学分析,考察受冷水刺激前后手部握拳运动时肌肉力和收缩功率等的变化。 结果与结论：冷水刺激后,食指各关节在屈伸过程中的平均角速度较冷水刺激前变小,指浅屈肌的肌肉力变化幅值也较冷水刺激前增大;指深屈肌的收缩功率下降明显,而指浅屈肌收缩功率变化不大。结果证实,冷水刺激会使正常人手握拳动作变慢,且正常人手的指浅屈肌对冷水刺激更敏感,进一步说明指浅屈肌在握拳动作中的重要性。     

等长收缩时食指肌力分析

本文详尽深入地探讨了在等长收缩时食指肌力冗余问题的求解方法。分别采用二维和三维肌骨模型选用７ 类２１ 种优化目标函数,求得食指在进行按压动作时的肌肉作用力;在此基础上,分析了不同模型和不同的优化目标函数对肌力解的影响,得到了一些很有意义的结论,如：三维模型中不同目标函数的选择对肌力解的影响比在二维模型中小,浅层屈肌和深层屈肌作用力的之和基本不随优化目标函数的不同而改变,而蚓状肌和骨间肌的力解对优化目标函数的选择却很敏感     

四种常用假肢材料与人体皮肤摩擦学特性的研究

研究了目前应用广泛的四种假肢接受腔及内衬套材料与皮肤的摩擦学特性，试验部位分别选择在小腿截肢残疾患者的残肢及正常人小腿胫骨脊外侧进行。试验前对皮肤和材料的表面形貌、材料亲水性进行了测试。摩擦学试验结果表明，法向载荷P为0．3N和0．7N下，由于硅橡胶具有特殊性质（含有硅油），与皮肤摩擦系数明显大于其他材料，并且在残疾人和正常人皮肤之间具有明显差异（P〈0．05）；其它三种材料均符合“材料表面越憎水、与皮肤的摩擦系数越低”的规律。法向载荷P为8N下，残疾人和正常人皮肤与各材料之间的摩擦系数无明显差异（P〉0．05）。     

先天性心脏病皮纹特点初探

对５８例先天性心脏病患者及３８０例正常儿童进行了皮肤纹理的调查研究，发现先心病患者的皮纹，与正常儿童皮纹有多处不同：（１）双手指纹≥８个斗型纹者明显高于对照组；双箕斗型纹也显著多；（２）ａｔｄ角明显大于对照组，且ａｔｄ角≥４０度的明显多于对照组，但ｔ距比略小；（３）ａ－ｂＲＣ比对照组明显下降；（４）指间区真实花纹出现率高，尤以３－４指间、大鱼际区、小鱼际区显著多于对照组。     

人体各部位皮肤黑素细胞的分布及超微结构观察

对３６个不同部位正常皮肤表皮中黑素细胞的数量、形态及其超微结构进行了观察分析。结果表明：黑素细胞数量存在较大的个体差异，且部位不同，其分布数量也显著不同，即面颈部及上肢等暴露部位皮肤中黑素细胞数量显著高于躯干及十肢等暴露较少部位皮肤中的含量，部位不同，其黑素细胞的形态结构也略有差异。     

勃起状态下阴茎感觉阈值测量在原发性早泄诊断中的研究

目的比较阴茎头振动感觉阈在勃起前后的变化,并进一步观察勃起状态下正常人和早泄患者的阴茎头振动感觉阈的差异,从而评估勃起状态下阴茎感觉阈值测量在原发性早泄诊断中的价值。方法使用生物振动测试仪,对62例正常志愿者（对照组）及97例早泄患者（早泄组）阴茎勃起前后的振动感觉阈进行测定,测定部位为示指、阴茎头、阴茎干、阴囊4部位的皮肤。结果正常人和早泄患者在阴茎勃起状态下,其阴茎头、阴茎干的振动感阈值都显著低于未勃起状态下的振动感阈值（P〈0.01）。在勃起状态下,早泄患者的阴茎头、阴茎干的振动感阈值都显著低于正常人的振动感阈值（P〈0.01）。结论无论是正常人还是早泄患者,阴茎头、阴茎干的振动感阈值在勃起前后有显著的统计学差异。在勃起状态下进行阴茎感觉阈值测量对原发性早泄的诊断具有一定的价值。     

Influence of skin temperature on heat pain threshold in humans

We compared the effect of skin temperature on the critical threshold temperature eliciting heat pain with the effect of skin temperature on the response latency to the first heat pain sensation in healthy human subjects. Also, we determined the effect of the duration of a heat stimulus ramp on pain threshold. Furthermore, we determined the effect of skin temperature on mechanically induced pain. We found that the latency to the first pain sensation induced by a radiant heat stimulus was significantly decreased with an increase in the skin temperature (25–35 °C). However, independent of the rate of the stimulus rise (3–10 °C/s) and independent of the stimulus location (hairy vs glabrous skin), the threshold temperature for eliciting the heat pain sensation, determined with a contact thermostimulator, was not changed by a change in the skin temperature in the same subjects. With a fast rate of stimulus rise, a higher pain threshold was obtained than with a slow rise of stimulus temperature. However, this difference was found only with subject-controlled ascending stimuli (method of limits) but not with experimenter-controlled, predetermined stimulus ramps (method of levels). The heat pain threshold was higher in the glabrous skin of the hand than in the hairy skin of the forearm. With increasing stimulus duration (2.5–10s), the threshold temperature eliciting the heat pain sensation was significantly decreased. The mechanically induced pain threshold was not influenced by the skin temperature. The results indicate that the critical temperature for eliciting heat pain is independent of the skin temperature in humans. However, a change in skin temperature is an important source of an artefactual change in heat pain sensitivity when the radiant heat method (latency or energy) is used as an index of pain sensitivity. With a method dependent on reaction time (the method of limits), the heat pain threshold was artefactually increased, with fast rates of stimulus rise due to the long delay of slowly conducting heat pain signals in reaching the brain. With an increase in the duration of the heat stimulus, the critical temperature for eliciting pain sensation was significantly decreased, which may be explained by central neuronal mechanisms (temporal summation).     

Painful and non-painful pressure sensations from human skeletal muscle

Painful and non-painful pressure sensations from muscle are generally accepted to exist but the peripheral neural correlate has not been clarified. The aim of the present human study was to assess the non-painful and painful pressure sensitivity with (1) anaesthetised skin, and (2) anaesthetised skin combined with a block of large diameter muscle afferents. The skin was anaesthetised by a topically applied anaesthetic cream and later lidocaine was administrated subcutaneously. The pressure sensitivity was assessed quantitatively by computer-controlled pressure stimulation on the anterior tibial muscle. Thresholds to detection, pain and pain tolerance were assessed. In the first experiment, computer-controlled needle insertion depths evoking touch and pain sensations were used to assess the efficacy of cutaneous anaesthesia. Touch and pain sensations evoked during needle insertions were found to be superficial in intact skin but when anaesthetised, touch sensation was occasionally evoked at depths related to penetration of the fascia. With the skin completely anaesthetised to brush and von Frey hair pinprick stimulation, skin indentation with the strongest von Frey hair caused a sensation described as a deep touch sensation. Simultaneously, pressure detection and pain thresholds increased but it was still possible to elicit non-painful and painful pressure sensation in all subjects. In a second experiment, a differential nerve block of group I and II afferent fibres was obtained by full-leg ischaemia simultaneously with cutaneous anaesthesia. The efficacy of the tourniquet block was continuously assessed by a battery of somatosensory tests (heat, brush, vibration, electrical and movement detection) applied at the foot simultaneously with pressure stimulation on the anterior tibial muscle. After 20 min of ischaemia, group II afferent fibres mediating the sensations of movement detection, vibration and brush on the foot was blocked but the heat pain threshold was not affected. In this condition (anaesthetised skin and block of group I and II fibres from deep tissue) a pressure sensation was evoked in 70% of subjects although the pressure detection threshold was increased. The pressure pain sensitivity was decreased, which, however, might indicate a partial block of group III and IV muscle afferents. In a third experiment, the tactile sensations elicited by electrical stimulation of the tibialis anterior muscle and skin at the lower leg were significantly decreased after 20 min of ischaemia, validating the blocking effects of group I and II nerve fibres. The present data show a marginal contribution of cutaneous afferents to the pressure pain sensation that, however, is relatively more dependent on contributions from deep tissue group III and IV afferents. Moreover, a pressure sensation can be elicited from deep tissue probably mediated by group III and IV afferents involving low-threshold mechanoreceptors.     

Hypoxia induces no change in cutaneous thresholds for warmth and cold sensation

Hypoxia can affect perception of temperature stimuli by impeding thermoregulation at a neural level. Whether this impact on the thermoregulatory response is solely due to affected thermoregulation is not clear, since reaction time may also be affected by hypoxia. Therefore, we studied the effect of hypoxia on thermal perception thresholds for warmth and cold. Thermal perception thresholds were determined in 11 healthy overweight adult males using two methods for small nerve fibre functioning: a reaction-time inclusive method of limits (MLI) and a reaction time exclusive method of levels (MLE). The subjects were measured under normoxic and hypoxic conditions using a cross-over design. Before the thermal threshold tests under hypoxic conditions were conducted, the subjects were acclimatized by staying 14 days overnight (8 h) in a hypoxic tent system (Colorado Altitude Training: 4,000 m). For normoxic measurements the same subjects were not acclimatized, but were used to sleep in the same tent system. Measurements were performed in the early morning in the tent. Normoxic MLI cold sensation threshold decreased significantly from 30.3 +/- 0.4 (mean +/- SD) to 29.9 +/- 0.7 degrees C when exposed to hypoxia (P < 0.05). Similarly, mean normoxic MLI warm sensation threshold increased from 34.0 +/- 0.9 to 34.5 +/- 1.1 degrees C (P < 0.05). MLE measured threshold for cutaneous cold sensation was 31.4 +/- 0.4 and 31.2 +/- 0.9 degrees C under respectively normoxic and hypoxic conditions (P > 0.05). Neither was there a significant change in MLE warm threshold comparing normoxic (32.8 +/- 0.9 degrees C) with hypoxic condition (32.9 +/- 1.0 degrees C) (P > 0.05). Exposure to normobaric hypoxia induces slowing of neural activity in the sensor-to-effector pathway and does not affect cutaneous sensation threshold for either warmth or cold detection.     

Neurosensory changes in a human model of endothelin-1 induced pain: a behavioral study

Although pain is a frequent feature in patients with cancer, its etiology is still poorly understood. In recent years, endothelin-1 (ET-1) has become a major target molecule in the etiology of cancer pain. In this randomised, double-blind study the effects of intradermal injection of ET-1 on spontaneous pain, temperature perception and sensation of punctate stimulation were evaluated. Thirty-five subjects were randomised to receive either placebo or one of four concentrations of ET-1 (ranging from 10(-10) to 10(-6)M). Besides assessment of spontaneous pain, three neurosensory testings were performed: (1) cold and warm sensation, (2) cold and heat pain, and (3) punctate stimulation using a von Frey monofilament. ET-1 produced a dose-dependent flare zone that was absent after placebo injection. Subjects reported a short-lasting spontaneous pain upon administration of the highest concentrations of ET-1. Injection of ET-1 induced a long-lasting and dose-dependent punctate hyperalgesia in an area around the injection site (secondary hyperalgesia). Thermal testing revealed a short period of hypoesthesia to non-noxious warm and cold stimuli after some doses of ET-1. In addition to the mechanical hyperalgesia, intradermal injection of ET-1 almost instantaneously induced a state of cold hyperalgesia outlasting the study period (120 min). No development of heat hyperalgesia was observed. The observed psychophysical characteristics of this new model of ET-1 induced nociception indicate its potential as a human experimental model for cancer pain.     

Unmyelinated afferents in human skin and their responsiveness to low temperature

In humans, there are different types of cutaneous cold-sensitive afferents responsible for cold sensation and cold pain. Innocuous cold is primarily mediated by a population of slow A delta afferents, based on psychophysical and neurophysiological studies. Noxious cold (usually below 15 °C) is mediated, at least in part, by polymodal nociceptors. There is also a population of unmyelinated afferents responsive to innocuous low temperature, some of which also respond to heat, whose sensory function has not been completely defined. A paradoxical hot/burning evoked by cooling is unmasked by A-fibre block, and similar sensations are evoked by applying simultaneous cool and warm stimuli to adjacent skin areas. These unmyelinated fibres activated by innocuous cooling (and heating) may contribute to this hot/burning sensation, along with other thermoregulatory functions.     

Desensitization of menthol-activated cold receptors in lower extremities during local cooling in young women with a cold constitution

To test the hypothesis that topical menthol-induced reactivity of cold sensation and cutaneous vasoconstriction to local cooling is augmented in individuals with a cold constitution, we examined thermal sensation and cutaneous vasoconstrictor responses at menthol-treated and untreated sites in the legs during local skin cooling in young women complaining of chilliness (C group) and young women with no complaint as a normal control group (N group). During local skin cooling, the sensitivity to cold sensation was greater in the C group than in the N group. The application of menthol enhanced the cold sensation at a low temperature in the N group, but not in the C group. Cutaneous vasoconstrictor responses to local skin cooling were not altered by menthol treatment in either of the two groups. These findings suggest the desensitization of menthol-activated cold receptors in the legs of C group subjects, and a minor role of cold receptor activity in cutaneous vasoconstrictor response to local cooling.     

Comparative cerebral responses to non-painful warm vs. cold stimuli in man: EEG power spectra and coherence.

AIMS: The cerebral processing of painful thermal (heat/cold) stimulation have been extensively studied, but little is known about cerebral activation to non-painful warm and cold stimuli. This study aimed to investigate the comparative EEG effects of warm vs. cold stimulus in man. MATERIALS AND METHODS: The left nondominant hands of 13 healthy male subjects were stimulated by non-painful warm (40-43 degrees C) and cold (12-15 degrees C) water. The somatic sensations were continuously assessed with an analogue visual scale device. EEG data (32 channels) recorded before, during and after the warm and cold stimulations were analysed quantitatively. RESULTS: No significant difference in intensity of sensation was found during warm and cold stimulations. Different patterns of EEG activity were superimposed on the similar background of EEG activation during and after warm and cold stimulations. Significant decrease of theta activity in contra-stimulus frontal region was observed during cold stimulation rather than warm stimulation. EEG power spectra in theta, alpha-1 and alpha-2 bands significantly increased after cold stimulation compared to baseline. EEG coherence in delta, alpha-1 and alpha-2 bands significantly increased in the contra-stimulus hemisphere during stimulations. CONCLUSION: This suggests that similar neural networks may process somatic warm and cold sensory inputs differently and the differential EEG patterns may be encoded by the qualities of thermal stimuli.     

Cardiovascular responses after brisk finger movement and their dependency on the "eigenfrequency" of the baroreflex loop

The ‘thermal grill illusion’ refers to paradoxical sensations of heat and pain, resulting from simultaneous application of interlaced warm and cold stimuli to the skin. It provides an interesting model of integrative mechanisms in the nervous system, supposed to be relevant in explaining the hypersensitivity found in chronic pain of unclear etiology. The aim of this study is to investigate the perceptual qualities elicited by a reconstruction of the original grill stimulator and to compare these qualities with those elicited by a single temperature thermode of identical dimensions. Healthy participants performed these comparisons by choosing adjectives describing the perceived sensory qualities. We hypothesized that the thermal grill would be perceived as different from a single temperature hot stimulus near pain threshold because of varying sensory qualities. Moreover, the qualities elicited by the grill were expected to be different from the qualities elicited by its single component temperatures. The thermal grill elicited a complex percept, which was distinguished almost perfect from a hot stimulus. The pattern of perceived qualities of the thermal grill differed from single temperature warm and hot stimuli. Pain-related sensations were less present in the grill percept than in a single hot stimulus near pain threshold. The spectrum of qualities of the grill stimulus changed marginally with stimulus duration by decrease of a cold component and concurrent increase of a heat component. In conclusion, the percept of the thermal grill is not simply pain - it can be understood as a metaesthetic percept at the transition from heat to pain.     

Innocuous cooling can produce nociceptive sensations that are inhibited during dynamic mechanical contact

In a previous study of the heat grill illusion, sensations of burning and stinging were sometimes reported when the skin was cooled by as little as 2°C. Informal tests subsequently indicated that these nociceptive sensations were experienced if cooling occurred when the stimulating thermode rested on the skin, but not when the thermode was cooled and then touched to the skin. In experiment 1 subjects judged the intensity of thermal (cold/warm) and nociceptive (burning/stinging) sensations when the volar surface of the forearm was cooled to 25°C (1) via a static thermode (Static condition), or (2) via a cold thermode touched to the skin (Dynamic condition). The total area of stimulation was varied from 2.6 to 10.4 cm² to determine if the occurrence of nociceptive sensations depended upon stimulus size. Burning/stinging was rated 10.3 times stronger in the Static condition than in the Dynamic condition, and this difference did not vary significantly with stimulus size. In experiment 2, thermal and nociceptive sensations were measured during cooling to just 31°, 29° or 27°C, and data were obtained on the frequency at which different sensation qualities were experienced. Stinging was the most frequently reported nociceptive quality in the Static condition, and stinging and burning were both markedly reduced in the Dynamic condition. In experiment 3 we tested the possibility that dynamic contact might have inhibited burning and stinging not because of mechanical contact per se, but rather because dynamic contact caused higher rates of cooling. However, varying cooling rate over a tenfold range (–0.5° to –5.0°/s) had no appreciable effect on the frequency of stinging and burning. Overall, the data show that mild cooling can produce nociceptive sensations that are suppressed under conditions of dynamic mechanical contact. The latter observation suggests that cold is perceived differently during active contact with objects than during passive heat loss to the environment. Hypotheses about the physiological basis of the nociceptive sensations at mild temperatures and their possible role in the phenomena of paradoxical heat and synthetic heat are discussed. Electronic Publication     

Relationships between skin temperature and temporal summation of heat and cold pain

Temporal summation of heat pain during repetitive stimulation is dependent on C nociceptor activation of central N-methyl-d-aspartate (NMDA) receptor mechanisms. Moderate temporal summation is produced by sequential triangular ramps of stimulation that control skin temperature between heat pulses but do not elicit distinct first and second pain sensations. Dramatic summation of second pain is produced by repeated contact of the skin with a preheated thermode, but skin temperature between taps is not controlled by this procedure. Therefore relationships between recordings of skin temperature and psychophysical ratings of heat pain were evaluated during series of repeated skin contacts. Surface and subcutaneous recordings of skin temperatures revealed efficient thermoregulatory compensation for heat stimulation at interstimulus intervals (ISIs) ranging from 2 to 8 s. Temporal summation of heat pain was strongly influenced by the ISIs and cannot be explained by small increases in skin temperature between taps or by heat storage throughout a stimulus series. Repetitive brief contact with a precooled thermode was utilized to evaluate whether temporal summation of cold pain occurs, and if so, whether it is influenced by skin temperature. Surface and subcutaneous recordings of skin temperature revealed a sluggish thermoregulatory compensation for repetitive cold stimulation. In contrast to heat stimulation, skin temperature did not recover between cold stimuli throughout ISIs of 3-8 s. Psychophysically, repetitive cold stimulation produced an aching pain sensation that progressed gradually and radiated beyond the site of stimulation. The magnitude of aching pain was well related to skin temperature and thus appeared to be established primarily by peripheral factors.