Verdugo R J, Ochoa J L
Department of Neurology, Good Samaritan Hospital and Medical Center, Portland.
Muscle Nerve. 1993 Oct;16(10):1056-62. doi: 10.1002/mus.880161009.
A number of laboratory tests are critically important in the quest to diagnose presence or absence of organic neuropathic dysfunction and to establish the relevance of such to the subjective pain complaints. However, none of these tests has absolute diagnostic value and their results must be interpreted in the light of the clinical picture. Conventional electrophysiology evaluates function of large caliber afferent and motor fibers leaving the function of small caliber afferent fibers unexplored, and cannot explore the basis for positive sensory phenomena. The quantitative somatosensory thermotest is the best test available to explore function of small caliber afferents. It allows documentation of positive sensory phenomena in the form of thermal hyperalgesia. Because it is a psychophysical test, it lacks localizing value. Thermography sensitively detects and precisely delineates areas of cutaneous thermal change of neural origin. Three types of diagnostic neurologic blocks are used in the clinic: compression-ischemia, local anesthetic and sympathetic blocks. Although they may provide important information about the pathophysiology of pain and hyperalgesias, adequate placebo control is of the essence because chronic neuropathic pain patients may express a high incidence of placebo response.
在诊断是否存在器质性神经病变功能障碍以及确定其与主观疼痛主诉的相关性方面，一些实验室检查至关重要。然而，这些检查均无绝对的诊断价值，其结果必须结合临床表现来解读。传统电生理学评估的是大口径传入神经纤维和运动纤维的功能，而未探讨小口径传入神经纤维的功能，且无法探究感觉阳性现象的基础。定量体感温度测试是用于探究小口径传入神经纤维功能的最佳检查。它能够记录以热痛觉过敏形式出现的感觉阳性现象。由于它是一种心理物理学检查，所以缺乏定位价值。热成像能够灵敏地检测并精确描绘神经源性皮肤热变化区域。临床上使用三种诊断性神经阻滞：压迫 - 缺血阻滞、局部麻醉阻滞和交感神经阻滞。尽管它们可能提供有关疼痛和痛觉过敏病理生理学的重要信息，但充分的安慰剂对照至关重要，因为慢性神经病理性疼痛患者可能表现出较高的安慰剂反应发生率。
