Duncan M Elizabeth, Hansen Stig, Tadesse Terefe, Bezuneh Elisabeth, Yassin Mohammed A, Zeleke Assefa, Solomon Abebe, Jamal Goran A, Hunegnaw Mesfin, Kazen Roland, Aseffa Abraham, Challis Andrew, Wagaye Wondu
Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
Ethiop Med J. 2007 Oct;45 Suppl 1:25-33.
In Ethiopia, a large percentage of leprosy patients present with established nerve damage. Present techniques for measuring nerve function impairment show no abnormality until 30% of nerve axons are destroyed. Nerve damage in leprosy occurs first in small diameter unmyelinated fibres, then in small myelinated fibres, and much later in large myelinated fibres. The Thermal Threshold Tester (TTT) was used to measure function in nerves carrying heat sensation (unmyelinated C fibres) and cold sensation (thinly myelinated Adelta fibres).
A school and community health survey, assessed 234 students and adults aged 10-75 years from Chencha Woreda, an area with low endemicity of leprosy. A group of students in Addis Ababa, exposed to leprosy, were also studied.
The upper limits of normal were: wrist hot threshold (HT): 0.17 degrees C, wrist cold threshold (CT): 0.19 degrees C, foot HT: 0.17 degrees C and foot CT: 0.20 degrees C. Both the leprosy group and also controls in Addis Ababa showed significantly increased TTT values.
The TTT detects nerve damage before clinical neuritis occurs and is a valuable tool for early diagnosis of leprosy or detecting clinical relapse of treated patients and for sequential and quantitative monitoring of small diameter nerve function in other neuropathies.
在埃塞俄比亚，很大一部分麻风病患者存在已确诊的神经损伤。目前用于测量神经功能损害的技术在神经轴突被破坏30%之前均未显示异常。麻风病中的神经损伤首先发生在小直径无髓纤维，然后是小髓纤维，很久之后才发生在大髓纤维。热阈值测试仪（TTT）用于测量传导热觉（无髓C纤维）和冷觉（薄髓Aδ纤维）的神经功能。
一项学校和社区健康调查评估了来自麻风病低流行区陈查县的234名10至75岁的学生和成年人。还对亚的斯亚贝巴一组接触过麻风病的学生进行了研究。
正常上限为：手腕热阈值（HT）：0.17℃，手腕冷阈值（CT）：0.19℃，足部HT：0.17℃，足部CT：0.20℃。麻风病组和亚的斯亚贝巴的对照组TTT值均显著升高。
TTT可在临床神经炎发生之前检测到神经损伤，是早期诊断麻风病或检测已治疗患者临床复发以及对其他神经病变中小直径神经功能进行连续定量监测的有价值工具。
