title: Thermal threshold tester, a useful tool for detection of very early nerve damage--determination of normal values in a healthy population unexposed to Mycobacterium leprae and its application in the A9 study.
abstract: BACKGROUND
  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).
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors: Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
authors: M Elizabeth
authors: ME
authors: Duncan
authors: Stig
authors: S
authors: Hansen
authors: Terefe
authors: T
authors: Tadesse
authors: Elisabeth
authors: E
authors: Bezuneh
authors: Mohammed A
authors: MA
authors: Yassin
authors: Assefa
authors: A
authors: Zeleke
authors: Abebe
authors: A
authors: Solomon
authors: Goran A
authors: GA
authors: Jamal
authors: Mesfin
authors: M
authors: Hunegnaw
authors: Roland
authors: R
authors: Kazen
authors: Abraham
authors: A
authors: Aseffa
authors: Andrew
authors: A
authors: Challis
authors: Wondu
authors: W
authors: Wagaye
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D006306:Health Surveys; D006358:Hot Temperature; D006801:Humans; D007918:Leprosy / Q000150:complications*; D008297:Male; D008875:Middle Aged; D009166:Mycobacterium leprae; D009460:Neurologic Examination / Q000295:instrumentation*; D010523:Peripheral Nervous System Diseases / Q000175:diagnosis* / Q000209:etiology; D012684:Sensory Thresholds