Thermal threshold testing for the assessment of small fibre dysfunction: normal values and reproducibility

Area of Science:

• Neurology
• Diabetology
• Sensory Physiology

Background:

• Diabetic mellitus frequently leads to small and large fiber neuropathy.
• Accurate assessment of thermal perception thresholds is crucial for diagnosing neuropathy.
• Establishing normative data is essential for interpreting patient results.

Purpose of the Study:

• To determine normal values for warm and cold thermal perception thresholds.
• To assess the influence of age on thermal perception in healthy individuals.
• To evaluate the repeatability of thermal threshold measurements.

Main Methods:

• Utilized the Thermal Threshold Tester device to generate controlled thermal stimuli.
• Measured warm and cold thresholds using a forced-choice method with an up-and-down transform rule.
• Assessed 80 healthy subjects across four age groups (25-65 years) at the wrist and foot.
• Evaluated repeatability in 39 diabetic patients without neuropathy.

Main Results:

• A significant age-related increase in warm thermal threshold was observed in the hand.
• A significant age-related increase in cold thermal threshold was observed in the foot.
• Thermal thresholds in the hand (cold) and foot (warm) did not show significant age-related differences.
• Good repeatability was found for hand measurements, but poor repeatability for foot measurements.

Conclusions:

• Normal thermal perception thresholds were established for healthy adults.
• Age is a significant factor influencing thermal perception, particularly cold sensation in the feet and warm sensation in the hands.
• The Thermal Threshold Tester demonstrates good repeatability for hand measurements but requires further validation for foot measurements.