Diagnosis of nerve entrapment syndromes by thermal imaging

Thermal images of 154 hands were studied to show that patients suffering from thoracic outlet syndrome or carpal tunnel syndrome can be differentiated from healthy subjects by the occurrence of a thermal asymmetry between the index and the little finger. A temperature difference between these fingers higher than 0.5°C was regarded as a pathological finding. With respect to clinical, neurographic and thermographic criteria, hands were allocated into four groups: healthy controls, carpal tunnel syndrome, thoracic outlet syndrome and the combination of carpal tunnel with thoracic outlet syndrome. A discriminant analysis of grouping with respect to the temperature difference between index and little finger, found correct classification in 44,8% of cases. After transfer of the combined syndrome to the thoracic outlet group, the number of correct classifications increased to 63,3%. The calculation for sensitivity and specificity of pathological temperature differences for the diagnosis of thoracic outlet syndrome yielded values of 71,60 and 42,9%. The determination of the temperature distribution on the hand seems to be a valuable test for the detection of patients with thoracic outlet syndrome