Normative values of skin temperature and thermal sensory thresholds in the pudendal nerve territory.

Aims: The aim of this study was to define normative values of skin temperature and thermal sensory threshold in the pudendal nerve territory.

Methods: Warm and cold detection thresholds (using the method of limits) and skin temperature were measured in a group of 41 presumably healthy female volunteers aged 41 years (range: 23-66 years) at left thenar eminence and in the pudendal nerve territory. Outlying data were discarded and 95% normative values were derived assuming Normal distributions.

Results: Room temperature averaged 24.3 ± 1.1°. Skin temperature and cold detection threshold value were greater anteriorly (clitoris, labia) than posteriorly (para-anal). Para-anal skin temperature and cold detection threshold value were also significantly lower on the right side than on the left side. The warm detection threshold was significantly lower at the clitoris level than at left and right labia. A significant positive effect of skin temperature on cold and warm detection thresholds values was noted especially at thenar and para-anal levels. Age had no effect on skin temperature but warm detection thresholds at clitoris were higher in older subjects. The only qualitative abnormalities observed were after-sensation (4.9%) and habituation (2.8%). Allodynia, dysesthesia, radiation, and dyslocalization were not observed. Two-sided normative values were determined for skin temperature, vertical, and horizontal differences, while one-sided values were derived for cold and warm detection thresholds as well as for their difference.

Conclusions: Normative values for perineal skin temperature and thermal detection thresholds can be used as an alternative non-invasive way to evaluate pudendal neuropathy.