Sweating responses of normal, paraplegic and anhidrotic subjects

Dynamic sudomotor response to changing ambient temperatures (30 C to 45 C) was measured on eight unacclimatized subjects including five normals, two paraplegics and one anhidrotic patient. Mean sweating rates, computed from five simultaneously observed local rates, were used to compare the overall sudomotor response to heat exposure of the three groups. In the normal subjects, an average rise of 0.34 C in oral temperature and 2.5 C in mean skin temperature was found in a period of 65 minutes. The paraplegics developed a higher rise in both oral and skin temperatures due to a lower sweating rate in the insentinent region. (Insentient describes the sensory state of the skin below the level of the lesion where the subject has no awareness of surface stimulation). A relatively higher sweating rate was observed on the forehead and the cyclic sweating behavior of the insentient skin was not synchronous with that in the sentient. (Sentient describes the state where partial or total awareness is elicited by stimulation). The anhidrotic patient showed a twofold increase of moisture loss from the skin but no cyclic pattern of sweat gland activity on exposure to heat. In this case, hyperthermia developed with a rise in oral temperature of 1.1 C in 52 minutes versus 0.4 C rise in the controls in a period of 63 minutes.