This Is MS Multiple Sclerosis Community: Knowledge & Support

The relationship between the metabolic, thermal load of exercise, sudomotor (sweat) response, and core temperature was examined in 20 individuals with multiple sclerosis (MS) and eight non-MS control subjects. Participants performed an incremental bicycle test of maximal aerobic power (VO2peak) from which 50% of VO2peak was calculated. A 50% VO2peak endurance test was performed while subject wore a full-body water garment. Initial circulating water temperature of 27°C was increased 2°C every three minutes to enhance the thermal load. Core, skin, and circulating water temperatures were monitored. Onset of sweating was measured at five sites. Results showed that 50% of the subjects with MS had an abnormally low sweat response in spite of relatively high skin temperatures (> 35°C) at several sites. The thermal load (kJ/kg) of these subjects at test termination was 89% higher than that of the MS subjects with a normal sweat response.

Based upon the percentages from the present study, we might anticipate that 50% of any given sample of subjects might have a problem with normal sweating. Furthermore, if individuals with MS indicate that they do not sweat, there is a 70% likelihood that they are correct in their observation.

Results showed that 50% of the subjects with MS had an abnormally low sweat response in spite of relatively high skin temperatures (> 35°C) at several sites. The thermal load (kJ/kg) of these subjects at test termination was 89% higher than that of the MS subjects with a normal sweat response.

The abnormally high thermal load: could that be related to heat intolerance? In the shower, I am OK, as long as the water is cool enough. Past a very narrow temperature point, I shut down. Could the lack of sweat be causing some fatigue, dizziness, loss of control, due to inadequate cooling?

Or could the lack of sweating be actually the cause of thermal load as sweating is a mechanism to cool down inner temperature...

I wonder if there is a difference in this lack of sweating between RRMS and SPMS... It's only when I became SPMS that I noticed this problem... But sometimes I have drenching nightsweats though... weird...