Effect of Acetominophen an Gait Fatigue in Multiple Sclerosis

Persons with Multiple Sclerosis have difficulty with walking longer distances because of fatigue. The fatigue is in large part a result of heat sensitivity; during exercise the increase in metabolism results in increases in core temperature which reduces conduction through demyelinated nerves. Medications such as Acetaminophen are antipyretic which are used to reduce temperature in persons with a fever. Antipyretics may therefore result in lowering the temperature in persons with MS and allow them to walk longer distances. In this study, ambulatory persons with MS will be randomly assigned to receive either acetaminophen or a placebo. Participants will be blinded to which they receive. They will then perform a 25 foot walk test where they will be asked to walk 25 feet at their best comfortable speed. The walks will be 1 minute apart. The average speed of the 2 walks will be obtained. Subjects will then receive either the acetaminophen or the placebo and rest for 45 minutes so that the medication can reach peak effect, and then will walk on a treadmill at the previously obtained speed until they can no longer maintain the original speed, or they wish to stop. One week later subjects will return and take whichever pill they did not take the first time. We hypothesize that subjects who take the antipyretic will walk for a longer period than those who took the placebo. If our hypothesis is correct, it will suggest that antipyretics should be further investigated as a means of addressing thermosensitivy leading to gait fatigue in persons with MS