Autonomic and Cardiac Testing in Multiple Sclerosis Patients Complaining Fatigue During Rehabilitative Treatment

In Multiple Sclerosis (MS) abnormalities of autonomic nervous system and cardiac parameters have been reported separately. Our objectives were to investigate whether MS patients with moderate disability and autonomic dysfunction presented alterations in cardiac function under stress and to see whether these changes contribute to MS fatigue. In 33 MS patients we examined the cardiovascular autonomic system and the echocardiographic parameters (stroke volume and ejection fraction) at rest and under stress. Fatigue has been assessed by a self-reported measure, the Fatigue Severity Scale. We have found a statistically significant correlation between the findings of cardiovagal tests and changes in cardiac parameters under stress with the degree of self-evaluated fatigue. Our results suggest that a relationship between the autonomic dysfunction and blunted cardiac response under stress might exist and can contribute to perception of fatigue. This physiopathological mechanism may be one aspect of the complex and multidimensional MS fatigue.