Changes in Autonomic Nervous System in Patients with Multiple Sclerosis

Abstract
Background: Multiple sclerosis (MS) is one of the most disabling neurological disorders, in which autonomic impair-ment is not rare.
Aim of Study: To assess the frequency of cardiovascular (CV) autonomic dysfunction in MS patients as well as to relate these autonomic abnormalities to the brainstem dys-functions in thoe patients evidenced by brainstem auditory evoked potential (BAEP) studies.
Patients and Methods: We studied 20 patients with clin-ically definite relapsing remitting MS and 20 gender and age matched healthy control. The patients were evaluated clinically using expanded disability status scale (EDSS). Autonomic functions were evaluated with blood pressure response to both standing and static exercise (sympathetic), and 24-hour elec-trocardiographic (ECG) recording, time domain (parasympa-thetic). Brain stem auditory evoked potential was performed to all patients. Data were statistically analyzed using Epi-info software version 6.04.
Results: The MS patients included 11 (55%) males and nine (45%) females with a mean age of 29.8-}8.4 years, whereas control group was composed of five (50%) males and five (50%) females with a mean age of 34.2±13.4 years. Regarding tests of CV autonomic functions, 13 (65%) patients had at least one abnormal test. The results showed statistically significant differences in all CV autonomic tests when com-paring MS patients to controls. We found significant correla-tions between autonomic tests with duration of the disease. Significant correlations were detected between autonomic tests and brainstem lesions. BAEP findings were indicative of brainstem affection and there was a significant correlation between autonomic tests and I-V inter peak latency.
Conclusion: These results suggest that a significant number of patients with MS show evidence of CV autonomic dysfunc-tion, which is correlated with brainstem function.