Cardiovascular autonomic dysfunction in multiple sclerosis: Correlation with orthostatic intolerance
Julius-Maximilians-Universität Würzburg. Journal of Neurology
(Impact Factor: 3.38).
07/1999; 246(7):578-86. DOI: 10.1007/s004150050407
Autonomic dysfunction is frequently observed in patients with multiple sclerosis (MS), but clinical studies disagree on the frequency and type of abnormalities in autonomic function tests. Orthostatic dizziness (OD) has been reported in up to 49% of patients, but the pathophysiological mechanisms are poorly understood. This study investigated cardiovascular reflex tests and their association with OD in patients with MS in order to examine the hypothesis that the sympathetic nervous system is specifically involved in these patients. Forty patients with clinically active relapsing-remitting (n = 27) and secondary progressive MS (n = 13), aged 35.0+/-8.5 years, were studied by parasympathetic (heart rate responses to the Valsalva maneuver, deep breathing, and active change in posture) and sympathetic function tests (blood pressure responses to active change in posture and sustained handgrip), and by spectral analysis of heart rate variability during rest and during standing. Results were compared to those obtained in 24 healthy volunteers, aged 29.4+/-7.2 years. A standardized questionnaire was used to evaluate symptoms of orthostatic intolerance. Abnormal responses on at least one cardiovascular reflex test were observed in 40% of MS patients, compared to 17% of the control group, with a statistically significant involvement of the sympathetic vasomotor system. Orthostatic intolerance was reported in 50% of patients (controls: 14%, P<0.006). Subgroup comparison of patients with and without OD suggests that orthostatic intolerance results from impaired sympathetic vasoconstriction. These results provide further evidence that the sympathetic nervous system is involved in patients with MS.
Available from: Ollie Jay
- "The prevalence of impairments in the autonomic control of cardiovascular function in MS patients from the previous studies has ranged from 7% to 60% when using standard tests, including the Valsalva maneuver, hand grip test, deep breathing, and standing test (Acevedo et al., 2000; Flachenecker et al., 2001, 2003, 1999; Frontoni et al., 1996; Nasseri et al., 1998; Pentland and Ewing, 1987; Sanya et al., 2005; Senaratne et al., 1984; Sterman et al., 1985; Vita et al., 1993). Keller et al. recently reported that direct measures of spontaneous, resting muscle sympathetic nerve activity (MSNA) were reduced in MS patients compared to healthy individuals (Keller et al., 2014). "
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ABSTRACT: Multiple sclerosis (MS), a progressive neurological disease, can result in autonomic dysfunction. Impairments in the autonomic control of cardiovascular and thermoregulatory function during exercise have been observed in MS. Attenuated elevations in blood pressure during exercise in MS patients can negatively impact blood flow to skeletal muscle. Diminished sweating during exercise may impair heat dissipation likely limiting the exercise intensity that can be performed before detrimental core temperatures are reached. Further understanding the physiologic mechanisms of autonomic dysfunction during exercise in MS may lead to the development of novel therapeutic strategies targeted at improving quality of life in individuals with this disease.
Copyright © 2014. Published by Elsevier B.V.
Available from: Dominique Hansen
- "Anomalies in the cardiac autonomic function in MS patients can be observed by measuring heart rate (HR) and/or blood pressure responses to Valsalva maneuver, deep breathing and active changes in posture, and/or changes in blood pressure during sustained handgrip (Acevedo et al., 2000; Flachenecker et al., 1999; Gunal et al., 2002; Senaratne et al., 1984). These data suggest that demyelinating plaques interfere with autonomous nervous system descending fibers in the spinal cord and/or damage the vasomotor centres in the brainstem (Acevedo et al., 2000; Flachenecker et al., 1999; Gunal et al., 2002; Senaratne et al., 1984). More often patients with MS are being referred to rehabilitation centers to participate in exercise interventions because of an impaired exercise capacity (White et al., 2004). "
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ABSTRACT: To explore the etiology of exercise intolerance in patients with MS, it is analyzed whether a disturbed cardiac autonomic control could be observed during exercise testing in patients with MS, and is related to exercise tolerance.
From 26 MS patients and 15 healthy subjects, exercise-onset (first 20 and 60 seconds) and -offset (1-minute recovery) HR change was determined during a 6-minute constant-load exercise bout on bike. Blood lactate, HR, oxygen uptake, expiratory volume and perceived exertion were assessed during exercise, and compared between groups. In 15 MS patients, a 6-min walking test was executed.
Twenty-second exercise-onset HR increase was significantly smaller in MS patients (14 ± 7 bts/min) vs. healthy subjects (20 ± 8 bts/min, p < 0.05), and independently related to MS and age in total group (p < 0.05). Sixty-second exercise-onset and -offset HR changes were not different between groups, nor independently related to MS presence (p > 0.05). A significant correlation was found between 20-second exercise-onset HR increase and walking capacity in MS patients (r = 0.64, p < 0.01).
In MS patients, the early increase in heart rate during endurance exercise is significantly slowed, indicating a disturbed cardiac autonomic control, and is related to exercise tolerance.
Available from: Paolo Galluzzi
- "– Finally, an abnormal compliance of venous vessel wall might be due to MS affecting the autonomous nervous system.  "
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ABSTRACT: Internal Jugular Veins (IJVs) are the principle outflow pathway for intracranial blood in clinostatism condition. In the seated position, IJVs collapse, while Vertebral Veins (VVs) increase the venous outflow and partially compensate the venous drainage. Spinal Epidural Veins are an additional drainage pathway in the seated position. Colour- Doppler-Sonography (CDS) examination is able to demonstrate IJVs and VVs outflow in different postural and respiratory conditions. The purpose of this study was to evaluate CDS quantification of the cerebral venous outflow (CVF) in healthy subjects and patients with multiple sclerosis (MS).
In a group of 27 healthy adults (13 females and 14 males; mean age 37.8 ± 11.2 years), and 52 patients with MS (32 females and 20 males; mean age 42.6 ± 12.1 years), CVF has been measured in clinostatism and in the seated position as the sum of the flow in IJVs and VVs. The difference between CVF in clinostatism and CVF in the seated position (ΔCVF) has been correlated with patients' status (healthy or MS), and a number of clinical variables in MS patients. Statistical analysis was performed by Fisher's exact test, non-parametric Mann-Whitney U test, ANOVA Kruskal-Wallis test, and correntropy coefficient. The value of ΔCVF was negative in 59.6% of patients with MS and positive in 96.3% of healthy subjects. Negative ΔCVF values were significantly associated with MS (p<0.0001). There was no significant correlation with clinical variables.
Negative ΔCVF has a hemodynamic significance, since it reflects an increased venous return in the seated position. This seems to be a pathologic condition. In MS patients, a vascular dysregulation resulting from involvement of the autonomous nervous system may be supposed. ΔCVF value should be included in the quantitative CDS evaluation of the cerebral venous drainage, in order to identify cerebral venous return abnormalities.
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