The Effect of Multiple Sclerosis on Carotid Baroreflex Control of Heart Rate and Blood Pressure

Abstract

Multiple sclerosis (MS), a progressive neurological disease, can result in impairments in autonomic control of cardiovascular function. We tested the hypothesis that patients with MS (n=5) exhibit a blunted response following baroreflex perturbation compared to sex and age matched healthy controls (CON: n=5). At rest, 5‐sec pulses of neck suction (NS; ‐60 Torr) and neck pressure (NP; +40 Torr) were applied to simulate carotid hypertension and hypotension, respectively. Mean arterial pressure (MAP; finger photoplethysmography) and heart rate (HR) were continuously measured in response to the perturbations. Following NS, responses in MAP (MS: ‐11±5 mmHg, CON: ‐10±3 mmHg; p=0.59) and HR (MS: ‐8±3 BPM, CON: ‐8±4 BPM; p=0.93) were similar between groups. While HR response (MS: 5±5 BPM, CON: 5±4 BPM; p=0.94) following NP was no different, a difference in MAP approached significance (MS: 6±2 mmHg, CON: 8±2 mmHg; p=0.09). These data suggest that patients with MS demonstrate a diminished ability to increase MAP to hypotensive stimuli compared to healthy controls.
 Supported by NIH R15HL117224 and National MS Society RG4696A