Orthostasis and Cerebral Autoregulation in MS, ORCA-MS, - Version 5
Research type
Research Study
Full title
Are Vascular Reactivity and Cerebral Autoregulation Impaired in Multiple Sclerosis?
IRAS ID
273393
Contact name
Richard Nicholas
Contact email
Sponsor organisation
Joint Research Compliance Office, Imperial College London
Duration of Study in the UK
0 years, 7 months, 16 days
Research summary
There is some evidence that dysregulation of cerebral blood flow underlies some of the features of MS. The human brain is intolerant of even mild reductions in cerebral blood flow (CBF) and so homeostatic mechanisms serve to keep CBF stable, even in the context of a changing systemic blood pressure, which might otherwise challenge CBF. The homeostatic mechanism intrinsic to the brain itself is termed Cerebral Autoregulation (CA). The primary aim of this study is to assess whether CA is impaired in subjects with MS compared to healthy controls. This study is a physiological study involving the collection of waveform physiological data from human subjects during a head up tilt (HUT) protocol, using a tilt table. All experiments will be performed in the Cardiac Investigations Unit in the main building of the Hammersmith Hospital. 20 subjects will be recruited initially. Of these, 10 will have MS and 10 will act as healthy controls. 5 patients with MS will also be invited to receive an MRI. During the HUT protocol, subjects will be instrumented with monitors to measure blood pressure continuously, CBF using transcranial Doppler ultrasound (TCD), heart rate and also cerebral tissue blood oxygenation and volume using near infrared spectroscopy (NIRS) probes. All measurement devices are non-invasive. The tilt table protocol will consist of 5 phases, each of ten minutes. The phases will alternate between the supine and the upright position. CA can be calculated using waveform data of CBF and blood pressure. Comparison can then be made of CA in subjects with and without MS. In addition, MRI images will allow an alternative approach to measuring CA. MRI images will also allow assessment for correlation between cerebral lesion burden and any degree of CA impairment.
REC name
London - Stanmore Research Ethics Committee
REC reference
19/LO/1999
Date of REC Opinion
17 Dec 2019
REC opinion
Favourable Opinion