Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

Researchers in our Centre for the Prevention of Stroke and Dementia have begun a clinical trial to assess whether the drug sildenafil could improve blood flow to the brain.

Model brain © Robina Weermeijer/Unsplash

Chronic damage to small blood vessels deep in the brain is found in half of patients over the age of 60 and almost all patients over the age of 80, and is responsible for up to a third of strokes and around 40 per cent of dementia.​

Dr Alastair Webb, of the Wolfson Centre for Prevention of Stroke and Dementia, is leading the study. He explained: 'There is limited evidence for how this small vessel disease develops and no specific treatment. We aim to test whether sildenafil has the potential to reduce small vessel damage.'

Potential explanations for how small vessel disease develops include: a greater change in blood pressure with each beat of the heart (pulsatility), which hits the brain with increased force with each beat; or a reduced ability of the blood vessels in the brain to adapt to changes in the environment, also known as their reactivity.

Sildenafil is currently used to open up blood vessels in patients with erectile difficulties or poor blood supply to​ the lungs.

This trial, which is supported by the NIHR Oxford Biomedical Research Centre and the Wellcome Trust, will test sildenafil against a placebo tablet and against a similar drug called cilostazol in 75 patients​ who have had a stroke or mini-stroke previously and who also have evidence of injury to their small blood vessels on a brain scan.

'We will compare three weeks of treatment with sildenafil, cilostazol and the placebo to assess whether they improve pulsations in blood flow or reactivity of blood vessels in the brain,' Dr Webb said.

This will be measured using an ultrasound scanner whilst participants breathe air or a mixture of air and six percent carbon dioxide. To understand why any changes occur, the team will also measure the stiffness of arteries, the blood pressure at the heart and the body’s blood pressure control mechanisms.

Finally, 30 participants will have similar tests whilst undergoing an MRI brain scan to test changes in blood flow to the brain in even greater detail.​

This study will test whether these ‘vasodilating’ medications – drugs that widen the blood vessels – are good candidates to reduce the progression of small vessel disease in future clinical trials, and so reduce the risk of stroke and dementia.

'This would be the first specific treatment for this very common condition that is responsible for a significant amount of disability,' Dr Webb explained.

The trial is expected to last around two years.

Similar stories

Study reveals association between diagnosis of a neuropsychiatric condition and severe outcome from COVID-19 infection, and other severe acute respiratory infections

New research from the University of Oxford has shown an increased risk of severe illness and death from both COVID-19 and other severe respiratory infections, such as influenza and pneumonia, among people with a pre-existing mental health condition.

New study shows clinical symptoms for Alzheimer’s can be predicted in preclinical models

Establishing preclinical models of Alzheimer’s that reflect in-life clinical symptoms of each individual is a critically important goal, yet so far it has not been fully realised. A new collaborative study from the University of Oxford has demonstrated that clinical vulnerability to an abnormally abundant protein in Alzheimer’s brain is in fact reflected in individual patient induced pluripotent stem cell-derived cortical neurons.

Visit from the Sir Jules Thorn Charitable Trust

Earlier this month, we were delighted to welcome the Director of the Sir Jules Thorn Charitable Trust, Richard Benson, and its Chair of Trustees, Liz Charal.

Oxford receives £122m funding for healthcare research

Health and care research in Oxford is to receive £122 million in government funding over the next five years to improve diagnosis, treatment and care for NHS patients. Our department will play a major role.