Stimulating parts of the brain with electrodes can change a patient's blood pressure, researchers have found.
The electrodes stimulate very specific brain regions
Although this may seem a drastic way to treat hypertension, the authors say it could help in most extreme cases where conventional therapy has failed.
It also sheds light on where in the brain blood pressure is controlled which could lead to new treatments.
The findings from Imperial College London and Oxford University are published in Neuroreport.
The team of neurosurgeons and physiologists discovered the blood pressure effects while fitting brain electrodes to 15 patients for pain control.
Deep brain stimulation involves placing very thin electrodes on very exact locations in the brain and is already used to relieve pain and to help Parkinson's disease patients with their movement.
The researchers found that they could make patients' blood pressure increase or decrease by stimulating very specific regions of the brain with the electrodes - the dorsal or ventral periventricular and periaqueductal grey matter, respectively.
Lead author of the paper Alexander Green said: "Obviously, as this is brain surgery, we have to proceed with great caution.
"It would initially only be warranted in those patients for whom drug treatments just aren't working.
"However, other research groups are working on less invasive methods of stimulating exact locations in the brain, for example using nanotechnology, and if this becomes available then the treatment would be attractive to a much larger number of people."
In the UK, about one in five people, at least 10 million, have high blood pressure or hypertension.
Professor Peter Weissberg, medical director at the British Heart Foundation, said: "It has been known for some time that the brain can affect blood pressure.
"Although this research will help us understand better which parts of the brain are involved in blood pressure control, it is unlikely that this approach would be used to control high blood pressure in most heart patients because we already have other effective and well tolerated medicines are available to us.
"However, a very small number of patients have postural hypotension - a fall in blood pressure upon standing up - which can be debilitating and difficult to treat with existing medicines. This research may open up new avenues to treat these heart patients."