Novel therapy may help prevent dementia

Scientists have found a way to reverse the most common cause of dementia in rats, an advance that may pave the way for new therapies to prevent the neurodegenerative disorder in humans.

The treatment can reverse changes in blood vessels in the brain associated with the condition, called cerebral small vessel disease.

It also prevents damage to brain cells caused by these blood vessel changes, according to a study published in the journal Science Translational Medicine.

Small vessel disease, or SVD, is a major cause of dementia and can also worsen the symptoms of Alzheimer's disease. It is responsible for almost half of all dementia cases in the UK and is a major cause of stroke, accounting for around one in five cases.

Patients with SVD are diagnosed from brain scans, which detect damage to white matter - a key component of the brain's wiring.

Until now, it was not known how changes in small blood vessels in the brain associated with SVD can cause damage to brain cells.

"This important research helps us understand why small vessel disease happens, providing a direct link between small blood vessels and changes in the brain that are linked to dementia," said Anna Williams, a scientist at the University of Edinburgh in the UK.

"It also shows that these changes may be reversible, which paves the way for potential treatments," Williams said.

Dementia is one of the biggest problems facing society, as people live longer and the population ages, according to the researchers.

They found that SVD occurs when cells that line the small blood vessels in the brain become dysfunctional.

The dysfunctionalities in the brain's small blood vessels cause them to release a molecule which prevents the production of myelin - a protective layer that surrounds brain cells - resulting in brain damage.

Treating the brain damage with drugs that stop the dysfunctionalities reversed the symptoms of SVD, the researchers said.

"Changes to the blood supply in the brain play an important role in Alzheimer's disease as well as being a direct cause of vascular dementia," said Sara Imarisio from Alzheimer's Research UK.

"This pioneering research highlights a molecular link between changes to small blood vessels in the brain and damage to the insulating 'white matter' that helps nerve cells to send signals around the brain," said Imarisio.

"The findings highlight a promising direction for research into treatments that could limit the damaging effects of blood vessel changes and help keep nerve cells functioning for longer," she said.

Further studies will have to be done to test whether the treatment also works when the disease is firmly established and to check if the treatment can reverse the symptoms of dementia, the researchers said.