Dementia ‘can be caused by hypertension’

People with high blood pressure are at a higher risk of developing dementia, according to a new study published in the journal Cardiovascular Research.

This research also shows (for the first time) that an MRI can be used to detect very early signatures of neurological damage in people with high blood pressure, before any symptoms of dementia occur.

High blood pressure is a chronic condition that causes progressive organ damage. It is well known that the vast majority of cases of Alzheimer’s disease and related dementia are not due to genetic predisposition but rather to chronic exposure to vascular risk factors.

The study was carried out on patients with no sign of structural damage and no diagnosis of dementia. All patients underwent clinical examination to determine their hypertensive status.

The result indicated that hypertensive patients showed significant alterations in three specific white matter fiber-tracts. Hypertensive patients also scored significantly worse in the cognitive tests, showing decreased performances in executive functions, processing speed, memory and related learning tasks.

Overall, white matter fiber-tracking on MRIs showed an early signature of damage in hypertensive patients when otherwise undetectable by conventional neuroimaging.

Giuseppe Lembo, the study’s co-ordinator, said: ‘The problem is that neurological alterations related to hypertension are usually diagnosed only when the cognitive deficit becomes evident, or when traditional magnetic resonance shows clear signs of brain damage. In both cases, it is often too late to stop the pathological process.’

‘We have been able to see that, in the hypertensive subjects, there was a deterioration of white matter fibres connecting brain areas typically involved in attention, emotions and memory. An important aspect to consider is that all the patients studied did not show clinical signs of dementia and, in conventional neuroimaging, they showed no signs of cerebral damage. Of course, further studies will be necessary, but we think that the use of tractography will lead to the early identification of people at risk of dementia, allowing timely therapeutic interventions.’