Sydney:
Beware of the 'silent' stroke that doesn't leave any outward symptoms, but causes brain damage. It afflicts people over 60, especially those with high blood pressure.
"These strokes are not truly silent, because they have been linked to memory and thinking problems and are a possible cause of a type of dementia," said study author Perminder Sachdev, neuropsychiatry professor at the University of New South Wales (UNSW).
"High blood pressure (BP) is very treatable, so this may be a strong target for preventing vascular disease," said Sachdev, who did his MBBS and MD in 1978 and 1981 respectively from the All India Institute of Medical Sciences in New Delhi.
The study involved 477 people aged between 60 to 64 years who were followed for four years.
At the beginning, 7.8 per cent of the participants had the silent lacunar infarctions, small areas of damage to the brain seen on MRI that never caused obvious symptoms. They occur when blood flow is blocked in one of the arteries leading to areas deep within the brain, such as the putamen or the thalamus.
By the end of the study, an additional 1.6 per cent of the participants had developed 'silent' strokes, said an UNSW statement.
People with high BP were 60 per cent more likely to have silent strokes than those with normal blood pressure. Also, people with another type of small brain damage called white matter hyperintensities were nearly five times as likely to have silent strokes as those without the condition.
The study was published in Neurology journal.