Aged people at risk for silent stroke

People over the age of 60 years, especially those with high blood pressure, may experience a silent stroke and won't even know it.

Silent lacunar infarcts are strokes in which blood flow is blocked in one of the arteries leading to areas deep within the brain. As they do not cause any noticeable symptoms, they are referred to as silent lacunar infractions. 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.

Common signs of stroke are: sudden weakness or numbness of the arms, legs or face, especially on one side, quick onset of blurred vision in one or both eyes, difficulty in walking, dizziness, or loss of balance or coordination, sudden confusion or trouble speaking,or sudden severe headache with no known cause.

Researchers studied 477 Australians aged 60 to 64 years for four years to investigate the prevalence and risk factors of lacunar infraction. Demographic information and risk factor data was collected through MRI brain scans, four years apart.

It was found that 8 percent of the group had evidence of strokes that do not cause any noticeable symptoms. An additional 2 percent of the group had experienced silent strokes by the end of the fourth year. Those with high blood pressure had a 60 percent higher chance of having a silent stroke than those with normal blood pressure. Also, the participants with a condition called white matter hyperintensities were almost five times more likely to have a silent stroke than those without this small type of brain damage.

The researchers concluded that, although relatively symptom-free, silent strokes are a major health problem among the elderly. People who have had a silent stroke are at higher risk for subsequent strokes and for an accelerated loss of mental skills. In addition to high blood pressure, risk factors include diabetes, heart disease, smoking and older age.