Increased dementia risk after stroke

Aug 20 2004

One in four stroke victims will suffer from cognitive impairment severe enough to be diagnosed as dementia within three to six months of the attack, according to new research from the University of New South Wales.

The findings from the Sydney Stroke Study, which monitored 210 stroke victims, were presented at a recent international conference on Alzheimer's disease in the United States and are to be published in the journal Neurology.

"In the public's mind, stroke is usually associated with physical disability, rather than cognitive change," said Professor Perminder Sachdev of the School of Psychiatry in the Faculty of Medicine. "Neurologists have long known about this, but there has been less emphasis and relatively little research on this aspect of strokes."

A quarter of the stroke victims in the study developed vascular dementia, the second most common form of dementia after Alzheimer's disease.

"If you examine the brain of a stroke victim, you see evidence of a lot of lesions, either due to silent strokes or other consequences of reduced blood supply, that were likely to have been present prior to the stroke," said Professor Sachdev.

"When they have a big stroke and come to hospital, there is accumulated damage. They often have Alzheimer's type pathology as well. The combination of the two results in dementia".

Another of the key findings is that education is a protective factor against decline in stroke patients. "A low-level of education is a genuine risk factor for accelerated memory decline in elderly people and patients with dementia," he said.

Professor Sachdev, along with UNSW Professors Henry Brodaty and Gavin Andrews, also of the School of Psychiatry, have been awarded a $4.6 million grant from the NHMRC for a five year study to look at neurocognitive diseases in the elderly.

Professor Brodaty predicted that we could eventually see people take a daily drug to prevent dementia from taking hold. "The developments in this field are progressing very rapidly".