Preventing strokes has reduced dementia cases: study

A new study has found that preventing strokes reduces dementia in the elderly.

Researchers from Western University, the Lawson Health Research Institute and the Institute for Clinical Evaluative Sciences looked at data on stroke and dementia in Ontario in the most at-risk group, those 80 years of age and older, and found that a province-wide stroke prevention strategy implemented over the past 12 years has not only lowered new cases of stroke diagnoses by 37.9 per cent but decreased the incidence of dementia by 15.4 per cent for that age group.

“Some have said we’re on the cusp of an epidemic of dementia as the population ages,” said Joshua Cerasuolo, a PhD candidate in epidemiology and biostatistics at Western’s Schulich School of Medicine and Dentistry, and co-author of the study, in a press release. “What this data suggests is that by successfully fighting off the risks of stroke -with a healthy diet, exercise, a tobacco-free life and high blood-pressure medication where needed – we can also curtail the incidence of some dementias.”

First implemented in 2000, Ontario’s Integrated Stroke Strategy involved a $70-million commitment over four years from the province along with $30 million annually going forward, with the aim of decreasing the incidence of stroke, the fourth leading cause of death in Canada. Improved patient care, more effective responding to those at risk or who have had a stroke and wider promotion of the preventative lifestyle changes were all made central tenets of the approach, which so far has paid huge dividends. A 2006 report found that between 1997 and 2003, acute hospitalizations for stroke in Ontario decreased by 11.2 per cent from 20,382 to 18,098, despite population growth and an aging demographic in the province.

The new results are a testament to the interconnectedness of stroke and dementia, both of which are caused by a lack of blood flow to the brain. Dr. Vladimir Hachinski, clinical neuroscientists at Western’s Schulich School, says that people who have had a stroke are twice as likely to develop dementia and that those diagnosed with stroke have often had several “silent” strokes prior to diagnosis, which themselves can affect cognitive abilities.

“As clinicians and researchers, we are still trying to get a handle on how to reduce a person’s chances of dementia late in life. Some we can’t influence – yet – but here is a pretty clear indication that we can take specific definitive steps to reduce our chances of dementia related to vascular disease,” Hachinski said.

The researchers looked at data from 5.5 million Ontarians and correlated the incidence rates of stroke and dementia between the years 2002 and 2013. Along with the decrease in the rate of stroke for those 80 and over, the study found significant decreases in stroke in the 50 to 64 and 65 to 79 age groups, as well.

The new study is published in Alzheimer’s & Dementia – the Journal of the Alzheimer’s Association.