Alzheimer's disease and vascular dementia account for 80% of all dementias but the cause was unknown.
They monitored the occurrence of spontaneous cerebral emboli in 170 patients with dementia (85 with Alzheimer's disease, 85 with vascular dementia) and 150 controls of the same sex and age.
They detected cerebral emboli in 32 (40%) of patients with Alzheimer's disease and 31 (37%) of those with vascular dementia in only one hour of monitoring, compared with just 12 each (15% and 14%) of their controls. This suggests that both types of dementia have more in common than we've thought before, say the authors.
This study is the first of this type and more research is needed, but the authors conclude that spontaneous cerebral emboli are significantly associated with both Alzheimer's disease and vascular dementia and may represent a potentially preventable or treatable cause of both types of dementia.