In a study comparing patients with each form of dementia with age- and sex-matched controls, surgeon Charles McCollum, M.D., of the University of Manchester and colleagues found that spontaneous brain blood clots were significantly more frequent in patients with Alzheimer's or vascular dementia.
The findings shows some dementias may be caused by silent cerebral infarctions or "mini-strokes." Both Alzheimer's and vascular dementia are associated with vascular risk factors such as smoking, hypertension, high cholesterol, and diabetes, as well as carotid atherosclerosis.
They speculated that spontaneous brain blood clots of vascular or cardiac origin, could be a common feature of both Alzheimer's disease and vascular dementia, together accounting for about 80% of all dementia cases.
During a single hour of transcranial Doppler monitoring, they found that spontaneous cerebral emboli occurred in 40% of the patients with Alzheimer's disease and in 37% of those with vascular dementia, but in only 15% and 14% of the respective controls. The remarkable frequency of spontaneous cerebral emboli during a single hour in patients with dementia raises the possibility that the true prevalence is even higher and that emboli would be detected in many more patients if they were monitored over several hours.
As expected, spontaneous blood clots in brain were associated with the dementia, but it doesn't mean blood clots in our brain may bring dementias necessarily. More researches need to be done.