Multi-infarct dementia and Alzheimer disease, contribution of cerebral circulation ultrasonography to pathogenesis and differential diagnosis. Value of microembolisation.

OBJECTIVES: Dementias are one of the most serious health and socioeconomic issues. Multi-infarct dementia (MID) and Alzheimer´s type dementia (AD) exhibit differences in cerebrovascular blood flow velocity profiles and in presence of microemboli, detected by transcranial Doppler sonography.

MATERIAL AND METHODS: A group of 77 persons was divided into 4 subgroups: 1. subgroup of patients with MID (n=19; 10 male and 9 female, mean age was 74.32±8.30 years); 2. subgroup of patients with AD (n=19; 11 male and 8 female, mean age was 70.37±87.85 years); 3. subgroup of patients with hypertension (n=19; 11 male and 8 female, age adjusted) and 4. sex and age adjusted control group (CG) of 20 persons without hypertension or other serious risk factors. The duplex ultrasonographic examination of extracranial and intracranial circulation was preceded by neurologic, neuropsychological and psychiatric examination. The presence of microemboli was determined using Multi Dop X2 device (maker DWL), 60 minutes monitoring. All patients underwent brain computer tomography (CT) or magnetic resonance imaging (MRI).

RESULTS: We found significantly higher incidence (68.4%, p=0.5267) of asymptomatic microemboli in ACM in the group of patients with MID compared to the AD group, the group of patients with hypertension and CG.

CONCLUSION: The occurrence of "asymptomatic" emboli in the middle cerebral artery in patients with multi-infarct dementia is higher in the current study. Although these microemboli do not cause immediate symptoms, the evidence suggests, that they may be a risk factor for cognitive impairment, especially for multi-infarct dementia.