Use of rheoencephalography for primary stroke prevention

Stroke is the third leading cause of death worldwide and the most frequent cause of brain damage in adults. Screening for arteriosclerosis at an early stage of disease could detect high-risk individuals and populations before the onset of stroke. Doppler ultrasound, the traditional method to detect carotid disease, is expensive and difficult to administer on a large scale. The aim of this study was to test the applicability of a computerized screening system utilizing rheoencephalography (REG) to identify individuals at high-risk for stroke. REG estimates cerebrovascular alteration caused by arteriosclerosis, expressed as the elongated rise time of the REG pulse wave. Methodology was previously published^{1, 2}. Data were collected in a rural area (Hungary) using the computerized screening system to record risk factors for arteriosclerosis, including a history of transient ischemic attack. Carotid flow (CF) data measured by Doppler ultrasound were also collected for comparison. A cross-sectional survey was conducted for 546 people (REG, N=390; CF, N=252). Subjects' blood chemistry data and EKG were also assessed. In evaluating elasticity of brain arteries, the REG standard originally established by Jenkner was modified. A REG peak time of 180 ms or above (CF: mean velocity above 40 cm/sec) was considered a cerebrovascular alteration ³ . REG and Doppler (CF) data: sclerotic brain arteries estimated by REG were 52.78% (m) and 55.8% (f). Pathologic CF was 29.41% (m) and 39.08% (f). The regression lines of age versus REG rise time and CF in male and female groups were similar, but the slope of REG was about ten times steeper than that of CF^{1, 4}. Brain vessel responses (CBF autoregulation) have been found to be size dependent. Previous results support the hypothesis that REG reflects CBF autoregulation (arteriolar functioning). Animal studies have shown that REG may reflect CBF autoregulation more accurately than Doppler. These results are consistent with REG literature indicating that an increase in REG rise time indicates decreased arteriolar elasticity. REG rise time may be the earliest sign of cerebrovascular sclerosis, indicating the presence of disease at an earlier stage than Doppler. The computerized system utilizing REG is simple to administer, non-invasive, cheap, and has potential as a tool for mass screenings of target populations.