Relation of postischemic delayed hypoperfusion and cerebral edema after transient forebrain ischemia.

Postischemic delayed hypoperfusion (PDH) is based on the imbalance between local vasodilators and vasoconstrictors. We evaluated the time course of cerebral blood flow and cerebral specific gravity representing cerebral edema after transient forebrain ischemia induced by bilateral occlusion of the common carotid arteries in anesthetized gerbils to determine whether PDH is a significant factor in development of cerebral edema. PDH appeared 45 minutes after reperfusion followed by the increase of cerebral edema. Thereafter, the local cerebral blood flow recovered from PDH 24 hours after reperfusion in spite of the stable cerebral specific gravity. Furthermore, cerebral specific gravity established a linear correlation with the local cerebral blood flow 120 minutes after reperfusion in the 3 different durations of cerebral ischemia (30, 60, and 90 minutes). It is suggested that cerebral edema is not the cause in PDH development, but PDH may cause cerebral edema.

Smoking, fasting serum insulin, and obesity are the predictors of carotid atherosclerosis in relatively young subjects.

The purpose of this study was to identify predictors of atherosclerosis in a healthy young cohort comprised of 241 subjects who underwent a regular employee medical check-up at Ohshima National Sanatorium over a 9-month period. All subjects underwent carotid ultrasound examinations to determine maximal common carotid artery intima media thickness. In addition, serum total cholesterol, triglycerides, high-density lipoprotein cholesterol, blood urea nitrogen, creatinine, glucose, and insulin were evaluated. The subjects were relatively young (mean age, 44 years; range, 18 to 62 years), with 130 females (54%) and 111 males (46%). Maximal common carotid artery intima media thickness was predicted by smoking habit, body mass index, fasting blood sugar, fasting serum insulin, and systolic blood pressure (F(5,235) = 52.8, P < 10(-5)). There was clear separation in common carotid artery intima media thickness values based on body mass index, smoking, and fasting serum insulin, and somewhat more overlap with systolic blood pressure and fasting blood sugar. These findings suggest that smoking and high values of body mass index, fasting serum insulin, systolic blood pressure, and fasting blood sugar are warning factors for early atherosclerosis development, and could conceivably serve as the basis of diagnostic screening. Smoking is particularly deleterious, as smokers with high body mass index, high fasting serum insulin, or high systolic blood pressure tend to have larger common carotid artery intima media thickness values than would have been predicted by consideration solely of the individual risk factors.

Carotid turbulent flow observed by convergent color Doppler flowmetry in silent cerebral infarction.

AIM: A newly developed convergent color Doppler (CCD) was used for evaluating the possible relationship of the flow dynamics of the internal carotid artery to silent cerebral infarction (SCI). METHODS: In 108 patients (65+/-8 years) with stroke risk factors, the CCD simultaneously images information, on both flow direction and Doppler signal energy. The relation between turbulent flow and the incidence of brain lesions of SCI as identified by magnetic resonance imaging was investigated in 212 vessels, excluding four occluded vessels. Percent area stenosis was measured as (vessel area - lumen area)/(vessel area) on cross-sectional echo image of stenotic site. RESULTS: Incidence of turbulent flow in SCI patients with 50-70% or 70-90% stenosis was higher (76.5 or 59.1%) than that in non-SCI patients (17.4 or 33.3%, both p < 0.0001). CONCLUSION: Non-invasive assessment of flow dynamics by CCD imaging can be useful for proposing the early stages of brain damage even in patients free from neurological deficits.