This study suggests that ischemic tolerance may play a role in patients with ipsilateral TIAs before CI, allowing better recovery from a subsequent ischemic stroke.

Background: An impairment of cerebral microvessels is reported both in normal ageing and in senescence-associated processes, as well as in Alzheimer’s disease (AD) and vascular dementia (VaD). The aim of this study was to explore cerebral hemodynamics by transcranial Doppler in VaD and AD, compared with age-matched control subjects. Methods: Transcranial Doppler was investigated in all patients in the basal condition. Cerebral vasoreactivity to hyper- and hypocapnia was evaluated with CO₂ mixture inhalation followed by hyperventilation. Results: We studied 60 AD and 58 VaD patients and 62 nondemented controls. Both AD and VaD subjects showed lower flow velocities (FV) and higher pulsatility indices (PI) as compared with controls. Lower total vasomotor reactivity and lower response to hypercapnia were observed in the AD and VaD groups as compared with controls. AD and VaD patients did not show significant differences in FV, PI values or cerebral vasoreactivity. Conclusions: Reduced FV and increased PI with a significant vasoreactivity reduction in VaD and AD patients are indicators of impairment of cerebral microvasculature circulation in both diseases. The identification of vascular function impairment in all kinds of dementia could be of help in identifying patients who would thus benefit more from specific therapeutic approaches.

Background and Purpose-Adventitial vasa vasorum and plaque vascularization have been established as predictors of unstable atheromasic lesions in cerebro-and cardiovascular patients. Ultrasound contrast agents provide reliable information on tissue perfusion and microcirculation. We used contrast ultrasound duplex scanning to identify carotid plaque vascularization. Methods-Contrast carotid duplex scanning was performed in 23 patients with plaques of different degree of stenosis and echogenicity. Results-Plaque vascularization was detected in the fibrous and fibro-fatty tissue and not observed in the calcific nor in the necrotic and hemorrhagic tissue. Constantly, a small vessel was observed under ulcerations. Conclusions-Carotid contrast ultrasound imaging appears to be an emerging technique for identifying plaque angiogenesis. Further studies are needed to clarify the role of plaque angiogenesis for assessing cerebrovascular risk and to monitor effects of therapies aimed to plaque remodelling.

During the 4-year follow-up, the incidence of dementia increased gradually, shifting from an Alzheimer disease-type picture in the first years to a vascular dementia type later in years 2 to 4.