Does cerebrovascular reserve capacity (CVRC) measured by Transcranial Doppler differ between symptomatic and asymptomatic patients with >70% internal carotid artery stenosis?
CVRC measured by TCD is significantly reduced in symptomatic compared to asymptomatic patients with severe carotid stenosis, suggesting its potential utility as an early marker for stroke risk.
Cerebrovascular reserve capacity (CVRC) is a hemodynamic parameter indicating the brain's capacity to overcome ischemia. Transcranial Doppler (TCD) is a useful device to measure CVRC, with high availability and low cost. The aim of the study is to investigate asymptomatic patients with affected CVRC, who could benefit from CEA. One hundred and forty five consecutive patients (60 symptomatic and 65 asymptomatic), with internal carotid artery (ICA) stenosis >70 % and 20 healthy individuals without internal carotid stenosis underwent TCD-inhalation CO(2) tests in order to measure the CVRC in both hemispheres of each patient. CVRC between asymptomatic and symptomatic patients were significantly different in the 95 % confidence interval (CI) as well as the mean CVRC value in contralateral carotid artery. The correlation between CVRC in the carotid artery with stenosis and the existence of symptoms is significant at the 0.01 level. Additionally, symptoms and CVRC of the contralateral carotid artery are also significant at the 0.05 level and CVRC values in asymptomatic patients and the control group at the 0.01 level. None of the covariant factors, except the age, are significantly correlated with CRVC. CVRC could be an early mark-index to evaluate the risk of stroke in this group of patients and to design their therapeutic approach.
DOUVAS et al. (Sun,) studied this question.