Evaluation of Vasomotor Reactivity by Transcranial Doppler Sonography in Patients With Acute Stroke Who Have Symptomatic Intracranial and Extracranial Stenosis

Abstract

Objective. In patients with large artery disease, determining the cerebral hemodynamic state and following its alterations may be a good marker for predicting long-term outcome. The aim of our study was to compare the changes in vasomotor reactivity (VMR) of patients with symptomatic intracranial and extracranial artery stenosis. We also examined whether VMR after stroke influences the long-term prognosis for these patients. Methods. Forty-one patients were included in the study. To determine the cerebral hemodynamic state, transcranial Doppler ultrasound examinations and acetazolamide tests were performed after acute stroke and repeated after 6 months. We compared the VMR on admission and at 6 months, together with changes in VMR, of the patients with symptomatic intracranial and extracranial artery stenosis. By calculating the Barthel index at 6 months, we examined whether VMR had an effect on an improvement in their quality of life. Results. We observed a significantly higher initial VMR of the ipsilateral hemisphere in patients with intracranial stenosis (22.4 ± 9.1 versus 13.4 ± 12.8; P = .013). At 6 months, the VMR obtained from the ipsilateral hemisphere was better in patients with extracranial stenosis than in the patients with intracranial stenosis (P = .01). The ipsilateral VMR measured on admission showed a positive correlation with the Barthel index at 6 months (P = .007; r = 0.434). Conclusions. Our study showed that VMR in patients with acute stroke who have extracranial and intracranial artery stenosis measured by using a transcranial Doppler examination may have value in predicting long-term outcome. Key words: large artery atherothrombosis; transcranial Doppler examination; vasomotor reactivity. erebral insufficiency is associated with the presence of severe stenotic disease of the carotid arteries. 1 The risk of carotid artery stenosis increases with age. It has been reported that of the population older than 75 years, 7% of the women and 9% of the men had internal carotid artery (ICA) stenosis of more than 50%; however, of the population younger than 50 years, only 1% had ICA stenosis of more than 50%.2 Intracranial stenosis represents approximately 8% to 12% of all ischemic strokes. 3Vasomotor reactivity (VMR) is used to evaluate cerebral perfusion reserve. Vasomotor reactivity is the capacity of cerebral circulation to respond to vasomotor stimuli and shows the vasodilatator capacity of cerebral arterioles.

Current diagnosis and management of symptomatic intracranial atherosclerotic disease

“…[36] Impaired VMR has been used to identify those patients who are at a high-risk for stroke in both intra- and extracranial large vessel disease. [37,40] TCD with CO 2 challenge correlates with degree of stenosis in IAD. [41] Using acetazolamide Xenon-SPECT, impaired VMR has been reported in 14–33%, with annual risk of ipsilateral stroke 17.4–21.8% versus 0.6–2.4% in those with impaired and normal VMR.…”

Diagnosis of Intracranial Stenosis

“…Autoregulatory vasodilation in response to a vasodilatory challenge, such as carbon dioxide (CO 2 ), defines VMR [36]. Impaired VMR can be used to identify those patients who are at a high-risk for stroke in both intra-and extracranial large vessel disease [58,[67][68][69][70][71][72]. While the hemodynamics of extracranial large vessel disease has been more extensively investigated [36], hemodynamic compromise associated with intracranial occlusive disease may have even greater significance on outcome.…”

“…In a study evaluating 70 cases with intracranial large vessel occlusion using Xenon-SPECT with acetazolamide challenge, one-third had impaired VMR. The annual risk of ipsilateral stroke with impaired VMR was 17.4% versus 1.2% with normal reactivity [68]. TCD with CO 2 challenge, performed by measuring the blood flow with breath-holding, evaluates the degree of dilatation that occurs in distal arterioles in response to hypercarbia [73,74].…”

Elevated fasting glucose as a potential predictor for asymptomatic cerebral artery stenosis: A cross-sectional study in Chinese adults

“…It accounts for about 15% of ischemic stroke [8]. Patients with combined intracranial and extracranial arterial stenosis tend to have higher incidence of stroke [4] with poor prognosis [9]. Furthermore, patients with cerebral artery stenosis are at high risk of recurrent stroke [10,11].…”