Impaired Vasoreactivity of the Basilar Artery System in Patients with Brainstem Lacunar Infarcts

Abstract

Background and Purpose: Diminished vasoreactivity (VR) has been evidenced in patients with hemispheric small vessel disease, however, there is no data regarding vertebrobasilar (VB) territory VR changes in patients with subcortical vascular encephalopathy located in the brainstem. Therefore, we compared the cerebral blood flow velocity (CBFV) responses of the VB system during different vasoregulatory challenges in healthy volunteers to those in patients with brainstem lacunar infarcts. Methods: In 20 patients with brainstem lacunar infarcts and in 10 healthy volunteers the VR of the VB system was measured by analyzing the CBFV changes during different stimulation paradigms (ventilation, tilting and acetazolamide tests). During transcranial Doppler registration the systemic blood pressure and the expiratory partial CO₂ pressure were monitored. Results: During hypercapnia the VR was significantly higher in the control group than in the patient group (10.1 ± 4.9 vs. 3.4 ± 5.0 cm/s/kPa, p = 0.0025). In a subgroup of patients with mean baseline CBFV <25 cm/s the VR was 1.5 ± 2.4 cm/ s/kPa, while patients with mean baseline CBFV >25 cm/s showed a significantly higher value (7.8 ± 6.9 cm/s/kPa). Furthermore, in patients with mean baseline CBFV <25 cm/s the pulsatility index was significantly higher than in patients with mean baseline CBFV >25 cm/s (1.11 ± 0.26 vs. 0.86 ± 0.19, p = 0.0325), reflecting significantly higher vascular resistance in the former group. Although CBFV measurements during tilting and acetazolamide tests tended to support these findings, they showed no significant differences between patients and controls. Conclusion: Patients with cerebral microangiopathy involving the brainstem showed impaired VR in the VB flow territory in association with baseline CBFV.

Integration of cerebrovascular CO2reactivity and chemoreflex control of breathing: mechanisms of regulation, measurement, and interpretation

“…As highlighted throughout this review, numerous efforts have been made to establish normal criteria for CO 2 reactivity of the cerebral circulation by the use of TCD. Although there has been ample research involving normal values for the anterior half of the circle of Willis, mainly for the MCA, we have found few studies involving these values for the basilar artery (19,67,80,96,139,148,154). Nonetheless, these studies seem to support the notion that MCAv measurement is likely to reflect blood flow in the region(s) of the central chemoreceptors.…”

Transcranial Doppler Pulsatility Indices as a Measure of Diffuse Small‐Vessel Disease

“…[22][23][24][25][26][27] For example, Molina et al 24 found a significantly lower cerebrovascular reactivity (CVR) in patients with lacunar strokes, and Bakker and colleagues 25 found a strong association between impaired vasomotor reactivity and periventricular white matter lesions. In addition, Panczel and colleagues 26 reported impaired basilar artery CVR in patients with brainstem lacunar strokes compared with healthy volunteers and attributed this finding to microangiopathy within the brainstem. Puls et al 27 demonstrated the use of TCD arteriovenous cerebral transit time measurements to evaluate the cerebral microcirculation, finding substantially prolonged transit times in patients with vascular dementia compared with controls.…”

A Systematic Review of Dynamic Cerebral and Peripheral Endothelial Function in Lacunar Stroke Versus Controls

“…Most papers excluded patients with carotid stenosis (except 1 30 ), 5 excluded cardiogenic sources of emboli, 32,33,36,38,41 and 3 excluded middle cerebral artery (MCA) stenosis 35,39,40 from the lacunar stroke group.…”