Simultaneously Measured CO2 Reactivity in the Basilar and Middle Cerebral Artery: The Utilization of Power M-mode Doppler and Anterior-posterior Probes Fixating Device

J Korean Neurol Assoc > Volume 25(1); 2007 > Article

Journal of the Korean Neurological Association 2007;25(1): 75-80.

동시에 측정한 기저동맥과 중대뇌동맥의 이산화탄소 반응성: Power M-mode 도플러와 전-후 탐침 고정장치의 이용

홍지만, 신동훈 허 균 주인수 신상건 이승남a

아주대학교 의과대학 신경과학교실, 아주대학교병원 의용공학팀a

Simultaneously Measured CO2 Reactivity in the Basilar and Middle Cerebral Artery: The Utilization of Power M-mode Doppler and Anterior-posterior Probes Fixating Device

Ji Man Hong,

Department of Neurology, Ajou University School of Medicine, Suwon; Medical Engineering Team of Ajou University Hospitala, Suwon, Korea

Abstract

Background: Studies using a transcranial Doppler (TCD) to establish cerebral vasoreactivity (CVR) have mostly focused on the anterior circulation. The purpose of this study is not only to evaluate the feasibility of the power motion mode Doppler (PMD) with a probes fixating device, but also to simultaneously measure the CVR between the middle cerebral artery (MCA) and the basilar artery (BA) during hypercapnea simulated by the rebreathing technique.
Methods: Twenty eight healthy volunteers were enrolled. Baseline hemodynamic values (heart rate, blood pressure) were measured while volunteers sat in a comfortable position for 5 minutes. The TCD was performed in two steps. First, velocities and spectra of the MCAs were simultaneously monitored. Then, the velocities and spectra of the MCA and BA were simultaneously monitored by a headset that included an anterior-posterior probes fixating device. The equation for CVR was ([maximum mean velocity baseline mean velocity]×100/baseline mean velocity).
Results: Baseline mean velocities were revealed as follows: (64.0±13.7, 65.0±11.9 cm/s in right and left MCA; p>0.05; 67.3±12.2, -45.3±7.6 cm/s in dominant MCA and BA). CVR did not differ between the dominant MCA and the BA (46.1±12.1, 46.0±15.1%; p>0.05), nor between the right and left MCAs (46.9±15.2, 46.4±14.8%; p>0.05). There was a positive linear correlation between the CVR of the dominant MCA and that of the BA (r=0.856; p<0.001).
Conclusions: PMD with a probes fixating device for accurate insonation is a useful tool for evaluating the relative CVR between the MCA and BA. Our study suggests that CVR values of the BA are similar to those of the MCA.KeyWords:Cerebral autoregulation, Cerebral vasoreactivity, Transcranial doppler, Basilar artery