Blood flow velocity and vasomotor reactivity in patients with arteriovenous malformations. A transcranial Doppler study.

Abstract

Background and Purpose A large percentage of patients with a cerebral arteriovenous malformation (AVM) show focal neurological signs or have a history of intracranial hemorrhage. The present study used transcranial Doppler sonography to assess the clinical significance of hemodynamic disturbances in the intracranial arteries of patients with an AVM.Methods Eighteen patients with untreated AVMs were examined clinically, angiographically, and with transcranial Doppler sonography (blood flow velocity measurement and vasomotor reactivity in all main intracranial arteries).Results A pathological increase in blood flow velocity (57.6%) and a decrease in vasomotor reactivity (72.7%) were frequently found in AVM feeding arteries. Vasomotor reactivity was also reduced in several nonfeeding arteries both ipsilateral (53.3%) and contralateral (30.8%) to the AVM. AVM size was a poor predictor of pathological transcranial Doppler results. Vasomotor reactivity of arteries ipsilateral to an AVM in patients with a history of hemorrhage was significantly higher (2.10±1.66% per mm Hg; mean±SD) than in

Revisiting normal perfusion pressure breakthrough in light of hemorrhage-induced vasospasm

“…NPPB theory rests on the assumption that lost autoregulatory capacity persists following resection of a cerebral AVM. Nevertheless, several studies demonstrate a postoperative return to normal CO2 reactivity in vessels with previously diminished reactivity [3,[10][11][12][13][14][15][16] . Young et al [12,13] showed intact CO2 reactivity both before and after resection.…”

Patterns of Cortical Oxygen Saturation Changes During CO 2 Reactivity Testing in the Vicinity of Cerebral Arteriovenous Malformations

“…The inability to measure CBF quantitatively with sufficient temporal and spatial resolution in a clinical setting has resulted in the use of substitutes such as blood flow velocity 3,8 or HbO 2 with nearly infrared spectroscopy (NIRS). 10,11 We have adopted the latter approach because Smielewski et al 10,11 have shown that HbO 2 changes after induced alterations in CO 2 allow valid assessment of CVR.…”

“…For example, in studies using transcranial Doppler, one has to take into account which vessels were insonated. In one study, the results were considered indicative of pathological vasoreactivity without clearly stating whether these arteries were involved in AVM supply, 3 whereas other authors found evidence for intact CVR in nonfeeding arteries with transcranial Doppler sonography 8 or intraoperative micro-Doppler. 7 Other authors found impaired CVR and hyperresponsiveness to vasodilative stimuli and thought that they were predictive of the occurrence of postoperative hyperemic complications.…”

“…Some authors even speculate that these patterns might be predictive of the occurrence of neurological deficits or the so-called postoperative hyperperfusion injury syndrome. [1][2][3][4][5][6] "CVR overshoot" and impaired reactivity have been noted and were rather arbitrarily interpreted as being AVM specific and/or predictive. 1,2 The results of other studies, however, speak for a uniformly preserved vasoreactivity in the brain surrounding AVMs before and after their obliteration.…”

The application of ultrasound in the management of cerebral arteriovenous malformation

“…Diehl et al [24] reported a pathological increase in blood flow velocity (57.6%) and a decrease in vasomotor reactivity (72.7%) were frequently found in AVM feeding arteries. Vasomotor reactivity was also reduced in several nonfeeding arteries both ipsilateral (53.3%) and contralateral (30.8%) to the AVM.…”