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 patients with no history of bleeding (1.12 +/- 1.48% per mm Hg; P < .05). In patients with focal neurological signs but no history of hemorrhage, the percentage of arteries ipsilateral (100%) and contralateral (63.6%) to an AVM showing a pathological vasomotor reactivity was significantly larger than in nonhemorrhagic patients without focal signs (66.7% and 22.2%, respectively; both P < .05).
Conclusions: Our results suggest two distinct relations between transcranial Doppler results and clinical findings: (1) Relatively normal vasomotor reactivity values in arteries ipsilateral to an AVM indicate a high-pressure AVM with an increased risk of hemorrhage. (2) A strongly pathological vasomotor reactivity in arteries ipsilateral and contralateral to an AVM indicates a low-pressure AVM with a higher prevalence of hemodynamically induced neurological signs.