Use of transcranial Doppler in monitoring cerebral vasospasm secondary to subarachnoid hemorrhage

Abstract

Cerebral vasospasm accounts for an increased morbidity and mortality in patients with spontaneous subarachnoid hemorrhage (SAH). Its early and non invasive detection by transcranial Doppler (TCD) may contribute to a better prognosis in such cases. To discuss the use of transcranial Doppler (TCD) in the detection of cerebral vasospasm secondary cerebral to spontaneous subarachnoid hemorrhage (SAH). We analyzed the flow velocities registered by TCD in intracranial arteries in 31 patients with SAH, performed sequentially, associated with neurological examinations. All patients (except one) had intracranial aneurysms. Clinical vasospasm was found in 11 patients (36,6% from the total), with correspondent sonographic vasospasm present in 9 cases (82%). In 3 cases (33.3%) the flow velocity alterations preceded the clinical symptoms. Between the 20 asymptomatic patients, 15 (75%) had normal flow velocity, with evidence of sonographic vasospasm without clinical repercussion in 5 (25%). The index of false negatives in the correlation between clinical examination and TCD (symptomatic vasospasm with normal flow velocity records) was 18%. However, there was correspondence between clinical and ultrasonographic findings in 26 of the 31 patients (83.8%). The average flow velocity values in the various arteries and its interpretation for each subgroup are discussed with further details. TCD is a valuable auxiliary method in the detection of cerebral vasospasm (even pre-symptomatic) secondary to SAH, allowing a more precocious therapeutic intervention. Our results are similar to those described in the literature.