TRANSCRANIAL DOPPLER IN THE EVALUATION OF INTERNAL CAROTID-ARTERY DISSECTION

Background and Purpose A subject with dissection of the internal carot id artery (ICAI may present with a variety of symptoms, from headache to stroke. Thus far, it has not been possible to identify the subset o f patients at risk for cerebral ischemia. Because the majority of thes e ischemic events are secondary to embolic phenomena, we used transcra nial Doppler (TCD) evaluation with emboli monitoring to study 17 conse cutive patients with ICA dissection treated at Harborview Medical Cent er, Seattle, Wash, during a 2-year period from 1992 until 1994. Method s Ten patients with ICA dissection secondary to trauma and seven with spontaneous ICA dissection were diagnosed by carotid angiography and s tudied by TCD) from the time of diagnosis through initiation of therap y. Emboli monitoring was pet-formed in the middle cerebral artery (MCA ) ipsilateral to the dissection at the initial evaluation and intermit tently thereafter to ensure that the emboli stopped with treatment. Re sults Emboli were detected in the MCA distal to the dissection in 10 o f 17 patients (59%). Patients with microemboli detected by TCD present ed with a stroke (70%) much more frequently than those without emboli (14%) (P=.0498). The presence of a pseudoaneurysm did not increase the risk of either microemboli or stroke. Conclusions We have demonstrate d a high incidence of intracranial microemboli in the MCA distal to ca rotid dissections and a significant correlation between the presence o f emboli and stroke. TCD can therefore be used as an adjunctive tool t o manage patients with suspected carotid dissection and may prove usef ul in evaluating the efficacy of treatment in reducing microemboli and subsequent stroke.