CLUSTERS OF MICROEMBOLIC SIGNALS - A NEW FORM OF CEREBRAL MICROEMBOLISM PRESENTATION IN A PATIENT WITH MIDDLE CEREBRAL-ARTERY STENOSIS

Background-Middle cerebral artery (MCA) stenosis is a rare occlusive d isease in western populations, with a high risk of stroke recurrence. An artery-to-artery embolic mechanism has been argued. We report the d etection of a new pattern of microembolic signals (MES) in the MCA pos tstenotic segment in a patient with multiple recurrent transient ische mic attacks. Case Description-A 75-year-old man was admitted to our ho spital with a transient leg monoparesis on the left side. Right MCA st enosis was detected by transcranial Doppler ultrasonogaphy (TCD), In s pite of aspirin treatment, the patient had a recurrent right hemispher ic transient ischemic attack, and anticoagulant therapy was started. A new, similar event happened after correct anticoagulation. The bigate d TCD monitoring study of both MCAs disclosed clusters of MES at the p oststenotic MCA segment. Each cluster contained between 12 and 45 embo lic signals, The patient became asymptomatic and clusters of MES disap peared, coinciding with the combination of ticlopidine and oral antico agulants. Conclusions-We describe a new presentation of MES, ie, group ed in clusters of signals, that may be associated with a high risk of stroke recurrence.