[Bilateral carotid artery occlusion: prognosis and neurosonological features].

INTRODUCTION: Bilateral carotid artery occlusion (BCAO) is a rare and poorly studied entity. The medium-long term prognosis reported is variable. Collateral circulation must play a crucial role in the outcome, however, the evidence in literature is scarce.

AIM: To describe the prognosis and the neurosonological features in a series of patients with BCAO.

PATIENTS AND METHODS: Patients were recruited from our Neurosonology laboratory database for 5 years. BCAO was detected with duplex ultrasonography and confirmed with computed tomography angiography and/or conventional digital substraction angiography. Clinical features and follow-up were recorded and a complete neurosonological workup was performed to study the collateral pathways and the cerebrovascular reserve capacity (CRC) with the administration of intravenous acetazolamide.

RESULTS: 2,780 neurosonological studies were reviewed. BCAO was confirmed in 10 patients. Eight patients suffered a hemispheric stroke or transient ischemic attack (TIA) at diagnosis. Patients were followed for an average period of 2.7 years. A patient suffered a right carotid TIA in the follow-up period, resulting in an annual stroke rate of 4.1%. Six patients remained functionally independent and two patients died. Six patients underwent a complete neurosonological study, showing an extensive collateral circulation and a pathological CRC in all patients. The patient who suffered the recurrence presented an exhausted CRC and the collateral circulation was less favourable in the symptomatic hemisphere.

CONCLUSIONS: In the present study, the annual ischaemic stroke rate in patients with BCAO was low. A pathological CRC and an inadequate collateral circulation could be related with an increased risk of recurrences.