title: [Bilateral carotid artery occlusion: prognosis and neurosonological features].
abstract: BACKGROUND
  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.
  
  
  OBJECTIVE
  To describe the prognosis and the neurosonological features in a series of patients with BCAO.
  
  
  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.
authors.forename: Javier R
authors.initials: JR
authors.lastname: Pérez-Sánchez
authors.affiliation: Hospital General Universitario Gregorio Maranon, 28007 Madrid, Espana.
authors.forename: Andrés
authors.initials: A
authors.lastname: García-Pastor
authors.forename: Fernando
authors.initials: F
authors.lastname: Díaz-Otero
authors.forename: Pilar
authors.initials: P
authors.lastname: Sobrino-García
authors.forename: Pedro M
authors.initials: PM
authors.lastname: Rodríguez-Cruz
authors.forename: Gema
authors.initials: G
authors.lastname: Vicente-Peracho
authors.forename: Pilar
authors.initials: P
authors.lastname: Vázquez-Alén
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Fernández-Bullido
authors.forename: José A
authors.initials: JA
authors.lastname: Villanueva-Osorio
authors.forename: Antonio
authors.initials: A
authors.lastname: Gil-Núñez
mesh_terms: D000086:Acetazolamide; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography; D002545:Brain Ischemia / Q000209:etiology; D016893:Carotid Stenosis / Q000150:complications / Q000000981:diagnostic imaging / Q000453:epidemiology*; D003097:Collateral Circulation; D003287:Contrast Media; D005500:Follow-Up Studies; D006261:Headache / Q000209:etiology; D006439:Hemodynamics; D006801:Humans; D002546:Ischemic Attack, Transient / Q000209:etiology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012008:Recurrence; D014057:Tomography, X-Ray Computed; D018616:Ultrasonography, Doppler, Duplex; D014786:Vision Disorders / Q000209:etiology
chemical_list: D003287:Contrast Media; D000086:Acetazolamide