title: Hypoplasia of the internal carotid artery: collateral circulation and ultrasonographic findings. A case report.
abstract: BACKGROUND
  Hypoplasia of the internal carotid artery (HICA) is a rare congenital anomaly caused by an incomplete development of the organ, and only a few cases are reported in the literature. The prevalence of HICA (including agenesia and aplasia) is estimated to about 0.01%.
  
  
  METHODS
  We describe a case of a 66-year-old man with hearing loss on the left side and no other symptoms or signs related to vascular impairment. HICA was discovered incidentally by color duplex sonography of the extracranial cerebral vessel and confirmed by magnetic resonance imaging angiography (angio MRI) and computed tomography (CT) of the head.
  
  
  CONCLUSIONS
  Compensatory flow allows HICA patients to remain asymptomatic, but complications may occur. The pathways of the collateral circulation in association with aplasia or HICA are described. A differential diagnosis was made on the basis of ultrasonographic (US) detection of diffuse luminal narrowing of the internal carotid artery (ICA). Recognition of this disease has important clinical implications.
authors: Department of Geriatrics, Madonna delle Grazie Hospital, Matera, Italy.
authors: G
authors: G
authors: Nicoletti
authors: S
authors: S
authors: Sanguigni
authors: F
authors: F
authors: Bruno
authors: S
authors: S
authors: Tardi
authors: G
authors: G
authors: Malferrari
keywords: Arteries, abnormalities; Extracranial duplex sonography; Hypoplasia internal carotid artery; Transcranial duplex sonography
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