Anterior inferior cerebellar artery

Dr Craig Hacking and A.Prof Frank Gaillard et al.

The anterior inferior cerebellar artery (AICA) is one of three vessels that provides arterial blood supply to the cerebellum. It has a variable origin, course and supply, with up to 40% of specimens not having an identifiable standard AICA. The amount of tissue supplied by the AICA is variable (PICA-AICA dominance) but usually includes:

Origin 

99% of AICAs arise from the basilar artery, but where along the vessel is variable:

  • 75% lower third
  • 16% middle third
  • 9% vertebrobasilar junction

Branches

  • internal auditory branch (80% single, 20% double) passes into the IAM
  • lateral branch passes around the flocculus and into the hemispheric fissure (supplying both superior and inferior semilunar lobules)
  • medial branch supplies the biventral lobule

Before cross-sectional imaging, the AICA (along with venous displacement) was used to identify posterior fossa intra- or extra-axial masses, especially at the CP angle. Extra-axial masses (e.g. acoustic schwannomas or meningiomas) would displace the vessel whereas intra-axial masses tend not to.

Neuroanatomy
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Article information

rID: 5014
Section: Anatomy
Tags: refs, artery
Synonyms or Alternate Spellings:
  • Anterior inferior cerebellar artery (AICA)

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Cases and figures

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    Figure 1: normal COW anatomy
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    Fig 2: origin of the cerebellar arteries
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    Fig 3: posterior fossa vascular territories
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    Fig 4: mid-cerebellum
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    PICA AICA SCA AP ...
    Fig 5: PICA, AICA and SCA
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