Anterior Inferior Cerebellar Artery (AICA)

Summary

AICA stroke refers to the occlusion of the anterior inferior cerebellar artery. Since this artery supplies blood to the lateral pons, it’s also known as Lateral Pontine Syndrome. Clinical symptoms for patients with AICA stroke vary depending on the location of the lesion. Involvement of the facial nerve nuclei results in ipsilateral facial paralysis, decreased lacrimation and salivation, and loss of taste sensation from the anterior 2/3rds of the tongue. Involvement of the vestibular nuclei can cause ipsilateral vertigo, nystagmus, and vomiting. Involvement of the spinothalamic tract results in a contralateral loss of pain and temperature sensation. Involvement of the spinal trigeminal nucleus causes ipsilateral loss of facial sensation. Involvement of the sympathetic fibers causes ipsilateral Horner’s Syndrome. Involvement of the middle and inferior cerebellar peduncles causes ipsilateral ataxia and dysmetria. Finally, involvement of the labyrinthine artery causes ipsilateral sensorineural deafness, as well as vertigo.

Key Points

• Anterior Inferior Cerebellar Artery (AICA)
  • Also known as Lateral Pontine Syndrome
    • Loss of blood supply to lateral pons
  • Area of lesion
    • Facial nucleus (CN VII)
      • Paralysis of Face (LMN lesion vs. UMN lesion in cortical stroke)
        • Decreased lacrimation
        • Decreased salivation
        • Decreased taste from anterior ⅔ of tongue
    • Vestibular nuclei (CN VIII)
      • Vomiting, vertigo, nystagmus
    • Spinothalamic tract
      • Decreased pain and temperature sensation from contralateral body
    • Spinal trigeminal nucleus (CN V)
      • Loss of sensation to ipsilateral face
    • Sympathetic fibers
      • Ipsilateral Horner syndrome
    • Middle and inferior cerebellar peduncles
      • Cerebellar signs: Ipsilateral ataxia, dysmetria
    • Labyrinthine artery
      • Ipsilateral sensorineural deafness, vertigo