Medicine & USMLE

Basilar Artery

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Strokes
  1. Anterior Cerebral Artery (ACA)
  2. Middle Cerebral Artery (MCA)
  3. Posterior Cerebral Artery (PCA)
  4. Lenticulostriate Artery
  5. Anterior Inferior Cerebellar Artery (AICA)
  6. Posterior Inferior Cerebellar Artery (PICA)
  7. Anterior Spinal Artery (ASA)
  8. Basilar Artery

Summary

Basilar artery stroke is an occlusion of the two joined vertebral arteries that lie in the central pontine groove of the pons. This stroke affects the entire brainstem, and can cause a rare condition known as locked-in syndrome. This is characterized by quadriplegia, with the only remaining voluntary muscle movements being vertical eye movement and blinking. Consciousness is preserved in patients with locked-in syndrome.

Key Points

  • Basilar Artery
    • Also known as Locked-in Syndrome
    • Area of lesion
      • Entire brainstem (pons, medulla, lower midbrain)
        • If RAS spared, consciousness is preserved
      • Corticospinal + corticobulbar tracts
        • Quadriplegia
        • Loss of voluntary face, mouth, and tongue movements
      • Ocular cranial nerve nuclei, Paramedian pontine reticular formation (PPRF)
        • Loss of horizontal, but intact vertical eye movements
        • Intact blinking