Middle Cerebral Artery Aneurysm

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1- Introduction

2- Anatomical Overview

3- Causes

4- Treatment 


A middle cerebral artery (MCA) aneurysm is a cerebrovascular disorder characterized by a localized dilation or ballooning of the MCA wall. The MCA is a major artery within the brain, responsible for supplying blood to critical areas that control motor and sensory functions, speech, and other vital brain activities.
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Anatomical Overview

Anatomy of the Middle Cerebral Artery

  1. Origin:

    • The MCA originates from the internal carotid artery, branching off into the lateral parts of the cerebral hemisphere.
  2. Branches:

    • The MCA bifurcates into several branches supplying the lateral aspects of the frontal, temporal, and parietal lobes.
  3. Segments:

    • M1 Segment: The initial horizontal segment from the internal carotid artery.
    • M2 Segment: The insular segment that runs within the Sylvian fissure.
    • M3 and M4 Segments: The cortical segments that extend to the cortical surfaces.


    • Congenital Factors:

      • Weakness in the arterial wall present from birth.
    • Hypertension:

      • Chronic high blood pressure can contribute to the formation of aneurysms.
    • Atherosclerosis:

      • Plaque buildup in the arteries weakens the vessel wall.
    • Trauma:

      • Physical injury to the vessel wall.
    • Infections:

      • Inflammatory conditions affecting the vascular walls.
    • Genetic Factors:

      • Family history of aneurysms or connective tissue disorders like Ehlers-Danlos syndrome or Marfan syndrome.


    • Observation:

      • Small, asymptomatic aneurysms may be monitored with regular imaging.
    • Surgical Clipping:

      • A neurosurgical procedure where a clip is placed around the neck of the aneurysm to prevent blood flow into it.
    • Endovascular Coiling:

      • Minimally invasive procedure where coils are inserted into the aneurysm to induce clotting and prevent rupture.
    • Flow Diversion Devices:

      • Stents that divert blood flow away from the aneurysm, promoting healing of the vessel wall.
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