Middle cerebral artery
Updates to Article Attributes
The middle cerebral artery (MCA) is one of the three major paired arteries that supply blood to the brain. The MCA arises from the internal carotid artery (ICA) as the larger of the two main terminal branches (MCA and anterior cerebral artery) and continues into the lateral sulcus where it branches and provides many branches that supply the cerebral cortex.
Gross anatomy
Segments
The MCA is divided into M1, M2, M3 and M4four segments:
- M1: from the origin to bifurcation/trifurcation (the limen insulae); also known as horizontal or sphenoidal segment
- M2: also known as insular segment, from bi(tri)furcation to circular sulcus of insula where it makes hairpin bend to continue as M3
- M3: opercular branches (those within the Sylvian fissure); also known as opercular segment
- M4: branches emerging from the Sylvian fissure onto the convex surface of the hemisphere; also known as cortical segment
Branches
M1
- medial lenticulostriate penetrating arteries
- lateral lenticulostriate penetrating arteries
- anterior temporal artery
- polar temporal artery
- uncal artery (with branches also from the anterior choroidal artery)
M2
Division of the MCA is variable after the horizontal segment, although most commonly, it divides into two trunks-superior and inferior:
- 78% bifurcate into superior and inferior divisions
- 12% trifucate into superior, middle and inferior divisions
- 10% branch into many smaller branches
Superior terminal branch
- lateral frontobasal artery
- prefrontal sulcal artery
- pre-Rolandic (precentral) and Rolandic (central) sulcal arteries
Inferior terminal branch
- three temporal branches (anterior, middle, posterior)
- branch to the angular gyrus
- two parietal branches (anterior, posterior)
Supply
The middle cerebral arteries supply the majority of the lateral surface of the hemisphere apart from the superior portion of the parietal lobe and the inferior portion of the temporal lobe and occipital lobe. In addition, they supply part of the internal capsule and basal ganglia.
Normal variantsVariant anatomy
- MCA duplication-reported incidence of ~1.5% (range 0.2-2.9%); parallels the main MCA and supplies the anterior lobe
- accessory MCA
- MCA fenestration is rare with a report incidence of <1%
- early branching of the MCA-bi/trifurcation occurs within 1 cm of origin
-<p>The <strong>middle cerebral artery</strong> (<strong>MCA</strong>) is one of the three major paired arteries that supply blood to the brain. The MCA arises from the <a href="/articles/internal-carotid-artery-1">internal carotid artery</a> (ICA) as the larger of the two main terminal branches (MCA and <a href="/articles/anterior-cerebral-artery">anterior cerebral artery</a>) and continues into the <a href="/articles/lateral-sulcus">lateral sulcus</a> where it branches and provides many branches that supply the cerebral cortex.</p><h4>Segments</h4><p>The MCA is divided into M1, M2, M3 and M4 segments:</p><ul>- +<p>The <strong>middle cerebral artery</strong> (<strong>MCA</strong>) is one of the three major paired arteries that supply blood to the brain. The MCA arises from the <a href="/articles/internal-carotid-artery-1">internal carotid artery</a> (ICA) as the larger of the two main terminal branches (MCA and <a href="/articles/anterior-cerebral-artery">anterior cerebral artery</a>) and continues into the <a href="/articles/lateral-sulcus">lateral sulcus</a> where it branches and provides many branches that supply the cerebral cortex.</p><h4>Gross anatomy</h4><h5>Segments</h5><p>The MCA is divided into four segments:</p><ul>
-</ul><h4>Branches</h4><h5>M1</h5><ul>- +</ul><h5>Branches</h5><h6>M1</h6><ul>
-</ul><h5>M2</h5><p>Division of the MCA is variable after the horizontal segment, although most commonly, it divides into two trunks-superior and inferior:</p><ul>- +</ul><h6>M2</h6><p>Division of the MCA is variable after the horizontal segment, although most commonly, it divides into two trunks-superior and inferior:</p><ul>
-</ul><h5>Superior terminal branch</h5><ul>- +</ul><h6>Superior terminal branch</h6><ul>
-</ul><h5>Inferior terminal branch</h5><ul>- +</ul><h6>Inferior terminal branch</h6><ul>
-</ul><h4>Supply</h4><p>The middle cerebral arteries supply the majority of the lateral surface of the hemisphere apart from the superior portion of the <a href="/articles/parietal-lobe">parietal lobe</a> and the inferior portion of the <a href="/articles/temporal-lobe">temporal lobe</a> and <a href="/articles/occipital-lobe">occipital lobe</a>. In addition, they supply part of the <a href="/articles/internal-capsule">internal capsule</a> and <a href="/articles/basal-ganglia">basal ganglia</a>.</p><h4>Normal variants</h4><ul>- +</ul><h4>Supply</h4><p>The middle cerebral arteries supply the majority of the lateral surface of the hemisphere apart from the superior portion of the <a href="/articles/parietal-lobe">parietal lobe</a> and the inferior portion of the <a href="/articles/temporal-lobe">temporal lobe</a> and <a href="/articles/occipital-lobe">occipital lobe</a>. In addition, they supply part of the <a href="/articles/internal-capsule">internal capsule</a> and <a href="/articles/basal-ganglia">basal ganglia</a>.</p><h4>Variant anatomy</h4><ul>