Middle cerebral artery

Middle cerebral artery

Outer surface of cerebral hemisphere, showing areas supplied by cerebral arteries. (Pink is region supplied by middle cerebral artery.)

The arterial circle and arteries of the brain. The middle cerebral arteries (top of figure) arise from the internal carotid arteries.
Source internal carotid arteries
Branches anterolateral central arteries
Vein middle cerebral vein
Supplies cerebrum
Latin arteria cerebri media
TA A12.2.07.046
FMA 50079

Anatomical terminology

The middle cerebral artery (MCA) is one of the three major paired arteries that supply blood to the cerebrum. The MCA arises from the internal carotid and continues into the lateral sulcus where it then branches and projects to many parts of the lateral cerebral cortex. It also supplies blood to the anterior temporal lobes and the insular cortices.

The left and right MCAs rise from trifurcations of the internal carotid arteries and thus are connected to the anterior cerebral arteries and the posterior communicating arteries, which connect to the posterior cerebral arteries. The MCAs are not considered a part of the Circle of Willis.[1]


Middle cerebral artery
Middle cerebral artery and its branches (patient has a hypoplastic A1 segment and an absent PCOM, resulting in a purely MCA angio from internal carotid artery injection)

The middle cerebral artery can be classified into 4 parts:[2]

The M2 and M3 segments may each split into 2 or 3 main trunks (terminal branches) with an upper trunk, lower trunk and occasionally a middle trunk. Bifurcations and trifurcations occurs in 50% and 25% of the cases respectively. Other cases include duplication of the MCA at the internal carotid artery (ICA) or an accessory MCA (AccMCA) which arise not from the ICA but as a branch from the anterior cerebral artery.[3] The middle trunk that exist in parts of the population, when present provides the pre-Rolandic, Rolandic, anterior parietal, posterior parietal and the angular artery for irrigation instead of the upper and lower trunks.

The branches (ramus) of the MCA can be described by the areas that they irrigate.

Frontal lobe

Parietal lobe

Temporal lobe


Areas supplied by the middle cerebral artery include:

MCA occlusion site and resulting Aphasia

Clinical signifiance


Occlusion of the middle cerebral artery results in Middle cerebral artery syndrome, potentially showing the following defects:

  1. Paralysis (-plegia) or weakness (-paresis) of the contralateral face and arm (faciobrachial)
  2. Sensory loss of the contralateral face and arm.
  3. Damage to the dominant hemisphere (usually the left hemisphere) results in aphasia i.e. Broca's or Wernicke's
  4. Damage to the non-dominant hemisphere (usually the right hemisphere) results in contralateral neglect syndrome
  5. Large MCA infarcts often have déviation conjuguée, a gaze preference towards the side of the lesion, especially during the acute period. Contralateral homonymous hemianopsia is often present.

See also

Wikimedia Commons has media related to Middle cerebral artery.
This article uses anatomical terminology; for an overview, see Anatomical terminology.


  1. Moore KL, Dalley AR. Clinically Oriented Anatomy, 4th Ed., Lippincott Williams & Wilkins, Toronto. Copyright 1999. ISBN 0-683-06141-0.
  2. Krayenbühl, Hugo; Yaşargil, Mahmut Gazi; Huber, Peter; Bosse, George (1982), Cerebral Angiography, Thieme, pp. 105–123, ISBN 978-0-86577-067-6
  3. Osborn, Anne G.; Jacobs, John M. (1999), Diagnostic Cerebral Angiography, Lippincott Williams & Wilkins, pp. 143–144, ISBN 978-0-397-58404-8
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