Middle cerebral artery occlusion (MCAO) mainly happen as a result of thromboembolism. This occurs more often in the middle cerebral artery (MCA) than in the other cerebral arteries, as the former branches off directly from the internal carotid artery. The MCA supplies part of the cerebral cortex, as well as the basal ganglia and internal capsules. Thus MCAO leads to an MCA territory stroke, which presents with a wide range of neurological manifestations. The ischemic strokes that arise from MCAO are the result of cell hypoxia and energy depletion, which eventually lead to cytotoxic edema of the affected area [1] [2] [3].

The typical findings in MCA territory stroke are contralateral hemiparesis and contralateral hemisensory loss. The weakness experienced in MCA territory strokes is typically more pronounced in the upper limbs and face than in the lower limbs. Furthermore, patients may have homonymous hemianopsia. If the stroke affects the dominant hemisphere, patients may also present with expressive, receptive, or global aphasia, depending on whether the infarcted area supplied by the MCA is anterior, posterior, or total. If the stroke affects the non-dominant hemisphere, patients may exhibit neglect. Other possible manifestations of MCAO and MCA territory stroke are agnosia and gaze preference to the side of the lesion.

• Collapse

  One pattern (Pattern 1) was darkening of venous blood, small vessel collapse, and blood pooling with no venous return in cortical veins. [ncbi.nlm.nih.gov]

• Orthostatic Hypotension

  The recurrence of chorea was not observed after antiplatelet therapy and instruction on how to cope with orthostatic hypotension. [ncbi.nlm.nih.gov]

  Of the alpha-adrenergic blockers, tamsulosin is associated with less orthostatic hypotension than terazosin, doxazosin, prazosin, and alfuzosin. [89] Anticholinergics such as oxybutynin and tolterodine may also be used. [emedicine.medscape.com]

• Hemianopsia

  Furthermore, patients may have homonymous hemianopsia. [symptoma.com]

  Click Image to Enlarge Clinical symptoms associated with occlusion of the posterior cerebral artery depend on the location of the occlusion and may include thalamic syndrome, thalamic perforate syndrome, Weber’s syndrome, contralateral hemplegia, hemianopsia [strokecenter.org]

  Contralateral homonymous hemianopsia is often present. See also [ edit ] Leptomeningeal collateral circulation References [ edit ] Moore KL, Dalley AR. Clinically Oriented Anatomy, 4th Ed., Lippincott Williams & Wilkins, Toronto. Copyright 1999. [en.wikipedia.org]

• Hemichorea

  Hemichorea is usually caused by a structural lesion in the contralateral basal ganglia or subthalamic nuclei or it develops as a form of a neurologic complication including hyperglycemia. [ncbi.nlm.nih.gov]

• Chorea

  The recurrence of chorea was not observed after antiplatelet therapy and instruction on how to cope with orthostatic hypotension. [ncbi.nlm.nih.gov]

When evaluating patients with middle cerebral artery occlusion, medical imaging is a key. The imaging studies often conducted are:

• Computed tomography (CT): This may be carried out with or without a contrast agent. MCAO leads to the visualization of the MCA at the point of the occlusion, as a hyperdense lesion immediately after the thromboembolic event [4]. Cytotoxic edema will be most evident in the distortion of grey matter, and the border between grey and white matter becomes less prominent [5] [6].
• Magnetic resonance imaging (MRI): Occlusion of the MCA and tissue ischemia can be observed via this technique.

In the assessment of a patient with an ischemic stroke, it is important to identify what risk factors the individual carries. Non-modifiable risk factors include age, sex, ethnicity, and genetic traits related to family history of strokes and transient ischemic attacks (TIAs). Modifiable risk factors include hypertension, obesity, cardiac conditions such as atrial fibrillation and valvular heart disease, diabetes mellitus, and high cholesterol levels [7].

Further studies that may be carried out include a complete blood count, basic metabolic panel, clotting studies, toxicology screening, and lumbar puncture.

• Estrogen Increased

  Abstract Although estrogens are neuroprotective in young adult animal models of stroke, clinical trials demonstrate that estrogens increase the incidence and severity of stroke in aged women. [ncbi.nlm.nih.gov]

• Lymphocytic Infiltrate

  RESULTS: In mice subjected to transient MCAO or photothrombotic stroke, we found that lymphocyte infiltration persists in the ischemic brain until at least day 14 after surgery, during which brain infarct volume significantly diminished. [ncbi.nlm.nih.gov]

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2. Dirnagl U, Iadecola C, Moskowitz MA. Pathobiology of ischaemic stroke: an integrated view. Trends Neurosci. 1999;22(9):391-397.
3. Yuan J, Yankner BA. Apoptosis in the nervous system. Nature. 2000;407(6805):802-809.
4. Pressman BD, Tourje EJ, Thompson JR. An early CT sign of ischemic infarction: increased density in a cerebral artery. AJR Am J Roentgenol. 1987;149(3):583-586.
5. Moulin T, Cattin F, Crépin-Leblond T, et al. Early CT signs in acute middle cerebral artery infarction: predictive value for subsequent infarct locations and outcome. Neurology. 1996;47(2):366-375.
6. Nakano S, Iseda T, Kawano H, Yoneyama T, Ikeda T, Wakisaka S. Correlation of early CT signs in the deep middle cerebral artery territories with angiographically confirmed site of arterial occlusion. AJNR Am J Neuroradiol. 2001;22(4):654-659.
7. Goldstein LB, Bushnell CD, Adams RJ, et al. Guidelines for the primary prevention of stroke: a guideline for healthcare professionals from the American Heart Association/American Stroke Association. Stroke. 2011;42(2):517-584.