【Bilingual case】Acute embolism of the middle cerebral artery

History: 67-year-old man with sudden hemiplegia, admitted to the emergency department within 30 minutes, with a history of
atrial fibrillation.

Non-contrast brain CT and CTA are shown below
.

Angiography is performed, and DSA images are shown below
.

Thrombectomy is performed
.

Findings

Plain brain CT scan: the gray-white matter division of the right basal ganglia and insular cortex is blurred, and the M1 segment of the right middle cerebral artery is limited and high-density, which may represent acute thrombosis
.

Cranial CTA: filling defect is seen in the proximal segment of the M1 segment of the right middle cerebral artery, and its distal vascular branch shows poorly
.

Cerebral DSA and mechanical thrombectomy: filling defect in the proximal segment of the M1 segment of the right middle cerebral artery, and no perfusion
in the distal segment.
After mechanical thrombus removal using a stent embolectomy device, distal vascular perfusion is complete and the THICI score for cerebral infarction thrombolysis is 3
.

Differential diagnosis:

Diagnosis: acute embolic infarction of the right middle cerebral artery

Pathophysiology Pathophysiology

The most common cause of acute embolism of the middle cerebral artery is embolus blockage, resulting in ischemia and infarction in the area it supplies
.
Other causes include: arterial dissection, rupture or inflammation of atherosclerotic plaque to form a thrombosis, vasculitis
.

Demographics demographics

Usually seen in older people
.

The incidence is the same
for men and women.

Patients with atrial fibrillation have a higher
incidence of emboli obstruction.

Imaging Image

Non-contrast CT scan: showing a certain mass effect, cerebral sulci loss, midline structure displacement, gray-white matter demarcation blurred, middle cerebral artery high density sign (intravascular acute thrombosis), brain parenchymal density is relatively reduced
.

CTA: sudden occlusion of a blood vessel with distal branches absent or a small amount of enhanced development
.

Angiography: Same as CTA, the vessel suddenly occludes and its peripheral blood flow decreases
.

MRI: limited diffusion in the middle cerebral artery supply area, manifested by DWI high intensity and ADC plot low signal
.
Some mass effects can be seen, such as the loss of the sulci and the shift of the midline
.
On water-sensitive imaging FLAIR, the ischemic region is highly intensive, and magnetically sensitive-weighted GRE sequences are important
to assess for bleeding.

Supplement knowledge

The middle cerebral artery (MCA) is the larger of the two terminal branches of the internal carotid artery, and ischemia and infarction most commonly involve this area
.
MCA is generally anatomically divided into 4 or 5 segments, M1 = horizontal segment, M2 = insular segment, M3 = insular segment, M4, M5 collectively called terminal segment or cortical branch
.

1 = internal carotid artery

2 = anterior cerebral artery

3 = Heubner recurrent artery

4 = anterior temporal artery

5 = lateral bean artery

6 = bifurcation of the middle cerebral artery

7 = middle cerebral artery knee

8 = top of lateral fissure (upper limit of annular sulcus)

M1 segment: extending from the beginning of the bifurcation of the internal carotid artery to the lateral fissure, it can be seen that it contains two parts, the anterior segment of the bifurcation and the posterior segment
of the bifurcation.
The front segment of the fork is a separate trunk, while the rear segment of the fork may be single, double, triple trunk or even more
.

Criteria for determining the hyperdense middle cerebral artery sign (HMCAS):