Left Side Weakness

On clinical examination, tone was reduced in left upper and lower limbs and power was zero on left side of body. Patient was conscious, oriented to time, place, and person.

Figure 1. MRI brain contrast images. Multiple foci of altered signal intensity noted involving right centrum semiovale and subcortical and periventricular white matter of right parietal and occipital suggestive of acute lacunar infarcts.

Figure 2. MRI brain angiography images. Postcontrast MR angiography study showing a concentric filling defect with resultant near complete luminal narrowing right common carotid artery at bifurcation suggestive of severe carotid stenosis.

Diagnosis: Carotid artery stenosis

On postcontrast MR angiography study, right common carotid artery at bifurcation shows a concentric filling defect resultant near complete luminal narrowing suggestive of severe carotid stenosis.

The North American Symptomatic Carotid Endarterectomy Trial (NASCET) demonstrated a conclusive benefit for carotid endarterectomy in patients with symptomatic 70%-99% ICA stenosis.

NASCET was established by angiographic calculation of ICA stenosis percentage using a specific formula.

Carotid artery stenosis, also referred to as extra-cranial carotid artery stenosis, is usually caused by an atherosclerotic process and is one of the major causes of stroke and transient ischemic attack (TIA). 

Carotid artery stenosis can result in wide-ranging stroke syndromes or TIA symptoms. 

The main differential diagnosis is carotid dissection or sub-intimal hematoma, which on MR angiography shows the intimal flap and intramural thrombus.