Mechanical thrombectomy for middle cerebral artery occlusion caused by intracranial internal carotid artery stenosis: A case report.

Tandem internal carotid artery (ICA)/middle cerebral artery (MCA) occlusions are occasionally observed in patients with acute ischemic stroke. Most of them are caused by lesions at the origin of the ICA. In cases of intracranial ICA stenosis, the formation of a large thrombus causing MCA occlusion is extremely rare. Herein We report a case of acute MCA occlusion caused by intracranial ICA stenosis. A 62-year-old female presented with aphasia, right-side weakness, and a National Institute of Health Stroke Scale (NIHSS) score of 5. Magnetic resonance imaging (MRI) showed early ischemic infarction at the precentral gyrus. Left ICA and M1 occlusion were suspected on magnetic resonance angiography. However, the patient had complained of right-side numbness 6 days before the onset. Hence the stroke was assumed to have progressed slowly, and acute occlusion of the left ICA was eliminated as a suspected diagnosis. After admission, the symptoms worsened. MRI showed enlargement of the cerebral infarction. Computed tomography angiography showed complete occlusion of the left M1 and recanalization of the left ICA with severe stenosis of the petrous portion. The etiology of the MCA occlusion was determined to be atherothromboembolism. Percutaneous transluminal angioplasty (PTA) was performed for ICA stenosis, followed by mechanical thrombectomy (MT) for the MCA occlusion. Recanalization of the MCA was achieved. After Seven days, the NIHSS score reduced from a pre-MT assessment of 17-2. PTA followed by MT was safe and effective for treating MCA occlusion caused by intracranial ICA stenosis.