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E-060 A case of twig-like or unfused middle cerebral artery and review of literature
  1. A Schnure1,
  2. A Sweidan2,
  3. I Yuki1,
  4. S Suzuki1
  1. 1Neurosurgery, UC Irvine, Orange, CA
  2. 2Neurology, UC Irvine, Orange, CA


Introduction Twig-like or unfused middle cerebral arteries (MCA) are rare vascular anomalies. During embryologic development, it is hypothesized that the primitive MCA is made up of arterial twigs which develop into the definitive MCA. Failure of these arterial twigs to fuse result in the twig-like or unfused MCA.

Methods A retrospective single case report of twig-like MCA with literature review. The patient established care at our institution in 6/2018 and still follows with us.

Results A 55-year-old woman with a past medical history of hyperlipidemia and tobacco use presented in the outpatient setting with an electrical-like sensation over her right neck. She denied focal weakness, speech difficulty, visual problems or numbness. There was no history of trauma or neck manipulation. She has a family history of stroke and aneurysm. She was evaluated by magnetic resonance angiography (MRA) of the head which showed a small right internal carotid artery (ICA) and high-grade stenosis of the right ICA and right MCA. Computed tomography (CT) angiography demonstrated small caliber of the entire right ICA and critical stenosis versus occlusion of the right ICA and MCA with distal reconstitution compatible with a moyamoya pattern with lenticulostriate collateralization. CT brain perfusion demonstrated a significant reduction in cerebral blood flow of the entire right MCA territory without a decrease in cerebral blood volume. Cerebral angiography revealed a right twig-like MCA with contralateral ICA cavernous segment aneurysm. The patient has been treated conservatively with aspirin and atorvastatin.

The figure 1 illustrates the right internal common carotid injection with 3D rotational angiography reconstruction image (A) and AP subtraction image (B). The right M1 segment of the middle cerebral artery has a plexiform arterial network that is consistent with an unfused middle cerebral artery. There are no moyamoya vessels in the basal region and no occlusion in the terminus segment of the internal carotid artery. The twig-like artery can be traceable to the distal M1 or proximal M2 segment. There is no intracranial atherosclerotic change.

Conclusion Twig-like or unfused MCA are rare vascular anomalies that may be mistaken for moyamoya disease. The detailed trans-femoral cerebral angiogram interpretation of the twig-like MCA depicts distinctive differences from the findings of moyamoya disease.

Disclosures A. Schnure: 4; C; General Electric, CYTRX, Portola Pharmaceuticals. A. Sweidan: None. I. Yuki: None. S. Suzuki: None.

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