Patient With Severe Moyamoya Disease Who Presents With Acute Cortical Blindness

A previously healthy 16-year-old girl presented to a local emergency room with intense headache, severe nausea, and vision loss. The week before, she had intermittent headaches and nonspecific visual changes that resolved with acetaminophen or NSAIDs and rest. On admission to the hospital, she was found to be extremely hypertensive and had bilateral occipital hypodensities consistent with infarcts on noncontrast computed tomography.On transfer to the regional pediatric hospital, she had severe vision loss (light perception only), and magnetic resonance imaging showed bilateral infarctions, especially affecting the posterior circulation and occipital lobes (Figure 1). Magnetic resonance perfusion revealed severe bilateral hemispheric hypoperfusion, and magnetic resonance imaging fluid-attenuated inversion-recovery sequence demonstrated linear hyperdensities along sulci—the ivy sign often seen in moyamoya. Cerebral angiography revealed complete occlusion of the bilateral internal carotid arteries distal to the anterior choroidal arteries with dense moyamoya collaterals and extreme attenuation of the posterior cerebral artery circulation, also with moyamoya collaterals (Figure 2). Biochemical, hemostatic, and genetic evaluations were normal, with the exception of a significantly elevated d-dimer level (1850 ng/mL; normal range: 0–543 ng/µL). Apart from her mother experiencing a deep venous thrombosis during pregnancy, the patient’s family history was unremarkable for coagulopathies.Figure 1. Axial T2 magnetic resonance imaging with bilateral fluid-attenuated inversion-recovery changes revealing infarctions of the right posterior temporal and occipital lobes and of the left parietal, occipital, and posterior temporal lobes. In addition, there were small chronic white matter infarcts in the bifrontal middle cerebral artery–anterior cerebral artery watershed territories (not pictured).Figure 2. Angiographic images (lateral views) showing effects of surgical treatment with pial synangiosis. A and B , Right external carotid artery injections, preoperatively ( A ) and at 1-y follow-up ( B ). There is extensive revascularization in the right middle cerebral artery territory and superior part of the right anterior cerebral artery territory (boxed area). …