Bilateral Internal Carotid Artery Dissection in Cystathionine Beta-Synthase Deficiency

1 1.05 and arched palate. Neither skin abnormalities nor hyperextensible joints were found. She was treated with aspirin at 250 mg daily. Three days later, she suddenly became comatose and was transferred to the neurological intensive care unit for respiratory assistance. Her Glasgow Coma Scale rated 6, she presented with spastic tetraparesis. Cerebral CT scan, Doppler sonography and cerebral MRI suggested ischemic stroke by occlusion of both internal carotid arteries (ICA). On MRA, the left ICA was missing and the right ICA had tapering narrowing aspect. Axial CT angiography confirmed the dissection of both ICAs with intracranial extension ( fig. 1 a). Transthoracic echocardiography and 24-hour Holter results were normal. Blood sampling found major hyperhomocysteinemia, with total Dear Sir, Homocystinuria is the second most common congenital aminoacidopathy after phenylcetonuria [1–3] . The most commonly involved enzyme is cystathionine beta-synthase (CBS) (MIM 236200), responsible for major hyperhomocysteinemia and homocystinuria. Commonly diagnosed during childhood, it is rarely revealed in adult life. Here we report a patient who presented strokes due to bilateral internal carotid occlusion. Etiological workup found CBS deficiency. The mechanism of occlusion was bilateral artery dissection. Only one case of cervical artery dissection in major homocysteinemia has been reported previously [4] . However, increased homocysteine levels were recently described [5, 6] in spontaneous cervical artery dissection in young adults.