Specific Shrinkage of Carotid Forks in Moyamoya Disease: A Novel Key Finding for Diagnosis

Abstract

This study was aimed to analyze the outer diameter of the involved arteries in moyamoya disease, using three-dimensional (3D) constructive interference in steady state (CISS) and direct surgical inspection. Radiological evaluation was performed in 64 patients with moyamoya disease. As the controls, six patients with severe middle cerebral artery (MCA) stenosis and 17 healthy subjects were also recruited. On 3D-CISS, the outer diameter was quantified in the supraclinoid portion of internal carotid artery (C1), the horizontal portions of MCA (M1) and anterior cerebral artery (A1), and basilar artery. The involved carotid fork was directly observed during surgery in another series of three adult patients with moyamoya disease. In 53 adult patients with moyamoya disease, the outer diameters of C1, M1, and A1 segments were 2.3 ± 0.7 mm, 1.3 ± 0.5 mm, and 1.0 ± 0.4 mm in the involved side (n = 91), being significantly smaller than the control (n = 17), severe M1 stenosis (n = 6), and non-involved side in moyamoya disease (n = 15, P < 0.01). There were significant correlations between Suzuki’s angiographical stage and the outer diameters of C1, M1, and A1 (P < 0.001). The laterality ratio of C1 and M1 was significantly smaller in unilateral moyamoya disease (n = 20) than the controls and severe MCA stenosis (P < 0.01). Direct observations revealed a marked decrease in the outer diameter of the carotid fork (n = 3). These findings strongly suggest specific shrinkage of the involved arteries in moyamoya disease, which may provide essential information to distinguish moyamoya disease from other intracranial arterial stenosis and shed light on the etiology and novel diagnosis cue of moyamoya disease.

Hemorrhagic Moyamoya Disease : A Recent Update

“…Kaku et al [ 21 ] proposed the constrictive remodeling theory that the outer diameter narrowing of the affected intracranial major arteries was the early characteristic of MMD, as demonstrated by three-dimensional (3D) constructive interference in steady-state (CIISS) MR imaging. Similar observation on 3D CIISS MR imaging in the diagnosis of MMD was reported by Kuroda and colleagues [ 27 ]. Ryoo and colleagues [ 31 ] reported that MMD was characterized by concentric enhancement on distal ICA and shrinkage of MCA, while atherosclerosis represented focal eccentric enhancement at the symptomatic segment of intracranial arteries.…”

Anomalies of the Middle Cerebral Artery

“…Kuroda et al demonstrated the specific shrinkage of the involved arteries in MMD by using 3D constructive interference in steady state (CISS) and direct surgical inspection. 25) On the other hand, a twig-like MCA should already have been formed at birth, if the hypothesis that the twig-like MCA is the persistent fetal arterial network, is correct. If an infant with a twig-like MCA is found, the hypothesis is persuasive.…”

Clinical Management of Moyamoya Patients

“…Histopathological findings in the carotid terminations include fibrocellular thickening of the intima, irregular waving of the internal elastic lamina, and attenuation of the media, all contributing to the progressive luminal stenosis ("shrinkage") in the carotid fork. However, it has also been demonstrated that the outer diameter simultaneously decreases, as opposed to atherosclerotic degeneration [27,28].…”

“…In addition, "indirect symptoms" likely caused by the aberrant collateralization have been described. Migraine-like (with or without aura) and tension-type-like headache attacks have been reported in up to 50-70% in different series of Eastern and Western MMA patients [3,4,[27][28][29][30][31]37]. Headache, which has been supposed to be due to collateralization processes and stimulation of dural nociceptors by dilated transdural collaterals, was also associated with brain hypoperfusion [40].…”