Vessel Wall Changes on Serial High-Resolution MRI and the Use of Cilostazol in Patients With Adult-Onset Moyamoya Disease

Background and Purpose The natural course of adult-onset moyamoya disease (MMD) is unknown, and there is no medical treatment that halts its progression. We hypothesized that progressive shrinkage of large intracranial arteries occurs in adult-onset MMD, and that cilo-stazol inhibits this process. Methods Serial high-resolution magnetic resonance imaging (HR-MRI) was performed on 66 patients with MMD: 30 patients received cilostazol, 21 received other antiplatelets, and 15 received no antiplatelets or had poor compliance to them. Serial HR-MRI was performed (in-terval between MRI scans: 29.67±18.02 months, mean±SD), and changes in outer diameter, luminal stenosis, and vascular enhancement were measured. Factors affecting HR-MRI changes were evaluated, including vascular risk factors and the ring finger protein 213 gene variant. Results The progression of stenosis to occlusion, recurrent ischemic stroke, and the development of new stenotic segments were observed in seven, seven, and three patients, respec-tively. Serial HR-MRI indicated that the degree of stenosis increased with negative remodeling (outer diameter shrinkage). Patients who received cilostazol presented significantly larger outer diameters and lower degrees of stenosis compared with other groups (p=0.005 and p=0.031, re-spectively). After adjusting for clinical and genetic factors, only cilostazol use was independent-ly associated with negative remodeling (odds ratio=0.29, 95% confidence interval=0.10–0.84, p=0.023). While vascular enhancement was observed in most patients (61 patients), the progression of enhancement or the occurrence of new vascular enhancement was rarely observed on follow-up HR-MRI (6 and 1 patients, respectively). Conclusions Adult-onset MMD induces progressive shrinkage of large intracranial arteries, which cilostazol treatment may prevent. Further randomized clinical trials are warranted. Trial registration ClinicalTrials.gov identifier NCT02074111.