Recurrent Bleeding in Hemorrhagic Moyamoya Disease : Prognostic Implications of the Perfusion Status

Objective : Hemorrhagic moyamoya disease (hMMD) is associated with a poor clinical course. Furthermore, poorer clinical outcomes occur in cases of recurrent bleeding. However, the effect of hemodynamic insufficiency on rebleeding risk has not been investigated yet. This study evaluated the prognostic implications of the perfusion status during the clinical course of adult hMMD. Methods : This retrospective study enrolled 52 adult hMMD patients between April 1995 and October 2010 from a single institute. Demographic data, clinical and radiologic characteristics, including hemodynamic status using single photon emission computed tomography (SPECT), and follow up data were obtained via a retrospective review of medical charts and imaging. Statistical analyses were performed to explore potential prognostic factors. Results : Hemodynamic abnormality was identified in 44 (84.6%) patients. Subsequent revascularization surgery was performed in 22 (42.3%) patients. During a 58-month (median, range 3-160) follow-up assessment period, 17 showed subsequent stroke (hemorrhagic n=12, ischemic n=5, Actuarial stroke rate $5.8{\pm}1.4%/year$). Recurrent hemorrhage was associated with decreased basal perfusion (HR 19.872; 95% CI=1.196-294.117) and omission of revascularization (10.218; 95%; CI=1.532-68.136). Conclusion : Decreased basal perfusion seems to be associated with recurrent bleeding. Revascularization might prevent recurrent stroke in hMMD by rectifying the perfusion abnormality. A larger-sized, controlled study is required to address this issue.