The Differences of Cerebral Hyperperfusion in Patients With Moyamoya Disease and Atherosclerotic Occlusive Cerebrovascular Disease Evaluated by 99mTc-ECD SPECT One Day After Revascularization Surgery

Background: To examine the relationship between postoperative cerebral hyperperfusion (CHP) and preoperative cerebral blood flow (CBF) SPECT findings in patients with moyamoya disease (MMD) or atherosclerotic occlusive cerebrovascular disease (AOCD). Patients and Methods: We calculated the preoperative-postoperative CBF and postoperative increase rate (IR) in the frontal, temporal, and parietal lobes of 100 cerebral hemispheres and then compared the CHP patterns and severities among the patients with adult-onset MMD (AMMD), pediatric-onset MMD (PMMD), and AOCD. We investigated the associations among CHP, preoperative CBF, and cerebrovascular reactivity (CVR). Results: CHP (≥30% change in the IR) occurred in 27 hemispheres. The incidence of the frontal lobe-dominant pattern (19.0%) was significantly higher than those of the temporal and parietal lobe-dominant patterns (4.0% each, P < 0.001). Severe CHP (≥50% change) occurred more frequently in the AMMD group (2 patients suffered major complications) versus the patients with PMMD and AOCD (21.5% vs 2.9%, P = 0.01). In the combined patients with MMD, reduced preoperative CBF more accurately predicted the occurrence of mild/severe or severe CHP than CVR (AUCs: 0.84 vs 0.67; 0.81 vs 0.73), while neither preoperative CBF nor CVR was correlated with CHP in the AOCD group. As demonstrated by 13 SPECT studies conducted after postoperative day 2, CHP was promptly resolved in 12 hemispheres; 1 hemisphere progressed to severe CHP. Conclusions: CHP in the frontal lobe occurred more often and with greater severity in patients with AMMD. Preoperative CBF reduction was more closely associated with CHP than CVR in patients with MMD. Nonactivated 99m Tc-ethyl cysteinate dimer SPECT was suitable for preoperative/postoperative CBF evaluations.