1Department of Neurosurgery and.
2Cyclotron Research Center, School of Medicine, Iwate Medical University, Morioka, Japan.
J Neurosurg. 2018 Dec 14;131(6):1716-1724. doi: 10.3171/2018.7.JNS18149. Print 2019 Dec 1.
Some adult patients with moyamoya disease (MMD) undergoing revascularization surgery show an improvement or decline in cognition postoperatively. Revascularization surgery for ischemic MMD augments cerebral blood flow (CBF) and improves cerebral oxygen metabolism. However, cerebral hyperperfusion, which is a short-term, major increase in ipsilateral CBF that is much greater than the metabolic needs of the brain, sometimes occurs as a complication. Cerebral hyperperfusion produces widespread, minimal injury to the ipsilateral white matter and cortical regions. The aim of the present prospective study was to determine how changes in CBF due to arterial bypass surgery affect cognitive function in adult patients with symptomatic ischemic MMD and misery perfusion.
Thirty-two patients with cerebral misery perfusion, as determined on the basis of 15O gas positron emission tomography, underwent single superficial temporal artery-middle cerebral artery (M4 in the precentral region) anastomosis. Brain perfusion single-photon emission computed tomography (SPECT) studies were performed preoperatively, on the 1st postoperative day, and 2 months after surgery. Neuropsychological tests were also performed preoperatively and 2 months after surgery.
Postoperative neuropsychological assessments demonstrated cognitive improvement in 10 cases (31%), no change in 8 cases (25%), and decline in 14 cases (44%). Based on brain perfusion SPECT and symptoms, 10 patients were considered to have cerebral hyperperfusion syndrome, and all of these patients exhibited a postoperative decline in cognition. Relative precentral CBF on the 1st postoperative day was significantly greater in patients with postoperative cognitive decline (167.3% ± 15.3%) than in those with improved (105.3% ± 18.2%; p < 0.0001) or unchanged (131.4% ± 32.1%; p = 0.0029) cognition. The difference between relative precentral CBF 2 months after surgery and that before surgery was significantly greater in patients with postoperative cognitive improvement (17.2% ± 3.8%) than in those with no postoperative change (10.1% ± 2.4%; p = 0.0003) or with postoperative decline (11.5% ± 3.2%; p = 0.0009) in cognition.
Cerebral hyperperfusion in the acute stage after arterial bypass surgery impairs cognitive function. An increase in CBF in the chronic stage without acute-stage cerebral hyperperfusion improves cognitive function in adult patients with symptomatic ischemic MMD and misery perfusion.
一些接受血运重建手术的成人烟雾病（MMD）患者术后认知功能改善或下降。缺血性 MMD 的血运重建手术可增加脑血流量（CBF）并改善脑氧代谢。然而，作为一种并发症，有时会发生短暂的、显著增加同侧 CBF 的脑过度灌注，其程度远远超过大脑的代谢需求。脑过度灌注会导致同侧白质和皮质区域广泛、轻微损伤。本前瞻性研究旨在确定动脉旁路手术后 CBF 的变化如何影响有症状的缺血性 MMD 和苦难灌注的成人患者的认知功能。
32 例脑苦难灌注患者（根据 15O 气体正电子发射断层扫描确定）接受单条外侧颞浅动脉-大脑中动脉（M4 在中央前区）吻合术。术前、术后第 1 天和术后 2 个月进行脑灌注单光子发射计算机断层扫描（SPECT）研究。术前和术后 2 个月进行神经心理学测试。
术后神经心理学评估显示 10 例（31%）认知改善，8 例（25%）无变化，14 例（44%）认知下降。根据脑灌注 SPECT 和症状，10 例患者被认为患有脑过度灌注综合征，所有这些患者术后认知能力下降。术后认知下降患者第 1 天的中央前区相对 CBF 显著大于认知改善患者（167.3%±15.3%比 105.3%±18.2%；p<0.0001）或认知无变化患者（131.4%±32.1%；p=0.0029）。术后认知改善患者术后 2 个月与术前的相对中央前区 CBF 差异明显大于术后认知无变化患者（17.2%±3.8%比 10.1%±2.4%；p=0.0003）或术后认知下降患者（11.5%±3.2%；p=0.0009）。
动脉旁路手术后急性期的脑过度灌注会损害认知功能。慢性期无急性期脑过度灌注的 CBF 增加可改善有症状的缺血性 MMD 和苦难灌注的成年患者的认知功能。
