Cerebral Blood Flow and Metabolism of Hyperperfusion after Cerebral Revascularization in Patients with Moyamoya Disease

Abstract

In moyamoya disease (MMD), surgical revascularization may be complicated with postoperative hyperperfusion. We analyzed cerebral perfusion and metabolism using positron emission tomography (PET) or single-photon emission computed tomography (SPECT) before and after bypass surgery on 42 sides of 34 adult patients with MMD. In seven cases (16.7%) with symptomatic hyperperfusion, diagnosed by qualitative 123 I-iodoamphetamine (IMP) SPECT, a subsequent PET study during postoperative subacute stages revealed significantly increased cerebral blood flow (CBF) from 34.1 ± 8.2 to 74.3 ± 12.8 mL/100 g per minute (P < 0.01), a persistent increase in cerebral blood volume (CBV) from 5.77±1.67 to 7.01±1.44 mL/100 g and a significant decrease in oxygen extraction fraction (OEF) from 0.61 ± 0.09 to 0.40 ± 0.08 (P < 0.01). Mean absolute CBF values during symptomatic hyperperfusion were more than the normal control + 2 standard deviations, the predefined criteria of PET. Interestingly, two patients with markedly increased cerebral metabolic rate of oxygen (CMRO 2 ) at hyperperfusion were complicated with postoperative seizure. Among preoperative PET parameters, increased OEF was the only significant risk factor for symptomatic hyperperfusion (P < 0.05). This study revealed that symptomatic hyperperfusion in MMD is characterized by temporary increases in CBF > 100% over preoperative values caused by prolonged recovery of increased CBV.

The Leptomeningeal Ivy Sign on Fluid-Attenuated Inversion Recovery Images in Moyamoya Disease: Positron Emission Tomography Study

“…PET scans were carried out to quantitatively assess cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO 2 ) preoperatively, according to the dual-tracer autoradiographic protocol developed by Kudomi et al [9], with the minor modification of replacing intravenous administration of 15 O-water by 15 O-carbon dioxide inhalation [10]. The PET scanner used was ECAT ACCEL from Siemens-CTI (Knoxville, Tenn., USA), and data were acquired in the 2D mode.…”

Time-of-Flight MR Angiography for Detection of Cerebral Hyperperfusion Syndrome after Superficial Temporal Artery-Middle Cerebral Artery Anastomosis in Moyamoya Disease

“…[2][3][4][5] In addition, CHPS occurs more frequently in adult MMD than in pediatric MMD [3][4][5]13 and leads to transient neurologic deterioration, seizures, or delayed intracerebral hemorrhage. 6 Therefore, careful management of CHPS is mandatory after anastomosis for MMD.…”

“…Although SPECT, positron-emission tomography, xenonenhanced CT, dynamic perfusion CT, and MR imaging with dynamic susceptibility contrast and arterial spin-labeling have been reported useful for evaluating cerebral hemodynamics in MMD, 4,8,9 they involve radiation exposure or have limitations in availability. In contrast, TOF-MRA does not require the administration of radioisotopes and contrast agents, can be undertaken quickly, and is widely available.…”

“…The incidence of cerebral hyperperfusion syndrome (CHPS) after STA-MCA anastomosis for MMD was reported to range from 15.0% to 38.2%. [2][3][4][5] With CHPS, transient focal neurologic deterioration is often exhibited, and if intracerebral hemorrhage occurs, it may lead to permanent neurologic deficits. 6 Therefore, it is important to evaluate the regional cerebral blood flow after STA-MCA anastomosis for MMD.…”

“…6 Therefore, it is important to evaluate the regional cerebral blood flow after STA-MCA anastomosis for MMD. Positron-emission tomography and single-photon emission CT are criterion standard tools for the evaluation of regional CBF in patients with MMD 4,[7][8][9] ; however, they are time-consuming modalities and require the injection of a radiotracer. MR imaging is a powerful method for comprehensive assessment of the brain without radiation exposure, and time-of-flight MR angiography is widely available.…”