Symptomatic Cerebral Hyperperfusion Research Articles

Intraoperative Hemodynamics of Parasylvian Cortical Arteries for Predicting Postoperative Symptomatic Cerebral Hyperperfusion after Direct Revascularization in Patients with Moyamoya Disease: A Preliminary Study.

Objective. The search for methods by which to predict the risks of cerebral hyperperfusion syn-drome (CHS) in adults with moyamoya disease (MMD), including those utilizing new biomarkers, still deserves further research. The objective of this study was to investigate the association between the hemodynamics of parasylvian cortical arteries (PSCAs) and postoperative CHS. Methods. A consecutive number of adults with MMD who had undergone direct bypass between September 2020 and December 2022 were recruited. Intraoperative microvascular doppler ultrasonography (MDU) was performed to evaluate the hemodynamics of PSCAs. The intraoperative flow direction, mean value of velocity (MVV) of recipient artery (RA) and bypass graft were recorded. According to flow direction after bypass, RA was divided into entering sylvian (RA.ES) and leaving sylvian (RA.LS) subtypes. Univariate, multivariate, and ROC analyses of the risk factors for postoperative CHS were performed. Results. A total of 16 (15.09%) cases in 106 consecutive hemispheres (101 patients) sat-isfied the postoperative CHS criteria. According to univariate analysis, advanced Suzuki stage, MVV of RA before bypass, and fold increase of MVV in RA.ES after bypass were significantly associated with postoperative CHS (p < 0.05). Multivariate analysis indicated that left-operated hemisphere (OR (95%CI), 4.58 (1.05-19.97), p = 0.043), advanced Suzuki stage (OR (95%CI), 5.47 (1.99-15.05), p = 0.017), and fold increase of MVV in RA.ES (OR (95%CI), 1.17 (1.06-1.30), p = 0.003) were statistically significantly associated with the occurrence of CHS. The cut-off value of fold increase of MVV in RA.ES was 2.7-fold (p < 0.05). Conclusions. Left-operated hemisphere, advanced Suzuki stage, and postoperative fold increase of MVV in RA.ES were potential risk factors for postoperative CHS. Intraoperative MDU was useful for evaluating hemodynamics and predicting CHS.

Association of RNF213 polymorphism and cortical hyperintensity sign on fluid-attenuated inversion recovery images after revascularization surgery for moyamoya disease: possible involvement of intrinsic vascular vulnerability.

A cortical hyperintensity on fluid-attenuated inversion recovery images (FLAIR cortical hyperintensity (FCH)) is an abnormal finding after revascularization surgery for moyamoya disease. This study aimed to investigate the pathophysiology of FCH through genetic analyses of RNF213 p.R4810K polymorphism and perioperative hemodynamic studies using single-photon emission computed tomography. We studied 96 hemispheres in 65 adults and 47 hemispheres in 27 children, who underwent combined direct and indirect revascularization. Early or late FCH was defined when it was observed on postoperative days 0-2 and 6-9, respectively. FCH scores (range: 0-6) were evaluated according to the extent of FCH in the operated hemisphere. FCHs were significantly more prevalent in adult patients than pediatric patients (early: 94% vs. 78%; late: 97% vs. 59%). In pediatric patients, FCH scores were significantly improved from the early to late phase regardless of the RNF213 genotype (mutant median [IQR]: 2 [1-5] vs. 1 [0-2]; wild-type median: 4 [0.5-6] vs. 0.5 [0-1.75]). In adults, FCH scores were significantly improved in patients with the wild-type RNF213 allele (median: 4 [2-5.25] vs. 2 [2, 3]); however, they showed no significant improvement in patients with the RNF213 mutation. FCH scores were significantly higher in patients with symptomatic cerebral hyperperfusion than those without it (early median: 5 [4, 5] vs. 4 [2-5]; late median: 4 [3-5] vs. 3 [2-4]). In conclusion, the RNF213 p.R4810K polymorphism was associated with prolonged FCH, and extensive FCH was associated with symptomatic cerebral hyperperfusion in adult patients with moyamoya disease.

Designing a flow-controlled STA-MCA anastomosis based on the Hagen-Poiseuille law for preventing postoperative hyperperfusion in adult moyamoya disease.

Technical improvements for preventing postoperative symptomatic cerebral hyperperfusion (CHP) during superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis for moyamoya disease (MMD) were seldom reported. The aim of this study was to investigate the significance of application of a novel flow-controlled concept which voluntarily reduces the hemodynamic difference between the donor and recipient arteries based on the Hagen-Poiseuille law when performing direct anastomoses of recipient parasylvian cortical arteries (PSCAs) with anterograde hemodynamic sources from the MCA (M-PSCAs) in adult MMD. This was a retrospective observational study. Direct anastomoses of recipient M-PSCAs were performed on 89 symptomatic hemispheres in 82 adult MMD patients in our hospital from January 2020 to June 2021. They were divided into the flow-controlled group (patients who received direct anastomosis under designed flow-controlled principles) and non-flow-controlled group (patients who received conventional direct anastomosis to obtain maximum flow). The patients' basic characteristics and incidence of postoperative CHP were compared between the two groups. Risk factors for occurrence of postoperative CHP were analyzed. Overall, 36 hemispheres were included in the non-flow-controlled group and 53 in flow-controlled group. The incidences of postoperative focal (22.6%) and symptomatic CHP (5.7%) in the flow-controlled group were significantly lower than those (focal, 52.8%; symptomatic, 25.0%) in the non-flow-controlled group (p = 0.003 and 0.009, respectively). Multivariate analysis revealed that the flow-controlled concept was significantly associated with the development of focal (p = 0.005) and symptomatic (p = 0.012) CHP. The flow-controlled STA-MCA anastomosis can significantly decrease the incidence of postoperative CHP during direct anastomoses of recipient M-PSCAs in adult MMD.

Solitaire stents deployment may reduce ischemic events in staged angioplasty for severe carotid stenosis.

Cerebral hyperperfusion syndrome is a fatal complication that can occur after stent angioplasty in patients with severe carotid artery stenosis. Staged angioplasty can prevent cerebral hyperperfusion syndrome. Conventional staged angioplasty consists of small balloon angioplasty in the first stage and carotid artery stenting in the second stage two to four weeks later. Sometimes, antegrade flow during stage 1 could hardly be maintained and stent will be needed. Solitaire stents were used in some patients in our center. This study aimed to examine the safety and effectiveness of Solitaire stents in staged angioplasty. A retrospective analysis was performed on patients with severe carotid artery stenosis and preoperative computed tomography perfusion indicating risk of cerebral hyperperfusion syndrome from 2011 to 2018. Small balloon angioplasty (<3 mm in diameter) only was performed in stage 1 (group 1). If antegrade flow during stage 1 is compromised, then a solitaire stent is deployed (group 2). After two to four weeks, cerebral angiography was undertaken in both groups to determine whether to perform stage 2. If the residual stenosis was more than 50%, carotid artery stenting was deployed. Angiographic results, clinical results, and follow-up results were collected and analyzed. Twenty-five patients were included in the study (group 1, n = 19; group 2, n = 6). After stage 1, no patient in group 2 and two patients in group 1 developed new symptomatic cerebral infarction (0.0% vs. 10.5%, p = 1.000). One patient in group 2 and three patients in group 1 (16.7% vs. 15.8%, p = 1.000) developed symptomatic cerebral hyperperfusion syndrome. One patient in group 2 (n = 4) and three patients in group 1 (n = 12) (25% vs. 25%, p = 1.000) developed hyperperfusion phenomenon. Two patients in group 2 and five patients in group 1 (33.3% vs. 26.3%, p = 1.000) developed symptomatic cerebral hyperperfusion syndrome or hyperperfusion phenomenon. One patient in group 1 developed symptomatic cerebral hyperperfusion syndrome and hyperperfusion phenomenon. After stage 2, no new cerebral infarction occurred in both groups. No patient in group 2 (n = 3) and one patient in group 1 (n = 17) developed symptomatic cerebral hyperperfusion syndrome (0.0% vs. 5.9%, p = 1.000). In the combined analysis of both stages, two patients (10.5%) developed new symptomatic cerebral infarction and four patients (21.1%) developed symptomatic cerebral hyperperfusion syndrome in group 1, no patient (0.0%) developed symptomatic cerebral infarction and one patient (16.7%) developed symptomatic cerebral hyperperfusion syndrome in group 2. There was no significant difference in symptomatic cerebral infarction and symptomatic cerebral hyperperfusion syndrome between the two groups (p = 1.000; p = 1.000). Three patients in group 2 and 17 patients in group 1 (50% vs. 89.5%, p = 0.070) underwent stage 2 angioplasty. No cerebral hemorrhage or cerebral infarction occurred in the Solitaire group during the one-year follow-up period. Solitaire stents deployment may reduce ischemic events in staged angioplasty for severe carotid stenosis.

Preoperative platelet count may predict postoperative symptomatic cerebral hyperperfusion syndrome after superficial temporal artery–middle cerebral artery anastomosis in moyamoya patients

ObjectivePlatelets play a critical role in the inflammatory response, accompanied by microvascular endothelial dysfunction, underlying postoperative symptomatic cerebral hyperperfusion syndrome (PSCHS) after superficial temporal artery–middle cerebral artery (STA-MCA) anastomosis in moyamoya patients. We examined whether the preoperative platelet count can predict PSCHS after STA-MCA anastomosis in such patients. MethodsIn 160 adult moyamoya patients undergoing 186 STA-MCA anastomoses, preoperative (demographics, initial clinical manifestation, and Suzuki grade), intraoperative (surgical time, operative side, fluid balance, and maximum and minimum mean blood pressure before and after vessel anastomosis), immediate postoperative (APACHE 2 score), and laboratory (hemoglobin and C-reactive protein levels and white blood cell and platelet counts) data were collected retrospectively. Results84 patients (90 sides, 48.4 %) developed PSCHS with a median(IQR) onset of postoperative day 1(0–3) and duration of 4(3–7) days. The preoperative (25.2[22.8–28.0] vs. 23.1[19.7–26.2] ×104/μL, p = 0.009) platelet count was significantly higher in patients with PSCHS than in those without. The preoperative platelet count (odds ratio[95 % confidence interval], 1.14[1.03–1.27], p = 0.011), operation on the dominant hemisphere (6.84 [3.26–14.36], p < 0.001), and negative fluid balance (2.41[1.04–5.59], p = 0.040) were significant independent predictors of PSCHS. The optimal cut-off value for preoperative platelet count was 22.7 ×104/μL, and PSCHS developed more frequently in cases with a preoperative platelet count ≥ 22.7 × 104/μL (2.90[1.54–5.45]; p = 0.001). ConclusionA high preoperative platelet count may be associated with the development of PSCHS after STA-MCA anastomosis in adult moyamoya patients.

In Reply to the Letter to the Editor Regarding “Effect of Sevoflurane Postconditioning on the Incidence of Symptomatic Cerebral Hyperperfusion After Revascularization Surgery in Adult Patients with Moyamoya Disease”

In Reply to the Letter to the Editor Regarding “Effect of Sevoflurane Postconditioning on the Incidence of Symptomatic Cerebral Hyperperfusion After Revascularization Surgery in Adult Patients with Moyamoya Disease”

Letter to the Editor Regarding “Effect of Sevoflurane Postconditioning on the Incidence of Symptomatic Cerebral Hyperperfusion After Revascularization Surgery in Adult Patients with Moyamoya Disease”

Letter to the Editor Regarding “Effect of Sevoflurane Postconditioning on the Incidence of Symptomatic Cerebral Hyperperfusion After Revascularization Surgery in Adult Patients with Moyamoya Disease”

Hemodynamic analysis of the recipient parasylvian cortical arteries for predicting postoperative hyperperfusion during STA-MCA bypass in adult patients with moyamoya disease.

Superficial temporal artery-middle cerebral artery (STA-MCA) bypass is a common approach for treating moyamoya disease (MMD); however, the selection of recipient vessels is still controversial, and its relationship with postoperative cerebral hyperperfusion (CHP) has not been revealed. The aim of the study was to investigate the relationship between the hemodynamic sources of the recipient parasylvian cortical arteries (PSCAs) and the occurrence of postoperative CHP. The authors retrospectively analyzed the clinical data from 68 adult patients (75 hemispheres) with MMD who underwent STA-MCA bypass. Based on their hemodynamic sources from the MCA and non-MCAs, the PSCAs were classified as M-PSCAs and non-M-PSCAs, and their distributional characteristics were studied. Moreover, the patients' demographics, incidence of postoperative CHP, and post- and preoperative relative cerebral blood flow values were examined. The digital subtraction angiography analysis demonstrated that 40% (30/75) of the recipient PSCAs had no hemodynamic relationship with the MCA. The post- and preoperative relative cerebral blood flow values of the M-PSCA group were significantly higher than those of the non-M-PSCA group (p < 0.001). Multivariate analysis revealed that the hemodynamic source of PSCAs from the MCA was significantly associated with the development of focal (p = 0.003) and symptomatic (p = 0.021) CHP. Twelve (85.7%) of the 14 patients with symptomatic CHP and all 4 (100%) patients with postoperative hemorrhage were from the M-PSCA group. This study revealed that direct anastomoses of PSCAs with anterograde hemodynamic sources from the MCA had a high risk of postoperative CHP during STA-MCA bypass in adult patients with MMD.

Effect of Sevoflurane Postconditioning on the Incidence of Symptomatic Cerebral Hyperperfusion After Revascularization Surgery in Adult Patients with Moyamoya Disease

Various experimental studies have reported neuroprotective effects of sevoflurane postconditioning against cerebral ischemia-reperfusion injury. We therefore investigated its neuroprotective effects on hyperperfusion-related transient neurologic deterioration, called symptomatic cerebral hyperperfusion (SCH), and also identified predictive factors for SCH in patients with moyamoya disease after revascularization surgery. A total of 152 adult patients with moyamoya disease undergoing anastomosis of the superficial temporal artery to middle cerebral artery were randomly allocated into 2 groups. The postconditioning group (group S, n= 76) inhaled sevoflurane of 1 minimum alveolar concentration for 15 minutes immediately after reperfusion and then washed it out slowly for 15 minutes. The control group (group C, n= 76) received no intervention. The incidence of SCH was compared between the 2 groups. The incidence of SCH was not significantly different between groups S and C (53.3% vs. 43.4%, respectively; P= 0.291). The incidence of postoperative complications and the Glasgow Outcome Scale score at hospital discharge also did not differ significantly. Predictive factors for SCH included a decreased vascular reserve in preoperative single-photon emission computed tomography scan (odds ratio [OR], 7.18; 95% confidence interval [CI], 1.78-29.02; P= 0.006), an operation performed on the dominant hemisphere (OR, 3.32; 95% CI, 1.57-6.98; P= 0.002), temporal occlusion time (OR, 1.06; 95% CI, 1.01-1.11; P= 0.017), and intraoperative minimum partial pressure of carbon dioxide (PaCO2) (OR, 0.86; 95% CI, 0.78-0.94; P= 0.001). Sevoflurane postconditioning did not reduce the incidence of SCH after revascularization surgery in patients with moyamoya disease. Rather, a decreased vascular reserve, operation on the dominant hemisphere, increased temporal occlusion time, and decreased intraoperative minimum PaCO2 were associated with SCH in these patients.

Effectiveness of Near-Infrared Spectroscopy (NIRO-200NX, Pulse Mode) for Risk Management in Carotid Artery Stenting

Near-infrared spectroscopy (NIRS) is an alternative monitoring method during carotid artery stenting (CAS). NIRS has been reported to be effective in emergency care; however, it is unknown whether it can predict intraoperative ischemic intolerance and cerebral hyperperfusion during CAS. Perioperative ischemic intolerance and cerebral hyperperfusion are potential events during CAS for carotid artery stenosis. We evaluated whether perioperative monitoring of the tissue oxygenation index (TOI) using NIRS with the NIRO system can predict the occurrence of ischemic intolerance and cerebral hyperperfusion. The TOI of 27 patients was measured during CAS. The relationship between the TOI and ischemic intolerance or cerebral hyperperfusion was analyzed, and the cutoff TOI was calculated to predict their occurrence. Ischemic intolerance occurred in 5 patients during balloon protection. The TOI in the presence of ischemic intolerance was significantly lower than that without ischemic intolerance. The cutoff TOI to detect ischemic intolerance was 50% and that of the TOI change rate before and after balloon protection was 80%. The ischemic symptoms in all patients had resolved immediately after balloon deflation. The cerebral hyperperfusion phenomenon was detected using single-photon emission computed tomography in 4 patients. These patients showed a transient increase in the TOI immediately after CAS; however, none of these patients showed symptomatic cerebral hyperperfusion phenomenon. The cutoff TOI to detect cerebral hyperperfusion was 109% compared with the TOI before CAS. Monitoring of the TOI using the NIRO system could be useful for the detection of ischemic intolerance and cerebral hyperperfusion during CAS and to prevent perioperative adverse events.

Preeclampsia postpartum: Impairment of cerebral autoregulation and reversible cerebral hyperperfusion.

Preeclampsia is a pregnancy-related hypertensive disorder with endothelial dysfunction. Impaired cerebral autoregulation may lead to symptomatic cerebral hyperperfusion, which sometimes manifests not until after delivery. This study investigated, whether cerebral autoregulation was altered after delivery in healthy and preeclamptic women, and whether this associated with cerebral hyperperfusion. In a prospective study, 35 preeclamptic and 35 healthy women were examined with transcranial Doppler within 10 days postpartum and 6 months later. Continuous arterial blood pressure and cerebral blood flow velocities (CBFV) in the middle (MCA) and posterior cerebral arteries (PCA) were recorded at rest. Dynamic cerebral autoregulation was assessed upon regular breathing at 0.1 Hz via transfer function phase and gain between arterial blood pressure and CBFV oscillations. In preeclamptic women, phase was reduced after delivery in both, MCA and PCA. During the postpartum period, CBFV of the MCA, but not PCA, correlated with higher arterial blood pressure and poorer dynamic cerebral autoregulation. In healthy women with only moderately altered cerebral autoregulation, CBFV remained in the normal range. At both measurements, arterial blood pressure was higher in preeclamptic compared to healthy women. Women with preeclampsia had poorer cerebral autoregulation and an increased risk of transient cerebral hyperperfusion after delivery.

Risk factors for and outcomes of postoperative complications in adult patients with moyamoya disease.

The risk factors and clinical significance of postoperative complications in moyamoya disease are still unclear. The aim of this study was to investigate the predictors of postoperative complications in moyamoya disease and examine the impact of complications on outcomes. The authors reviewed consecutive cases involving adult moyamoya disease patients who underwent indirect, direct, or combined bypass surgery in their hospital between 2009 and 2015. Preoperative clinical characteristics and radiographic features were recorded. Postoperative complications within 14 days after surgery were examined. Multivariate logistic regression analyses were performed to identify the risk factors for either postoperative ischemia or postoperative cerebral hyperperfusion. Outcome data, including recurrent strokes and neurological status (modified Rankin Scale [mRS]) during follow-up, were collected. Outcomes were compared between patients who had complications with those without complications, using propensity-score analysis to account for between-group differences in baseline characteristics. A total of 500 patients (610 hemispheres) were included in this study. Postoperative complications were observed in 74 operations (12.1%), including new postoperative ischemia in 30 cases (4.9%), hyperperfusion in 27 (4.4%), impaired wound healing in 12 (2.0%), and subdural effusion in 6 (1.0%). The complication rates for different surgery types were as follows: 12.6% (n = 25) for indirect bypass, 12.7% (n = 37) for direct bypass, and 10.0% (n = 12) for combined bypass (p = 0.726). Postoperative ischemic complications occurred in 30 hemispheres (4.9%) in 30 different patients, and postoperative symptomatic hyperperfusion occurred after 27 procedures (4.4%). Advanced Suzuki stage (OR 1.669, 95% CI 1.059-2.632, p = 0.027) and preoperative ischemic presentation (OR 5.845, 95% CI 1.654-20.653, p = 0.006) were significantly associated with postoperative ischemia. Preoperative ischemic presentation (OR 5.73, 95% CI 1.27-25.88, p = 0.023) and admission modified Rankin Scale (mRS) score (OR 1.81, 95% CI 1.06-3.10, p = 0.031) were significantly associated with symptomatic postoperative cerebral hyperperfusion syndrome (CHS). Compared with patients without postoperative complications, patients who experienced any postoperative complications had longer hospital stays and worse mRS scores at discharge (both p < 0.0001). At the final follow-up, no significant differences in functional disability (mRS score 3-6, 11.9% vs 4.5%, p = 0.116) and future stroke events (p = 0.513) between the 2 groups were detected. Advanced Suzuki stage and preoperative ischemic presentation were independent risk factors for postoperative ischemia; the mRS score on admission and preoperative ischemic presentation were independently associated with postoperative CHS. Although patients with postoperative complications had worse neurological status at discharge, postoperative complications had no associations with future stroke events or functional disability during follow-up.

Predictive factors of symptomatic cerebral hyperperfusion after superficial temporal artery-middle cerebral artery anastomosis in adult patients with moyamoya disease

Symptomatic cerebral hyperperfusion (SCH) is a potential complication after superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis in patients with moyamoya disease. This retrospective study was designed to determine factors associated with SCH after STA-MCA anastomosis in adult moyamoya patients. Eighty-two adult moyamoya patients undergoing STA-MCA anastomosis between July 2005 and December 2010 were enrolled. Laboratory data such as haemoglobin and white blood cell (WBC) count, preoperative (patient characteristic data, initial clinical manifestation, the angiographic staging), intraoperative (surgical time, the operative side, anaesthetic technique, fluid balance, arterial pressure, arterial partial pressure of carbon dioxide, the lowest haematocrit, and intraoperative transfusion), and postoperative (arterial pressure, Acute Physiology and Chronic Health Evaluation II score) data were collected and used as predictable factors for postoperative SCH, in which a focal intense increase in cerebral blood flow at the anastomosis site was shown in postoperative single-photon emission computed tomography. Among 82 patients with 99 surgeries, 39 patients (47 sides, 47%) suffered from transient neurological deterioration due to SCH from 1 to 9 days after operation (median: 2 days), which was sustained for 1-14 days (median: 7 days). The operation on the dominant hemisphere [odds ratio (OR), 5.09; 95% confidence interval (CI), 2.07-12.54, P<0.001] was an independent risk factor for SCH. Also, WBC count on postoperative day 1 was significantly correlated with SCH (OR 1.19; 95%CI, 1.02-1.38, P=0.029). The operation on the dominant hemisphere and increased postoperative WBC count may be associated with SCH after STA-MCA anastomosis in adult-onset moyamoya patients.

Symptomatic Cerebral Hyperperfusion on SPECT After Indirect Revascularization Surgery for Moyamoya Disease

Six patients who experienced transient neurological deteriorations with no evidences of hemorrhage and infarction after encephaloduroarteriogaleosynangiosis for moyamoya disease were evaluated with semiquantitative analysis using brain perfusion SPECT. Postoperative transient neurological deteriorations topographically corresponded to hyperperfusion areas on SPECT. Cerebral blood flows of both the operated hemisphere and focal hyperperfusion area increased significantly after surgery (P=0.046 and 0.028, respectively), compared with the preoperative ones. Symptomatic cerebral hyperperfusion may occur transiently after indirect revascularization surgery for adult moyamoya disease. Further study is needed to clarify the exact mechanism of cerebral hyperperfusion after indirect surgery.

Hyperperfusion Syndrome after Stent/Coiling of a Ruptured Carotid Bifurcation Aneurysm

The authors report a syndrome of regional, symptomatic cerebral hyperperfusion, and edema mimicking infarction in a 54-year-old woman following coiling of a ruptured right carotid bifurcation aneurysm and stenting of the right middle cerebral artery. The patient presented with a Hunt and Hess grade III subarachnoid hemorrhage 7 days after developing thunderclap headache. She underwent successful coiling under general anesthesia of the 1.6 × 1.5 × 1.6 cm aneurysm, but immediately after the coil was placed occlusion of the proximal M1 segment was developed. This occlusion was stented after ~5-min delay, and flow restored without angiographic evidence of distal emboli. Following the procedure, she was extubated and noted to have left hemiparesis, neglect, and mutism without a CT correlate. Cerebral infarction was suspected, but urgent repeat angiography demonstrated patent cerebral vasculature. On the following day, symptoms persisted, and non-contrast head CT now showed cerebral edema localized to the right middle cerebral artery territory mimicking subacute infarction. CT perfusion imaging and angiography showed a widely patent MCA circulation, and suggested a regional hyperperfusion syndrome. The blood pressure was incrementally lowered, with rapid and sustained neurological improvement. Hyperperfusion events following aneurysm repair and related circumstances are reviewed.

Efficacy of Prophylactic Blood Pressure Lowering according to a Standardized Postoperative Management Protocol to Prevent Symptomatic Cerebral Hyperperfusion after Direct Revascularization Surgery for Moyamoya Disease

Background: Cerebral hyperperfusion is a potential complication of superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis for moyamoya disease, but the optimal postoperative management has not been determined. Aggressive blood pressure lowering is controversial because of the risk of ischemic complications. Objective: To establish the optimal postoperative management protocol to prevent symptomatic cerebral hyperperfusion in moyamoya disease. Methods: N-isopropyl-p-[¹²³I]-iodoamphetamine single-photon emission computed tomography was performed 1 and 7 days after STA-MCA anastomosis on 152 hemispheres from 108 consecutive patients with moyamoya disease (2–69, mean 33.3 years). Between 2004 and 2007 (period 1), 65 patients were maintained under normotensive conditions after 93 operations, and only patients with cerebral hyperperfusion underwent blood pressure lowering. Between 2008 and 2010 (period 2), all 43 patients were prospectively subjected to intensive blood pressure lowering (<130 mm Hg of systolic blood pressure) immediately after 59 operations. Then the incidence of symptomatic cerebral hyperperfusion was compared between the two groups. Results: Systolic blood pressure the day after surgery was significantly lower in period 2 (mean, 120.9 mm Hg) than in period 1 (133.9 mm Hg) (p < 0.0001). Symptomatic cerebral hyperperfusion was seen in 22 patients during period 1 (23 hemispheres, 24.7%), but only in 4 patients during period 2 (6.7%, p = 0.0047). Multivariate analysis revealed that prophylactic blood pressure lowering was significantly associated with the prevention of symptomatic cerebral hyperperfusion (p = 0.015). Symptomatic cerebral hyperperfusion was relieved in all patients without developing a permanent neurological deficit due to cerebral hyperperfusion. Conclusion: Prophylactic blood pressure lowering prevents symptomatic cerebral hyperperfusion after STA-MCA anastomosis in patients with moyamoya disease. Accurate diagnosis of cerebral hyperperfusion and blood pressure lowering, and considering the severity of hemodynamic compromise in the contralateral and/or remote areas are essential for postoperative management of moyamoya disease.

Prolonged and regionally progressive symptomatic cerebral hyperperfusion syndrome after superficial temporal artery-middle cerebral artery anastomosis in a patient with moyamoya disease

Background:The incidence of symptomatic hyperperfusion syndrome after superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis for patients with moyamoya disease (MMD) approaches 30%. In most cases, hyperperfusion occurs in a localized area and disappears within 1-2 weeks.Case Description:A 59-year-old female diagnosed with asymptomatic MMD for 4 months became rapidly symptomatic with transient ischemic attacks (TIAs). After left STA-MCA anastomosis surgery, she developed symptomatic hyperperfusion, initially (1-2 weeks after surgery) manifesting with severe headache and lesions located in the left basal ganglia. She then developed (2-5 weeks after surgery) aphasia and right hemiparesis caused by new hyperperfusion lesions located in the left frontal area. At discharge (7 weeks after surgery), she recovered fully without any remaining neurologic deficit and no ischemic lesions.Conclusion:This report details a rare case of a patient with MMD who presented with regionally progressive hyperperfusion lesions after STA-MCA anastomosis and symptoms that persisted for 5 weeks following surgery. Results from this case suggest that regional differences exist in the functional recovery of cerebrovascular reactivity (CVR) in a patient with rapidly progressive MMD.

Significance of Focal Cerebral Hyperperfusion as a Cause of Transient Neurologic Deterioration After Extracranial-Intracranial Bypass for Moyamoya Disease: Comparative Study With Non-Moyamoya Patients Using N-Isopropyl-p-[123I]Iodoamphetamine Single-Photon Emission Computed Tomography

Superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis prevents cerebral ischemic attack by improving cerebral blood flow in patients with occlusive cerebrovascular disease and hemodynamic compromise. Recent evidence suggests that focal cerebral hyperperfusion is a potential complication of this procedure for moyamoya disease. To clarify the exact differences in the incidence and clinical manifestations of this phenomenon between patients with and without moyamoya disease. N-isopropyl-p-[(123)I]iodoamphetamine single-photon emission computed tomography was performed 1 and 7 days after STA-MCA anastomosis on 121 hemispheres from 86 consecutive patients with moyamoya disease (2-67 years of age; mean, 34.3 years) and on 28 hemispheres from 28 non-moyamoya patients (12-67 years of age; mean, 56.5 years). The incidence of symptomatic hyperperfusion, defined as a significant focal increase in cerebral blood flow at the site of the anastomosis that is responsible for the apparent neurological signs, was compared between groups. Symptomatic cerebral hyperperfusion including mild focal neurological signs was seen in 25 patients with moyamoya disease (26 hemispheres, 21.5%) but in none of the patients without moyamoya disease (P = .0069). Multivariate analysis revealed that moyamoya disease was significantly associated with the development of symptomatic cerebral hyperperfusion (P = .0008). All patients with symptomatic hyperperfusion were relieved by intensive blood pressure control, and no patients suffered from permanent neurological deficit caused by hyperperfusion. Symptomatic cerebral hyperperfusion is a potential complication of STA-MCA anastomosis, especially in patients with moyamoya disease. Accurate diagnosis and adequate management of hyperperfusion are recommended, especially in patients with moyamoya disease.

Efficacy of Revascularization Surgery for Moyamoya Syndrome Associated With Graves' Disease

Appropriate management of moyamoya syndrome associated with Graves' disease is undetermined because of the rarity of this combination. Patients tend to present with cerebrovascular events such as transient ischemic attack (TIA) in a thyrotoxic state, which is relieved by proper antithyroid therapy. Four patients with moyamoya syndrome associated with Graves' disease were successfully treated with revascularization surgery on 5 hemispheres among 58 consecutive patients (2-62 years old, mean 34.4 years) with moyamoya disease in 80 hemispheres treated from March 2004 to May 2007. Three patients presented with TIA, and one patient presented with intracerebral hemorrhage. Three patients were thyrotoxic at the onset of the cerebrovascular events. All patients underwent revascularization surgery after normalization of thyroid function. Euthyroid state was strictly maintained perioperatively. One patient developed symptomatic cerebral hyperperfusion, which was resolved by blood pressure control. Postoperative courses of the other patients were uneventful, and all 4 patients have remained neurologically stable after discharge. Cerebrovascular reconstruction surgery is a successful treatment option for moyamoya syndrome associated with Graves' disease. Timing of surgery during the euthyroid state and perioperative management considering the thyroid function and the cerebral hemodynamic change are the keys to successful surgical treatment.

Clinical implications of intraoperative infrared brain surface monitoring during superficial temporal artery–middle cerebral artery anastomosis in patients with moyamoya disease

Surgical revascularization for moyamoya disease prevents cerebral ischemic attacks by improving cerebral blood flow (CBF). Symptomatic cerebral hyperperfusion is a potential complication of this procedure, but its treatment is contradictory to that for ischemia. Because intraoperative techniques to detect hyperperfusion are still lacking, the authors performed intraoperative infrared monitoring in moyamoya disease using a novel infrared imaging system. During superficial temporal artery-middle cerebral artery anastomosis in 25 patients (26 hemispheres) with moyamoya disease, the authors monitored the brain surface temperature intraoperatively with the IRIS-V infrared imaging system. The average gradation value change (indicating temperature change) was calculated using commercial software. Magnetic resonance imaging, MR angiography, and N-isopropyl-p-[(123)I]iodoamphetamine SPECT studies were performed routinely before and within 10 days after surgery. Patency of bypass, detailed local hemodynamics, and changes in cortical surface temperature around the anastomosis site were well recognized by the IRIS-V infrared imaging system in all cases. In the present study, 10 patients suffered transient neurological symptoms accompanied by an increase in CBF around the anastomosis site, recognized as symptomatic hyperperfusion. The increase in temperature was significantly higher in these patients. Intensive blood pressure control was undertaken, and free-radical scavengers were administered. No patient in the present study suffered a permanent neurological deficit. Although the present method does not directly monitor surface CBF, temperature rise around the anastomosis site during surgery might be an indicator of postoperative hyperperfusion. Prospective evaluation with a larger number of patients is necessary to validate this technique.