Xiaofeng Deng

Comparison of language cortex reorganization patterns between cerebral arteriovenous malformations and gliomas: a functional MRI study

OBJECT Cerebral arteriovenous malformations (AVMs) are congenital malformations that may grow in the language cortex but usually do not lead to aphasia. In contrast, language dysfunction is a common presentation for patients with a glioma that involves language areas. The authors attempted to demonstrate the difference in patterns of language cortex reorganization between cerebral AVMs and gliomas by blood oxygen level-dependent (BOLD) functional MRI (fMRI) evaluation. METHODS The authors retrospectively reviewed clinical and imaging data of 63 patients with an unruptured cerebral AVM (AVM group) and 38 patients with a glioma (glioma group) who underwent fMRI. All the patients were right handed, and all their lesions were located in the left cerebral hemisphere. Patients were further categorized into 1 of the 2 following subgroups according to their lesion location: the BA subgroup (overlying or adjacent to the inferior frontal or the middle frontal gyri [the Broca area]) and the WA subgroup (overlying or adjacent to the supramarginal, angular, or superior temporal gyri [the Wernicke area]). Lateralization indices of BOLD signal activations were calculated separately for the Broca and Wernicke areas. Statistical analysis was performed to identify the difference in patterns of language cortex reorganization between the 2 groups. RESULTS In the AVM group, right-sided lateralization of BOLD signal activations was observed in 23 patients (36.5%), including 6 with right-sided lateralization in the Broca area alone, 12 in the Wernicke area alone, and 5 in both areas. More specifically, in the 34 patients in the AVM-BA subgroup, right-sided lateralization of the Broca area was detected in 9 patients (26.5%), and right-sided lateralization of the Wernicke area was detected in 4 (11.8%); in the 29 patients in the AVM-WA subgroup, 2 (6.9%) had right-sided lateralization of the Broca area, and 13 (44.8%) had right-sided lateralization of the Wernicke area. In the glioma group, 6 patients (15.8%) showed right-sided lateralization of the Wernicke area, including 2 patients in the glioma-BA subgroup and 4 patients in the glioma-WA subgroup. No patient showed right-sided lateralization of the Broca area. Moreover, although the incidence of right-sided lateralization was higher in cases of low-grade gliomas (5 in 26 [19.2%]) than in high-grade gliomas (1 in 12 [8.3%]), no significant difference was detected between them (p = 0.643). Compared with the AVM group, the incidence of aphasia was significantly higher (p < 0.001), and right-sided lateralization of language areas was significantly rarer (p = 0.026) in the glioma group. CONCLUSIONS Right-sided lateralization of BOLD signal activations was observed in patients with a cerebral AVM and in those with a glioma, suggesting that language cortex reorganization may occur with both diseases. However, the potential of reorganization in patients with gliomas seems to be insufficient compared with patients AVMs, which is suggested by clinical manifestations and the fMRI findings. Moreover, this study seems to indicate that in patients with an AVM, a nidus near the Broca area mainly leads to right-sided lateralization of the Broca area, and a nidus near the Wernicke area mainly leads to right-sided lateralization of the Wernicke area.

Direct versus indirect bypasses for adult ischemic-type moyamoya disease: a propensity score–matched analysis

OBJECTIVE The optimal surgical modality for moyamoya disease (MMD) remains unclear. The aim of this study was to compare the surgical effects of direct bypass (DB) and indirect bypass (IB) in the treatment of adult ischemic-type MMD. METHODS Adult patients with ischemic-type MMD who underwent either DB or IB from 2009 to 2015 were identified retrospectively from a prospective database. Patients lost to follow-up or with a follow-up period less than 12 months were excluded. Recurrent stroke events and modified Rankin Scale (mRS) scores at the last follow-up were compared between the 2 surgical groups after 1:1 propensity score matching. RESULTS A total of 220 patients were considered, including 143 patients who underwent DB and 77 patients who underwent IB. After propensity score matching, 70 pairs were obtained. The median follow-up period was 40.5 months (range 14-75 months) in the DB group and 31.5 months (range 14-71 months) in the IB group (p = 0.004). Kaplan-Meier analysis showed that patients who received DB had a longer stroke-free time (mean 72.1 months) compared with patients who received IB (mean 61.0 months) (p = 0.045). Good neurological status (mRS score ≤ 2) was achieved in 64 patients in the DB group (91.4%) and 66 patients in the IB group (94.3%), but there was no significant difference (p = 0.512). CONCLUSIONS Although neurological function outcome was not determined by the surgical modality, DB is more effective in preventing recurrent ischemic strokes than IB for adult ischemic-type MMD.

Comparison of 7.0- and 3.0-T MRI and MRA in ischemic-type moyamoya disease: preliminary experience

OBJECT The authors compared the image quality and diagnostic sensitivity and specificity of 7.0-T and 3.0-T MRI and time-of-flight (TOF) MR angiography (MRA) in patients with moyamoya disease (MMD). METHODS MR images of 15 patients with ischemic-type MMD (8 males, 7 females; age 13-48 years) and 13 healthy controls (7 males, 6 females; age 19-28 years) who underwent both 7.0-T and 3.0-T MRI and MRA were studied retrospectively. The main intracranial arteries were assessed by using the modified Houkins grading system (MRA score). Moyamoya vessels (MMVs) were evaluated by 2 grading systems: the MMV quality score and the MMV area score. Two diagnostic criteria for MMD were used: the T2 criteria, which used flow voids in the basal ganglion on T2-weighted images, and the TOF criteria, which used the high-intensity areas in the basal ganglion on source images from TOF MRA. All data were evaluated by 2 independent readers who were blinded to the strength field and presence or absence of MMD. Using conventional angiography as the gold standard, the sensitivity and specificity of 7.0-T and 3.0-T MRI/MRA in the diagnosis of MMD were calculated. The differences between 7.0-T and 3.0-T MRI and MRA were statistically compared. RESULTS No significant differences were observed between 7.0-T and 3.0-T MRA in MRA score (p = 0.317) or MRA grade (p = 0.317). There was a strong correlation between the Suzukis stage and MRA grade in both 3.0-T (rs = 0.930; p < 0.001) and 7.0-T (rs = 0.966; p < 0.001) MRA. However, MMVs were visualized significantly better on 7.0-T than on 3.0-T MRA, suggested by both the MMV quality score (p = 0.001) and the MMV area score (p = 0.001). The correlation between the Suzukis stage and the MMV area score was moderate in 3.0-T MRA (rs = 0.738; p = 0.002) and strong in 7.0-T MRA (rs = 0.908; p < 0.001). Moreover, 7.0-T MR images showed a greater capacity for detecting flow voids in the basal ganglion on both T2-weighted MR images (p < 0.001) and TOF source images (p < 0.001); 7.0-T MRA also revealed the subbranches of superficial temporal arteries much better. Receiver operating characteristic curve analysis showed that, according to the T2 criteria, 7.0-T MRI/MRA was more sensitive (sensitivity 1.000; specificity 0.933) than 3.0-T MRI/MRA (sensitivity 0.692; specificity 0.933) in diagnosing MMD; based on the TOF criteria, 7.0-T MRI/MRA was more sensitive (1.000 vs 0.733, respectively) and more specific (1.000 vs 0.923, respectively) than 3.0-T MRI/MRA. CONCLUSIONS Compared with 3.0-T MRI/MRA, 7.0-T MRI/MRA detected and delineated MMVs more clearly and provided higher diagnostic sensitivity and specificity, although it did not show significant improvement in depicting main intracranial arteries. The authors speculate that 7.0-T MRI/MRA is a promising technique in the diagnosis of MMD because it is noninvasive compared with conventional angiography and it is more sensitive than 3.0-T MRI/MRA.

Effects of different surgical modalities on the clinical outcome of patients with moyamoya disease: a prospective cohort study

OBJECTIVE Bypass surgery is the most common treatment for moyamoya disease (MMD), but there is controversy over which surgical modality is best. The objective of this study was to evaluate the clinical outcome of patients with MMD after undergoing different surgical modalities. METHODS A series of 696 consecutive MMD patients treated between June 2009 and May 2015 were screened in this prospective cohort study. Patients who did not undergo revascularization surgeries and those who underwent different surgical modalities in bilateral hemispheres were excluded. Finally, 529 patients who were observed for at least 12 months were included: 438 patients underwent unilateral surgery, and 91 patients underwent bilateral surgery. Of these, 241 patients underwent direct bypass (DB); 81, a combined bypass (CB); and 207, an indirect bypass (IB). Three clinical outcomes were evaluated and compared between surgical groups: recurrent stroke events, modified Rankin Scale (mRS) scores, and change in the main symptoms. RESULTS The mean follow-up period was 40 months. During the follow-up period, recurrent stroke was observed in 43 patients, including 15 patients with hemorrhage, 26 patients with ischemia (transient ischemic attack in 19 patients and infarction in 7 patients), and 2 patients with both hemorrhage and cerebral infarction. Kaplan-Meier analysis showed that patients who underwent a CB or DB had a longer ischemia-free time than those who underwent IB (p = 0.013); however, there was no significant difference in the hemorrhage-free time between the different surgical modalities (p = 0.534). A good neurological status (mRS score ≤ 2) was achieved in 495 patients (93.6%) and was significantly achieved by more children (98.2%) than adults (92.3%; p = 0.022). Surgical modalities were not significantly associated with outcome neurological status (p = 0.860). Moreover, improvement in symptoms was observed in 449 patients (84.9%) and was also significantly more common in children (93.0%) than in adults (82.7%; p = 0.006). No significant difference was observed between the different surgical modalities (p = 0.548). CONCLUSIONS CB and DB are more effective at preventing recurrent ischemic strokes than IB. However, there is no evidence that these 3 surgical modalities demonstrate significant differences in preventing recurrent hemorrhage.

Segmented TOF at 7 T MRI: Technique and clinical applications

PURPOSE Time-of-flight (TOF) MR angiography has an advantage of contrast and resolution in ultra-high field (7 T) MRI systems. However, increased specific absorption rate (SAR) prohibits the application of spatial saturation band, leading to venous contamination in maximum intensity projection (MIP) images. METHODS A segmented k-space filling scheme with sparse venous saturation pulses was developed for 7 T TOF-MRA. The effectiveness of the segmented TOF sequence was verified by Bloch equation simulation and experiments on 3 T. The protocol on 7 T was optimized and applied for healthy volunteers and patients with vascular diseases. RESULTS Segmented TOF achieved equivalent contrast and venous suppression effect as conventional methods, while SAR values had a remarkable reduction and obeyed the limit of a 7 T MRI system. The decreased number of saturation pulses allowed shorter acquisition time than existing solutions. The comparison of segmented TOF and conventional TOF revealed flow direction in vascular diseases. CONCLUSION Segmented TOF is proved to be a time-efficient way to achieve high-resolution angiograms without venous contamination at ultra-high field. The sequence holds strong promise for non-contrast clinical diagnosis on cerebrovascular diseases.

Comparison of Stroke Prediction Accuracy of ABCD2 and ABCD3-I in Patients with Transient Ischemic Attack: A Meta-Analysis

BACKGROUND A direct comparison of the stroke prediction utility of the ABCD2 and ABCD3-I scores has not been performed. Thus, we conducted a diagnostic meta-analysis and applied the results to a hypothetical cohort of 1000 patients with transient ischemic attack (TIA) to assess the power of stroke prediction by ABCD2 and ABCD3-I scores. METHODS Medline, PubMed, Embase, and manuscript references were searched to identify studies that directly compared the stroke predictive powers of ABCD2 and ABCD3-I scores. We conducted a diagnostic meta-analysis using bivariate random effects models, and the predictive powers of ABCD2 and ABCD3-I scores were assessed by their summary sensitivity and specificity. Then, we applied the results to a hypothetical cohort of 1000 patients with TIA to calculate the effect per 1000 patients triaged for stroke prevention in a virtual setting. RESULTS Of the 35 identified studies on ABCD2 and ABCD3-I, 6 studies (7364 participants) directly compared the diagnostic accuracies of ABCD2 and ABCD3-I scores for occurrence of a future stroke. The pooled sensitivities of ABCD2 versus ABCD3-I were 79.9% (62.2%-90.6%) versus 96.1% (90.2%-98.5%) at 7 days (P = .022), and 76.6% (63.8%-85.8%) versus 94.6% (88.9%-97.5%) at 90 days (P = .001). The pooled specificities of ABCD2 versus ABCD3-I were 29.2% (18.2%-43.3%) versus 17.7% (8.5%-33.3%) at 7 days (P = .214), and 40.3% (25.0%-57.7%) versus 20.2% (12.6%-30.6%) at 90 days (P = .032). CONCLUSIONS ABCD3-I scores had a better sensitivity but poorer specificity than ABCD2 scores. However, in community-based referring settings, it is more suitable to use ABCD2 at initial triage and deciding on urgency of specialist assessment. The prognostic utility of each of the components of the scores should be carefully considered rather than dichotomized scores during clinical triage.

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

OBJECTIVEThe 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.METHODSThe 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.RESULTSA 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.CONCLUSIONSAdvanced 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.

Lacunar infarction in adult patients with moyamoya disease

OBJECTIVES Lacunar infarctions in moyamoya disease have rarely been described. We aimed to evaluate the features and prognosis of adult moyamoya patients with lacunar infarction. PATIENTS AND METHODS We reviewed 696 consecutive moyamoya patients admitted to our hospital from 2009 to 2015 to identify patients with lacunar infarctions. We compared the clinical features and prognosis of adult moyamoya patients with lacunar infarction and those with non-lacunar infarction. Follow-up was conducted by face-to-face reviews or by a structured telephone interview. Outcome measures were recurrent stroke events and functional outcomes by modified Rankin Scale (mRS). RESULTS We identified 32 patients with lacunar infarction among 197 adult moyamoya disease patients with infarctions. Patients with lacunar infarctions demonstrated similar angiographic features with patients with non-lacunar infarctions. During a mean follow-up of 33.02±20.49months, we observed recurrent stroke events in 1 patients with lacunar infarction and 14 patients with non-lacunar infarction. The mean follow-up mRS was significantly better in the lacunar group than in the non-lacunar group (0.59±0.56 vs. 1.13±1.24; P<0.001). CONCLUSION We identified that the moyamoya patients with lacunar infarctions had better functional outcomes comparing with patients with non-lacunar infarction after revascularization.

Association of Ring Finger Protein 213 Gene P.R4810k Polymorphism with Intracranial Major Artery Stenosis/Occlusion

BACKGROUND Intracranial major artery stenosis/occlusion (ICASO) is a common cause of ischemic stroke worldwide. A number of studies have assessed the association of the p.R4810K polymorphism in the ring finger protein 213 (RNF213) gene with ICASO, but the results have not been entirely consistent. METHODS We conducted a case-control study to estimate the association between the p.R4810K polymorphism and the risk of ICASO in a Chinese population. A total of 124 patients and 230 controls were enrolled. Moreover, a meta-analysis was performed to evaluate this association in the East Asian populations. RESULTS In our case-control study, the frequencies of the G/A genotype of p.R4810K were significantly higher in the ICASO patients than in the control group (4.03% versus .43%, P = .021, respectively). Moreover, in the meta-analysis, we assessed 7 case-control studies that included 1239 patients and 1377 controls. The pooled odds ratios (ORs) indicated significant association between the p.R4810K polymorphism and the ICASO risk in the dominant model (OR = 9.37, 95% confidence interval: 4.61-19.02, P = .000), the heterozygote comparison (OR = 8.97, 95% CI: 4.41-18.25, P = .000), and the allele comparison (OR = 9.50, 95% confidence interval: 4.71-19.19, P = .000) in the East Asian populations. Subgroup analysis based on ethnicity revealed that the risks in the Japanese and the Korean populations were higher than that in the Chinese population. CONCLUSIONS The p.R4810K polymorphism was associated with an increased risk of ICASO in the East Asian populations. Further studies on the function of the RNF213 protein and the clinical features of this subtype of ICASO are needed.

Moyamoya disease with occlusion of bilateral vertebral arteries and the basilar artery fed by the collateral vessels of vertebral arteries: A rare case report☆

The main change of moyamoya disease (MMD) is steno-occlusion at the terminal portion of the bilateral internal carotid arteries (ICAs). Occlusion of distal portions of the bilateral vertebral arteries (VAs) in MMD has never been reported. An 18-year old female was admitted with repeated headache for 13years. Cerebral digital subtraction angiography (DSA) demonstrated occlusion of bilateral ICAs at their terminal portions, moyamoya vessels at the skull base, occlusion of bilateral distal VAs and the basilar artery (BA) fed by the tortuous collateral vessels arising from the cervical segment of VAs. We report this unique case for its rarity and discuss its mechanism.