Tianyi Qian, Wenjing Zhou, Zhipei Ling, Shangkai Gao, Hesheng Liu and Bo Hong
Electrocorticography (ECoG) is a powerful tool for presurgical functional mapping. Power increase in the high gamma band has been observed from ECoG electrodes on the surface of the sensory motor cortex during the execution of body movements. In this study the authors aim to validate the clinical usage of high gamma activity in presurgical mapping by comparing ECoG mapping with traditional direct electrical cortical stimulation (ECS) and functional MRI (fMRI) mapping.
Seventeen patients with epilepsy participated in an ECoG motor mapping experiment. The patients executed a 5-minute hand/tongue movement task while the ECoG signal was recorded. All 17 patients also underwent extraoperative ECS mapping to localize the motor cortex. Eight patients also participated in a presurgical fMRI study. The high gamma activity on ECoG was modeled using the general linear model (GLM), and the regions showing significant gamma power increase during the task condition compared with the rest condition were localized. The maps derived from GLM-based ECoG mapping, ECS, and fMRI were then compared.
High gamma activity in the motor cortex can be reliably modulated by motor tasks. Localization of the motor regions achieved with GLM-based ECoG mapping was consistent with the localization determined by ECS. The maps also appeared to be highly localized compared with the fMRI activations. Using the ECS findings as the reference, GLM-based ECoG mapping showed a significantly higher sensitivity than fMRI (66.7% for ECoG, 52.6% for fMRI, p < 0.05), while the specificity was high for both techniques (> 97%). If the current-spreading effect in ECS is accounted for, ECoG mapping may produce maps almost identical to those produced by ECS mapping (100% sensitivity and 99.5% specificity).
General linear model–based ECoG mapping showed a superior performance compared to traditional ECS and fMRI mapping in terms of efficiency and accuracy. Using this method, motor functions can be reliably mapped in less than 5 minutes.
Bing Zhou, Qian Huang, Ping-Hung Shen, Shun-Jiu Cui, Cheng-Shuo Wang, Yun-Chuan Li, Zhen-Kun Yu, Xiao-Hong Chen and Ting Ye
This study was undertaken to analyze the results of a novel surgical method—the endoscopic prelacrimal recess approach (PLRA)—in patients with tumors involving the pterygopalatine fossa (PPF) and infratemporal fossa (ITF). The surgical technique and indications for this approach are also discussed.
The authors analyzed data from 7 cases involving patients who underwent resection of PPF and ITF tumors by means of the endoscopic PLRA from 2004 to 2013. Preoperative and postoperative imaging studies were available in all cases and were reviewed. The surgical specimens were all confirmed to be schwannomas.
All tumors were completely resected via endoscopic PLRA. There were no recurrences noted over a 28-month follow-up period. In 4 cases, the patients experienced postoperative facial numbness during the first two weeks after surgery, which gradually lessened thereafter. One patient continued to have mild facial numbness at most recent follow-up. The numbness had fully resolved in the other 3 cases.
The intranasal endoscopic removal of schwannoma from PPF and ITF via PLRA can spare the whole lateral nasal wall, resulting in a reduction in morbidity. This is a novel minimally invasive surgical method for PPF and ITF tumors.
Qian Zhang, Yaping Liu, Dong Zhang, Rong Wang, Yan Zhang, Shuo Wang, Lanbing Yu, Chaoxia Lu, Fang Liu, Jian Zhou, Xue Zhang and Jizong Zhao
Moyamoya disease (MMD) is a rare, genetically heterogeneous cerebrovascular disease. The authors conducted a genetic study of really interesting new gene (RING) finger protein 213 (RNF213); actin alpha 2 (ACTA2); BRCA1/BRCA2-containing complex subunit 3 (BRCC3); and guanylate cyclase 1, soluble, alpha 3 (GUCY1A3) as well as a clinical phenotype analysis in Chinese MMD patients to determine whether genetic differences are responsible for the different clinical features that appear in MMD in different ethnicities.
A panel was designed to identify disease-causing mutations in MMD genes and those involved in related disorders (RNF213, ACTA2, BRCC3, and GUCY1A3). The panel was used to detect disease-causing mutations in 255 Chinese MMD patients. Genotype and allele frequencies were compared between patients and 300 controls. A mutation segregation analysis was performed in 34 families, and genotype-phenotype correlations were made.
Twenty-seven rare missense variants of RNF213 were identified and were not found in controls. Among them, p.R4810K was identified in 31.4% of patients (80 of 255) with MMD. Significantly higher frequencies of the A allele and G/A genotype of p.R4810K were observed in MMD patients compared with controls (χ2 = 104.166, p < 0.000). Twenty-five rare variants were identified in 10.6% of patients (27 of 255) without p.R4810K variants. Segregation analysis supported an association between MMD and 3 variants. No possible disease-causing mutations were identified in ACTA2, BRCC3, or GUCY1A3. Compared with patients without the rare variants in RNF213, the p.R4810K heterozygous patients were younger at diagnosis (25 vs 29 years old, p = 0.049) and had more familial cases (24% vs 4.4%, p = 0.000), ischemic cases (81.3% vs 67.5%, p = 0.037), and involvement of the posterior cerebral artery (52% vs 32.5%, p = 0.007).
RNF213 is the major susceptibility gene in Chinese MMD patients. The spectrum of rare variants identified in Chinese MMD patients was diverse. Compared to patients without the rare variants in RNF213, the p.R4810K heterozygous patients exhibited different clinical features.