Intraoperative visualisation of functional structures facilitates safe frameless stereotactic biopsy in the motor eloquent regions of the brain.

BACKGROUND: For stereotactic brain biopsy involving motor eloquent regions, the surgical objective is to enhance diagnostic yield and preserve neurological function. To achieve this aim, we implemented functional neuro-navigation and intraoperative magnetic resonance imaging (iMRI) into the biopsy procedure. The impact of this integrated technique on the surgical outcome and postoperative neurological function was investigated and evaluated. METHOD: Thirty nine patients with lesions involving motor eloquent structures underwent frameless stereotactic biopsy assisted by functional neuro-navigation and iMRI. Intraoperative visualisation was realised by integrating anatomical and functional information into a navigation framework to improve biopsy trajectories and preserve eloquent structures. iMRI was conducted to guarantee the biopsy accuracy and detect intraoperative complications. The perioperative change of motor function and biopsy error before and after iMRI were recorded, and the role of functional information in trajectory selection and the relationship between the distance from sampling site to nearby eloquent structures and the neurological deterioration were further analyzed. RESULTS: Functional neuro-navigation helped modify the original trajectories and sampling sites in 35.90% (16/39) of cases to avoid the damage of eloquent structures. Even though all the lesions were high-risk of causing neurological deficits, no significant difference was found between preoperative and postoperative muscle strength. After data analysis, 3mm was supposed to be the safe distance for avoiding transient neurological deterioration. During surgery, the use of iMRI significantly reduced the biopsy errors (p = 0.042) and potentially increased the diagnostic yield from 84.62% (33/39) to 94.87% (37/39). Moreover, iMRI detected intraoperative haemorrhage in 5.13% (2/39) of patients, all of them benefited from the intraoperative strategies based on iMRI findings. CONCLUSIONS: Intraoperative visualisation of functional structures could be a feasible, safe and effective technique. Combined with intraoperative high-field MRI, it contributed to enhance the biopsy accuracy and lower neurological complications in stereotactic brain biopsy involving motor eloquent areas.

Facial and Cochlear Nerve Complications following Microsurgical Resection of Vestibular Schwannomas in a Series of 221 Cases.

BACKGROUND: Despite improvements in microsurgical technique and the use of intraoperative electrophysiological monitoring, the potential for facial and cochlear nerve injury remains a possibility in the resection of vestibular schwannomas (VS). We reviewed a series of 221 cases of VS resected via a retrosigmoid approach at our institution from October 2008 to April 2014 and determined the incidence of postoperative facial and cochlear deficits. MATERIAL AND METHODS: A total of 221 patients - 105 (47.5%) male and 116 (52.5%) female - with a mean age of 46.1 years (range 29-73 years), with VS ≥3 cm (n=183, 82.8%) and <3 cm (n=38, 17.2%) underwent surgical resection via a retrosigmoid approach and were evaluated for postoperative facial and cochlear nerve deficits. RESULTS: Near-total resection (>95% removal) was achieved in 199 cases (90%) and subtotal resection (>90% removal) in 22 cases (10%). At 6 month follow-up, House-Brackmann grades I-III were observed in 183 cases (82.8%), grade IV in 16 cases (7.2%), and grade V in 22 cases (10%). Of the 10 patients that had preoperative functional hearing, 3 (33%) retained hearing postoperatively. Cerebrospinal fluid leakage occurred in 6 patients (2.7%), lower cranial nerve palsies in 9 patients (4.1%), and intracranial hematomas 3 cases (1.4%). CONCLUSIONS: The observed incidence of persistent postoperative nerve deficits is very low. Meticulous microsurgical dissection of and around the facial and cochlear nerves with the aid of intraoperative electrophysiological nerve monitoring in the retrosigmoid approach allows for near-total resection of medium and large VS with the possibility of preservation of facial and cochlear nerve function.

Paraventricular or centrum ovale cavernous hemangioma involving the pyramidal tract in children: intraoperative MRI and functional neuronavigation-guided resection.

OBJECTIVES: In this study, we investigated whether visualization of the pyramidal tract and intraoperative MRI combined with functional navigation was helpful in the resection of paraventricular or centrum ovale cavernous hemangioma in children. METHODS: Twelve patients with cavernous hemangioma located in the paraventricular area or in the centrum ovale adjacent to the pyramidal tract were prospectively enrolled in the study. The pyramidal tract of all patients was visualized preoperatively, and all patients underwent tailored craniotomy with white matter trajectory to resect the lesion, with the help of intraoperative MRI and microscope-based functional neuronavigation. RESULTS: In our study, of the total of 12 patients (nine males and three females), five patients had lesions on the left side, and seven had lesions located in the right hemisphere. The lesion volume varied from 0.2 to 11.45 cm(3). In seven cases, the distance of the lesion from the pyramidal tract was 0-5 mm (the 0-5 mm group), and five cases were in the 5-10 mm group. The 3D visualization of the lesion and the pyramidal tract helped the surgeon design the optimal surgical approach and trajectory. Intraoperative functional neuronavigation allowed them to obtain access to the lesion accurately and precisely. All lesions had been removed totally at the end of the surgery. Compared with the preoperative level, muscle strength at 2 weeks had decreased in six cases, was unchanged in four cases, and improved in two cases; at 3 months, it was improved in five cases, unchanged in six cases, and decreased in one case. CONCLUSIONS: Pyramidal tract visualization and intraoperative MRI combined with functional neuronavigation can aid in safe removal of paraventricular or centrum ovale cavernous hemangioma involving the pyramidal tract.

The transfrontal isthmus approach for insular glioma surgery.

OBJECTIVE: The classic transopercular or transsylvian approach to insular gliomas removes the tumor laterally through the insular cortex. This study describes a new anteroposterior approach through the frontal isthmus for insular glioma surgery. METHODS: The authors detailed the surgical techniques for resection of insular gliomas through the transfrontal isthmus approach. Fifty-nine insular gliomas with at least Berger-Sanai zone I involvement were removed with the new approach, and extent of resection and postoperative neurological outcomes were assessed. RESULTS: Fifty-nine patients were enrolled in the study, including 35 men and 24 women, with a mean (range) age 44.3 (19-75) years. According to the Berger-Sanai classification system, the most common tumor was a giant glioma (67.8%), followed by involvement of zones I and IV (18.6%). Twenty-two cases were Yasargil type 3A/B, and 37 cases were Yasargil type 5A/B. The average angle between the lateral plane of the putamen and sagittal line was 33.53°, and the average width of the isthmus near the anterior insular point was 33.33 mm. The average angle between the lateral plane of the putamen and the sagittal line was positively correlated with the width of the isthmus near the anterior insular point (r = 0.935, p < 0.0001). The median (interquartile range [IQR]) preoperative tumor volume was 67.82 (57.64-92.19) cm3. Of 39 low-grade gliomas, 26 (66.67%) were totally resected; of 20 high-grade gliomas, 19 (95%) were totally resected. The median (IQR) extent of resection of the whole group was 100% (73.7%-100%). Intraoperative diffusion-weighted imaging showed no cases of middle cerebral artery- or lenticulostriate artery-related stroke. Extent of insular tumor resection was positively correlated with the angle of the lateral plane of the putamen and sagittal line (r = -0.329, p = 0.011) and the width of the isthmus near the anterior insular point (r = -0.267, p = 0.041). At 3 months postoperatively, muscle strength grade exceeded 4 in all cases, and all patients exhibited essentially normal speech. The median (IQR) Karnofsky performance score at 3 months after surgery was 90 (80-90). CONCLUSIONS: The transfrontal isthmus approach changes the working angle from lateral-medial to anterior-posterior, allowing for maximal safe removal of insular gliomas.

[Microsurgery assisted by intraoperative magnetic resonance imaging and neuronavigation for small lesions in deep brain].

OBJECTIVE: To explore the practicability of resecting small lesions in deep brain by intraoperative magnetic resonance imaging (iMRI) and neuronavigator-assisted microsurgery and its clinical efficacies. METHODS: A total of 42 cases with small lesions in deep brain underwent intraoperative MRI and neuronavigator-assisted microsurgery. The drifting of neuronavigation was corrected by images acquired from intraoperative MR rescanning. RESULTS: All lesions were successfully identified and 40 cases totally removed without mortality. Only 3 cases developed new neurological deficits post-operatively while 2 of them returned to normal neurological functions after a follow-up duration of 3 months to 2 years. CONCLUSION: The application of intraoperative MRI can effectively correct the drifting of neuronavigation and enhance the accuracy of microsurgical neuronavigation for small lesions in deep brain.

Resection of Insular Glioma Through the Transfrontal Limiting Sulcus Approach.

BACKGROUND: The current transsylvian or transopercular approaches make access difficult because of the limited exposure of insular tumors. Hence, maximal and safe removal of insular gliomas is challenging. In this article, a new approach to resect insular gliomas is presented. OBJECTIVE: To determine whether the new transfrontal limiting sulcus approach is helpful for maximal and safe removal of insular gliomas. METHODS: The authors reported surgical techniques for insular gliomas resected through the transfrontal limiting sulcus approach. The authors evaluated the surgical resections of 69 insular gliomas performed through the new approach in their department. The extents of resection and postoperative neurological outcomes were analyzed to determine the value of this new approach. RESULTS: Based on the Berger-Sanai classification, most insular gliomas were giant tumors (59.42%), followed by zone I + IV tumors (24.64%). The median (interquartile range) extent of resection of all patients was 100% (91%, 100%). The total resection rate for all gliomas was (55 of 69, 79.7%), and the total resection rate for low-grade gliomas was (28 of 40, 70%), which was significantly lower than that for high-grade gliomas (27 of 29, 93.1%) (P = .019). All patients had muscle strength greater than grade 4 3 months after surgery. Only 1 patient had a speech disorder 3 months after surgery. The median Karnofsky Performance Status score at the time of the 3-month follow-up was 90. CONCLUSION: The transfrontal limiting sulcus approach can help to achieve maximal and safe removal of insular gliomas.

Deep Learning model-based approach for preoperative prediction of Ki67 labeling index status in a noninvasive way using magnetic resonance images: A single-center study.

OBJECTIVES: Ki67 is an important biomarker of pituitary adenoma (PA) aggressiveness. In this study, PA invasion of surrounding structures is investigated and deep learning (DL) models are established for preoperative prediction of Ki67 labeling index (Ki67LI) status using conventional magnetic resonance (MR) images. METHODS: We reviewed 362 consecutive patients with PAs who underwent endoscopic transsphenoidal surgery, of which 246 patients with primary PA are selected for PA invasion analysis. MRI data from 234 of these PA patients are collected to develop DL models to predict Ki67LI status, and DL models were tested on 27 PA patients in the clinical setting. RESULTS: PA invasion is observed in 46.8% of cases in the Ki67 ≥ 3% group and 33.3% of cases in the Ki67 < 3% group. Three deep-learning models are developed using contrast-enhanced T1-weighted images (ceT1WI), T2-weighted images (T2WI), and multimodal images (ceT1WI+T2WI), respectively. On the validation dataset, the prediction accuracy of the ceT1WI model, T2WI model, and multimodal model were 87.4%, 89.4%, and 89.2%, respectively. In the clinical test, 27 MR slices with the largest tumors from 27 PA patients were tested using the ceT1WI model, T2WI model, and multimodal model, the average accuracy of Ki67LI status prediction was 63%, 77.8%, and 70.4%, respectively. CONCLUSION: Preoperative prediction of PA Ki67LI status in a noninvasive way was realized with the DL model by using MRI. T2WI model outperformed the ceT1WI model and multimodal model. This end-to-end model-based approach only requires a single slice of T2WI to predict Ki67LI status and provides a new tool to help clinicians make better PA treatment decisions.

[Application of diffusion tensor imaging-based arcuate fasciculus tractography and intraoperative arcuate fasciculus navigation].

OBJECTIVE: To investigate the feasibility of applying diffusion tensor imaging (DTI)-based arcuate fasciculus tractography and intraoperative arcuate fasciculus navigation for neurosurgery. METHODS: Totally 85 patients with interhemispheric tumors who had undergone intra-operative magnetic resonance imaging (MRI) and neuronavigation were divided into sinistrocerebral tumor (SCT) group (n = 55) and sham group (n = 30). All patients accepted routine MRI and DTI preoperatively. The results from both DTI-based arcuate fasciculus tractography and neuronavigation were applied to guide the surgery. All patients were followed up at 2-4 weeks and 3-6 months postoperatively. RESULTS: All patients smoothly received the pre-operative DTI-based arcuate fasciculus tractography. The three dimensional arcuate fasciculus was successfully integrated with the neuronavigation and achieved microscope heads-up display. Long-term follow-up showed that there were only 4 patients suffered from persistent language dysfunction. CONCLUSIONS: The combined application of DTI-based arcuate fasciculus tractography and intraoperative arcuate fasciculus navigation is feasible for guiding brain surgery. It can improve the surgical outcomes of intracranial tumor involving language functional area. The technology also maximizes the retention of language function and improves the post-operative quality of life.

Identification of risk factors for poor language outcome in surgical resection of glioma involving the arcuate fasciculus: an observational study.

The arcuate fasciculus is a critical component of the neural substrate of human language function. Surgical resection of glioma adjacent to the arcuate fasciculus likely damages this region. In this study, we evaluated the outcome of surgical resection of glioma adjacent to the arcuate fasciculus under the guidance of magnetic resonance imaging and diffusion tensor imaging, and we aimed to identify the risk factors for postoperative linguistic deficit. In total, 54 patients with primary glioma adjacent to the arcuate fasciculus were included in this observational study. These patients comprised 38 men and 16 women (aged 43 ± 11 years). All patients underwent surgical resenction of glioma under the guidance of magnetic resonance imaging and diffusion tensor imaging. Intraoperative images were updated when necessary for further resection. The gross total resection rate of the 54 patients increased from 38.9% to 70.4% by intraoperative magnetic resonance imaging. Preoperative language function and glioma-to-arcuate fasciculus distance were associated with poor language outcome. Multivariable logistic regression analyses showed that glioma-to-arcuate fasciculus distance was the major independent risk factor for poor outcome. The cutoff point of glioma-to-arcuate fasciculus distance for poor outcome was 3.2 mm. These findings suggest that intraoperative magnetic resonance imaging combined with diffusion tensor imaging of the arcuate fasciculus can help optimize tumor resection and result in the least damage to the arcuate fasciculus. Notably, glioma-to-arcuate fasciculus distance is a key independent risk factor for poor postoperative language outcome. This study was approved by the Ethics Committee of the Chinese PLA General Hospital, China (approval No. S2014-096-01) on October 11, 2014.

TRIM24 promotes stemness and invasiveness of glioblastoma cells via activating Sox2 expression.

BACKGROUND: Glioblastoma stem cells (GSCs) are a subpopulation of glioblastoma (GBM) cells that are critical for tumor invasion and treatment resistance. However, little is known about the function and mechanism of tripartite motif-containing 24 (TRIM24) in GSCs. METHODS: Immunofluorescence, flow cytometry, and western blot analyses were used to evaluate TRIM24 and cluster of differentiation (CD)133 expression profiles in GBM surgical specimens and GSC tumorspheres. Different TRIM24 expression levels in patients' tumors, as measured by both immunohistochemistry and western blot, were related to their corresponding MRI data. Wound healing, Matrigel invasion, and xenograft immunohistochemistry were conducted to determine GBM cell invasion. RESULTS: We identified that TRIM24 was coexpressed with CD133 and Nestin in GBM tissues and tumorsphere cells. Limiting dilution assays and xenotransplantation experiments illustrated that knockdown of TRIM24 expression reduced GSC self-renewal capacity and invasive growth. TRIM24 expression levels were positively associated with the volumes of peritumoral T2 weighted image abnormality. Rescue experiments indicated TRIM24 participation in GBM infiltrative dissemination. Chromatin immunoprecipitation, reporter gene assay, PCR, western blot, and immunohistochemistry demonstrated that TRIM24 activated the expression of the pluripotency transcription factor sex determining region Y-box 2 (Sox2) to regulate GBM stemness and invasion in vitro and in vivo. Finally, the close relationship between TRIM24 and Sox2 was validated by testing samples enrolled in our study and exploring external databases. CONCLUSIONS: Our findings uncover essential roles of the TRIM24-Sox2 axis in GBM stemness and invasiveness, suggesting TRIM24 as a potential target for effective GBM management.

Image-guided endoscopic surgery for spontaneous supratentorial intracerebral hematoma.

OBJECTIVE Endoscopic removal of intracerebral hematomas is becoming increasingly common, but there is no standard technique. The authors explored the use of a simple image-guided endoscopic method for removal of spontaneous supratentorial hematomas. METHODS Virtual reality technology based on a hospital picture archiving and communications systems (PACS) was used in 3D hematoma visualization and surgical planning. Augmented reality based on an Android smartphone app, Sina neurosurgical assist, allowed a projection of the hematoma to be seen on the patient's scalp to facilitate selection of the best trajectory to the center of the hematoma. A obturator and transparent sheath were used to establish a working channel, and an endoscope and a metal suction apparatus were used to remove the hematoma. RESULTS A total of 25 patients were included in the study, including 18 with putamen hemorrhages and 7 with lobar cerebral hemorrhages. Virtual reality combined with augmented reality helped in achieving the desired position with the obturator and sheath. The median time from the initial surgical incision to completion of closure was 50 minutes (range 40-70 minutes). The actual endoscopic operating time was 30 (range 15-50) minutes. The median blood loss was 80 (range 40-150) ml. No patient experienced postoperative rebleeding. The average hematoma evacuation rate was 97%. The mean (± SD) preoperative Glasgow Coma Scale (GCS) score was 6.7 ± 3.2; 1 week after hematoma evacuation the mean GCS score had improved to 11.9 ± 3.1 (p < 0.01). CONCLUSIONS Virtual reality using hospital PACS and augmented reality with a smartphone app helped precisely localize hematomas and plan the appropriate endoscopic approach. A transparent sheath helped establish a surgical channel, and an endoscope enabled observation of the hematoma's location to achieve satisfactory hematoma removal.

Impact of Virtual and Augmented Reality Based on Intraoperative Magnetic Resonance Imaging and Functional Neuronavigation in Glioma Surgery Involving Eloquent Areas.

BACKGROUND: The utility of virtual and augmented reality based on functional neuronavigation and intraoperative magnetic resonance imaging (MRI) for glioma surgery has not been previously investigated. METHODS: The study population consisted of 79 glioma patients and 55 control subjects. Preoperatively, the lesion and related eloquent structures were visualized by diffusion tensor tractography and blood oxygen level-dependent functional MRI. Intraoperatively, microscope-based functional neuronavigation was used to integrate the reconstructed eloquent structure and the real head and brain, which enabled safe resection of the lesion. Intraoperative MRI was used to verify brain shift during the surgical process and provided quality control during surgery. The control group underwent surgery guided by anatomic neuronavigation. RESULTS: Virtual and augmented reality protocols based on functional neuronavigation and intraoperative MRI provided useful information for performing tailored and optimized surgery. Complete resection was achieved in 55 of 79 (69.6%) glioma patients and 20 of 55 (36.4%) control subjects, with average resection rates of 95.2% ± 8.5% and 84.9% ± 15.7%, respectively. Both the complete resection rate and average extent of resection differed significantly between the 2 groups (P < 0.01). Postoperatively, the rate of preservation of neural functions (motor, visual field, and language) was lower in controls than in glioma patients at 2 weeks and 3 months (P < 0.01). CONCLUSION: Combining virtual and augmented reality based on functional neuronavigation and intraoperative MRI can facilitate resection of gliomas involving eloquent areas.

Functional Neuronavigation-Guided Transparieto-Occipital Cortical Resection of Meningiomas in Trigone of Lateral Ventricle.

BACKGROUND: This study investigated whether functional neuronavigation can be used to remove lesions in the lateral ventricle while preserving patients' neurologic functionality. METHODS: A total of 60 patients with lateral ventricular meningiomas were divided into study and control groups (n = 30 each). Diffusion tensor and blood oxygenation level-dependent functional magnetic resonance imaging were used for fiber tracking and eloquent cortex localization, respectively, in the study group. The surgical approach was based on coregistered data sets from 3-D lesion and brain structure reconstructions. Patients in the control group underwent anatomic neuronavigation-guided surgery. The patients' demographics, degree of resection, visual field, language score, movement, preoperative and postoperative Karnofsky Performance Status (KPS) scores, and surgical complications were recorded. RESULTS: Tumors were completely removed in both groups. Patients in the study group had a higher rate of visual field preservation than controls (P = 0.01). The two groups had similar motor and language functions after surgery, except that fewer cases of transient aphasia were observed in the former (P < 0.05). KPS scores for the study and control groups were 80 (70-80) and 70 (60-70), respectively (P < 0.01), at 2 weeks and 90 (80-100) and 85 (70-90), respectively (P = 0.022), at 3 months after surgery. CONCLUSIONS: Functional neuronavigation preserved neurologic functionality and was especially beneficial for protecting optical functionality and for the rapid recovery of patients.

Combining pyramidal tract mapping, microscopic-based neuronavigation, and intraoperative magnetic resonance imaging improves outcome of epilepsy foci resection in the sensorimotor cortex.

AIM: To explore the clinical value of combining pyramidal tract mapping, microscopic-based neuronavigation, and intraoperative magnetic resonance imaging (iMRI) in the surgical treatment of epileptic foci involving sensorimotor cortex. MATERIAL AND METHODS: We retrospectively analyzed 69 patients with focal epilepsy involving motor and sensory cortex. The surgical operations in Group I (n=38) were performed under the guidance of conventional neuronavigation, and the operations of Group II (n=31) were aided by combining pyramidal tract mapping, microscopic-based neuronavigation and the iMRI technique. Chi square test was used to compare seizure outcome and neurological deficits across groups. RESULTS: 7 patients (18.4%) in Group I, and 3 patients (9.7%) in Group II didn't recover to the level of preoperative strength within one year post-operation. The 2-year follow-up survey showed that more patients in Group II compared to Group I (71% vs. 55.3%, p=0.181) had a good outcome (Engel class I ~ II). CONCLUSION: The techniques of combining pyramidal tract mapping, microscopic-based neuronavigation and iMRI aid in precise mapping and hence resection of epileptic foci in sensorimotor cortex, which lead to improvement of surgical efficacy and significant reduction of postoperative loss of function.

Intraoperative MRI with integrated functional neuronavigation-guided resection of supratentorial cavernous malformations in eloquent brain areas.

Between March 2009 and January 2010, 36 patients with 38 supratentorial cavernous malformations in eloquent brain areas underwent surgery with the aid of intraoperative MRI (iMRI), functional neuronavigation, and electrocorticography (ECoG). To optimize outcomes, the hemosiderin-stained tissue surrounding the lesion in addition to the cavernous malformation itself (lesion) was microsurgically removed, leaving behind only small areas adjacent to, or overlapping with, functional areas. According to the Zabramski classification, there were 13 type I lesions, which all underwent total resection. There were 25 type II or III lesions with a surrounding hypointense rim, and all of these lesions were completely removed; the surrounding hypointense rims were completely removed in 15 patients and partially removed in 10. No new neurologic disorders occurred postoperatively. Twenty patients had preoperative epileptic seizures, nine of whom were refractory to treatment. During follow-up, seizure outcome was assessed using the Engel classification, and 11 patients with non-refractory epilepsy had a class I outcome. Of the nine patients with refractory epilepsy, seven (77.8%) had a class I outcome, one (11.1%) had a class II outcome, and one (11.1%) had a class III outcome.

Intraoperative high-field magnetic resonance imaging combined with fiber tract neuronavigation-guided resection of cerebral lesions involving optic radiation.

BACKGROUND: Intraoperative magnetic resonance imaging (iMRI) combined with optic radiation neuronavigation may be safer for resection of cerebral lesions involving the optic radiation. OBJECTIVE: To investigate whether iMRI combined with optic radiation neuronavigation can help maximize tumor resection while protecting the patient's visual field. METHODS: Forty-four patients with cerebral tumors adjacent to the optic radiation were enrolled in the study. The reconstructed optic radiations were observed so that a reasonable surgical plan could be developed. During the surgery, microscope-based fiber tract neuronavigation was routinely implemented. The lesion location (lateral or not to the optic radiation) and course of the optic radiation (stretched or not) were categorized, and their relationships to the visual field defect were determined. RESULTS: Analysis of the visible relationship between the optic radiation and the lesion led to a change in surgical approach in 6 patients (14%). The mean tumor residual rate for glioma patients was 5.3% (n = 36) and 0% for patients with nonglioma lesions (n = 8). Intraoperative MRI and fiber tract neuronavigation increased the average size of resection (first and last iMRI scanning, 88.3% vs 95.7%; P < .01). Visual fields after surgery improved in 5 cases (11.4%), exhibited no change in 36 cases (81.8%), and were aggravated in 3 cases (6.8%). CONCLUSION: Diffusion tensor imaging information was helpful in surgical planning. When iMRI was combined with fiber tract neuronavigation, the resection rate of brain lesions involving the optic radiation was increased in most patients without harming the patients' visual fields.

[Application of intraoperative magnetic resonance imaging and functional neuronavigation in microsurgery for lesions near language-related brain regions].

OBJECTIVE: To explore the clinical value of intraoperative magnetic resonance imaging (MRI) and functional neuronavigation in the preservation of the language function during microsurgery for lesions near language-related brain regions. METHODS: Sixty-one right-handed patients underwent microsurgical resection of the lesions near the language-related brain regions with the assistance of intraoperative MRI and blood oxygen level- and diffusion tensor imaging-based functional neuronavigation. The patients were divided into 2 groups according to the location of the lesions, namely group A with lesions near the left posterior inferior frontal gyrus and group B with lesions near the left posterior superior temporal gyrus. The aphasia quotient (AQ) of all patients were obtained using Western Aphasia Battery (WAB) before and 2 weeks after the operation. RESULTS: In the 33 patients with a normal AQ score (≥93.8) before the operation, the AQ score underwent no significant changes after the operation (P>0.05). Twenty-eight patients had lowered AQ scores (〈93.8) preoperatively, which were improved significantly after the operation (P<0.01). At 2 weeks after the operation, the language function worsened in 14 patients (23.0%), and only 2 (3.2%) showed a persistent language deficit at 6 months. Of the 61 patients, radical resection of the lesions was achieved in 41 and subtotal resection in 20 patients. The variation of AQ scores after the operation was not found to correlate to the degree of lesion resection, and the patients in group A showed a greater AQ variation than those in group B. CONCLUSIONS: Intraoperative MRI and functional neuronavigation can well demonstrate the structural relations between the lesions, the cortical areas and the fasciculi related to language functions, thus helping to better preserve the language function during microsurgical lesion resection in patients with lesions near language-related brain regions.