Tianming Qiu

Awake language mapping and 3-Tesla intraoperative MRI-guided volumetric resection for gliomas in language areas.

The use of both awake surgery and intraoperative MRI (iMRI) has been reported to optimize the maximal safe resection of gliomas. However, there has been little research into combining these two demanding procedures. We report our unique experience with, and methodology of, awake surgery in a movable iMRI system, and we quantitatively evaluate the contribution of the combination on the extent of resection (EOR) and functional outcome of patients with gliomas involving language areas. From March 2011 to November 2011, 30 consecutive patients who underwent awake surgery with iMRI guidance were prospectively investigated. The EOR was assessed by volumetric analysis. Language assessment was conducted before surgery and 1 week, 1 month, 3 months and 6 months after surgery using the Aphasia Battery of Chinese. Awake language mapping integrated with 3.0 Tesla iMRI was safely performed for all patients. An additional resection was conducted in 11 of 30 patients (36.7%) after iMRI. The median EOR significantly increased from 92.5% (range, 75.1-97.0%) to 100% (range, 92.6-100%) as a result of iMRI (p<0.01). Gross total resection was achieved in 18 patients (60.0%), and in seven of those patients (23.3%), the gross total resection could be attributed to iMRI. A total of 12 patients (40.0%) suffered from transient language deficits; however, only one (3.3%) patient developed a permanent deficit. This study demonstrates the potential utility of combining awake craniotomy with iMRI; it is safe and reliable to perform awake surgery using a movable iMRI.

Sensorimotor cortical changes assessed with resting-state fMRI following total brachial plexus root avulsion

Objective Peripheral nerve injury can induce immediate and long-standing remodelling of the brain cortex, which may affect outcomes of nerve repair. This study examined changes of corresponding cortical representations in patients with brachial plexus injuries. Methods Resting-state fMRI was acquired for 13 adult patients with total brachial plexus root avulsion, three of whom underwent second scans 7 or 8 months later. The time of examination ranged from 1 to 16 months after injuries. Nine healthy adults were enrolled as control. Seed-based functional connectivity was performed for all subjects. Results For nine patients whose first fMRI was performed from 1 to 4 months after brachial plexus injuries, images showed that their cortical maps of sensorimotor areas corresponding to the hand and arm in the hemisphere contralateral to the injured side had much weaker correlation with the supplementary motor area (SMA) than those ipsilateral to the injured side. Symmetrical maps of bilateral cortical sensorimotor areas corresponding to the hand and arm were observed in other four cases with fMRI tested from 7 to 16 months after injuries. For three of the nine patients with asymmetrical cortical representations, second scans indicated symmetric results or even stronger correlation with SMA in the cerebral cortex contralateral to the injured side. Conclusions Total brachial plexus root avulsion causes cortical representations of the brachial plexus to undergo a change from an inactive to an active state. This implies that peripheral deafferentation after brachial plexus injuries will induce corresponding cortical representations to be occupied by adjacent non-deafferented cortical territories.

Awake intraoperative functional MRI (ai-fMRI) for mapping the eloquent cortex: Is it possible in awake craniotomy?

As a promising noninvasive imaging technique, functional MRI (fMRI) has been extensively adopted as a functional localization procedure for surgical planning. However, the information provided by preoperative fMRI (pre-fMRI) is hampered by the brain deformation that is secondary to surgical procedures. Therefore, intraoperative fMRI (i-fMRI) becomes a potential alternative that can compensate for brain shifts by updating the functional localization information during craniotomy. However, previous i-fMRI studies required that patients be under general anesthesia, preventing the wider application of such a technique as the patients cannot perform tasks unless they are awake. In this study, we propose a new technique that combines awake surgery and i-fMRI, named “awake” i-fMRI (ai-fMRI). We introduced ai-fMRI to the real-time localization of sensorimotor areas during awake craniotomy in seven patients. The results showed that ai-fMRI could successfully detect activations in the bilateral primary sensorimotor areas and supplementary motor areas for all patients, indicating the feasibility of this technique in eloquent area localization. The reliability of ai-fMRI was further validated using intraoperative stimulation mapping (ISM) in two of the seven patients. Comparisons between the pre-fMRI-derived localization result and the ai-fMRI derived result showed that the former was subject to a heavy brain shift and led to incorrect localization, while the latter solved that problem. Additionally, the approaches for the acquisition and processing of the ai-fMRI data were fully illustrated and described. Some practical issues on employing ai-fMRI in awake craniotomy were systemically discussed, and guidelines were provided.

Preliminary application of pyramidal tractography in evaluating prognosis of patients with hypertensive intracerebral hemorrhage.

OBJECTIVE To discover the practical value of pyramidal tractography in evaluating the prognosis of hypertensive intracerebral hemorrhage (ICH) patients. METHODS Eight acute-stage patients with hypertensive ICH were studied. We used magnetic resonance diffusion tensor imaging (DTI), applied white matter fiber tracking to deal with the raw DTI data, and thereafter obtained tractography data. The form, conformation, and spatial position of pyramidal tracts were observed, and the extent of injury assessed by measurement of continuity, integrity, and spatial displacement. Meanwhile, a 6-month follow-up survey was conducted to obtain patient neurological function index in order to analyze potential correlations with the tractography data. RESULTS Tractography accurately identified the number of white matter fiber tracts, which showed a positive correlation with neurological function outcomes. CONCLUSIONS Pyramidal tractography is able to clearly identify form, conformation, and spatial displacement range of pyramidal tracts, and therefore can effectively predict long-term neurological function outcomes for hypertensive ICH patients.

Clinical features and microsurgical treatment of pediatric patients with cerebral cavernous malformation

The aim of the present study was to describe the clinical features and to evaluate the surgical treatment outcomes of pediatric patients with cerebral cavernous malformations (CCM). We investigated 85 children (53 boys and 32 girls), aged from 6 months to 17.9 years with CCM. Seizures and symptomatic hemorrhages, which were the most frequent symptoms, occurred in 81 patients. Nine patients had a positive family history of CCM. Eighty patients underwent microsurgical treatment after strict operative indications were met. Neuronavigation, combined with intraoperative ultrasonography or functional MRI, was used for precise localization of the lesions. The principles of minimally invasive techniques were followed during surgery. A total of 89 lesions were removed in 80 patients, and there were no deaths. During their hospital stay, only nine patients suffered from postoperative seizures, which were controlled with medication. Postoperative neurological deficits improved in 27 patients, were unchanged in nine, and worsened in two. With the help of advanced neuroimaging, a satisfactory surgical outcome was achieved for 10 lesions located in eloquent brain areas and four lesions in the brain stem. A follow-up study of 66 patients showed that all of these patients remained seizure-free, and nine patients with postoperative neurological deficits gradually recovered. Microsurgical treatment should be performed early for pediatric patients with CCM. Accurate localization of the lesions and the use of minimally invasive techniques and functional MRI monitoring were the key features of the surgical procedures.

Direct evidence from intraoperative electrocortical stimulation indicates shared and distinct speech production center between Chinese and English languages.

Chinese processing has been suggested involving distinct brain areas from English. However, current functional localization studies on Chinese speech processing use mostly “indirect” techniques such as functional magnetic resonance imaging and electroencephalography, lacking direct evidence by means of electrocortical recording. In this study, awake craniotomies in 66 Chinese‐speaking glioma patients provide a unique opportunity to directly map eloquent language areas. Intraoperative electrocortical stimulation was conducted and the positive sites for speech arrest, anomia, and alexia were identified separately. With help of stereotaxic neuronavigation system and computational modeling, all positive sites elicited by stimulation were integrated and a series of two‐ and three‐dimension Chinese language probability maps were built. We performed statistical comparisons between the Chinese maps and previously derived English maps. While most Chinese speech arrest areas located at typical language production sites (i.e., 50% positive sites in ventral precentral gyrus, 28% in pars opercularis and pars triangularis), which also serve English production, an additional brain area, the left middle frontal gyrus (Brodmanns areas 6/9), was found to be unique in Chinese production (P < 0.05). Moreover, Chinese speakers’ inferior ventral precentral gyrus (Brodmanns area 6) was used more than that in English speakers. Our finding suggests that Chinese involves more perisylvian region (extending to left middle frontal gyrus) than English. This is the first time that direct evidence supports cross‐cultural neurolinguistics differences in human beings. The Chinese language atlas will also helpful in brain surgery planning for Chinese‐speakers. Hum Brain Mapp 36:4972–4985, 2015.

An automated method for identifying an independent component analysis-based language-related resting-state network in brain tumor subjects for surgical planning

As a noninvasive and “task-free” technique, resting-state functional magnetic resonance imaging (rs-fMRI) has been gradually applied to pre-surgical functional mapping. Independent component analysis (ICA)-based mapping has shown advantage, as no a priori information is required. We developed an automated method for identifying language network in brain tumor subjects using ICA on rs-fMRI. In addition to standard processing strategies, we applied a discriminability-index-based component identification algorithm to identify language networks in three different groups. The results from the training group were validated in an independent group of healthy human subjects. For the testing group, ICA and seed-based correlation were separately computed and the detected language networks were assessed by intra-operative stimulation mapping to verify reliability of application in the clinical setting. Individualized language network mapping could be automatically achieved for all subjects from the two healthy groups except one (19/20, success rate = 95.0%). In the testing group (brain tumor patients), the sensitivity of the language mapping result was 60.9%, which increased to 87.0% (superior to that of conventional seed-based correlation [47.8%]) after extending to a radius of 1 cm. We established an automatic and practical component identification method for rs-fMRI-based pre-surgical mapping and successfully applied it to brain tumor patients.

Real-Time Motor Cortex Mapping for the Safe Resection of Glioma: An Intraoperative Resting-State fMRI Study

The authors conducted preoperative and intraoperative resting-state intrinsic functional connectivity analyses of the motor cortex in 30 patients with brain tumors. Factors that may influence intraoperative imaging quality, including anesthesia type and tumor cavity, were studied. Additionally, direct cortical stimulation was used to validate the accuracy of intraoperative resting-state fMRI in mapping the motor cortex. Fourteen patients who successfully completed both sufficient intraoperative resting-state fMRI and direct cortical stimulation were used for further analysis of sensitivity and specificity. Compared with those subjected to direct cortical stimulation, the sensitivity and specificity of intraoperative resting-state fMRI in localizing the motor area were 61.7% and 93.7%, respectively. They conclude that using intraoperative resting-state fMRI can avoid the risk of intraoperative seizures due to direct cortical stimulation and may provide neurosurgeons with valuable information to facilitate the safe resection of gliomas. BACKGROUND AND PURPOSE: Resting-state functional MR imaging has been used for motor mapping in presurgical planning but never used intraoperatively. This study aimed to investigate the feasibility of applying intraoperative resting-state functional MR imaging for the safe resection of gliomas using real-time motor cortex mapping during an operation. MATERIALS AND METHODS: Using interventional MR imaging, we conducted preoperative and intraoperative resting-state intrinsic functional connectivity analyses of the motor cortex in 30 patients with brain tumors. Factors that may influence intraoperative imaging quality, including anesthesia type (general or awake anesthesia) and tumor cavity (filled with normal saline or not), were studied to investigate image quality. Additionally, direct cortical stimulation was used to validate the accuracy of intraoperative resting-state fMRI in mapping the motor cortex. RESULTS: Preoperative and intraoperative resting-state fMRI scans were acquired for all patients. Fourteen patients who successfully completed both sufficient intraoperative resting-state fMRI and direct cortical stimulation were used for further analysis of sensitivity and specificity. Compared with those subjected to direct cortical stimulation, the sensitivity and specificity of intraoperative resting-state fMRI in localizing the motor area were 61.7% and 93.7%, respectively. The image quality of intraoperative resting-state fMRI was better when the tumor cavity was filled with normal saline (P = .049). However, no significant difference between the anesthesia types was observed (P = .102). CONCLUSIONS: This study demonstrates the feasibility of using intraoperative resting-state fMRI for real-time localization of functional areas during a neurologic operation. The findings suggest that using intraoperative resting-state fMRI can avoid the risk of intraoperative seizures due to direct cortical stimulation and may provide neurosurgeons with valuable information to facilitate the safe resection of gliomas.

Cyclic Mechanical Stretch Induced Smooth Muscle Cell Changes in Cerebral Aneurysm Progress by Reducing Collagen Type IV and Collagen Type VI Levels

Background/Aims: Cerebral aneurysm growth is characterized by continuous structural weakness of local smooth muscle cells, though the mechanism is unclear. In this study, we examine protein changes in cerebral aneurysm and human brain vascular smooth muscle cells after cyclic mechanical stretch. We further explore the relationship between the smooth muscle cell changes and reductions in the levels of collagen types IV and VI. Methods: Saccular cerebral aneurysms (n=10) were collected, and temporal artery samples were used as controls. Quantitative proteomics were analyzed and histopathological changes were examined. Smooth muscle cells were cultured in a flexible silicone chamber and subjected to 15% cyclic mechanical stretch. The effect of stretch on the cell viability, function, gene and protein expression were further studied for the understanding the molecular mechanism of aneurysm development. Results: Proteomics analysis revealed 92 proteins with increased expression and 88 proteins with decreased expression compared to the controls (p<0.05). KEGG pathway analysis showed that the change in focal adhesion and extracellular matrix-receptor interaction, suggesting the involvement of collagen type IV and VI. The aneurysm tissue exhibited fewer smooth muscle cells and lower levels of collagen type IV and VI. Human brain vascular smooth muscle cell culture showed spindle-like cells and obvious smooth muscle cell layer. Cell proteomics analysis showed that decreased expression of 118 proteins and increased expression of 32 proteins in smooth muscle cells after cyclic mechanical stretch. KEGG pathway analysis indicated that focal adhesion and ECM-receptor interaction were involved. After cyclic mechanical stretch, collagen type IV and IV expression were decreased. Moreover, the stretch induced MMP-1 and MMP-3 expression elevation. Conclusion: We demonstrated that collagen type IV and VI were decreased in cerebral aneurysms and continuous cyclic mechanical stretch induced smooth muscle cell changes. Smooth muscle cell protection provides an additional therapeutic option to prevent the growth of cerebral aneurysms.

208 Connectivity-Based Functional Parcellation and Localization of the Human Supplementary Motor Area Based on Resting-State Functional Magnetic Resting Imaging and Its Utility in Brain Tumor Surgery.

INTRODUCTION To investigate the utility of resting-state functional MRI (R-fMRI) in the functional parcellation and localization of supplementary motor area (SMA) in healthy subjects and patients with glioma. The utility of this novel technique in brain tumor surgery around SMA was also assessed. METHODS R-fMRI was acquired from 249 healthy and 8 patients. Defined by AAL template, SMA was parcellated into 3 subregions according to functional connectivity (FC) patterns based on R-fMRI among healthy subjects. The function of each subregion was characterized by assessing whole-brain FC and meta-analysis of existing functional imaging studies. In areas consisting of voxels within and around (2-voxel expansion) SMA, FC was calculated between each voxel and the SMA subregions. Support vector machine was used to discriminate voxels in or outside each subregion. Then, the technique was used to localize the SMA in patients with glioma. The subregions of SMA were precisely stimulated using direct cortical stimulation (DCS) guided by intraoperative MRI when patients do finger opposition motor tasks during surgery. RESULTS The method has successfully parcellated SMA into 3 subregions, including pre-, mid-, and post-SMA. The function of pre-, mid-, and post-SMA was supposed to be correlated with conflict, eye movement, and hand movement and coordination, respectively. The accuracy of localizing the SMA in the contralateral hemisphere was 87.4% with 1-voxel error by 10-fold cross-validation in the healthy subjects. SMA localization was validated in all patients with DCS. Complete surgical resection was achieved in 6 patients and subtotal in 2 patients. In the short-term period, 3 patients experienced postoperative worsening, however, all recovered to normal at 1-month follow-up. CONCLUSION Connectivity-based technique based on R-fMRI is effective to parcellate and localize the SMA. Integration of R-fMRI and DCS is useful to identify and protect the SMA in patient-specific surgery for cerebral glioma around SMA.