Magnetoencephalographic Imaging of Resting-State Functional Connectivity Predicts Postsurgical Neurological Outcome in Brain Gliomas

Abstract BACKGROUND: The removal of brain tumors in perieloquent or eloquent cortex risks causing new neurological deficits in patients. The assessment of the functionality of perilesional tissue is essential to avoid postoperative neurological morbidity. OBJECTIVE: To evaluate preoperative magnetoencephalography-based functional connectivity as a predictor of short- and medium-term neurological outcome after removal of gliomas in perieloquent and eloquent areas. METHODS: Resting-state whole-brain magnetoencephalography recordings were obtained from 79 consecutive subjects with focal brain gliomas near or within motor, sensory, or language areas. Neural activity was estimated using adaptive spatial filtering. The mean imaginary coherence between voxels in and around brain tumors was compared with contralesional voxels and used as an index of their functional connectivity with the rest of the brain. The connectivity values of the tissue resected during surgery were correlated with the early (1 week postoperatively) and medium-term (6 months postoperatively) neurological morbidity. RESULTS: Patients undergoing resection of tumors with decreased functional connectivity had a 29% rate of a new neurological deficit 1 week after surgery and a 0% rate at 6-month follow-up. Patients undergoing resection of tumors with increased functional connectivity had a 60% rate of a new deficit at 1 week and a 25% rate at 6 months. CONCLUSION: Magnetoencephalography connectivity analysis gives a valuable preoperative evaluation of the functionality of the tissue surrounding tumors in perieloquent and eloquent areas. These data may be used to optimize preoperative patient counseling and surgical strategy.

Download Full-text

Sex Difference in Language Processing in Patients With Malignant Brain Tumors

Neurosurgery ◽

10.1093/neuros/nyz310_507 ◽

2019 ◽

Vol 66 (Supplement_1) ◽

Author(s):

Shun Yao ◽

Einat Liebenthal ◽

Parikshit Juvekar ◽

Adomas Bunevicius ◽

Matthew Vera ◽

...

Keyword(s):

Functional Connectivity ◽

Brain Tumors ◽

Language Processing ◽

Resting State ◽

Precentral Gyrus ◽

Language Function ◽

Brain Areas ◽

Brain Organization ◽

Malignant Brain Tumors ◽

Parietal Lobule

Abstract INTRODUCTION Numerous differences between males and females in brain organization have been described including in the development, performance, and lateralization of language function. However, there is very limited knowledge of whether language processing differs across sex in patients with brain lesions. In particular, malignant brain tumors (MBT) demonstrate significant sex differences in incidence and long-term survival. Given the importance of brain organization and planning surgical treatment for patients with brain tumors, we investigated the effect of sex on the organization of language in a cohort of patients with MBT. METHODS In the current study, we carried out a retrospective analysis in 47 patients with MBT (22 females, 25 males), retrieving their clinical characteristics and task-based and resting-state functional magnetic resonance image (fMRI) data from our clinical database. General Linear Model (GLM) and region-of-interest (ROI) based resting-state functional connectivity (RSFC) analyses were applied to explore the effect of sex on language tasks associated activations and functional connectivity. RESULTS Across the Sentence Completion task and Antonym Generation task, female patients showed greater activation volumes in the left inferior frontal gyrus, right precuneus, and left superior parietal lobule, while male patients showed larger clusters of activation of the left supplemental motor area (SMA), left inferior parietal lobule (IPL), left precuneus, bilateral precentral gyrus, and right supramarginal gyrus (SMG). Furthermore, the left SMA was a highly sex-specific brain area during the language performance, and it showed stronger resting-state correlations with brain areas within the intrinsic language network in females, while it showed stronger resting-state connections with brain areas involving the visuomotor/higher level cognitive functions in males. CONCLUSION These findings enhance our understanding of the role of sex in language organization in patients with MBT, helping neurosurgeons assess surgical risk and plan surgery in patients with MBT to best preserve language function.

Download Full-text

Presurgical Evaluation of Epilepsy Using Resting-State MEG Functional Connectivity

Frontiers in Human Neuroscience ◽

10.3389/fnhum.2021.649074 ◽

2021 ◽

Vol 15 ◽

Author(s):

Na Xu ◽

Wei Shan ◽

Jing Qi ◽

Jianping Wu ◽

Qun Wang

Keyword(s):

Functional Connectivity ◽

Resting State ◽

Preoperative Evaluation ◽

Brain Regions ◽

Electrophysiological Recording ◽

Epileptogenic Zone ◽

Resting State Functional Connectivity ◽

Presurgical Evaluation ◽

Resting State Connectivity ◽

The Brain

Epilepsy is caused by abnormal electrical discharges (clinically identified by electrophysiological recording) in a specific part of the brain [originating in only one part of the brain, namely, the epileptogenic zone (EZ)]. Epilepsy is now defined as an archetypical hyperexcited neural network disorder. It can be investigated through the network analysis of interictal discharges, ictal discharges, and resting-state functional connectivity. Currently, there is an increasing interest in embedding resting-state connectivity analysis into the preoperative evaluation of epilepsy. Among the various neuroimaging technologies employed to achieve brain functional networks, magnetoencephalography (MEG) with the excellent temporal resolution is an ideal tool for estimating the resting-state connectivity between brain regions, which can reveal network abnormalities in epilepsy. What value does MEG resting-state functional connectivity offer for epileptic presurgical evaluation? Regarding this topic, this paper introduced the origin of MEG and the workflow of constructing source–space functional connectivity based on MEG signals. Resting-state functional connectivity abnormalities correlate with epileptogenic networks, which are defined by the brain regions involved in the production and propagation of epileptic activities. This paper reviewed the evidence of altered epileptic connectivity based on low- or high-frequency oscillations (HFOs) and the evidence of the advantage of using simultaneous MEG and intracranial electroencephalography (iEEG) recordings. More importantly, this review highlighted that MEG-based resting-state functional connectivity has the potential to predict postsurgical outcomes. In conclusion, resting-state MEG functional connectivity has made a substantial progress toward serving as a candidate biomarker included in epileptic presurgical evaluations.

Download Full-text

Inter-Network Functional Connectivity Changes in Patients With Brain Tumors: A Resting-State Functional Magnetic Resonance Imaging Study

World Neurosurgery ◽

10.1016/j.wneu.2020.01.177 ◽

2020 ◽

Vol 138 ◽

pp. e66-e71 ◽

Cited By ~ 2

Author(s):

Hussam Metwali ◽

Mathijs Raemaekers ◽

Tamer Ibrahim ◽

Amir Samii

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Functional Connectivity ◽

Brain Tumors ◽

Functional Magnetic Resonance Imaging ◽

Resting State ◽

Imaging Study ◽

Magnetic Resonance Imaging Study ◽

Functional Magnetic Resonance ◽

Resonance Imaging

Download Full-text

Awake Craniotomy vs Surgery Under General Anesthesia for Resection of Supratentorial Lesions4

Neurosurgery ◽

10.1227/neu.0b013e31820c02a3 ◽

2011 ◽

Vol 68 (5) ◽

pp. 1192-1199 ◽

Cited By ~ 123

Author(s):

Oumar Sacko ◽

Valérie Lauwers-Cances ◽

David Brauge ◽

Musa Sesay ◽

Adam Brenner ◽

...

Keyword(s):

General Anesthesia ◽

Brain Mapping ◽

Neurological Outcome ◽

Neurological Complication ◽

Awake Craniotomy ◽

Neurological Deficits ◽

Complication Rates ◽

Eloquent Areas ◽

Duration Of Surgery

Abstract BACKGROUND: The use of an awake craniotomy in the treatment of supratentorial lesions is a challenge for both patients and staff in the operation theater. OBJECT: To assess the safety and effectiveness of an awake craniotomy with brain mapping in comparison with a craniotomy performed under general anesthesia. METHODS: We prospectively compared 2 groups of patients who underwent surgery for supratentorial lesions: those in whom an awake craniotomy with intraoperative brain mapping was used (AC group, n = 214) and those in whom surgery was performed under general anesthesia (GA group, n = 361, including 72 patients with lesions in eloquent areas). The AC group included lesions in close proximity to the eloquent cortex that were surgically treated on an elective basis. RESULTS: Globally, the 2 groups were comparable in terms of sex, age, American Society of Anesthesiologists score, pathology, size of lesions, quality of resection, duration of surgery, and neurological outcome, and different in tumor location and preoperative neurological deficits (higher in the AC group). However, specific data analysis of patients with lesions in eloquent areas revealed a significantly better neurological outcome and quality of resection (P < .001) in the AC group than the subgroup of GA patients with lesions in eloquent areas. Surgery was uneventful in AC patients and they were discharged home sooner. CONCLUSION: AC with brain mapping is safe and allows maximal removal of lesions close to functional areas with low neurological complication rates. It provides an excellent alternative to craniotomy under GA.

Download Full-text