Glioma localization and excision using direct electrical stimulation for language mapping during awake surgery

AbstractBoth electrical microstimulation (EMS) and direct electrical stimulation (DES) of the brain are used to perform functional brain mapping. EMS is applied to animal fundamental neuroscience experiments, whereas DES is performed in the operating theatre on neurosurgery patients. The objective of the present review was to shed new light on electrical stimulation techniques in brain mapping by comparing EMS and DES. There is much controversy as to whether the use of DES during wide-awake surgery is the ‘gold standard’ for studying the brain function. As part of this debate, it is sometimes wrongly assumed that EMS and DES induce similar effects in the nervous tissues and have comparable behavioural consequences. In fact, the respective stimulation parameters in EMS and DES are clearly different. More surprisingly, there is no solid biophysical rationale for setting the stimulation parameters in EMS and DES; this may be due to historical, methodological and technical constraints that have limited the experimental protocols and prompted the use of empirical methods. In contrast, the gap between EMS and DES highlights the potential for new experimental paradigms in electrical stimulation for functional brain mapping. In view of this gap and recent technical developments in stimulator design, it may now be time to move towards alternative, innovative protocols based on the functional stimulation of peripheral nerves (for which a more solid theoretical grounding exists).

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Two Different Subcortical Networks of Language System: Morphogram and Phonogram, Through the Analysis of Unique Japanese Characters

10.21203/rs.3.rs-554010/v1 ◽

2021 ◽

Author(s):

Sho Tamai ◽

Masashi Kinoshita ◽

Riho Nakajima ◽

Hirokazu Okita ◽

Mitsutoshi Nakada

Keyword(s):

Electrical Stimulation ◽

White Matter ◽

Surgical Resection ◽

Parietal Lobe ◽

The Other ◽

Reading Process ◽

Direct Electrical Stimulation ◽

Cerebral Glioma ◽

Language Mapping ◽

Language Assessments

Abstract Language systems worldwide are based on morphograms or phonograms, and Japanese is a unique language that uses a complicated combination of kanji (morphogram) and kana (phonogram) characters. The white matter networks associated with reading have been investigated previously but remain unclear. In this study, we performed intraoperative language mapping under local anesthesia and postoperative language assessments of 65 consecutive patients who underwent surgical resection for cerebral glioma within the dominant temporal or parietal lobe. The cases showing intraoperative dyslexia elicited by direct electrical stimulation (DES) or postoperative kanji and/or kana dyslexia were extracted. Five patients showed transient kanji or kana dyslexia intraoperatively, and 8 patients showed kanji or kana dyslexia postoperatively. During intraoperative mapping, kanji or kana dyslexia were indeed reproduced by DES. We investigated the maximal overlapping lesions of the resection cavity that were associated with kanji or kana dyslexia, and then determined the subcortical elicited points that evoked kanji or kana dyslexia. These areas were localized near three white matter bundles: the arcuate fascicle, posterior superior longitudinal fascicle, and inferior longitudinal fascicle (ILF). The intraoperative DES distributions for kanji dyslexia were especially associated with the anterior-inferior side of the ILF. On the other hand, the DES point associated with kana dyslexia was localized on the posterior-superior side of the complex of these three tracts. These results suggested the presence of specific non-interfering networks that subserved the reading process for morphograms and phonograms.

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Language Localization in Multilingual Patients—Evidence From Direct Electrical Stimulation: A Systematic Review and Single Institution Case Series

Neurosurgery ◽

10.1093/neuros/nyz310_509 ◽

2019 ◽

Vol 66 (Supplement_1) ◽

Author(s):

Colin Teo Kok Ann ◽

Djaina Satoer ◽

Hui Minn Chan ◽

Marco Rossi ◽

Tseng Tsai Yeo ◽

...

Keyword(s):

Electrical Stimulation ◽

Standardized Test ◽

Case Series ◽

Awake Craniotomy ◽

Direct Electrical Stimulation ◽

Language Function ◽

Language Mapping ◽

Second Languages ◽

First Languages ◽

L1 And L2

Abstract INTRODUCTION To enable the safe mapping of language function in multilinguals, we need to understand how language organization in multilinguals differ from well-described organizations in monolingual patients. The development and appropriate administration of standardized test batteries intraoperatively is important to ensure accuracy of mapping, as interlanguage differences cannot be accounted by accurate translations alone. Individual or linguistic factors affects language organization. This study aims to review the published literature on language organization in multilinguals and illustrate intraoperative findings from a case series of multilingual patients who underwent language mapping during awake craniotomy at an Asian institution. METHODS This PRISMA guided review included studies on multilingual patients undergoing awake craniotomy utilizing direct electrical stimulation (DES) to localize language sites during awake craniotomy. Similar details from case series of multilingual individuals with more than one language mapped at our center, and strategies used to develop intraoperative tasks for non-English languages are also presented. RESULTS A total of 142 patients in 21 studies were included. These studies included 80.9% bilinguals, 10.5% trilinguals, 6.3% tetralinguals, 2.8% pentalinguals. Most common first languages (L1) are French (26.7%), English (16.9%), Spanish (14.0%), second languages (L2) are English (38%), Spanish (19.7%), Mandarin (7.7%). Our study noted large variation in fluency definition and evaluation methods for language and cognitive evaluation. Stimulation protocols, error definitions were similar. Naming and counting tasks most commonly used. Majority of studies (76.1%) found distinct cortical sites for L1 and L2, and shared sites as well (66.7%). There was no clear relationship between pattern of distribution and age of acquisition, proficiency or nature of language. Sites for specific tasks such as voluntary and involuntary switching, translation, and reading were identified. CONCLUSION There are distinct differences language organization between multilinguals and monolinguals. It is crucial for understanding of these differences for maximal preservation of each mapped language function to achieve maximal quality of life.

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Intraoperative mapping of executive function using electrocorticography for patients with low-grade gliomas

Acta Neurochirurgica ◽

10.1007/s00701-020-04646-6 ◽

2020 ◽

Author(s):

Yaara Erez ◽

Moataz Assem ◽

Pedro Coelho ◽

Rafael Romero-Garcia ◽

Mallory Owen ◽

...

Keyword(s):

Electrical Stimulation ◽

Executive Function ◽

Executive Functions ◽

Neural Activity ◽

Task Difficulty ◽

Awake Surgery ◽

Low Grade ◽

Direct Electrical Stimulation ◽

High Gamma ◽

Gamma Power

Abstract Background Intraoperative functional mapping with direct electrical stimulation during awake surgery for patients with diffuse low-grade glioma has been used in recent years to optimize the balance between surgical resection and quality of life following surgery. Mapping of executive functions is particularly challenging because of their complex nature, with only a handful of reports published so far. Here, we propose the recording of neural activity directly from the surface of the brain using electrocorticography to map executive functions and demonstrate its feasibility and potential utility. Methods To track a neural signature of executive function, we recorded neural activity using electrocorticography during awake surgery from the frontal cortex of three patients judged to have an appearance of diffuse low-grade glioma. Based on existing functional magnetic resonance imaging (fMRI) evidence from healthy participants for the recruitment of areas associated with executive function with increased task demands, we employed a task difficulty manipulation in two counting tasks performed intraoperatively. Following surgery, the data were extracted and analyzed offline to identify increases in broadband high-gamma power with increased task difficulty, equivalent to fMRI findings, as a signature of activity related to executive function. Results All three patients performed the tasks well. Data were recorded from five electrode strips, resulting in data from 15 channels overall. Eleven out of the 15 channels (73.3%) showed significant increases in high-gamma power with increased task difficulty, 26.6% of the channels (4/15) showed no change in power, and none of the channels showed power decrease. High-gamma power increases with increased task difficulty were more likely in areas that are within the canonical frontoparietal network template. Conclusions These results are the first step toward developing electrocorticography as a tool for mapping of executive function complementarily to direct electrical stimulation to guide resection. Further studies are required to establish this approach for clinical use.

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Intraoperative mapping of executive function using electrocorticography for patients with low-grade gliomas

10.31219/osf.io/gy84r ◽

2020 ◽

Author(s):

Yaara Erez ◽

Moataz Assem ◽

Pedro Coelho ◽

Rafael Romero-Garcia ◽

Mallory Owen ◽

...

Keyword(s):

Electrical Stimulation ◽

Executive Function ◽

Executive Functions ◽

Neural Activity ◽

Task Difficulty ◽

Awake Surgery ◽

Low Grade ◽

Direct Electrical Stimulation ◽

High Gamma ◽

Gamma Power

Background: Intraoperative functional mapping with direct electrical stimulation during awake surgery for patients with diffuse low-grade glioma has been used in recent years to optimize the balance between surgical resection and quality of life following surgery. Mapping of executive functions is particularly challenging because their complex nature, with only a handful of reports so far. Here, we propose recording of neural activity directly from the surface of the brain using electrocorticography to map executive functions and demonstrate its feasibility and potential utility.Methods: To track a neural signature of executive function, we recorded neural activity using electrocorticography during awake surgery from the frontal cortex of three patients judged to have an appearance of diffuse low-grade glioma. Based on existing functional magnetic resonance imaging (fMRI) evidence from healthy participants for the recruitment of areas associated with executive function with increased task demands, we employed a task difficulty manipulation in two counting tasks performed intraoperatively. Following surgery, the data were extracted and analyzed offline to identify increases in broadband high-gamma power with increased task difficulty, equivalent to fMRI findings, as a signature of activity related to executive function.Results: All three patients performed the tasks well. Data were recorded from five electrode strips, resulting in data from 15 channels overall. 73.3% of the channels (11/15) showed significant increases in high-gamma power with increased task difficulty, 26.6% channels (4/15) showed no change in power, and none of the channels showed power decrease. High-gamma power increases with increased task difficulty were more likely in areas that are within the canonical frontoparietal network template.Conclusions: These results are the first step towards developing electrocorticography as a tool for mapping of executive function complementarily to direct electrical stimulation to guide resection. Further studies and clinical trials are required to establish this approach for clinical use.

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Direct Electrical Stimulation of Premotor Areas: Different Effects on Hand Muscle Activity during Object Manipulation

Cerebral Cortex ◽

10.1093/cercor/bhz139 ◽

2019 ◽

Vol 30 (1) ◽

pp. 391-405 ◽

Cited By ~ 5

Author(s):

Luca Fornia ◽

Marco Rossi ◽

Marco Rabuffetti ◽

Antonella Leonetti ◽

Guglielmo Puglisi ◽

...

Keyword(s):

Electrical Stimulation ◽

Muscle Activity ◽

Premotor Cortex ◽

Object Manipulation ◽

Awake Surgery ◽

Direct Electrical Stimulation ◽

Task Execution ◽

Hand Muscles ◽

Premotor Areas ◽

Stimulation Of

Abstract Dorsal and ventral premotor (dPM and vPM) areas are crucial in control of hand muscles during object manipulation, although their respective role in humans is still debated. In patients undergoing awake surgery for brain tumors, we studied the effect of direct electrical stimulation (DES) of the premotor cortex on the execution of a hand manipulation task (HMt). A quantitative analysis of the activity of extrinsic and intrinsic hand muscles recorded during and in absence of DES was performed. Results showed that DES applied to premotor areas significantly impaired HMt execution, affecting task-related muscle activity with specific features related to the stimulated area. Stimulation of dorsal vPM induced both a complete task arrest and clumsy task execution, characterized by general muscle suppression. Stimulation of ventrocaudal dPM evoked a complete task arrest mainly due to a dysfunctional recruitment of hand muscles engaged in task execution. These results suggest that vPM and dPM contribute differently to the control of hand muscles during object manipulation. Stimulation of both areas showed a significant impact on motor output, although the different effects suggest a stronger relationship of dPM with the corticomotoneuronal circuit promoting muscle recruitment and a role for vPM in supporting sensorimotor integration.

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The verb and noun test for peri-operative testing (VAN-POP): standardized language tests for navigated transcranial magnetic stimulation and direct electrical stimulation

Acta Neurochirurgica ◽

10.1007/s00701-019-04159-x ◽

2019 ◽

Vol 162 (2) ◽

pp. 397-406 ◽

Cited By ~ 2

Author(s):

Ann-Katrin Ohlerth ◽

Antonio Valentin ◽

Francesco Vergani ◽

Keyoumars Ashkan ◽

Roelien Bastiaanse

Keyword(s):

Electrical Stimulation ◽

Transcranial Magnetic Stimulation ◽

Magnetic Stimulation ◽

Language Skills ◽

Word Retrieval ◽

Direct Electrical Stimulation ◽

Navigated Transcranial Magnetic Stimulation ◽

Single Word ◽

Language Mapping ◽

Language Tests

Abstract Background Protocols for intraoperative language mapping with direct electrical stimulation (DES) often include various language tasks triggering both nouns and verbs in sentences. Such protocols are not readily available for navigated transcranial magnetic stimulation (nTMS), where only single word object naming is generally used. Here, we present the development, norming, and standardization of the verb and noun test for peri-operative testing (VAN-POP) that measures language skills more extensively. Methods The VAN-POP tests noun and verb retrieval in sentence context. Items are marked and balanced for several linguistic factors known to influence word retrieval. The VAN-POP was administered in English, German, and Dutch under conditions that are used for nTMS and DES paradigms. For each language, 30 speakers were tested. Results At least 50 items per task per language were named fluently and reached a high naming agreement. Conclusion The protocol proved to be suitable for pre- and intraoperative language mapping with nTMS and DES.

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