Cortical calculation localization using electrostimulation

Object A naming task has been used to spare cortical areas involved in language. In the present study, a calculation task was combined with electrostimulation mapping (awake surgery) to spare cortical areas involved in calculation in patients undergoing surgery for brain lesions. The organization of language and calculation areas was analyzed in relation to these surgical data. Methods Twenty patients with brain lesions close to areas possibly involved in calculation (dominant parietal lobe and F2) were prospectively studied over a 4-year period. Four patients had preoperative symptoms of acalculia and therefore were not included in the brain mapping procedure. Results In 16 patients, direct electrostimulation caused calculation interferences in localized small cortical areas (< 2 cm2). Of the 53 calculation interferences found, 23 were independent of language areas, especially those in the inferior left parietal lobule. Various patterns of interference were observed (11 complete acalculia, 5 acalculia with wrong answers, 2 hesitations, and 5 mixed responses), although error patterns were fairly similar across angular, parietal, and frontal stimulation sites. Calculation areas in 4 patients could not be spared for oncological reasons; postoperatively, 3 of these patients showed significant acalculia symptoms. In contrast, none of the patients whose calculation areas were spared had arithmetic difficulties 1 month after surgery. Improvements in acalculia symptoms after surgery were also found in 3 of the 4 patients with preoperative calculation difficulties. Conclusions To limit the risk of personal and professional disturbances caused by acquired anarithmetia in patients undergoing surgery for brain tumors or epilepsy, the authors think it is necessary to use a calculation task during brain mapping, especially when operating in the dominant parietal lobe.

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“The Mute Who Can Sing”: a cortical stimulation study on singing

Journal of Neurosurgery ◽

10.3171/2007.9.17565 ◽

2009 ◽

Vol 110 (2) ◽

pp. 282-288 ◽

Cited By ~ 11

Author(s):

Franck-Emmanuel Roux ◽

Stefano Borsa ◽

Jean-François Démonet

Keyword(s):

Brain Tumors ◽

Special Interest ◽

Clear Distinction ◽

Awake Surgery ◽

Cortical Mapping ◽

Cortical Areas ◽

Left Handed ◽

Surgical Data ◽

The Right ◽

Language Areas

Object In an attempt to identify cortical areas involved in singing in addition to language areas, the authors used a singing task during direct cortical mapping in 5 patients who were amateur singers and had undergone surgery for brain tumors. The organization of the cortical areas involved in language and singing was analyzed in relation with these surgical data. Methods One left-handed and 4 right-handed patients with brain tumors in left (2 cases) and right (3 cases) hemispheres and no significant language or singing deficits underwent surgery with the “awake surgery” technique. All patients had a special interest in singing and were involved in amateur singing activities. They were tested using naming, reading, and singing tasks. Results Outside primary sensorimotor areas, singing interferences were rare and were exclusively localized in small cortical areas (< 1 cm2). A clear distinction was found between speech and singing in the Broca region. In the Broca region, no singing interference was found in areas in which interference in naming and reading tasks were detected. Conversely, a specific singing interference was found in nondominant middle frontal gyri in one patient. This interference consisted of abrupt singing arrest without apparent face, mouth, and tongue contraction. Finally, nonspecific singing interferences were found in the right and left precentral gyri in all patients (probably by interference in final articulatory mechanisms of singing). Conclusions Dissociations between speech and singing found outside primary sensorimotor areas showed that these 2 functions use, in some cortical stages, different cerebral pathways.

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When “Abegg” is read and (“A, B, E, G, G”) is not: a cortical stimulation study of musical score reading

Journal of Neurosurgery ◽

10.3171/jns.2007.106.6.1017 ◽

2007 ◽

Vol 106 (6) ◽

pp. 1017-1027 ◽

Cited By ~ 13

Author(s):

Franck-Emmanuel Roux ◽

Vincent Lubrano ◽

Jean-Albert Lotterie ◽

Carlo Giussani ◽

Clémence Pierroux ◽

...

Keyword(s):

Parietal Lobe ◽

Brain Lesions ◽

Cortical Stimulation ◽

Neurosurgical Procedures ◽

Musical Score ◽

Musical Ability ◽

Direct Stimulation ◽

Reading Task ◽

Cortical Areas ◽

Surgical Data

Object To spare the cortical areas involved both in musical score reading and in language, the authors used a score reading task during direct cortical stimulation mapping in musicians undergoing operations for brain lesions. The organization of the cortical areas involved in language and score reading, respectively, was analyzed in relation with these surgical data. Methods Seven patients with brain lesions were tested using three language tasks and a score-reading task. Preoperatively, none of them had exhibited significant language or musical ability deficits, and all had a special interest in music. All were involved in professional or amateur musical activities. Interference in score reading was found in small cortical areas, mainly in the dominant parietal lobe and sometimes in the frontal gyri. During direct stimulation, interference was either language-specific (15 sites), common to language and score-reading tasks (18 sites), or specific to the score-reading task (four sites). Different patterns of score-reading interferences (score-reading arrest, semantic paraphasia) were observed, probably corresponding to different stages of score reading. Postoperatively, some patients showed transitory score-reading difficulties related to the surgical procedure. Conclusions The cortical areas involved in score reading can occasionally be distinct from other language areas. This could explain differential word- and score-reading impairments sometimes observed in musicians with brain lesions. Brain mapping for neurosurgical procedures in musicians should ideally be performed using a score-reading task in addition to standard language tasks, especially for mapping in the dominant parietal lobe.

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Variability of intraoperative electrostimulation parameters in conscious individuals: language cortex

Journal of Neurosurgery ◽

10.3171/2016.4.jns152434 ◽

2017 ◽

Vol 126 (5) ◽

pp. 1641-1652 ◽

Cited By ~ 9

Author(s):

Franck-Emmanuel Roux ◽

Jean-Baptiste Durand ◽

Imène Djidjeli ◽

Emmanuel Moyse ◽

Carlo Giussani

Keyword(s):

Brain Mapping ◽

Naming Task ◽

Clinical Results ◽

Scientific Data ◽

Temporal Region ◽

Msec Duration ◽

Train Duration ◽

Significant Difference ◽

The Mean ◽

Language Areas

OBJECTIVEElectrostimulation in awake brain mapping is widely used to guide tumor removal, but methodologies can differ substantially across institutions. The authors studied electrostimulation brain mapping data to characterize the variability of the current intensity threshold across patients and the effect of its variations on the number, type, and surface area of the essential language areas detected.METHODSOver 7 years, the authors prospectively studied 100 adult patients who were undergoing intraoperative brain mapping during resection of left hemisphere tumors. In all 100 cases, the same protocol of electrostimulation brain mapping (a controlled naming task—bipolar stimulation with biphasic square wave pulses of 1-msec duration and 60-Hz trains, maximum train duration 6 sec) and electrocorticography was used to detect essential language areas.RESULTSThe minimum positive thresholds of stimulation varied from patient to patient; the mean minimum intensity required to detect interference was 4.46 mA (range 1.5–9 mA), and in a substantial proportion of sites (13.5%) interference was detected only at intensities above 6 mA. The threshold varied within a given patient for different naming areas in 22% of cases. Stimulation of the same naming area with greater intensities led to slight changes in the type of response in 19% of cases and different types of responses in 4.5%. Naming sites detected were located in subcentimeter cortical areas (50% were less than 20 mm2), but their extent varied with the intensity of stimulation. During a brain mapping session, the same intensity of stimulation reproduced the same type of interference in 94% of the cases. There was no statistically significant difference between the mean stimulation intensities required to produce interfereince in the left inferior frontal lobe (Broca's area), the supramarginal gyri, and the posterior temporal region.CONCLUSIONSIntrasubject and intersubject variations of the minimum thresholds of positive naming areas and changes in the type of response and in the size of these areas according to the intensity used may limit the interpretation of data from electrostimulation in awake brain mapping. To optimize the identification of language areas during electrostimulation brain mapping, it is important to use different intensities of stimulation at the maximum possible currents, avoiding afterdischarges. This could refine the clinical results and scientific data derived from these mapping sessions.

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Is Preoperative Functional Magnetic Resonance Imaging Reliable for Language Areas Mapping in Brain Tumor Surgery? Review of Language Functional Magnetic Resonance Imaging and Direct Cortical Stimulation Correlation Studies

Neurosurgery ◽

10.1227/01.neu.0000360392.15450.c9 ◽

2010 ◽

Vol 66 (1) ◽

pp. 113-120 ◽

Cited By ~ 241

Author(s):

Carlo Giussani ◽

Frank-Emmanuel Roux ◽

Jeffrey Ojemann ◽

Erik Pietro Sganzerla ◽

David Pirillo ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Functional Magnetic Resonance Imaging ◽

Brain Mapping ◽

Brain Lesions ◽

Cortical Stimulation ◽

Functional Magnetic Resonance ◽

Resonance Imaging ◽

Direct Cortical Stimulation ◽

Language Areas

Abstract OBJECTIVE Language functional magnetic resonance imaging (fMRI) has been used extensively in the past decade for both clinical and research purposes. Its integration in the preoperative imaging assessment of brain lesions involving eloquent areas is progressively more diffused in neurosurgical practice. Nevertheless, the reliability of language fMRI is unclear. To understand the reliability of preoperative language fMRI in patients operated on for brain tumors, the surgical studies that compared language fMRI with direct cortical stimulation (DCS) were reviewed. METHODS Articles comparing language fMRI with DCS of language areas were reviewed with attention to the lesion pathology, the magnetic field, the language tasks used pre- and intraoperatively, and the validation modalities adopted to establish the reliability of language fMRI. We tried to explore the effectiveness of language fMRI in gliomas. RESULTS Nine language brain mapping studies compared the findings of fMRI with those of DCS. The studies are not homogeneous for tumor types, magnetic fields, pre- and intraoperative language tasks, intraoperative matching criteria, and results. Sensitivity and specificity were calculated in 5 studies (respectively ranging from 59% to 100% and from 0% to 97%). CONCLUSION The contradictory results of these studies do not allow consideration of language fMRI as an alternative tool to DCS in brain lesions located in language areas, especially in gliomas because of the pattern of growth of these tumors. However, language fMRI conducted with high magnet fields is a promising brain mapping tool that must be validated by DCS in methodological robust studies.

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Cortical stimulation of language fields under local anesthesia: optimizing removal of brain lesions adjacent to speech areas

Arquivos de Neuro-Psiquiatria ◽

10.1590/s0004-282x2008000400018 ◽

2008 ◽

Vol 66 (3a) ◽

pp. 534-538 ◽

Cited By ~ 15

Author(s):

Robson Luis Oliveira de Amorim ◽

Antônio Nogueira de Almeida ◽

Paulo Henrique Pires de Aguiar ◽

Erich Talamoni Fonoff ◽

Suely Itshak ◽

...

Keyword(s):

Local Anesthesia ◽

Brain Mapping ◽

Conscious Sedation ◽

Brain Lesions ◽

Neurological Deficits ◽

Consecutive Series ◽

Total Resection ◽

Safe Technique ◽

Language Areas ◽

Stimulation Of

OBJECTIVE: The main objective when resecting benign brain lesions is to minimize risk of postoperative neurological deficits. We have assessed the safety and effectiveness of craniotomy under local anesthesia and monitored conscious sedation for the resection of lesions involving eloquent language cortex. METHODS: A retrospective review was performed on a consecutive series of 12 patients who underwent craniotomy under local anesthesia between 2001 and 2004. All patients had lesions close to the speech cortex. All resection was verified by post-operative imaging. Six subjects were male and 6 female, and were aged between 14 and 52 years. RESULTS: Lesions comprised 7 tumour lesions, 3 cavernomas and 1 dermoid cyst. Radiological gross total resection was achieved in 66% of patients while remaining cases had greater than 80% resection. Only one patient had a post-operative permanent deficit, whilst another had a transient post-operative deficit. All patients with uncontrollable epilepsy had good outcomes after surgery. None of our cases subsequently needed to be put under general anesthesia. CONCLUSION: Awake craniotomy with brain mapping is a safe technique and the "gold standard" for resection of lesions involving language areas.

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Category-specific cortical mapping: color-naming areas

Journal of Neurosurgery ◽

10.3171/jns.2006.104.1.27 ◽

2006 ◽

Vol 104 (1) ◽

pp. 27-37 ◽

Cited By ~ 18

Author(s):

Franck-Emmanuel Roux ◽

Vincent Lubrano ◽

Valérie Lauwers-Cances ◽

Christopher R. Mascott ◽

Jean-François Démonet

Keyword(s):

Electrical Stimulation ◽

Naming Task ◽

Color Naming ◽

Individual Variability ◽

Cortical Mapping ◽

Object Naming ◽

Cortical Areas ◽

Language Deficit ◽

Language Areas ◽

Naming Tasks

Object It has been hypothesized that a certain degree of specialization exists within language areas, depending on some specific lexical repertories or categories. To spare hypothetical category-specific cortical areas and to gain a better understanding of their organization, the authors studied patients who had undergone electrical stimulation mapping for brain tumors and they compared an object-naming task with a category-specific task (color naming). Methods Thirty-six patients with no significant preoperative language deficit were prospectively studied during a 2-year period. Along with a reading task, both object- and color-naming tasks were used in brain mapping. During color naming, patients were asked to identify 11 visually presented basic colors. The modality specificity of the colornaming sites found was subsequently tested by asking patients to retrieve the color attributes of objects. High individual variability was observed in language organization among patients and in the tasks performed. Significant interferences in color naming were found in traditional language regions—that is, Broca (p < 0.003) and Wernicke centers (p = 0.05)—although some color-naming areas were occasionally situated outside of these regions. Color-naming interferences were exclusively localized in small cortical areas (< 1 cm2). Anatomical segregation of the different naming categories was apparent in 10 patients; in all, 13 color-specific naming areas (that is, sites evoking no object-naming interference) were detected in the dominant-hemisphere F3 and the supramarginal, angular, and posterior parts of the temporal gyri. Nevertheless, no specific brain region was found to be consistently involved in color naming (p > 0.05). At five sites, although visually presented color-naming tasks were impaired by stimulation, auditory color naming (for example, “What color is grass?”) was performed with no difficulty, showing that modality-specific areas can be found during naming. Conclusions Within language areas, a relative specialization of cortical language areas for color naming can be found during electrical stimulation mapping.

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Immersive Virtual Reality and Ocular Tracking for Brain Mapping During Awake Surgery: Prospective Evaluation Study (Preprint)

10.2196/preprints.24373 ◽

2020 ◽

Author(s):

Morgane Casanova ◽

Anne Clavreul ◽

Gwénaëlle Soulard ◽

Matthieu Delion ◽

Ghislaine Aubin ◽

...

Keyword(s):

Virtual Reality ◽

Eye Tracking ◽

Brain Mapping ◽

Eye Gaze ◽

Standard Procedure ◽

Naming Task ◽

Evaluation Study ◽

Awake Surgery ◽

Brain Surgery ◽

Language Mapping

BACKGROUND Language mapping during awake brain surgery is currently a standard procedure. However, mapping is rarely performed for other cognitive functions that are important for social interaction, such as visuospatial cognition and nonverbal language, including facial expressions and eye gaze. The main reason for this omission is the lack of tasks that are fully compatible with the restrictive environment of an operating room and awake brain surgery procedures. OBJECTIVE This study aims to evaluate the feasibility and safety of a virtual reality headset equipped with an eye-tracking device that is able to promote an immersive visuospatial and social virtual reality (VR) experience for patients undergoing awake craniotomy. METHODS We recruited 15 patients with brain tumors near language and/or motor areas. Language mapping was performed with a naming task, DO 80, presented on a computer tablet and then in 2D and 3D via the VRH. Patients were also immersed in a visuospatial and social VR experience. RESULTS None of the patients experienced VR sickness, whereas 2 patients had an intraoperative focal seizure without consequence; there was no reason to attribute these seizures to virtual reality headset use. The patients were able to perform the VR tasks. Eye tracking was functional, enabling the medical team to analyze the patients’ attention and exploration of the visual field of the virtual reality headset directly. CONCLUSIONS We found that it is possible and safe to immerse the patient in an interactive virtual environment during awake brain surgery, paving the way for new VR-based brain mapping procedures. CLINICALTRIAL ClinicalTrials.gov NCT03010943; https://clinicaltrials.gov/ct2/show/NCT03010943.

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Immersive Virtual Reality and Ocular Tracking for Brain Mapping During Awake Surgery: Prospective Evaluation Study

Journal of Medical Internet Research ◽

10.2196/24373 ◽

2021 ◽

Vol 23 (3) ◽

pp. e24373

Author(s):

Morgane Casanova ◽

Anne Clavreul ◽

Gwénaëlle Soulard ◽

Matthieu Delion ◽

Ghislaine Aubin ◽

...

Keyword(s):

Virtual Reality ◽

Eye Tracking ◽

Brain Mapping ◽

Eye Gaze ◽

Standard Procedure ◽

Naming Task ◽

Evaluation Study ◽

Awake Surgery ◽

Brain Surgery ◽

Language Mapping

Background Language mapping during awake brain surgery is currently a standard procedure. However, mapping is rarely performed for other cognitive functions that are important for social interaction, such as visuospatial cognition and nonverbal language, including facial expressions and eye gaze. The main reason for this omission is the lack of tasks that are fully compatible with the restrictive environment of an operating room and awake brain surgery procedures. Objective This study aims to evaluate the feasibility and safety of a virtual reality headset equipped with an eye-tracking device that is able to promote an immersive visuospatial and social virtual reality (VR) experience for patients undergoing awake craniotomy. Methods We recruited 15 patients with brain tumors near language and/or motor areas. Language mapping was performed with a naming task, DO 80, presented on a computer tablet and then in 2D and 3D via the VRH. Patients were also immersed in a visuospatial and social VR experience. Results None of the patients experienced VR sickness, whereas 2 patients had an intraoperative focal seizure without consequence; there was no reason to attribute these seizures to virtual reality headset use. The patients were able to perform the VR tasks. Eye tracking was functional, enabling the medical team to analyze the patients’ attention and exploration of the visual field of the virtual reality headset directly. Conclusions We found that it is possible and safe to immerse the patient in an interactive virtual environment during awake brain surgery, paving the way for new VR-based brain mapping procedures. Trial Registration ClinicalTrials.gov NCT03010943; https://clinicaltrials.gov/ct2/show/NCT03010943.

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Neurocognitive and functional outcomes in patients with diffuse frontal lower-grade gliomas undergoing intraoperative awake brain mapping

Journal of Neurosurgery ◽

10.3171/2019.3.jns19211 ◽

2020 ◽

Vol 132 (6) ◽

pp. 1683-1691 ◽

Cited By ~ 7

Author(s):

Kazuya Motomura ◽

Lushun Chalise ◽

Fumiharu Ohka ◽

Kosuke Aoki ◽

Kuniaki Tanahashi ◽

...

Keyword(s):

Working Memory ◽

Brain Mapping ◽

Functional Outcomes ◽

Digit Span ◽

Awake Surgery ◽

Motor Deficit ◽

Lower Grade ◽

Superior Frontal Gyrus ◽

Neurocognitive Functions ◽

Motor Disturbances

OBJECTIVELower-grade gliomas (LGGs) are often observed within eloquent regions, which indicates that tumor resection in these areas carries a potential risk for neurological disturbances, such as motor deficit, language disorder, and/or neurocognitive impairments. Some patients with frontal tumors exhibit severe impairments of neurocognitive function, including working memory and spatial awareness, after tumor removal. The aim of this study was to investigate neurocognitive and functional outcomes of frontal LGGs in both the dominant and nondominant hemispheres after awake brain mapping.METHODSData from 50 consecutive patients with diffuse frontal LGGs in the dominant and nondominant hemispheres who underwent awake brain surgery between December 2012 and September 2018 were retrospectively analyzed. The goal was to map neurocognitive functions such as working memory by using working memory tasks, including digit span testing and N-back tasks.RESULTSDue to awake language mapping, the frontal aslant tract was frequently identified as a functional boundary in patients with left superior frontal gyrus tumors (76.5%). Furthermore, functional boundaries were identified while evaluating verbal and spatial working memory function by stimulating the dorsolateral prefrontal cortex using the digit span and visual N-back tasks in patients with right superior frontal gyrus tumors (7.1%). Comparing the preoperative and postoperative neuropsychological assessments from the Wechsler Adult Intelligence Scale–Third Edition (WAIS-III) and Wechsler Memory Scale–Revised (WMS-R), significant improvement following awake surgery was observed in mean Perceptual Organization (Z = −2.09, p = 0.04) in WAIS-III scores. Postoperative mean WMS-R scores for Visual Memory (Z = −2.12, p = 0.03) and Delayed Recall (Z = −1.98, p = 0.04) were significantly improved compared with preoperative values for every test after awake surgery. No significant deterioration was noted with regard to neurocognitive functions in a comprehensive neuropsychological test battery. In the postoperative course, early transient speech and motor disturbances were observed in 30.0% and 28.0% of patients, respectively. In contrast, late permanent speech and motor disturbances were observed in 0% and 4.0%, respectively.CONCLUSIONSIt is noteworthy that no significant postoperative deterioration was identified compared with preoperative status in a comprehensive neuropsychological assessment. The results demonstrated that awake functional mapping enabled favorable neurocognitive and functional outcomes after surgery in patients with diffuse frontal LGGs.

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Is Lateropulsion Really Related with a Specific Lesion of the Brain?

Brain Sciences ◽

10.3390/brainsci11030354 ◽

2021 ◽

Vol 11 (3) ◽

pp. 354

Author(s):

Kyoung Lee ◽

Sang Yoo ◽

Eun Ji ◽

Woo Hwang ◽

Yeun Yoo ◽

...

Keyword(s):

Right Hemisphere ◽

Parietal Lobe ◽

Inferior Frontal Gyrus ◽

Brain Lesions ◽

Vertical Posture ◽

Lesion Volume ◽

Precentral Gyrus ◽

Stroke Patients ◽

The Right ◽

Right Hemisphere Stroke

Lateropulsion (pusher syndrome) is an important barrier to standing and gait after stroke. Although several studies have attempted to elucidate the relationship between brain lesions and lateropulsion, the effects of specific brain lesions on the development of lateropulsion remain unclear. Thus, the present study investigated the effects of stroke lesion location and size on lateropulsion in right hemisphere stroke patients. The present retrospective cross-sectional observational study assessed 50 right hemisphere stroke patients. Lateropulsion was diagnosed and evaluated using the Scale for Contraversive Pushing (SCP). Voxel-based lesion symptom mapping (VLSM) analysis with 3T-MRI was used to identify the culprit lesion for SCP. We also performed VLSM controlling for lesion volume as a nuisance covariate, in a multivariate model that also controlled for other factors contributing to pusher behavior. VLSM, combined with statistical non-parametric mapping (SnPM), identified the specific region with SCP. Lesion size was associated with lateropulsion. The precentral gyrus, postcentral gyrus, inferior frontal gyrus, insula and subgyral parietal lobe of the right hemisphere seemed to be associated with the lateropulsion; however, after adjusting for lesion volume as a nuisance covariate, no lesion areas were associated with the SCP scores. The size of the right hemisphere lesion was the only factor most strongly associated with lateropulsion in patients with stroke. These results may be useful for planning rehabilitation strategies of restoring vertical posture and understanding the pathophysiology of lateropulsion in stroke patients.

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