Cortical stimulation mapping of language cortex by using a verb generation task: effects of learning and comparison to mapping based on object naming

2002 ◽  
Vol 97 (1) ◽  
pp. 33-38 ◽  
Author(s):  
Jeffrey G. Ojemann ◽  
George A. Ojemann ◽  
Ettore Lettich
Keyword(s):  
Functional Neuroimaging ◽  
Cortical Stimulation ◽  
Object Naming ◽  
Generation Task ◽  
Content Type ◽  
Cortical Stimulation Mapping ◽  
Verb Generation ◽  
Language Areas ◽  
Language Cortex ◽  
Fine Print

Object. Cortical stimulation mapping has traditionally relied on disruption of object naming to define essential language areas. In this study, the authors reviewed the use of a different language task, verb generation, in mapping language. This task has greater use in brain imaging studies and may be used to test aspects of language different from those of object naming. Methods. In 14 patients, cortical stimulation mapping performed using a verb generation task provided a map of language areas in the frontal and temporoparietal cortices. These verb generation maps often overlapped object naming ones and, in many patients, different areas of cortex were found to be involved in the two functions. In three patients, stimulation mapping was performed during the initial performance of the verb generation task and also during learned performance of the task. Parallel to findings of published neuroimaging studies, a larger area of stimulated cortex led to disruption of verb generation in response to stimulation during novel task performance than during learned performance. Conclusions. Results of cortical stimulation mapping closely resemble those of functional neuroimaging when both implement the verb generation task. The precise map of the temporoparietal language cortex depends on the task used for mapping.

Writing-specific sites in frontal areas: a cortical stimulation study

2004 ◽  
Vol 101 (5) ◽  
pp. 787-798 ◽  
Author(s):  
Vincent Lubrano ◽  
Franck-Emmanuel Roux ◽  
Jean-François Démonet
Keyword(s):  
Brain Tumors ◽  
Individual Variability ◽  
Cortical Stimulation ◽  
Awake Surgery ◽  
Direct Stimulation ◽  
Content Type ◽  
Left Handed ◽  
Language Areas ◽  
Fine Print ◽  
Stimulation Of

Object. The aim of this study was to determine whether cortical areas involved in the writing process are associated with reading or naming areas in patients undergoing surgery for brain tumors in frontal areas. This study was undertaken to spare all language areas found in patients during surgery. Methods. Fourteen patients (eight women and six men [mean age 47 years] of whom 12 were right handed, two left handed, 12 monolingual, and two bilingual) who harbored brain tumors in the left (11 patients) or right (three patients) frontal gyri or in rolandic areas, were tested by direct stimulation by using the awake surgery technique for direct brain mapping. Mapping of the frontal gyri was performed using naming, reading, and writing under dictation tasks in the appropriate language(s). Considerable individual variability in language organization among patients was observed. Interferences in writing were found during direct stimulation in the frontal gyri, in cortical sites common or not common to interferences in naming or reading. In dominant regions, patterns of writing dysfunctions were variable and included writing arrest, illegible script, letter omissions, and paragraphia. These dysfunctions were nonspecific (stimulation-induced eye movements) in nondominant frontal regions and in rolandic gyri (hand contractions). In the same patient, different writing impairments could sometimes be observed during stimulation of different sites. As is the case for naming or reading interference sites, writing interference sites could be extremely localized (1 cm2 in diameter). In this group of patients, writing interference sites found in Broca areas were associated with other sites of language interference, whereas writing-specific interference sites were found twice in the dominant middle frontal gyrus. Conclusions. In this series, we found that writing interference sites could be detected by direct cortical stimulation in dominant inferior and middle frontal gyri regardless of whether they were associated with naming or reading interference sites. Writing disorders elicited by direct stimulation in the frontal lobes are varied and probably depend on the functional status of the stimulated cortical area.

Diffusion-tensor imaging—guided tracking of fibers of the pyramidal tract combined with intraoperative cortical stimulation mapping in patients with gliomas

2004 ◽  
Vol 101 (1) ◽  
pp. 66-72 ◽  
Author(s):  
Jeffrey I. Berman ◽  
Mitchel S. Berger ◽  
Pratik Mukherjee ◽  
Roland G. Henry
Keyword(s):  
Mr Imaging ◽  
Diffusion Tensor ◽  
Tumor Resection ◽  
Cortical Stimulation ◽  
Surgical Morbidity ◽  
Content Type ◽  
Motor Pathways ◽  
Cortical Motor ◽  
Cortical Stimulation Mapping ◽  
Fine Print

Object. The goal of this study was to use diffusion-tensor (DT) magnetic resonance (MR) imaging to track fibers combined with cortical stimulation mapping to delineate descending motor pathways. Subcortical localization of motor pathways in relation to a glioma may provide critical information to guide tumor resection and prevent surgical morbidity. Methods. Eleven adult patients harboring gliomas underwent MR imaging 1 day prior to image-guided intraoperative cortical motor mapping and tumor resection. Screens depicting 27 cortical motor sites on a surgical navigation system were saved to launch DT imaging of fiber tracks of descending motor pathways. The position and organization of motor tracts were visualized by fiber tracking. Tracks from 16 motor stimulation sites followed descending pathways from the precentral gyrus, through the corona radiata and internal capsule, and into the cerebral peduncle. These tracks were also observed on DT images to diverge along crossing white matter bundles (four patients) and to terminate or deviate in regions of peritumoral vasogenic edema (five patients). Conclusions. The use of precise intraoperative cortical mapping information and DT images of fiber tracks can reveal the course of motor pathways beneath the cortex. The subcortical fiber tracks generated are consistent with the known anatomical course and somatotopic organization of the motor tract in relation to its cortical origins. Tracking fibers by using DT imaging in combination with functional localization has the potential to reduce surgical morbidity by revealing subcortical connections of the functional cortex.

A new device for cortical stimulation mapping of surgically unexposed cortex

1993 ◽  
Vol 79 (4) ◽  
pp. 612-614 ◽  
Author(s):  
Daniel L. Silbergeld
Keyword(s):  
Cerebral Cortex ◽  
Functional Mapping ◽  
Cortical Stimulation ◽  
Content Type ◽  
New Device ◽  
Cortical Stimulation Mapping ◽  
Fine Print

✓ Intraoperative functional mapping is an integral facet of many supratentorial procedures involving cortical resection. A new device is described that can be used in conjunction with a standard cortical stimulator and strip electrodes to stimulate intraoperative regions of unexposed cerebral cortex. This permits the use of a smaller craniotomy, while providing the ability for functional mapping of large areas of surface cortex.

scholarly journals Dissociation of action and object naming: Evidence from cortical stimulation mapping

2004 ◽  
Vol 24 (1) ◽  
pp. 1-10 ◽  
Author(s):  
David P. Corina ◽  
Erin K. Gibson ◽  
Richard Martin ◽  
Andrew Poliakov ◽  
James Brinkley ◽  
...  
Keyword(s):  
Cortical Stimulation ◽  
Object Naming ◽  
Cortical Stimulation Mapping

Preoperative predictors of anterior temporal language areas

1998 ◽  
Vol 89 (6) ◽  
pp. 962-970 ◽  
Author(s):  
Theodore H. Schwartz ◽  
Orrin Devinsky ◽  
Werner Doyle ◽  
Kenneth Perrine
Keyword(s):  
Temporal Lobe ◽  
Right Hemisphere ◽  
Temporal Lobectomy ◽  
Seizure Onset ◽  
Anterior Temporal Lobe ◽  
Verbal Iq ◽  
Content Type ◽  
Language Areas ◽  
Fine Print

Object. Although it is known that 5 to 10% of patients have language areas anterior to the rolandic cortex, many surgeons still perform standard anterior temporal lobectomies for epilepsy of mesial onset and report minimal long-term dysphasia. The authors examined the importance of language mapping before anterior temporal lobectomy. Methods. The authors mapped naming, reading, and speech arrest in a series of 67 patients via stimulation of long-term implanted subdural grids before resective epilepsy surgery and correlated the presence of language areas in the anterior temporal lobe with preoperative demographic and neuropsychometric data. Naming (p < 0.03) and reading (p < 0.05) errors were more common than speech arrest in patients undergoing surgery in the anterior temporal lobe. In the approximate region of a standard anterior temporal lobectomy, including 2.5 cm of the superior temporal gyrus and 4.5 cm of both the middle and inferior temporal gyrus, the authors identified language areas in 14.5% of patients tested. Between 1.5 and 3.5 cm from the temporal tip, patients who had seizure onset before 6 years of age had more naming (p < 0.02) and reading (p < 0.01) areas than those in whom seizure onset occurred after age 6 years. Patients with a verbal intelligence quotient (IQ) lower than 90 had more naming (p < 0.05) and reading (p < 0.02) areas than those with an IQ higher than 90. Finally, patients who were either left handed or right hemisphere memory dominant had more naming (p < 0.05) and reading (p < 0.02) areas than right-handed patients with bilateral or left hemisphere memory lateralization. Postoperative neuropsychometric testing showed a trend toward a greater decline in naming ability in patients who were least likely to have anterior language areas, that is, those with higher verbal IQ and later seizure onset. Conclusions. Preoperative identification of markers of left hemisphere damage, such as early seizure onset, poor verbal IQ, left handedness, and right hemisphere memory dominance should alert neurosurgeons to the possibility of encountering essential language areas in the anterior temporal lobe (1.5–3.5 cm from the temporal tip). Naming and reading tasks are required to identify these areas. Whether removal of these areas necessarily induces long-term impairment in verbal abilities is unknown; however, in patients with a low verbal IQ and early seizure onset, these areas appear to be less critical for language processing.

Localization of somatosensory function by using positron emission tomography scanning: a comparison with intraoperative cortical stimulation

1999 ◽  
Vol 90 (3) ◽  
pp. 478-483 ◽  
Author(s):  
Richard G. Bittar ◽  
André Olivier ◽  
Abbas F. Sadikot ◽  
Frederick Andermann ◽  
Roch M. Comeau ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Somatosensory Cortex ◽  
Cortical Stimulation ◽  
Emission Tomography ◽  
Primary Somatosensory Cortex ◽  
Vibrotactile Stimulation ◽  
Content Type ◽  
Positron Emission ◽  
Pet Scanning ◽  
Fine Print

Object. To investigate the utility of [15O]H2O positron emission tomography (PET) activation studies in the presurgical mapping of primary somatosensory cortex, the authors compared the magnitude and location of activation foci obtained using PET scanning with the results of intraoperative cortical stimulation (ICS).Methods. The authors used PET scanning and vibrotactile stimulation (of the face, hand, or foot) to localize the primary somatosensory cortex before surgical resection of mass lesions or epileptogenic foci affecting the central area in 20 patients. With the aid of image-guided surgical systems, the locations of significant activation foci on PET scanning were compared with those of positive ICS performed at craniotomy after the patient had received a local anesthetic agent. In addition, the relationship between the magnitude and statistical significance of blood flow changes and the presence of positive ICS was examined.In 22 (95.6%) of 23 statistically significant (p < 0.05) PET activation foci, spatially concordant sites on ICS were also observed. Intraoperative cortical stimulation was positive in 40% of the PET activation studies that did not result in statistically significant activation. In the patients showing these results, there was a clearly identifiable t-statistic peak that was spatially concordant with the site of positive ICS in the sensorimotor area. All PET activation foci with a t statistic greater than 4.75 were associated with spatially concordant sites of positive ICS. All PET activation foci with a t statistic less than 3.2 were associated with negative ICS.Conclusions. Positron emission tomography is an accurate method for mapping the primary somatosensory cortex before surgery. The need for ICS, which requires local anesthesia, may be eliminated when PET foci with high (> 4.75) or low (< 3.20) t-statistic peaks are elicited by vibrotactile stimulation.

Intraoperative validation of functional magnetic resonance imaging and cortical reorganization patterns in patients with brain tumors involving the primary motor cortex

1999 ◽  
Vol 91 (2) ◽  
pp. 238-250 ◽  
Author(s):  
Javier Fandino ◽  
Spyros S. Kollias ◽  
Heinz G. Wieser ◽  
Anton Valavanis ◽  
Yasuhiro Yonekawa
Keyword(s):  
Motor Cortex ◽  
Motor Function ◽  
Primary Motor Cortex ◽  
Objective Evaluation ◽  
Cortical Stimulation ◽  
Cortical Reorganization ◽  
Motor Area ◽  
Primary Motor Area ◽  
Content Type ◽  
Fine Print

Object. The purpose of the present study was to compare the results of functional magnetic resonance (fMR) imaging with those of intraoperative cortical stimulation in patients who harbored tumors close to or involving the primary motor area and to assess the usefulness of fMR imaging in the objective evaluation of motor function as part of the surgical strategy in the treatment of these patients.Methods. A total of 11 consecutive patients, whose tumors were close to or involving the central region, underwent presurgical blood oxygen level—dependent fMR imaging while performing a motor paradigm that required them to clench and spread their hands contra- and ipsilateral to the tumor. Statistical cross-correlation functional maps covering the primary and secondary motor cortical areas were generated and overlaid onto high-resolution anatomical MR images. Intraoperative electrical cortical stimulation was performed to validate the presurgical fMR imaging findings. In nine (82%) of 11 patients, the anatomical fMR imaging localization of motor areas could be verified by intraoperative electrical cortical stimulation. In seven patients two or more activation sites were demonstrated on fMR imaging, which were considered a consequence of reorganization phenomena of the motor cortex: contralateral primary motor area (nine patients), contralateral premotor area (four patients), ipsilateral primary motor area (two patients), and ipsilateral premotor area (four patients).Conclusions. Functional MR imaging can be used to perform objective evaluation of motor function and surgical planning in patients who harbor lesions near or involving the primary motor cortex. Correlation between fMR imaging findings and the results of direct electrical brain stimulation is high, although not 100%. Based on their study, the authors believe that cortical reorganization patterns of motor areas might explain the differences in motor function and the diversity of postoperative motor function among patients with central tumors.

Nonlesional central lobule seizures: use of awake cortical mapping and subdural grid monitoring for resection of seizure focus

2003 ◽  
Vol 98 (6) ◽  
pp. 1255-1262 ◽  
Author(s):  
Aaron A. Cohen-Gadol ◽  
Jeffrey W. Britton ◽  
Frederic P. Collignon ◽  
Lisa M. Bates ◽  
Gregory D. Cascino ◽  
...  
Keyword(s):  
Seizure Frequency ◽  
Sensorimotor Cortex ◽  
Cortical Stimulation ◽  
Limited Resection ◽  
Awake Craniotomy ◽  
Sensory Loss ◽  
Precentral Gyrus ◽  
Content Type ◽  
Postcentral Gyrus ◽  
Fine Print

Object. Surgical treatment options for intractable seizures caused by a nonlesional epileptogenic focus located in the central sulcus region are limited. The authors describe an alternative surgical approach for treating medically refractory nonlesional perirolandic epilepsy. Methods. Five consecutive patients who were treated between 1996 and 2000 for nonlesional partial epilepsy that had originated in the central lobule were studied. The patients' ages ranged from 16 to 56 years (mean 28.6 years; there were four men and one woman). The duration of their epilepsy ranged from 8 to 39 years (mean 20.2 years), with a mean seizure frequency of 19 partial seizures per week. Preoperative assessment included video electroencephalography (EEG) and subtracted ictal—interictal single-photon emission computerized tomography coregistered with magnetic resonance imaging (SISCOM). Patients underwent an awake craniotomy stereotactically guided by the ictal EEG and SISCOM studies. Cortical stimulation was used to identify the sensorimotor cortex and to reproduce the patient's aura. A subdural grid was then implanted based on these results. Subsequent postoperative ictal electrocorticographic recordings and cortical stimulation further delineated the site of seizure onset and functional anatomy. During a second awake craniotomy, a limited resection of the epileptogenic central lobule region was performed while function was continuously monitored intraoperatively. One resection was limited to the precentral gyrus, two to the postcentral gyrus, and in two the excisions involved regions of both the pre- and postcentral gyri. In three patients a hemiparesis occurred postsurgery but later resolved. In the four patients whose resection involved the postcentral gyrus, transient cortical sensory loss and apraxia occurred, which completely resolved in three. Two patients are completely seizure free, two have experienced occasional nondisabling seizures, and one patient has benefited from a more than 75% reduction in seizure frequency. The follow-up period ranged from 2 to 5.5 years (mean 3.5 years). Conclusions. A limited resection of the sensorimotor cortex may be performed with acceptable neurological morbidity in patients with medically refractory perirolandic epilepsy. This procedure is an alternative to multiple subpial transections in the surgical management of intractable nonlesional epilepsy originating from the sensorimotor cortex.

Localization of Expressive Language Cortex in a 2-Year-Old Child Using High-Gamma Electrocorticography

2019 ◽  
Vol 34 (13) ◽  
pp. 837-841
Author(s):  
Abbas Babajani-Feremi ◽  
Stephen P. Fulton ◽  
Christen M. Holder ◽  
Asim F. Choudhri ◽  
Frederick A. Boop ◽  
...  
Keyword(s):  
Expressive Language ◽  
Inferior Frontal Gyrus ◽  
Young Patients ◽  
Cortical Stimulation ◽  
Older Children ◽  
Language Mapping ◽  
Language Deficit ◽  
High Gamma ◽  
Cortical Stimulation Mapping ◽  
Language Cortex

Cortical stimulation mapping is the gold standard for presurgical language mapping; however, it cannot be reliably performed in very young patients. Language mapping using noninvasive modalities is also challenging in very young patients. Although utility of language mapping using power of high-gamma in electrocorticographic recordings was demonstrated in adults and older children, there is a gap of knowledge in the ability of this procedure for localizing language-specific cortex in very young patients. We describe a case of a 2-year-old patient who, to our knowledge, is the youngest person to undergo successful high-gamma electrocorticographic presurgical language mapping for localization of the expressive language cortex (Broca area). The surgical plan was to resect a cortical tuber within the left inferior frontal gyrus and there was a strong concern about postoperative language deficit after resection. Presurgical language mapping using noninvasive modalities were attempted without success. Cortical stimulation mapping was not feasible in this patient. Therefore, high-gamma electrocorticography was the only viable option for language mapping, and it successfully localized the expressive language cortex. The patient underwent surgery for resection of the IFG tuber based on results of high-gamma electrocorticography and had no postoperative language deficit. High-gamma electrocorticography can be used for localizing language-specific cortex, especially Broca’s area, in very young patients.

Localization of language function in children: results of electrical stimulation mapping

2003 ◽  
Vol 98 (3) ◽  
pp. 465-470 ◽  
Author(s):  
Steven G. Ojemann ◽  
Mitchel S. Berger ◽  
Ettore Lettich ◽  
George A. Ojemann
Keyword(s):  
Electrical Stimulation ◽  
Language Function ◽  
Content Type ◽  
Site Distribution ◽  
Relative Paucity ◽  
Younger Age ◽  
Language Areas ◽  
Relationship Of ◽  
The Relationship ◽  
Fine Print

Object. The authors examined the localization of language sites and the frequency of naming errors at these sites in a population of children undergoing electrical stimulation mapping during surgeries in which epileptic foci and dominant hemisphere neoplasms were resected. The frequency with which essential language sites were found (that is, “the frequency of language sites”) in children was compared with that of a population of adults who had undergone this procedure, to assess the relationship of age to the distribution of essential areas for language. Methods. The results of electrical stimulation mapping to determine sites of naming and speech arrest in 26 children ranging in ages from 4 to 16 years are presented in this report. Mapping was performed in the intraoperative setting in eight patients and in the extraoperative setting, by stimulation across a subdural grid, in 18 patients. The frequency and distribution of essential language areas were analyzed in populations of different ages and according to the method used to obtain the map. Considerable variability was found in the localization of language sites. When the language site distribution in pediatric patients was compared with the language site distribution found previously in a population of patients older than 16 years of age, a relative paucity of language sites was found in all perisylvian cortices in the younger age group. This relationship was also found within the group of patients 16 years of age and younger, when segregated into two groups: those patients 8 years of age or younger, and those patients between 9 and 16 years of age. These findings are relevant to theories of the intrahemispheric organization of the cortex devoted to language function. Conclusions. The differences found between groups of younger and older patients in the frequencies of sites where stimulation produces naming errors was identified suggests the possibility that, with advancing age, maturational processes contribute new foci of cortex essential for language.

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