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Sala F. Intraoperative neurophysiology in pediatric neurosurgery: a historical perspective. Childs Nerv Syst 2023; 39:2929-2941. [PMID: 37776333 PMCID: PMC10613152 DOI: 10.1007/s00381-023-06155-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 09/07/2023] [Indexed: 10/02/2023]
Abstract
INTRODUCTION Intraoperative neurophysiology (ION) has been established over the past three decades as a valuable discipline to improve the safety of neurosurgical procedures with the main goal of reducing neurological morbidity. Neurosurgeons have substantially contributed to the development of this field not only by implementing the use and refinement of ION in the operating room but also by introducing novel techniques for both mapping and monitoring of neural pathways. METHODS This review provides a personal perspective on the evolution of ION in a variety of pediatric neurosurgical procedures: from brain tumor to brainstem surgery, from spinal cord tumor to tethered cord surgery. RESULTS AND DISCUSSION The contribution of pediatric neurosurgeons is highlighted showing how our discipline has played a crucial role in promoting ION at the turn of the century. Finally, a view on novel ION techniques and their potential implications for pediatric neurosurgery will provide insights into the future of ION, further supporting the view of a functional, rather than merely anatomical, approach to pediatric neurosurgery.
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Affiliation(s)
- Francesco Sala
- Section of Neurosurgery, Department of Neurosciences, Biomedicine and Movement Sciences, University Hospital, Verona, Italy.
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2
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Nolan SO, Melugin PR, Erickson KR, Adams WR, Farahbakhsh ZZ, Mcgonigle CE, Kwon MH, Costa VD, Lapish CC, Hackett TA, Cuzon Carlson VC, Constantinidis C, Grant KA, Siciliano CA. Recurrent activity within microcircuits of macaque dorsolateral prefrontal cortex tracks cognitive flexibility. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.23.559125. [PMID: 38529503 PMCID: PMC10962741 DOI: 10.1101/2023.09.23.559125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/27/2024]
Abstract
Human and non-human primate data clearly implicate the dorsolateral prefrontal cortex (dlPFC) as critical for advanced cognitive functions 1,2 . It is thought that intracortical synaptic architectures within dlPFC are the integral neurobiological substrate that gives rise to these processes, including working memory, inferential reasoning, and decision-making 3-7 . In the prevailing model, each cortical column makes up one fundamental processing unit composed of dense intrinsic connectivity, conceptualized as the 'canonical' cortical microcircuit 3,8 . Each cortical microcircuit receives sensory and cognitive information from a variety of sources which are represented by sustained activity within the microcircuit, referred to as persistent or recurrent activity 4,9 . Via recurrent connections within the microcircuit, activity can propagate for a variable length of time, thereby allowing temporary storage and computations to occur locally before ultimately passing a transformed representation to a downstream output 4,5,10 . Competing theories regarding how microcircuit activity is coordinated have proven difficult to reconcile in vivo where intercortical and intracortical computations cannot be fully dissociated 5,9,11,12 . Here, we interrogated the intrinsic features of isolated microcircuit networks using high-density calcium imaging of macaque dlPFC ex vivo . We found that spontaneous activity is intrinsically maintained by microcircuit architecture, persisting at a high rate in the absence of extrinsic connections. Further, using perisulcal stimulation to evoke persistent activity in deep layers, we found that activity propagates through stochastically assembled intracortical networks, creating predictable population-level events from largely non-overlapping ensembles. Microcircuit excitability covaried with individual cognitive performance, thus anchoring heuristic models of abstract cortical functions within quantifiable constraints imposed by the underlying synaptic architecture.
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3
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Asimakidou E, Abut PA, Raabe A, Seidel K. Motor Evoked Potential Warning Criteria in Supratentorial Surgery: A Scoping Review. Cancers (Basel) 2021; 13:2803. [PMID: 34199853 PMCID: PMC8200078 DOI: 10.3390/cancers13112803] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 05/30/2021] [Accepted: 05/31/2021] [Indexed: 12/31/2022] Open
Abstract
During intraoperative monitoring of motor evoked potentials (MEP), heterogeneity across studies in terms of study populations, intraoperative settings, applied warning criteria, and outcome reporting exists. A scoping review of MEP warning criteria in supratentorial surgery was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). Sixty-eight studies fulfilled the eligibility criteria. The most commonly used alarm criteria were MEP signal loss, which was always a major warning sign, followed by amplitude reduction and threshold elevation. Irreversible MEP alterations were associated with a higher number of transient and persisting motor deficits compared with the reversible changes. In almost all studies, specificity and Negative Predictive Value (NPV) were high, while in most of them, sensitivity and Positive Predictive Value (PPV) were rather low or modest. Thus, the absence of an irreversible alteration may reassure the neurosurgeon that the patient will not suffer a motor deficit in the short-term and long-term follow-up. Further, MEPs perform well as surrogate markers, and reversible MEP deteriorations after successful intervention indicate motor function preservation postoperatively. However, in future studies, a consensus regarding the definitions of MEP alteration, critical duration of alterations, and outcome reporting should be determined.
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Affiliation(s)
- Evridiki Asimakidou
- Department of Neurosurgery, Inselspital, Bern University Hospital, 3010 Bern, Switzerland; (E.A.); (P.A.A.); (A.R.)
| | - Pablo Alvarez Abut
- Department of Neurosurgery, Inselspital, Bern University Hospital, 3010 Bern, Switzerland; (E.A.); (P.A.A.); (A.R.)
- Department of Neurosurgery, Clínica 25 de Mayo, 7600 Mar del Plata, Argentina
| | - Andreas Raabe
- Department of Neurosurgery, Inselspital, Bern University Hospital, 3010 Bern, Switzerland; (E.A.); (P.A.A.); (A.R.)
| | - Kathleen Seidel
- Department of Neurosurgery, Inselspital, Bern University Hospital, 3010 Bern, Switzerland; (E.A.); (P.A.A.); (A.R.)
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4
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Yang PF, Phipps MA, Jonathan S, Newton AT, Byun N, Gore JC, Grissom WA, Caskey CF, Chen LM. Bidirectional and state-dependent modulation of brain activity by transcranial focused ultrasound in non-human primates. Brain Stimul 2021; 14:261-272. [PMID: 33460838 PMCID: PMC7988301 DOI: 10.1016/j.brs.2021.01.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 11/19/2020] [Accepted: 01/08/2021] [Indexed: 01/10/2023] Open
Abstract
Transcranial focused ultrasound (FUS) stimulation under MRI guidance, coupled with functional MRI (fMRI) monitoring of effects, offers a precise, noninvasive technology to dissect functional brain circuits and to modulate altered brain functional networks in neurological and psychiatric disorders. Here we show that ultrasound at moderate intensities modulated neural activity bi-directionally. Concurrent sonication of somatosensory areas 3a/3b with 250 kHz FUS suppressed the fMRI signals produced there by peripheral tactile stimulation, while at the same time eliciting fMRI activation at inter-connected, off-target brain regions. Direct FUS stimulation of the cortex resulted in different degrees of BOLD signal changes across all five off-target regions, indicating that its modulatory effects on active and resting neurons differed. This is the first demonstration of the dual suppressive and excitative modulations of FUS on a specific functional circuit and of ability of concurrent FUS and MRI to evaluate causal interactions between functional circuits with neuron-class selectivity.
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Affiliation(s)
- Pai-Feng Yang
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - M Anthony Phipps
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA
| | - Sumeeth Jonathan
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA
| | - Allen T Newton
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Nellie Byun
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA
| | - John C Gore
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | - William A Grissom
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | - Charles F Caskey
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Li Min Chen
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.
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5
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Kramer DR, Lamorie-Foote K, Barbaro M, Lee MB, Peng T, Gogia A, Nune G, Liu CY, Kellis SS, Lee B. Utility and lower limits of frequency detection in surface electrode stimulation for somatosensory brain-computer interface in humans. Neurosurg Focus 2021; 48:E2. [PMID: 32006952 DOI: 10.3171/2019.11.focus19696] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Accepted: 11/04/2019] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Stimulation of the primary somatosensory cortex (S1) has been successful in evoking artificial somatosensation in both humans and animals, but much is unknown about the optimal stimulation parameters needed to generate robust percepts of somatosensation. In this study, the authors investigated frequency as an adjustable stimulation parameter for artificial somatosensation in a closed-loop brain-computer interface (BCI) system. METHODS Three epilepsy patients with subdural mini-electrocorticography grids over the hand area of S1 were asked to compare the percepts elicited with different stimulation frequencies. Amplitude, pulse width, and duration were held constant across all trials. In each trial, subjects experienced 2 stimuli and reported which they thought was given at a higher stimulation frequency. Two paradigms were used: first, 50 versus 100 Hz to establish the utility of comparing frequencies, and then 2, 5, 10, 20, 50, or 100 Hz were pseudorandomly compared. RESULTS As the magnitude of the stimulation frequency was increased, subjects described percepts that were "more intense" or "faster." Cumulatively, the participants achieved 98.0% accuracy when comparing stimulation at 50 and 100 Hz. In the second paradigm, the corresponding overall accuracy was 73.3%. If both tested frequencies were less than or equal to 10 Hz, accuracy was 41.7% and increased to 79.4% when one frequency was greater than 10 Hz (p = 0.01). When both stimulation frequencies were 20 Hz or less, accuracy was 40.7% compared with 91.7% when one frequency was greater than 20 Hz (p < 0.001). Accuracy was 85% in trials in which 50 Hz was the higher stimulation frequency. Therefore, the lower limit of detection occurred at 20 Hz, and accuracy decreased significantly when lower frequencies were tested. In trials testing 10 Hz versus 20 Hz, accuracy was 16.7% compared with 85.7% in trials testing 20 Hz versus 50 Hz (p < 0.05). Accuracy was greater than chance at frequency differences greater than or equal to 30 Hz. CONCLUSIONS Frequencies greater than 20 Hz may be used as an adjustable parameter to elicit distinguishable percepts. These findings may be useful in informing the settings and the degrees of freedom achievable in future BCI systems.
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Affiliation(s)
- Daniel R Kramer
- Departments of1Neurosurgery and.,2Neurorestoration Center, and
| | | | - Michael Barbaro
- 3Keck School of Medicine, University of Southern California, Los Angeles; and
| | - Morgan B Lee
- 3Keck School of Medicine, University of Southern California, Los Angeles; and
| | - Terrance Peng
- 3Keck School of Medicine, University of Southern California, Los Angeles; and
| | - Angad Gogia
- 3Keck School of Medicine, University of Southern California, Los Angeles; and
| | | | - Charles Y Liu
- Departments of1Neurosurgery and.,2Neurorestoration Center, and
| | - Spencer S Kellis
- 2Neurorestoration Center, and.,5Department of Biology and Biological Engineering and.,6Tianqiao and Chrissy Chen Brain-Machine Interface Center, California Institute of Technology, Pasadena, California
| | - Brian Lee
- Departments of1Neurosurgery and.,2Neurorestoration Center, and
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6
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Jahodová A, Beňová B, Kudr M, Ježdík P, Janča R, Bělohlávková A, Liby P, Leško R, Tichý M, Čelakovský P, Kršek P. A novel effective paradigm of intraoperative electrical stimulation mapping in children. J Neurosurg Pediatr 2020; 26:150-156. [PMID: 32302987 DOI: 10.3171/2020.2.peds19451] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 02/05/2020] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Resective epilepsy surgery is an established treatment method for children with focal intractable epilepsy, but the use of this method introduces the risk of postsurgical motor deficits. Electrical stimulation mapping (ESM), used to define motor areas and pathways, frequently fails in children. The authors developed and tested a novel ESM protocol in children of all age categories. METHODS The ESM protocol utilizes high-frequency electric cortical stimulation combined with continuous intraoperative motor-evoked potential (MEP) monitoring. The relationships between stimulation current intensity and selected presurgical and surgery-associated variables were analyzed in 66 children (aged 7 months to 18 years) undergoing 70 resective epilepsy surgeries in proximity to the motor cortex or corticospinal tracts. RESULTS ESM elicited MEP responses in all children. Stimulation current intensity was associated with patient age at surgery and date of surgery (F value = 6.81, p < 0.001). Increase in stimulation current intensity predicted postsurgical motor deficits (F value = 44.5, p < 0.001) without effects on patient postsurgical seizure freedom (p > 0.05). CONCLUSIONS The proposed ESM paradigm developed in our center represents a reliable method for preventing and predicting postsurgical motor deficits in all age groups of children. This novel ESM protocol may increase the safety and possibly also the completeness of epilepsy surgery. It could be adopted in pediatric epilepsy surgery centers.
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Affiliation(s)
| | | | | | | | - Radek Janča
- 4Circuit Theory, Faculty of Electrical Engineering, Czech Technical University in Prague, Czech Republic
| | | | - Petr Liby
- 3Neurosurgery, Second Faculty of Medicine and Motol University Hospital; and
| | - Róbert Leško
- 3Neurosurgery, Second Faculty of Medicine and Motol University Hospital; and
| | - Michal Tichý
- 3Neurosurgery, Second Faculty of Medicine and Motol University Hospital; and
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7
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Hyslop A, Duchowny M. Electrical stimulation mapping in children. Seizure 2020; 77:59-63. [DOI: 10.1016/j.seizure.2019.07.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 07/25/2019] [Accepted: 07/29/2019] [Indexed: 12/01/2022] Open
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8
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Pindrik J, Hoang N, Smith L, Halverson M, Wojnaroski M, McNally K, Gedela S, Ostendorf AP. Preoperative evaluation and surgical management of infants and toddlers with drug-resistant epilepsy. Neurosurg Focus 2019; 45:E3. [PMID: 30173613 DOI: 10.3171/2018.7.focus18220] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Despite perioperative risks, epilepsy surgery represents a legitimate curative or palliative treatment approach for children with drug-resistant epilepsy (DRE). Several factors characterizing infants and toddlers with DRE create unique challenges regarding optimal evaluation and management. Epilepsy surgery within children < 3 years of age has received moderate attention in the literature, including mainly case series and retrospective studies. This article presents a systematic literature review and explores multidisciplinary considerations for the preoperative evaluation and surgical management of infants and toddlers with DRE. METHODS The study team conducted a systematic literature review based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, targeting studies that investigated children < 3 years of age undergoing surgical treatment of DRE. Using the PubMed database, investigators selected peer-reviewed articles that reported seizure outcomes with or without developmental outcomes and/or perioperative complications. Studies were eliminated based on the following exclusion criteria: sample size < 5 patients; and inclusion of patients > 3 years of age, when demographic and outcomes data could not be separated from the cohort of patients < 3 years of age. RESULTS The study team identified 20 studies published between January 1990 and May 2017 that satisfied eligibility criteria. All selected studies represented retrospective reviews, observational studies, and uncontrolled case series. The compiled group of studies incorporated 465 patients who underwent resective or disconnective surgery (18 studies, 444 patients) or vagus nerve stimulator insertion (2 studies, 21 patients). Patient age at surgery ranged between 28 days and 36 months, with a mean of 16.8 months (1.4 years). DISCUSSION The study team provided a detailed summary of the literature review, focusing on the etiologies, preoperative evaluation, surgical treatments, seizure and developmental outcomes, and potential for functional recovery of infants and toddlers with DRE. Additionally, the authors discussed special considerations in this vulnerable age group from the perspective of multiple disciplines. CONCLUSIONS While presenting notable challenges, pediatric epilepsy surgery within infants and toddlers (children < 3 years of age) offers significant opportunities for improved seizure frequency, neuro-cognitive development, and quality of life. Successful evaluation and treatment of young children with DRE requires special consideration of multiple aspects related to neurological and physiological immaturity and surgical morbidity.
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Affiliation(s)
- Jonathan Pindrik
- 1Division of Pediatric Neurosurgery, Department of Neurosurgery.,2Department of Neurological Surgery, The Ohio State University College of Medicine; and
| | - Nguyen Hoang
- 2Department of Neurological Surgery, The Ohio State University College of Medicine; and
| | - Luke Smith
- 2Department of Neurological Surgery, The Ohio State University College of Medicine; and
| | - Mark Halverson
- 3Division of Pediatric Neuroradiology, Department of Radiology, and
| | - Mary Wojnaroski
- 4Section of Pediatric Psychology and Neuropsychology, Department of Pediatrics, Nationwide Children's Hospital
| | - Kelly McNally
- 4Section of Pediatric Psychology and Neuropsychology, Department of Pediatrics, Nationwide Children's Hospital
| | - Satyanarayana Gedela
- 5Division of Child Neurology, Department of Pediatrics, Nationwide Children's Hospital and The Ohio State University College of Medicine, Columbus, Ohio
| | - Adam P Ostendorf
- 5Division of Child Neurology, Department of Pediatrics, Nationwide Children's Hospital and The Ohio State University College of Medicine, Columbus, Ohio
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9
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Vrba J, Janca R, Blaha M, Jezdik P, Belohlavkova A, Krsek P, Vrba D. Modeling of Brain Tissue Heating Caused by Direct Cortical Stimulation for Assessing the Risk of Thermal Damage. IEEE Trans Neural Syst Rehabil Eng 2019; 27:440-449. [PMID: 30763244 DOI: 10.1109/tnsre.2019.2898253] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This paper aims to employ the numerical simulations to assess the risk of cellular damage during the application of a novel paradigm of electrical stimulation mapping (ESM) used in neurosurgery. The core principle of the paradigm is the use of short, high-intensity and high-frequency stimulation pulses. We developed a complex numerical model and performed coupled electro-thermal transient simulations. The model was optimized by incorporating ESM electrodes' resistance obtained during multiple intraoperative measurements and validated by comparing them with the results of temperature distribution measurement acquired by thermal imaging. The risk of heat-induced cellular damage was assessed by applying the Arrhenius equation integral on the computed time-dependent spatial distribution of temperature in the brain tissue. Our results suggest that the impact of the temperature increase during our novel ESM paradigm is thermally non-destructive. The presented simulation results match the previously published thermographic measurement and histopathological examination of the stimulated brain tissue and confirm the safety of the novel ESM.
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10
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Kramer DR, Kellis S, Barbaro M, Salas MA, Nune G, Liu CY, Andersen RA, Lee B. Technical considerations for generating somatosensation via cortical stimulation in a closed-loop sensory/motor brain-computer interface system in humans. J Clin Neurosci 2019; 63:116-121. [PMID: 30711286 DOI: 10.1016/j.jocn.2019.01.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 01/04/2019] [Accepted: 01/18/2019] [Indexed: 10/27/2022]
Abstract
Somatosensory feedback is the next step in brain computer interface (BCI). Here, we compare three cortical stimulating array modalities for generating somatosensory percepts in BCI. We compared human subjects with either a 64-channel "mini"-electrocorticography grid (mECoG; 1.2-mm diameter exposed contacts with 3-mm spacing, N = 1) over the hand area of primary somatosensory cortex (S1), or a standard grid (sECoG; 1.5-mm diameter exposed contacts with 1-cm spacing, N = 1), to generate artificial somatosensation through direct electrical cortical stimulation. Finally, we reference data in the literature from a patient implanted with microelectrode arrays (MEA) placed in the S1 hand area. We compare stimulation results to assess coverage and specificity of the artificial percepts in the hand. Using the mECoG array, hand mapping revealed coverage of 41.7% of the hand area versus 100% for the sECoG array, and 18.8% for the MEA. On average, stimulation of a single electrode corresponded to sensation reported in 4.42 boxes (range 1-11 boxes) for the mECoG array, 19.11 boxes (range 4-48 boxes) for the sECoG grid, and 2.3 boxes (range 1-5 boxes) for the MEA. Sensation in any box, on average, corresponded to stimulation from 2.65 electrodes (range 1-5 electrodes) for the mECoG grid, 3.58 electrodes for the sECoG grid (range 2-4 electrodes), and 11.22 electrodes (range 2-17 electrodes) for the MEA. Based on these findings, we conclude that mECoG grids provide an excellent balance between spatial cortical coverage of the hand area of S1 and high-density resolution.
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Affiliation(s)
- Daniel R Kramer
- Department of Neurosurgery, University of Southern California, Los Angeles, CA, USA.
| | - Spencer Kellis
- Department of Neurosurgery, University of Southern California, Los Angeles, CA, USA; Department of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA; Tianqiao and Chrissy Chen Brain-machine Interface Center, California Institute of Technology, Pasadena, CA, USA
| | - Michael Barbaro
- Department of Neurosurgery, University of Southern California, Los Angeles, CA, USA
| | - Michelle Armenta Salas
- Department of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA; Tianqiao and Chrissy Chen Brain-machine Interface Center, California Institute of Technology, Pasadena, CA, USA
| | - George Nune
- Department of Neurology, University of Southern California, Los Angeles, CA, USA
| | - Charles Y Liu
- Department of Neurosurgery, University of Southern California, Los Angeles, CA, USA; Department of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Richard A Andersen
- Department of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA; Tianqiao and Chrissy Chen Brain-machine Interface Center, California Institute of Technology, Pasadena, CA, USA
| | - Brian Lee
- Department of Neurosurgery, University of Southern California, Los Angeles, CA, USA; Department of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
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11
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Jain P, Whitney R, Strantzas S, McCoy B, Ochi A, Otsubo H, Snead OC, Weiss S, Donner E, Pang E, Sharma R, Viljoen A, Keller A, Drake JM, Rutka JT, Go C. Intra-operative cortical motor mapping using subdural grid electrodes in children undergoing epilepsy surgery evaluation and comparison with the conventional extra-operative motor mapping. Clin Neurophysiol 2018; 129:2642-2649. [DOI: 10.1016/j.clinph.2018.07.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 05/31/2018] [Accepted: 07/25/2018] [Indexed: 10/28/2022]
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12
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Janca R, Jezdik P, Jahodova A, Kudr M, Benova B, Celakovsky P, Zamecnik J, Komarek V, Liby P, Tichy M, Krsek P. Intraoperative Thermography of the Electrical Stimulation Mapping: A Safety Control Study. IEEE Trans Neural Syst Rehabil Eng 2018; 26:2126-2133. [PMID: 30475703 DOI: 10.1109/tnsre.2018.2871875] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A standard procedure for continuous intraoperative monitoring of the integrity of the corticospinal tracts by eliciting muscle responses is the electric stimulation mapping (ESM). However, standard ESM protocols are ineffective in 20% of young children. We have developed a novel, highly efficient paradigm consisting of short-time burst (30 ms) of high frequency (500 Hz) and high peak current (≤100 mA), which may cause local tissue overheating. The presented safety control study was therefore designed. The infrared thermography camera captured to-be-resected cortex of 13 patients in vivo during ESM. Thermograms were image processed to reveal discrete ESM thermal effect of currents from 10 to 100 mA. Peak 100 mA currents induced a maximal increase in temperature of 3.1 °C, 1.23±0.72 °C in average. The warming correlated with stimulating electrode resistance ( ). The measurement uncertainty was estimated ± 1.01 ºC for the most skeptical conditions. The histopathological evaluation of stimulated tissue (performed in all cases) did not show any destructive changes. Our study demonstrates the ability of the thermographic camera to measure the discrete thermal effect of the ESM. The results provide evidence for the safety of the proposed protocol for full range currents with minimal risk of brain tissue damage.
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13
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Lee B, Kramer D, Armenta Salas M, Kellis S, Brown D, Dobreva T, Klaes C, Heck C, Liu C, Andersen RA. Engineering Artificial Somatosensation Through Cortical Stimulation in Humans. Front Syst Neurosci 2018; 12:24. [PMID: 29915532 PMCID: PMC5994581 DOI: 10.3389/fnsys.2018.00024] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 05/04/2018] [Indexed: 11/22/2022] Open
Abstract
Sensory feedback is a critical aspect of motor control rehabilitation following paralysis or amputation. Current human studies have demonstrated the ability to deliver some of this sensory information via brain-machine interfaces, although further testing is needed to understand the stimulation parameters effect on sensation. Here, we report a systematic evaluation of somatosensory restoration in humans, using cortical stimulation with subdural mini-electrocorticography (mini-ECoG) grids. Nine epilepsy patients undergoing implantation of cortical electrodes for seizure localization were also implanted with a subdural 64-channel mini-ECoG grid over the hand area of the primary somatosensory cortex (S1). We mapped the somatotopic location and size of receptive fields evoked by stimulation of individual channels of the mini-ECoG grid. We determined the effects on perception by varying stimulus parameters of pulse width, current amplitude, and frequency. Finally, a target localization task was used to demonstrate the use of artificial sensation in a behavioral task. We found a replicable somatotopic representation of the hand on the mini-ECoG grid across most subjects during electrical stimulation. The stimulus-evoked sensations were usually of artificial quality, but in some cases were more natural and of a cutaneous or proprioceptive nature. Increases in pulse width, current strength and frequency generally produced similar quality sensations at the same somatotopic location, but with a perception of increased intensity. The subjects produced near perfect performance when using the evoked sensory information in target acquisition tasks. These findings indicate that electrical stimulation of somatosensory cortex through mini-ECoG grids has considerable potential for restoring useful sensation to patients with paralysis and amputation.
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Affiliation(s)
- Brian Lee
- Department of Neurological Surgery, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, United States.,USC Neurorestoration Center, Keck School of Medicine of USC, Los Angeles, CA, United States
| | - Daniel Kramer
- Department of Neurological Surgery, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, United States.,USC Neurorestoration Center, Keck School of Medicine of USC, Los Angeles, CA, United States
| | - Michelle Armenta Salas
- Department of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Spencer Kellis
- USC Neurorestoration Center, Keck School of Medicine of USC, Los Angeles, CA, United States.,Department of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
| | - David Brown
- Department of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Tatyana Dobreva
- Department of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Christian Klaes
- Department of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Christi Heck
- Department of Neurology, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, United States
| | - Charles Liu
- Department of Neurological Surgery, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, United States.,USC Neurorestoration Center, Keck School of Medicine of USC, Los Angeles, CA, United States
| | - Richard A Andersen
- Department of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States.,Tianqiao and Chrissy Chen Brain-Machine Interface Center, Chen Institute for Neuroscience, California Institute of Technology, Pasadena, CA, United States
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14
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Yang PF, Phipps MA, Newton AT, Chaplin V, Gore JC, Caskey CF, Chen LM. Neuromodulation of sensory networks in monkey brain by focused ultrasound with MRI guidance and detection. Sci Rep 2018; 8:7993. [PMID: 29789605 PMCID: PMC5964220 DOI: 10.1038/s41598-018-26287-7] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 05/08/2018] [Indexed: 01/16/2023] Open
Abstract
Focused ultrasound (FUS) has gained recognition as a technique for non-invasive neuromodulation with high spatial precision and the ability to both excite and inhibit neural activity. Here we demonstrate that MRI-guided FUS is capable of exciting precise targets within areas 3a/3b in the monkey brain, causing downstream activations in off-target somatosensory and associated brain regions which are simultaneously detected by functional MRI. The similarity between natural tactile stimulation-and FUS- evoked fMRI activation patterns suggests that FUS likely can excite populations of neurons and produce associated spiking activities that may be subsequently transmitted to other functionally related touch regions. The across-region differences in fMRI signal changes relative to area 3a/3b between tactile and FUS conditions also indicate that FUS modulated the tactile network differently. The significantly faster rising (>1 sec) fMRI signals elicited by direct FUS stimulation at the targeted cortical region suggest that a different neural hemodynamic coupling mechanism may be involved in generating fMRI signals. This is the first demonstration of imaging neural excitation effects of FUS with BOLD fMRI on a specific functional circuit in non-human primates.
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Affiliation(s)
- Pai-Feng Yang
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - M Anthony Phipps
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - Allen T Newton
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - Vandiver Chaplin
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - John C Gore
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - Charles F Caskey
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.
- Vanderbilt University Institute of Imaging Science, Nashville, TN, USA.
| | - Li Min Chen
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.
- Vanderbilt University Institute of Imaging Science, Nashville, TN, USA.
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15
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Murrone D, Maduri R, Afif A, Chirchiglia D, Pelissou-Guyotat I, Guyotat J, Signorelli F. Insular gliomas: a surgical reappraisal based on a systematic review of the literature. J Neurosurg Sci 2017; 63:566-580. [PMID: 28548479 DOI: 10.23736/s0390-5616.17.04045-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
INTRODUCTION Insular gliomas are heterogeneous lesions whose management presents multiple challenges for their tendency to affect young patients in good neurological and cognitive conditions, their deep anatomic location and proximity with critical functional and vascular structures. The appropriate management of insular gliomas requires a multidisciplinary evidence-centred teamwork grounded on the best anatomic, neurophysiological and oncological knowledge. The present study provides a reappraisal of the management of insular gliomas based on a systematic review of the literature with the aim of guiding clinicians in the management of such tumors. EVIDENCE ACQUISITION A systematic review of the literature from the Medline, Embase and Cochrane Central databases was performed. From 2006 to 2016, all articles meeting specific inclusion criteria were included. EVIDENCE SYNTHESIS The present work summarizes the most relevant evidence about insular gliomas management. The anatomy and physiology of the insula, the new WHO 2016 classification and clinico-radiological presentation of insular gliomas are reviewed. Surgical pearls of insular gliomas resection as well as oncologic and functional outcomes after insular gliomas treatment are discussed. CONCLUSIONS Management of insular gliomas remains challenging despite improvement in surgical and oncological techniques. However, the literature review supports a growing evidence that recent developments in the multidisciplinary care account for constant improvements of survival and quality of life.
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Affiliation(s)
- Domenico Murrone
- Service of Neurosurgery, "Di Venere" Hospital of Bari, Bari, Italy
| | - Rodolfo Maduri
- Department of Clinical Neurosciences, Service of Neurosurgery, University Hospital of Lausanne (CHUV), Lausanne, Switzerland
| | - Afif Afif
- Service of Neurosurgery A, "Pierre Wertheimer" Neurological Neurosurgical Hospital of Lyon, Lyon, France
| | - Domenico Chirchiglia
- Department of Medical Sciences, "Magna Græcia" University of Catanzaro, Catanzaro, Italy
| | - Isabelle Pelissou-Guyotat
- Service of Neurosurgery A, "Pierre Wertheimer" Neurological Neurosurgical Hospital of Lyon, Lyon, France
| | - Jacques Guyotat
- Service of Neurosurgery A, "Pierre Wertheimer" Neurological Neurosurgical Hospital of Lyon, Lyon, France
| | - Francesco Signorelli
- Department of Basic Medical Sciences, Neurosciences and Sense Organs "Aldo Moro" University, Bari, Italy -
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Park JT, Baca Vaca GF, Avery J, Miller JP. Utility of Stereoelectroencephalography in Children with Dysembryoplastic Neuroepithelial Tumor and Cortical Malformation. Neurodiagn J 2017; 57:191-210. [PMID: 28898173 DOI: 10.1080/21646821.2017.1326270] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
BACKGROUND Uncontrolled seizures in children can contribute to irreversible cognitive impairment and developmental delay, in addition to placing them at risk for sudden unexplained death in epileptic patients (SUDEP). Since its introduction at Saint Ann Hospital in Paris in the 1960s, stereoelectroencephalography (SEEG) is increasingly being utilized at epilepsy centers in the United States as an invasive tool to help localize the seizure focus in drug-resistant focal epilepsy. INDICATIONS Children with symptomatic epilepsy, commonly due to cortical dysplasia and dysembryoplastic neuroepithelial tumor (DNET), may benefit from SEEG investigation. The arrangement of SEEG electrodes is individually tailored based on the suspected location of the epileptogenic zone (EZ). The implanted depth electrodes are used to electrically stimulate the corresponding cortices to obtain information about the topography of eloquent cortex and EZ. Morbidity: Surgical morbidity in these children undergoing SEEG investigation is low, but not negligible. The number of electrodes directly correlates with the risk of intraoperative complication. Thus a risk and benefit analysis needs to be carefully considered for each patient. Neurodiagnostic technology: Both during and after the SEEG electrode implantation, the intraoperative monitoring and EEG technologists play a vital role in the successful monitoring of the patient. CONCLUSION SEEG is an important tool in the process of epilepsy surgery in children with symptomatic epilepsy, commonly due to cortical dysplasia and DNET.
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Affiliation(s)
- Jun T Park
- a Epilepsy Center , Cleveland University Hospitals , Cleveland , Ohio
- b Case Western Reserve University School of Medicine , Cleveland , Ohio
| | - Guadalupe Fernandez Baca Vaca
- a Epilepsy Center , Cleveland University Hospitals , Cleveland , Ohio
- b Case Western Reserve University School of Medicine , Cleveland , Ohio
| | - Jennifer Avery
- a Epilepsy Center , Cleveland University Hospitals , Cleveland , Ohio
| | - Jonathan P Miller
- a Epilepsy Center , Cleveland University Hospitals , Cleveland , Ohio
- b Case Western Reserve University School of Medicine , Cleveland , Ohio
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Abstract
First-line treatment for epilepsy is antiepileptic drug and requires an interdisciplinary approach and enduring commitment and adherence from the patient and family for successful outcome. Despite adherence to antiepileptic drugs, refractory epilepsy occurs in approximately 30% of children with epilepsy, and surgical treatment is an important intervention to consider. Surgical management of pediatric epilepsy is highly effective in selected patients with refractory epilepsy; however, an evidence-based protocol, including best methods of presurgical imaging assessments, and neurodevelopmental and/or behavioral health assessments, is not currently available for clinicians. Surgical treatment of epilepsy can be critical to avoid negative outcomes in functional, cognitive, and behavioral health status. Furthermore, it is often the only method to achieve seizure freedom in refractory epilepsy. Although a large literature base can be found for adults with refractory epilepsy undergoing surgical treatment, less is known about how surgical management affects outcomes in children with epilepsy. The purpose of the review was fourfold: (1) to evaluate the available literature regarding presurgical assessment and postsurgical outcomes in children with medically refractory epilepsy, (2) to identify gaps in our knowledge of surgical treatment and its outcomes in children with epilepsy, (3) to pose questions for further research, and (4) to advocate for a more unified presurgical evaluation protocol including earlier referral for surgical candidacy of pediatric patients with refractory epilepsy. Despite its effectiveness, epilepsy surgery remains an underutilized but evidence-based approach that could lead to positive short- and long-term outcomes for children with refractory epilepsy.
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18
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Awake surgery for hemispheric low-grade gliomas: oncological, functional and methodological differences between pediatric and adult populations. Childs Nerv Syst 2016; 32:1861-74. [PMID: 27659829 DOI: 10.1007/s00381-016-3069-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Accepted: 03/14/2016] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Brain mapping through a direct cortical and subcortical electrical stimulation during an awake craniotomy has gained an increasing popularity as a powerful tool to prevent neurological deficit while increasing extent of resection of hemispheric diffuse low-grade gliomas in adults. However, few case reports or very limited series of awake surgery in children are currently available in the literature. METHODS In this paper, we review the oncological and functional differences between pediatric and adult populations, and the methodological specificities that may limit the use of awake mapping in pediatric low-grade glioma surgery. RESULTS This could be explained by the fact that pediatric low-grade gliomas have a different epidemiology and biologic behavior in comparison to adults, with pilocytic astrocytomas (WHO grade I glioma) as the most frequent histotype, and with WHO grade II gliomas less prone to anaplastic transformation than their adult counterparts. In addition, aside from the issue of poor collaboration of younger children under 10 years of age, some anatomical and functional peculiarities of children developing brain (cortical and subcortical myelination, maturation of neural networks and of specialized cortical areas) can influence direct electrical stimulation methodology and sensitivity, limiting its use in children. CONCLUSIONS Therefore, even though awake procedure with cortical and axonal stimulation mapping can be adapted in a specific subgroup of children with a diffuse glioma from the age of 10 years, only few pediatric patients are nonetheless candidates for awake brain surgery.
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Language mapping in temporal lobe epilepsy in children: special considerations. EPILEPSY RESEARCH AND TREATMENT 2012; 2012:837036. [PMID: 22957246 PMCID: PMC3420711 DOI: 10.1155/2012/837036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Accepted: 11/06/2011] [Indexed: 02/01/2023]
Abstract
Temporal lobe epilepsy (TLE) in children is a slightly different entity than TLE in adults not only because of its semiology and pathology but also because of the different approach to surgical treatment. Presurgical investigations for eloquent cortex, especially language, must take these differences into account. Most diagnostic tests were created for adults, and many of the assessment tools need to be adapted for children because they are not just small adults. This paper will highlight the specific challenges and solutions in mapping language in a pediatric population with TLE.
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Sala F, Manganotti P, Grossauer S, Tramontanto V, Mazza C, Gerosa M. Intraoperative neurophysiology of the motor system in children: a tailored approach. Childs Nerv Syst 2010; 26:473-90. [PMID: 20145936 DOI: 10.1007/s00381-009-1081-6] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Accepted: 12/30/2009] [Indexed: 10/19/2022]
Abstract
INTRODUCTION Intraoperative neurophysiology has moved giant steps forward over the past 15 years thanks to the advent of techniques aimed to reliably assess the functional integrity of motor areas and pathways. INTRAOPERATIVE NEUROPHYSIOLOGICAL TECHNIQUES Motor evoked potentials recorded from the muscles and/or the spinal cord (D-wave) after transcranial electrical stimulation allow to preserve the integrity of descending pathways, especially the corticospinal tract (CT), during brain and spinal cord surgery. Mapping techniques allow to identify the motor cortex through direct cortical stimulation and to localize the CT at subcortical levels during brain and brainstem surgery. These techniques are extensively used in adult neurosurgery and, in their principles, can be applied to children. However, especially in younger children, the motor system is still under development, making both mapping and monitoring techniques more challenging. In this paper, we review intraoperative neurophysiological techniques commonly used in adult neurosurgery and discuss their application to pediatric neurosurgery, in the light of preliminary experience from our and other centers. The principles of development and maturation of the motor system, and especially of the CT, are reviewed focusing on clinical studies with transcranial magnetical stimulation.
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Affiliation(s)
- Francesco Sala
- Section of Neurosurgery, Department of Neurological and Visual Sciences, University Hospital, Piazzale Stefani 1, 37124 Verona, Italy.
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Gallentine WB, Mikati MA. Intraoperative electrocorticography and cortical stimulation in children. J Clin Neurophysiol 2009; 26:95-108. [PMID: 19279495 DOI: 10.1097/wnp.0b013e3181a0339d] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Intraoperative electrocorticography has been used in the surgical management of children with medically refractory epilepsy to localize anatomic areas of focal seizure onset, guide the extent, and completeness of resective epilepsy surgery, aid in functional mapping of cortical anatomy, and predict epilepsy surgical outcome. Evidence to support its utility for these purposes is somewhat controversial, particularly in children where the literature is substantially lacking. Usefulness is often dependent on the underlying pathology, and type of resective surgery. It seems to be valuable in the following circumstances: (1) tailoring the extent of hippocampal resection during temporal lobectomies, (2) guiding resection of cortical brain malformations, low-grade tumors, and other neocortical lesions, especially those involving eloquent cortex, and (3) monitoring for afterdischarges during functional cortical mapping. Most literature on this topic is not purely pediatric, and in most circumstances, is the result of combination of both children and adults cases. Cortical stimulation has been shown to be a useful, reliable and safe technique to assess motor, sensory, and speech function in children. As compared with adults, children manifest the following: (1) they need higher Amperage thresholds to elicit responses. In children younger than 10 years, cortical stimulation identifies language cortex at a lower rate than in children older than 10 years or in adults. (2) They have variability within the same individual in the stimulation threshold depending on the cortical site. This often results in the need to maximize stimulation of currents at each cortical site regardless of adjacent afterdischarge threshold. (3) They demonstrate more difficultly to evoke motor responses particularly with certain pathologies such as retrorolandic low-grade tumors. Often also the effective current intensity decreases after lesion removal. As a consequence of the above, the pulse width used for cortical stimulation in children often varies between 0.14 and 200 ms, the frequency ranges between 20 and 50 Hz, the current intensity between 0.5 and 20 mA, and the train between 3 and 25 seconds. Cortical stimulation can identify cortex with reorganized function secondary to congenital lesions and cerebral plasticity. These lesions include brain tumors, cortical dysplasia resulting in intractable epilepsy, and cavernous angioma causing epilepsy. When compared with other presurgical tests, cortical stimulation was shown to have results consistent with those of functional magnetic resonance imaging and Wada testing. It has the disadvantage of being invasive but the advantage of being highly accurate allowing for surgical tailored resections. Although the evidence for the utility of electrocorticography and cortical stimulation is exclusively level IV evidence, it is unlikely that randomized studies are going to be performed due to practical, ethical, and other reasons. The weight of the uncontrolled data at this stage is such that in children electrocorticography remains to be a useful test in some cases of cortical resection and that cortical stimulation is usually indicated when resection in or near eloquent cortex is needed.
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Affiliation(s)
- William B Gallentine
- Division of Pediatric Neurology, Duke University Medical Center, Durham, North Carolina, USA
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22
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Schevon CA, Carlson C, Zaroff CM, Weiner HJ, Doyle WK, Miles D, Lajoie J, Kuzniecky R, Pacia S, Vazquez B, Luciano D, Najjar S, Devinsky O. Pediatric Language Mapping: Sensitivity of Neurostimulation and Wada Testing in Epilepsy Surgery. Epilepsia 2007; 48:539-45. [PMID: 17284300 DOI: 10.1111/j.1528-1167.2006.00962.x] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE Functional mapping of eloquent cortex with electrical neurostimulation is used both intra- and extraoperatively to tailor resections. In pediatric patients, however, functional mapping studies frequently fail to localize language. Wada testing has also been reported to be less sensitive in children. METHODS Thirty children (4.7 - 14.9 years) and 18 adult controls (18-59 years) who underwent extraoperative language mapping via implanted subdural electrodes at the NYU Comprehensive Epilepsy Center were included in the study. Ten children and 14 adults underwent preoperative Wada testing. Success of the procedures was defined as the identification of at least one language site by neurostimulation mapping and determination of hemispheric language dominance on the Wada test. RESULTS In children younger than 10.2 years, cortical stimulation identified language cortex at a lower rate than was seen in children older than 10.2 years and in adults (p<0.05). This threshold, demonstrated by survival and chi2 analysis, was sharply defined in our data set. Additionally, Wada testing was more likely to be successful than was extraoperative mapping in this younger age group (p<0.05). CONCLUSIONS Analysis of our series demonstrates that language cortex is less likely to be identified in children younger than 10 years, suggesting that alternatives to the current methods of cortical electrical stimulation, particularly the use of preoperative language lateralization, may be required in this age group.
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Affiliation(s)
- Catherine A Schevon
- Comprehensive Epilepsy Center, Neurological Institute of New York, Columbia College of Physicians and Surgeons, New York, NY, USA.
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Duffau H. New concepts in surgery of WHO grade II gliomas: functional brain mapping, connectionism and plasticity – a review. J Neurooncol 2006; 79:77-115. [PMID: 16607477 DOI: 10.1007/s11060-005-9109-6] [Citation(s) in RCA: 161] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2005] [Accepted: 12/21/2005] [Indexed: 10/24/2022]
Abstract
Despite a recent literature supporting the impact of surgery on the natural history of low-grade glioma (LGG), the indications of resection still remain a matter of debate, especially because of the frequent location of these tumors within eloquent brain areas - thus with a risk to induce a permanent postoperative deficit. Therefore, since the antagonist nature of this surgery is to perform the most extensive glioma removal possible, while preserving the function and the quality of life, new concepts were recently applied to LGG resection in order to optimize the benefit/risk ratio of the surgery.First, due to the development of functional mapping methods, namely perioperative neurofunctional imaging and intrasurgical direct electrical stimulation, the study of cortical functional organization is currently possible for each patient - in addition to an extensive neuropsychological assessment. Such knowledge is essential because of the inter-individual anatomo-functional variability, increased in tumors due to cerebral plasticity phenomena. Thus, brain mapping enables to envision and perform a resection according to individual functional boundaries.Second, since LGG invades not only cortical but also subcortical structures, and shows an infiltrative progression along the white matter tracts, new techniques of anatomical tracking and functional mapping of the subcortical white matter pathways were also used with the goal to study the individual effective connectivity - which needs imperatively to be preserved during the resection.Third, the better understanding of brain plasticity mechanisms, induced both by the slow-growing LGG and by the surgery itself, were equally studied in each patient and applied to the surgical strategy by incorporating individual dynamic potential of reorganization into the operative planning. The integration of these new concepts of individual functional mapping, connectivity and plastic potential to the surgery of LGG has allowed an extent of surgical indications, an optimization of the quality of resection (neuro-oncological benefit), and a minimization of the risk of sequelae (benefit on the quality of life). In addition, such a strategy has also fundamental applications, since it represents a new door to the connectionism and cerebral plasticity.
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Affiliation(s)
- Hugues Duffau
- Department of Neurosurgery, UMR-S678 Inserm, Hôpital Salpêtrière, Paris, France
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