Continuous somatosensory evoked potential monitoring during brain tumor resection

2002 ◽  
Vol 97 (3) ◽  
pp. 709-713 ◽  
Author(s):  
Gerald A. Grant ◽  
Donald Farrell ◽  
Daniel L. Silbergeld
Keyword(s):  
Brain Tumor ◽  
Functional Assessment ◽  
Evoked Potential ◽  
Tumor Resection ◽  
Extent Of Resection ◽  
Content Type ◽  
Case Examples ◽  
Brain Tumor Resection ◽  
Evoked Potential Monitoring ◽  
Fine Print

✓ The neurosurgical management of intrinsic brain tumors and brain metastases mandates maximum resection with preservation of functional cortex. There have been previous reports on the use of cortical somatosensory evoked potentials (SSEPs) for localization of functional cortex prior to resection. The identification of rolandic cortex with the use of intraoperative SSEP monitoring enables the neurosurgeon to tailor the surgery to achieve a greater extent of resection while minimizing the risk of morbidity. The use of continuous SSEP monitoring during resection to provide an ongoing functional assessment of somatosensory cortex has not been reported. This powerful technique is illustrated using four case examples.

Current neurosurgical management and the impact of the extent of resection in the treatment of malignant gliomas of childhood: a report of the Children's Cancer Group Trial No. CCG-945

1998 ◽  
Vol 89 (1) ◽  
pp. 52-59 ◽  
Author(s):  
Jeffrey H. Wisoff ◽  
James M. Boyett ◽  
Mitchel S. Berger ◽  
Catherine Brant ◽  
Hao Li ◽  
...  
Keyword(s):  
Glioblastoma Multiforme ◽  
Posterior Fossa ◽  
Anaplastic Astrocytoma ◽  
Tumor Resection ◽  
Radical Resection ◽  
Extent Of Resection ◽  
Total Resection ◽  
Content Type ◽  
Cancer Group ◽  
Fine Print

Object. One hundred seventy-two children with high-grade astrocytomas were treated by members of the Children's Cancer Group in a prospective randomized trial designed to evaluate the role of two chemotherapy regimens. Seventy-six percent of the patients (131 children) in whom a diagnosis of either anaplastic astrocytoma or glioblastoma multiforme was confirmed by central pathological review are the subject of this report. Methods. Patients were stratified according to the extent of tumor resection (biopsy [< 10%], partial resection [10–50%], subtotal resection [51–90%], near-total resection [> 90%], and total resection) as determined by surgical observation and postoperative computerized tomography scanning. Information on contemporary neurosurgical management was obtained from the patient's operative records and standardized neurosurgical report forms. The vast majority of tumors were supratentorial: 63% (83 tumors) in the superficial cerebral hemisphere, 28% (37 tumors) in the deep or midline cerebrum, and only 8% (11 tumors) in the posterior fossa. A significant association was detected between the primary tumor site and the extent of resection (p < 0.0001). A radical resection (> 90%) was performed in 37% of the children: 49% of the tumors in the superficial hemisphere and 45% of tumors in the posterior fossa compared with 8% of midline tumors. Tumor location could also be used to predict the need for both temporary and permanent cerebrospinal fluid (CSF) diversion. Half of the deep tumors and 8% of the hemispheric astrocytomas ultimately required a permanent CSF shunt. Improvement in preoperative neurological deficits and level of consciousness was seen in 36% and 34% of the children, respectively. New or increased deficits were present in 14% of the children, with 6% experiencing a diminished sensorium after surgery. Postoperative nonneurological complications were rare: infection, hematoma, and CSF fistula each occurred in 1.7% of the children. Univariate and multivariate analyses demonstrated that radical tumor resection (> 90%) was the only therapeutic variable that significantly improved progression-free survival (PFS) rates. For all patients with malignant astrocytomas, the distributions of PFS rates were significantly different (p = 0.006) following radical resection compared with less extensive (< 90%) resection. The 5-year PFS rates were 35 ± 7% and 17 ± 4%, respectively. The differences in the distribution of PFS rate were significant for the subsets of patients with anaplastic astrocytoma (p = 0.055) and glioblastoma multiforme (p = 0.046). The 5-year PFS rates for anaplastic astrocytoma were 44 ± 11% and 22 ± 6% for cases in which the tumor was radically resected and less than radically resected, respectively; whereas the 5-year PFS rates for glioblastoma multiforme were 26 ± 9% and 4 ± 3% for cases in which the tumor was radically resected and less than radically resected, respectively. Conclusions. The demonstration of a survival advantage provided by radical resection should prompt neurosurgeons to treat malignant pediatric astrocytomas with aggressive surgical resection prior to initiation of radiotherapy or adjuvant chemotherapy.

Transcranial Electrical Motor Evoked Potential Monitoring for Brain Tumor Resection

Neurosurgery ◽  
2001 ◽  
Vol 48 (5) ◽  
pp. 1075-1081 ◽  
Author(s):  
Henry H. Zhou ◽  
Patrick J. Kelly
Keyword(s):  
Brain Tumor ◽  
Evoked Potential ◽  
Tumor Resection ◽  
Motor Evoked Potential ◽  
Motor Deficits ◽  
Tumor Surgery ◽  
Brain Tumor Surgery ◽  
Stimulation Intensity ◽  
Potential System ◽  
Brain Tumor Resection

Abstract OBJECTIVE This study was designed to examine whether transcranial electrical motor evoked potential (MEP) monitoring is safe, feasible, and valuable for brain tumor surgery. METHODS Fifty consecutive patients undergoing brain tumor resection were studied, using nitrous oxide/propofol anesthesia. MEPs were continuously recorded throughout surgery, using a Sentinel 4 evoked potential system (Axon Systems, Inc., Hauppauge, NY). The MEPs were elicited by transcranial electrical stimulation (train of 5; stimulation rate, 0.5–2 Hz; square wave pulse with a time constant of 0.5 ms; stimulation intensity, 40–160 mA) through spiral electrodes placed over the primary motor cortex and were recorded by needle electrodes inserted into the contralateral orbicularis oris, biceps, abductor pollicis brevis, and anterior tibialis muscles. When MEP amplitudes decreased by more than 50%, MEP stimulation was repeated, with increased stimulation intensity, and MEP changes were reported to the surgeon. The motor function of each patient was examined before and after surgery, using a reproducible scale. The relationship between MEP amplitude decreases and worsening motor status was analyzed using linear regression. RESULTS Preoperative neurological examinations revealed mild to moderate motor deficits (2/5 to 4/5) for 38% of patients (19 of 50 patients). Most of the patients (96%) exhibited recordable baseline MEPs. Persistent MEP decreases of more than 50% were noted for eight patients (16%) (11 muscles). The MEPs were completely abolished in two patients (three muscles). The degree of postoperative worsening of motor status was correlated with the degree of intraoperative MEP amplitude reduction (r = −0.864; P &lt; 0.001). CONCLUSION Persistent intraoperative MEP reductions of more than 50% were associated with postoperative motor deficits. The degree of MEP amplitude reduction was correlated with postoperative worsening of motor status. Transcranial electrical MEP monitoring is feasible, safe, and valuable for brain tumor surgery.

scholarly journals Intraoperative infrared imaging of brain tumors

2004 ◽  
Vol 101 (6) ◽  
pp. 960-969 ◽  
Author(s):  
Alexander M. Gorbach ◽  
John D. Heiss ◽  
Leonid Kopylev ◽  
Edward H. Oldfield
Keyword(s):  
Blood Flow ◽  
Brain Tumor ◽  
Brain Tumors ◽  
Infrared Imaging ◽  
Tumor Resection ◽  
Temperature Gradients ◽  
Temporal Lobectomy ◽  
Neurological Deficits ◽  
Content Type ◽  
Fine Print

Object. Although clinical imaging defines the anatomical relationship between a brain tumor and the surrounding brain and neurological deficits indicate the neurophysiological consequences of the tumor, the effect of a brain tumor on vascular physiology is less clear. Methods. An infrared camera was used to measure the temperature of the cortical surface before, during, and after removal of a mass in 34 patients (primary brain tumor in 21 patients, brain metastases in 10 and falx meningioma, cavernous angioma, and radiation necrosis—astrocytosis in one patient each). To establish the magnitude of the effect on blood flow induced by the tumor, the images were compared with those from a group of six patients who underwent temporal lobectomy for epilepsy. In four cases a cerebral artery was temporarily occluded during the course of the surgery and infrared emissions from the cortex before and after occlusion were compared to establish the relationship of local temperature to regional blood flow. Discrete temperature gradients were associated with surgically verified lesions in all cases. Depending on the type of tumor, the cortex overlying the tumor was either colder or warmer than the surrounding cortex. Spatial reorganization of thermal gradients was observed after tumor resection. Temperature gradients of the cortex in patients with tumors exceeded those measured in the cortex of patients who underwent epilepsy surgery. Conclusions. Brain tumors induce changes in cerebral blood flow (CBF) in the cortex, which can be made visible by performing infrared imaging during cranial surgery. A reduction in CBF beyond the tumor margin improves after removal of the lesion.

Surgical resection of intrinsic insular tumors: complication avoidance

2001 ◽  
Vol 95 (4) ◽  
pp. 638-650 ◽  
Author(s):  
Frederick F. Lang ◽  
Nancy E. Olansen ◽  
Franco DeMonte ◽  
Ziya L. Gokaslan ◽  
Eric C. Holland ◽  
...  
Keyword(s):  
Surgical Resection ◽  
Tumor Resection ◽  
Extent Of Resection ◽  
Neurological Complications ◽  
Surgical Anatomy ◽  
Motor Dysfunction ◽  
Temporal Lobectomy ◽  
Content Type ◽  
Frontal Operculum ◽  
Fine Print

Object. Surgical resection of tumors located in the insular region is challenging for neurosurgeons, and few have published their surgical results. The authors report their experience with intrinsic tumors of the insula, with an emphasis on an objective determination of the extent of resection and neurological complications and on an analysis of the anatomical characteristics that can lead to suboptimal outcomes. Methods. Twenty-two patients who underwent surgical resection of intrinsic insular tumors were retrospectively identified. Eight tumors (36%) were purely insular, eight (36%) extended into the temporal pole, and six (27%) extended into the frontal operculum. A transsylvian surgical approach, combined with a frontal opercular resection or temporal lobectomy when necessary, was used in all cases. Five of 13 patients with tumors located in the dominant hemisphere underwent craniotomies while awake. The extent of tumor resection was determined using volumetric analyses. In 10 patients, more than 90% of the tumor was resected; in six patients, 75 to 90% was resected; and in six patients, less than 75% was resected. No patient died within 30 days after surgery. During the immediate postoperative period, the neurological conditions of 14 patients (64%) either improved or were unchanged, and in eight patients (36%) they worsened. Deficits included either motor or speech dysfunction. At the 3-month follow-up examination, only two patients (9%) displayed permanent deficits. Speech and motor dysfunction appeared to result most often from excessive opercular retraction and manipulation of the middle cerebral artery (MCA), interruption of the lateral lenticulostriate arteries (LLAs), interruption of the long perforating vessels of the second segment of the MCA (M2), or violation of the corona radiata at the superior aspect of the tumor. Specific methods used to avoid complications included widely splitting the sylvian fissure and identifying the bases of the periinsular sulci to define the superior and inferior resection planes, identifying early the most lateral LLA to define the medial resection plane, dissecting the MCA before tumor resection, removing the tumor subpially with preservation of all large perforating arteries arising from posterior M2 branches, and performing craniotomy with brain stimulation while the patient was awake. Conclusions. A good understanding of the surgical anatomy and an awareness of potential pitfalls can help reduce neurological complications and maximize surgical resection of insular tumors.

A multivariate analysis of 416 patients with glioblastoma multiforme: prognosis, extent of resection, and survival

2001 ◽  
Vol 95 (2) ◽  
pp. 190-198 ◽  
Author(s):  
Michel Lacroix ◽  
Dima Abi-Said ◽  
Daryl R. Fourney ◽  
Ziya L. Gokaslan ◽  
Weiming Shi ◽  
...  
Keyword(s):  
Glioblastoma Multiforme ◽  
Mr Imaging ◽  
Tumor Resection ◽  
Extent Of Resection ◽  
Karnofsky Performance Scale ◽  
Content Type ◽  
Predictive Variables ◽  
Significant Survival ◽  
Performance Scale ◽  
Fine Print

Object. The extent of tumor resection that should be undertaken in patients with glioblastoma multiforme (GBM) remains controversial. The purpose of this study was to identify significant independent predictors of survival in these patients and to determine whether the extent of resection was associated with increased survival time. Methods. The authors retrospectively analyzed 416 consecutive patients with histologically proven GBM who underwent tumor resection at the authors' institution between June 1993 and June 1999. Volumetric data and other tumor characteristics identified on magnetic resonance (MR) imaging were collected prospectively. Conclusions. Five independent predictors of survival were identified: age, Karnofsky Performance Scale (KPS) score, extent of resection, and the degree of necrosis and enhancement on preoperative MR imaging studies. A significant survival advantage was associated with resection of 98% or more of the tumor volume (median survival 13 months, 95% confidence interval [CI] 11.4–14.6 months), compared with 8.8 months (95% CI 7.4–10.2 months; p < 0.0001) for resections of less than 98%. Using an outcome scale ranging from 0 to 5 based on age, KPS score, and tumor necrosis on MR imaging, we observed significantly longer survival in patients with lower scores (1–3) who underwent aggressive resections, and a trend toward slightly longer survival was found in patients with higher scores (4–5). Gross-total tumor resection is associated with longer survival in patients with GBM, especially when other predictive variables are favorable.

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