C1-C2 posterior screw fixation in atlantoaxial fractures revisited: technical update based on 127 cases.

INTRODUCTION: Posterior fusion of traumatic odontoid fractures by C1 lateral mass and C2 isthmic screws (modified Harms-Goel technique) is a viable alternative to transarticular screw fixation due to its universal applicability. This retrospective study reports on a series of 127 patients. MATERIAL AND METHODS: Our clinical database was screened for patients with fractures of the upper cervical spine incorporating a C2 fracture, operated on between 2007 and 2015. Patients were included if fused by internal fixation via C1 lateral mass screws, C2 isthmic screws in freehand technique under lateral fluoroscopy. Screw placement was controlled postoperatively by computed tomography and rated using the Gertzbein & Robbins classification. Surgery-related complications, consecutive treatment, revision surgeries and duration of surgeries were registered. RESULTS: In total, 127 patients were identified with altogether 572 screws. Correct screw positions of grade A and B according to Gertzbein & Robbins were achieved in a total of 539 (94.2%) screws (grade A: 453 (79.2%); grade B: 86 (15%)), grade C screw malpositions noted in 21 (3.7%), grade D in 10 (1.7%) and grade E in 2 (0.3%) screws. Vertebral artery canal breaches occurred in 29 screws (5.1%), with vertebral artery occlusion in 4 patients. Coiling of injured vertebral artery had to be performed in one patient. None of these patients suffered clinically apparent cerebrovascular complications. Revision surgery was performed in 8 patients (6%). CONCLUSION: Posterior fixation of atlantoaxial fractures by C1 lateral mass and C2 isthmic screws with fluoroscopy without navigation is a safe and feasible method but not free of risk of vertebral artery injuries. These slides can be retrieved under Electronic Supplementary Material.

Can Early Postoperative O-(2-18FFluoroethyl)-l-Tyrosine Positron Emission Tomography After Resection of Glioblastoma Predict the Location of Later Tumor Recurrence?

OBJECTIVE: Glioblastoma inevitably recurs despite aggressive therapy. Therefore, it would be helpful to predict the location of tumor recurrence from postoperative imaging to customize further treatment. O-(2-18Ffluoroethyl)-l-tyrosine (FET) positron emission tomography (PET) might be a helpful technique, because tumor tissue can be differentiated from normal brain tissue with high specificity. METHODS: Thirty-two consecutive patients with perioperative and follow-up imaging data available were included. On postoperative FET-PET, the tumor/normal brain (TTB) ratio around the resection cavity borders was measured. Increased TTB ratios were recorded and anatomically correlated with the site of later tumor recurrence. On postoperative magnetic resonance imaging (MRI), residual contrast-enhancing tumor correlated with the site of later tumor recurrence. RESULTS: Location of progression was predictable using MRI alone in 42% of patients by residual tumor on postoperative MRI. FET-PET was predictive in 25 patients by a clear hot spot at the site of later tumor recurrence. In 3 patients, it was partially predictive and in 4 was not predictive of the tumor recurrence location. One patient without any tracer uptake was recurrence free at the last follow-up examination. In contrast to the postoperative MRI results, tumor recurrence was found in 79% at a site of elevated TTB ratio on postoperative FET-PET. Therefore, the predictability of the tumor recurrence location using postoperative FET-PET was greater than that with MRI, and all cases predictable using MRI could have been predicted using FET-PET. CONCLUSIONS: Postoperative FET-PET can be helpful for planning subsequent therapy, such as repeat resection or radiotherapy, because tumor recurrence can be predicted with relatively greater sensitivity than with MRI alone.

Publisher Correction: Factors influencing neurocognitive function in patients with neuroepithelial tumors.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Correction to: Prognostic Value of Tumor Volume in Glioblastoma Patients: Size Also Matters for Patients with Incomplete Resection.

Due to a metadata tagging error the names of Stephanie E. Combs and Jan S. Kirschke were indexed incorrectly. Stephanie E. is the author's given name, and Jan S. is the author's given name.

Revision Rate of Misplaced Pedicle Screws of the Thoracolumbar Spine-Comparison of Three-Dimensional Fluoroscopy Navigation with Freehand Placement: A Systematic Analysis and Review of the Literature.

BACKGROUND: Recent studies have shown higher accuracy rates of image-guided pedicle screw placement compared to freehand (FH) placement. However, data focusing on the impact of spinal navigation on the rate of revision surgeries caused by misplaced pedicle screws (PS) are scarce. OBJECTIVE: This study is aimed at identifying the rate of revision surgeries for misplaced PS comparing three-dimensional (3D) fluoroscopy navigation (3DFL) with FH PS placement. METHODS: A retrospective analysis was conducted of 2232 patients (mean age, 65.3 ± 13.5 years) with 13,703 implanted PS who underwent instrumentation of the thoracolumbar spine between 2007 and 2015. Group 1 received surgery with use of 3DFL (January 2011 to December 2015), group 2 received surgery in the FH technique (April 2007 to December 2015). Because the use of 3DFL was initiated in January 2011, the examined period for 3DFL-navigated surgeries is shorter. Patients routinely received postoperative computed tomography scans and/or intraoperative control 3D scans. RESULTS: There was an overall rate of revision surgeries for malpositioned PS of 2.9%. In the 3DFL group, the rate of secondary revision surgeries was significantly lower with 1.35% (15/1112 patients) compared to 4.38% (49/1120 patients) in the FH group, respectively (odds ratio, 3.35; P < 0.01). Of all PS in the 3DFL group (30/7548 PS), 0.40% needed revision surgery (P < 0.01) compared to 1.14% in the FH group (70/6155 PS). CONCLUSIONS: We were able to show that the use of 3DFL-navigated PS placement significantly reduces the rate of revision surgeries after posterior spinal instrumentation compared to freehand PS placement.

Prognostic Value of Tumor Volume in Glioblastoma Patients: Size Also Matters for Patients with Incomplete Resection.

BACKGROUND: Incomplete resection of glioblastoma is discussed controversially in the era of combined radiochemotherapy. OBJECTIVE: The aim of this study was to analyze the benefit of subtotal tumor resection for glioblastoma patients as this was recently questioned in the era of radiochemotherapy. METHODS: Overall, 209 patients undergoing surgery for newly diagnosed WHO grade IV gliomas were retrospectively analyzed, and pre- and postoperative tumor volumes were manually segmented (cm3). Survival analyses were performed, including prognostic factors such as age, Karnofsky performance score (KPS), O6-methylguanine-DNA-methyltransferase (MGMT) promoter methylation status, and adjuvant treatment regimen. RESULTS: Pre- and postoperative tumor volume is significantly associated with pre- and postoperative KPS, as well as age (p < 0.001). Postoperative tumor volume remained a significant prognostic factor in a multivariate analysis, independent of other prognostic factors (hazard ratio 1.0365, 95% confidence interval 1.0235-1.0497, p < 0.001). CONCLUSIONS: In the era of molecularly-driven radiochemotherapy, glioblastoma surgery remains a major prognostic factor. Even in situations in which a gross total resection cannot be achieved, maximum safe reduction of tumor burden should be attempted.

Factors influencing neurocognitive function in patients with neuroepithelial tumors.

Though cognitive function is proven to be an independent predictor of survival in patients with intrinsic brain tumors, cognitive functions are still rarely considered. Aim of this study was to assess neurocognitive function and to identify risk factors for neurocognitive deficits. 103 patients with primary neuroepithelial tumors who received tumor resections or biopsies were included in this prospective study. The following data was acquired: mini-mental state examination, preoperative tumor volume, WHO grade, tumor entity and location, and the Karnofsky performance status scale. Furthermore, patients participated in extensive neuropsychological testing of attentional, memory and executive functions. General factors like age, clinical status, WHO grade, tumor volume and tumor location correlated with patients' neurocognitive functions. Affection of the parietal lobe resulted in significant impairment of attention and memory functions. Frontal lobe involvement significantly affected patients' abilities in planning complex actions and novel problem solving. Patients with temporal lesions were more likely to have impaired memory and executive functions. Comparing results among neuroepithelial tumor patients enables the identification of risk factors for cognitive impairment. General parameters such as age, KPS score, tumor size, and WHO grade are apart from the respective tumor location of high importance for neurocognitive function.

Minimally invasive transforaminal lumbar interbody fusion versus open transforaminal lumbar interbody fusion: a technical description and review of the literature.

BACKGROUND: Minimally invasive spine surgery (MISS) has been increasingly advocated during the last decade with new studies being reported every year. Minimally invasive spine procedures, such as minimally invasive transforaminal interbody fusion (MI-TLIF), have been introduced to reduce approach-related muscle trauma, to minimise blood loss, and to achieve faster wound healing, quicker ambulation and earlier patient discharge. METHODS: The aim of this article was to give a comprehensive review of the available English literature comparing open TLIF with MI-TLIF techniques published or available online between 1990 and 2014 as identified by an electronic database search on http://www.ncbi.nlm.nih.gov/pubmed . Fourteen relevant studies comparing MI-TLIF and open TLIF cohorts could be identified. RESULTS AND CONCLUSION: MI-TLIF seems to be a valid alternative to open TLIF. Both methods yield good clinical results with similar improvements of Oswestry Disability Index (ODI) and visual analogue scale (VAS) on follow-up. There seems to be no significant differences in clinical outcome and fusion rates on comparison. These results are consistent throughout all reported studies in this review. The most pronounced benefits of MI-TLIF are a significant reduction of blood loss, shorter lengths of hospital stay (LOHS) and lower surgical site infection rates. On the downside, MI-TLIF seems to be associated with significantly higher intraoperative radiation doses, a shallow learning curve, at least in the beginning, longer operating times and potentially more frequent implant failures/cage displacements and revision surgeries.

(18)F-Fluoroethyl-l-Thyrosine Positron Emission Tomography to Delineate Tumor Residuals After Glioblastoma Resection: A Comparison with Standard Postoperative Magnetic Resonance Imaging.

OBJECTIVE: Complete resection of contrast-enhancing tumor is an important prognostic factor in glioblastoma therapy. The current clinical standard for control of resection is magnetic resonance imaging (MRI). (18)F-Fluoroethyl-l-thyrosine (FET) is a positron emission tomography (PET) radiopharmaceutical applicable for widespread use because of its long half-life radionuclide. We assessed the sensitivity of postoperative MRI versus FET-PET to detect residual tumor and the impact of the time interval between resection and FET-PET. METHODS: MRI and FET-PET were performed preoperatively and postoperatively in 62 patients undergoing 63 operations. FET-PET was performed in 43 cases within 72 hours after resection and in 20 cases >72 hours after resection. Detection and measurement of volume of residual tumors were compared. Correlations between residual tumor detection and timing of PET after resection and recurrence were examined. RESULTS: Complete resection was confirmed by both imaging modalities in 44% of cases, and residual tumor was detected consistently in 37% of cases. FET-PET detected residual tumor in 14% of cases in which MRI showed no residual tumor. MRI showed residual tumors in 5% of cases that were not identified by PET. Average PET-based residual tumor volume was higher than MRI-based volume (3.99 cm(3) vs. 1.59 cm(3)). Detection of and difference in volume of residual tumor were not correlated with timing of PET after resection or recurrence status. CONCLUSIONS: Postoperative FET-PET revealed residual tumor with higher sensitivity than MRI and showed larger tumor volumes. In this series, performing PET >72 hours after resection did not influence the results of PET. We recommend FET-PET as a helpful adjunct in addition to MRI for postoperative assessment of residual tumor.

Outcome after Surgical Treatment for Late Recurrent Lumbar Disc Herniations in Standard Open Microsurgery.

PURPOSE: There is a lack of studies highlighting the outcome by different scores or parameters after surgery for recurrent disc herniations of the lumbar spine at the initial herniation site. This study assessed the quality of life after surgical treatment of recurrent herniations with different standardized validated outcome instruments. METHODS: During a 24-month period, 64 patients underwent (microscope assisted) surgery for recurrent disc herniations of the lumbar spine. The postoperative quality of life was tested with Short Form-36, the Oswestry Disability Index, the EuroQol health status 5D, and Prolo questionnaires. Leg and back pain before and after surgery was assessed. RESULTS: The patients showed a good overall outcome, but still not satisfying enough compared with the very good surgical results reported in the literature, for the surgical treatment of primary disc herniations. CONCLUSIONS: Patients have to be informed carefully before surgery of recurrent lumbar disc herniations because of the less-promising outcome than after first time surgery for a lumbar disc herniation.

Early Morbidity and Mortality in 50 Very Elderly Patients After Posterior Atlantoaxial Fusion for Traumatic Odontoid Fractures.

BACKGROUND: Traumatic odontoid fractures (tOFs) in the very elderly are associated with high morbidity and mortality. The best treatment strategy (conservative vs. surgery) is still unclear. METHODS: Between April 2008 and April 2014, fifty (17 male, 33 female) patients (mean age 87.2 ± 4.4 years; range: 80-99) were included in this retrospective cohort study. All patients underwent posterior fusion surgery for tOF. Early outcome, morbidity and mortality, length of hospital and intensive care unit (ICU) stay, comorbidities, and perioperative complications were assessed. RESULTS: The mean age-adjusted Charlson Comorbidity Index (CCI) was 5.8 ± 3.9 (range: 0-13), and the mean American Society of Anesthesiologists score was 3 ± 0.5 (range: 2-4). Surgery was delayed in 48% of patients. Thirty percent of patients had preoperative complications (72.4% severe), of which a leading cause was dysphagia with subsequent pneumonia, and 18% required preoperative assessment or improvement of health status. Surgery-related complications were experienced in 14% with no neurovascular lesion. Postoperative medical complications occurred in 52% of patients (67.3% severe). Major complications were mostly respiratory/pulmonary (66.7%), of which postoperative pneumonia (36.4%) was leading. Twenty-four percent of patients were ICU monitored. Mean length of ICU stay was 9 ± 6.6 days (1-20). Mean length of hospital stay was 15 ± 8.6 days (4-56). There was no in-hospital mortality, and 30-day mortality was 6%. CONCLUSIONS: Posterior fusion for tOF in patients 80 years or older seems to be a feasible treatment option in these high-risk patients. Despite a high incidence of severe comorbidities and perioperative complications, outcome was satisfactory. LEVEL OF EVIDENCE: Our research was a retrospective cohort study, Level III.

Early [18F]FET-PET in Gliomas after Surgical Resection: Comparison with MRI and Histopathology.

BACKGROUND: The precise definition of the post-operative resection status in high-grade gliomas (HGG) is crucial for further management. We aimed to assess the feasibility of assessment of the resection status with early post-operative positron emission tomography (PET) using [18F]O-(2-[18F]-fluoroethyl)-L-tyrosine ([18F]FET). METHODS: 25 patients with the suspicion of primary HGG were enrolled. All patients underwent pre-operative [18F]FET-PET and magnetic resonance imaging (MRI). Intra-operatively, resection status was assessed using 5-aminolevulinic acid (5-ALA). Imaging was repeated within 72 h after neurosurgery. Post-operative [18F]FET-PET was compared with MRI, intra-operative assessment and clinical follow-up. RESULTS: [18F]FET-PET, MRI and intra-operative assessment consistently revealed complete resection in 12/25 (48%) patients and incomplete resection in 6/25 cases (24%). In 7 patients, PET revealed discordant findings. One patient was re-resected. 3/7 experienced tumor recurrence, 3/7 died shortly after brain surgery. CONCLUSION: Early assessment of the resection status in HGG with [18F]FET-PET seems to be feasible.

Volumetric Analysis of F-18-FET-PET Imaging for Brain Metastases.

BACKGROUND: The knowledge of exact tumor margins is of importance for the treating neurosurgeon, radiotherapist, and oncologist alike. The aim of this study was to investigate whether tumor volume and tumor margins acquired by magnetic resonance imaging (MRI) are congruent with the findings acquired by O-(2-(18F)-fluoroethyl)-L-tyrosine-positron emission tomography (FET-PET). METHODS: Patients received FET-PET and MRI before surgery for brain metastases. Metastases were quantified by calculating tumor-to-background uptake ratios using FET uptake. PET and MRI-based tumor volumes, as well as areas of intersection, were assessed. RESULTS: Forty-one patients were enrolled in the study. The maximum tumor-to-background uptake ratio measured in all of our patients harboring histologically proven viable tumor tissue was >1.6. Absolute tumor volumes acquired by FET-PET and MRI were not congruent in our patient cohort, and tumors identified in FET-PET and MRI only partially overlapped. The ratio of intersection (intersection of tumor defined by MRI and tumor defined by FET-PET at the ratio of tumor defined by FET-PET) was within a range of 0.27-0.68 when applying the different thresholds. CONCLUSIONS: Our study therefore indicates that treatment planning based on MRI or PET only might have a substantial risk of undertreatment at the tumor margins. These findings could have important implications for the planning of surgery as well as radiotherapy, although they have to be validated in further studies.

Intraoperative subcortical motor evoked potential stimulation: how close is the corticospinal tract?

OBJECT: Subcortical stimulation is a method used to evaluate the distance from the stimulation site to the corticospinal tract (CST) and to decide whether the resection of an adjacent lesion should be terminated to prevent damage to the CST. However, the correlation between stimulation intensity and distance to the CST has not yet been clearly assessed. The objective of this study was to investigate the appropriate correlation between the subcortical stimulation pattern and the distance to the CST. METHODS: Monopolar subcortical motor evoked potential (MEP) mapping was performed in addition to continuous MEP monitoring in 37 consecutive patients with lesions located in motor-eloquent locations. The proximity of the resection cavity to the CST was identified by subcortical MEP mapping. At the end of resection, the point at which an MEP response was still measurable with minimal subcortical MEP intensity was marked with a titanium clip. At this location, different stimulation paradigms were executed with cathodal or anodal stimulation at 0.3-, 0.5-, and 0.7-msec pulse durations. Postoperatively, the distance between the CST as defined by postoperative diffusion tensor imaging fiber tracking and the titanium clip was measured. The correlation between this distance and the subcortical MEP electrical charge was calculated. RESULTS: Subcortical MEP mapping was successful in all patients. There were no new permanent motor deficits. Transient new postoperative motor deficits were observed in 14% (5/36) of cases. Gross-total resection was achieved in 75% (27/36) and subtotal resection (> 80% of tumor mass) in 25% (9/36) of cases. Stimulation intensity with various pulse durations as well as current intensity was plotted against the measured distance between the CST and the titanium clip on postoperative MRI using diffusion-weighted imaging fiberitracking tractography. Correlational and regression analyses showed a nonlinear correlation between stimulation intensity and the distance to the CST. Cathodal stimulation appeared better suited for subcortical stimulation. CONCLUSIONS: Subcortical MEP mapping is an excellent intraoperative method to determine the distance to the CST during resection of motor-eloquent lesions and is highly capable of further reducing the risk of a new neurological deficit.

18F-fluoro-ethyl-tyrosine positron emission tomography for grading and estimation of prognosis in patients with intracranial gliomas.

INTRODUCTION: Histopathological examination is the standard for grading and determination of diagnosis in intrinsic brain tumors though the possibility of malignization and tumor heterogeneity always bears the possibility of tumor under-grading or misjudgement regarding the estimation of prognosis. The aim of the present study was to evaluate the use of (18)F-FET-PET (FET-PET) for the grading and estimation of prognosis in newly diagnosed patients with intracranial gliomas in a clinical setting. METHODS: Patients who were treated for a newly diagnosed intracranial glioma between January 2007 and May 2012, and had a preoperative FET-PET and MRI scan between were included. The ratio of counts in a tumor VOI (volume of interest) with maximum uptake to the respective counts in a background VOI was calculated to provide the tumor-to-normal (T/N) ratio. The clinical and histopathological data (tumor grading, pre- and postoperative neurological status, Karnofsky Performance Status Scale scores, and overall survival rates) were recorded. RESULTS: One hundred fifty-two patients (39 WHO II, 26 WHO III, 87 WHO IV) were included. The median T/N ratio was 2.81 (1.1-8.1). The median T/N ratio of low-grade glioma patients was 1.65 (1.1-3.7), and 3.14 (1.61-8.1, p<0.001) in high-grade glioma patients. The median survival for patients with WHO III tumors was 22.8 months (95% CI: 15.87%-NA) and 13.23 months (95% CI: 10.83-15.6.%) for patients with WHO IV tumors (p=0.0001). For T/N≤1.6, no deaths were recorded; for 1.63, median survival was 14.0 months (95% CI: 11.7-16.2%, p<0.001). The test of the maximally selected log-rank statistic resulted in a T/N ratio of 1.88 as the cut-off value, with the greatest difference in overall survival between patients with longer and shorter survival. The ROC curve for differentiation of low- vs. high-grade tumors with regard to the T/N ratio showed an area under the curve (AUC) of 0.903. Regarding the prognostic validity for overall survival ROC-curves for 12-month, 24-month and 48-month survival display a higher validity for the WHO-classification than for the imaging modalities though with an AUC of 0.847 for the 48-month survival T/N ratio and MRI contrast-enhancement have a high prognostic value as well. CONCLUSION: Our study suggests that FET-PET can predict prognosis and survival in patients harboring intracranial gliomas and serves as a valuable tool to supplement the established clinical and histopathological parameters.

Postoperative ischemic changes after glioma resection identified by diffusion-weighted magnetic resonance imaging and their association with intraoperative motor evoked potentials.

OBJECT: The aim of surgical glioma treatment is the complete resection of tumor tissue while preserving neurological function. Surgery-related neurological deficits arise from direct damage to the cortical or subcortical structures or from ischemia. The authors aimed to assess the incidence of resection-related ischemia of newly diagnosed or recurrent supratentorial gliomas and the sensitivity of intraoperative neuromonitoring (IOM) of motor evoked potentials (MEPs) for detecting such ischemic events and their influence on neurological motor function. METHODS: Between January 2009 and December 2010, 70 patients with tumors in motor-eloquent brain areas underwent intraoperative MEP monitoring during glioma resection and were examined by early postoperative MRI including diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) mapping. Postoperative areas of restricted diffusion were assessed by investigators blinded to the course of intraoperative MEPs and the neurological course. RESULTS: Among the 70 enrolled patients, a MEP amplitude decline below 50% of the baseline level was observed in 21 patients (30%). Sixteen of these patients (76%) had ischemic lesions identified on postoperative MRI scans. Forty-nine patients (70%) showed no decline in MEP amplitude, and only 16 (33%) of these patients harbored ischemic lesions. Moreover, 9 (69%) of 13 patients with a permanent loss of MEP amplitude showed postoperative ischemic lesions. Factors that promoted the occurrence of postoperative infarction were previous radiotherapy and location of the tumor close to the central arteries. CONCLUSIONS: Alterations in the MEP amplitude during tumor resection and postoperative ischemic lesions are associated with postoperative impairment of motor function. Rather than cortical or subcortical structural damage of eloquent brain tissue alone, peri- or postoperative ischemic lesions play a crucial role in the development of surgery-related motor deficits.

Postoperative ischemic changes following resection of newly diagnosed and recurrent gliomas and their clinical relevance.

OBJECT: The aim of surgical treatment of glioma is the complete resection of tumor tissue with preservation of neurological function. Inclusion of diffusion-weighted imaging (DWI) in the postoperative MRI protocol could improve the delineation of ischemia-associated postoperative neurological deficits. The present study aims to assess the incidence of infarctions following resection of newly diagnosed gliomas in comparison with recurrent gliomas and the influence on neurological function. METHODS: Patients who underwent glioma resection for newly diagnosed or recurrent gliomas had early postoperative MRI, including DWI and apparent diffusion coefficient (ADC) maps. Postoperative areas of restricted diffusion were classified as arterial territorial infarctions, terminal branch infarctions, or venous infarctions. Tumor entity, location, and neurological function were recorded. RESULTS: New postoperative ischemic lesions were identified in 26 (31%) of 84 patients with newly diagnosed gliomas and 20 (80%) of 25 patients with recurrent gliomas (p < 0.01). New permanent and transient neurological deficits were more frequent in patients with recurrent gliomas than in patients with newly diagnosed tumors. Patients with neurological deficits had a significantly higher rate of ischemic lesions. CONCLUSIONS: Postoperative infarctions occur frequently in patients with newly diagnosed and recurrent gliomas and do have an impact on postoperative neurological function. In this patient cohort there was a higher risk for ischemic lesions and for deterioration of neurological function after resection of recurrent tumors. Radiogenic and postoperative tissue changes could contribute to the higher risk of an ischemic infarction in patients with recurrent tumors.

Surgery of highly eloquent gliomas primarily assessed as non-resectable: risks and benefits in a cohort study.

BACKGROUND: Today, the treatment of choice for high- and low-grade gliomas requires primarily surgical resection to achieve the best survival and quality of life. Nevertheless, many gliomas within highly eloquent cortical regions, e.g., insula, rolandic, and left perisylvian cortex, still do not undergo surgery because of the impending risk of surgery-related deficits at some centers. However, pre and intraoperative brain mapping, intraoperative neuromonitoring (IOM), and awake surgery increase safety, which allows resection of most of these tumors with a considerably low rate of postoperatively new deficits. METHODS: Between 2006 and 2012, we resected 47 out of 51 supratentorial gliomas (92%), which were primarily evaluated to be non-resectable during previous presentation at another neurosurgical department. Out of these, 25 were glioblastomas WHO grade IV (53%), 14 were anaplastic astrocytomas WHO grade III (30%), 7 were diffuse astrocytomas WHO grade II (15%), and one was a pilocytic astrocytoma WHO grade I (2%). All data, including pre and intraoperative brain mapping and monitoring (IOM) by motor evoked potentials (MEPs) were reviewed and related to the postoperative outcome. RESULTS: Awake surgery was performed in 8 cases (17%). IOM was required in 38 cases (81%) and was stable in 18 cases (47%), whereas MEPs changed the surgical strategy in 10 cases (26%). Thereby, gross total resection was achieved in 35 cases (74%). Postoperatively, 17 of 47 patients (36%) had a new motor or language deficit, which remained permanent in 8.5% (4 patients). Progression-free follow-up was 11.3 months (range: 2 weeks - 64.5 months) and median survival was 14.8 months (range: 4 weeks - 20.5 months). Median Karnofsky Performance Scale was 85 before and 80 after surgery). CONCLUSIONS: In specialized centers, most highly eloquent gliomas are eligible for surgical resection with an acceptable rate of surgery-related deficits; therefore, they should be referred to specialized centers.

Presurgical navigated transcranial magnetic brain stimulation for recurrent gliomas in motor eloquent areas.

OBJECTIVE: Navigated transcranial magnetic stimulation (nTMS) has been repeatedly shown to be comparably accurate to direct cortical stimulation (DCS) for rolandic region mapping. However, there are no data on its use for recurrent gliomas in which scarring and radiotherapy can impair nTMS. We therefore evaluated the accuracy of nTMS versus DCS and functional MRI (fMRI) in recurrent gliomas compared to initially operated tumors. METHODS: We examined 8 patients with recurrent gliomas and 23 patients with initially operated lesions in or adjacent to the precentral gyrus by preoperative nTMS. RESULTS: Preoperative motor mapping correlated well with intraoperative DCS in recurrent gliomas (6.2±6.0mm), as well as in newly diagnosed tumor patients (5.7±4.6mm) with no significant difference. Compared to fMRI, the difference was larger for upper (recurrent: 8.5±7.2mm; new: 9.8±8.6mm) and lower (recurrent: 17.1±10.6mm; new: 13.8±13.0mm) extremities, with no significant differences. CONCLUSIONS: When comparing nTMS with DCS and fMRI, nTMS is as accurate in recurrent gliomas as it is prior to the first operation. It should be considered a helpful modality in recurrent glioma patients as well. SIGNIFICANCE: nTMS is also applicable in recurrent tumors.