Language hemispheric dominance analyzed with magnetic resonance DTI: correlation with the Wada test.

OBJECTIVE: Language lateralization is a major concern in some patients with pharmacoresistant epilepsy who will face surgery; in these patients, hemispheric dominance testing is essential to avoid further complications. The Wada test is considered the gold standard examination for language localization, but is invasive and requires many human and material resources. Functional MRI and tractography with diffusion tensor imaging (DTI) have demonstrated that they could be useful for locating language in epilepsy surgery, but there is no evidence of the correlation between the Wada test and DTI MRI in language dominance. METHODS: The authors performed a retrospective review of patients who underwent a Wada test before epilepsy surgery at their institution from 2012 to 2017. The authors retrospectively analyzed fractional anisotropy (FA), number and length of fibers, and volume of the arcuate fasciculus and uncinate fasciculus, comparing dominant and nondominant hemispheres. RESULTS: Ten patients with temporal lobe epilepsy were reviewed. Statistical analysis showed that the mean FA of the arcuate fasciculus in the dominant hemisphere was higher than in the nondominant hemisphere (0.369 vs 0.329, p = 0.049). Also, the number of fibers in the arcuate fasciculus was greater in the dominant hemisphere (881.5 vs 305.4, p = 0.003). However, no differences were found in the FA of the uncinate fasciculus or number of fibers between hemispheres. The length of fibers of the uncinate fasciculus was longer in the dominant side (74.4 vs 50.1 mm, p = 0.05). Volume in both bundles was more prominent in the dominant hemisphere (12.12 vs 6.48 cm3, p = 0.004, in the arcuate fasciculus, and 8.41 vs 4.16 cm3, p = 0.018, in the uncinate fasciculus). Finally, these parameters were compared in patients in whom the seizure focus was situated in the dominant hemisphere: FA (0.37 vs 0.30, p = 0.05), number of fibers (114.4 vs 315.6, p = 0.014), and volume (12.58 vs 5.88 cm3, p = 0.035) in the arcuate fasciculus were found to be statistically significantly higher in the dominant hemispheres. Linear discriminant analysis of FA, number of fibers, and volume of the arcuate fasciculus showed a correct discrimination in 80% of patients (p = 0.024). CONCLUSIONS: The analysis of the arcuate fasciculus and other tract bundles by DTI could be a useful tool for language location testing in the preoperative study of patients with refractory epilepsy.

Evolución morfométrica de descompresión obtenida tras corpectomía. Dirigiéndonos hacia abordajes posteriores / Morphometrical evaluation of decompression obtained through corpectomy. Heading towards to posterior approaches

Introducción: Hemos analizado la descompresión obtenida mediante corpectomía dorsal o dorsolumbar medida a través del ángulo de Cobb y el área del canal medular antes y después de la cirugía. Además, se ha comparado la evolución de la técnica entre los primeros 5 años del estudio y los 5 posteriores. Material y método: Se realizó un estudio retrospectivo de los pacientes operados entre 2005-2015 en nuestro centro mediante abordajes anteriores y posteriores. Resultados: Se intervinieron 24 pacientes y observamos una mejoría significativa entre los valores preoperatorios y postoperatorios en el análisis morfométrico (corrección de 4,18° de cifosis y un aumento del área del canal medular de 130,8mm2 con una significación de p<0,001 en ambos casos) y mejoría clínica (45,8% de los pacientes presentaron mejoría en la escala ASIA y una mejoría media de 13 puntos en el Karnofsky, p<0,001). Sin embargo, no se observa correlación entre los parámetros clínicos y morfométricos. También hemos observado que en los últimos 5 años del estudio los abordajes posteriores se utilizaron con mayor frecuencia y con buenos resultados. Conclusiones: La corpectomía dorsal permite una descompresión espinal significativa, con mejoría de la función neurológica sin que se correlacione con las mediciones de la descompresión. Gracias a las mejoras técnicas, las técnicas mínimamente invasivas (abordajes posteriores y técnicas MISS) permiten unos buenos resultados funcionales que son similares a los obtenidos con técnicas anteriores

Introduction: We analysed the decompression obtained by dorsal or dorsolumbar corpectomy measured by Cobb angle and the spinal area prior to and after surgery and compared the evolution of the technique over the last five years of the study. Material and method: A retrospective review of patients operated between 2005 and 2015 through anterior or posterior approaches was performed. Results: 24 patients were studied and a significant improvement was observed between the preoperative and postoperative morphometrical measurement (4.18° correction of the kyphosis and an increase of 130.8mm2 in the spinal canal, p<.001 in both cases) and in clinical parameters (45.8% of patients improved in ASIA, and Karnofsky showed 13 points of improvement, p<.001 in both cases). However, there was no correlation between clinical and morphological parameters. We also observed that in the last five years of the study posterior approaches were more frequently used with good results. Conclusions: Dorsal corpectomy allows significant spinal decompression, with neurological improvement but this does not correlate with the measurement of decompression. Thanks to technical improvements, less invasive techniques (posterior approaches and MISS) allow good clinical results, which are similar to those obtained by anterior techniques

Morphometrical evaluation of decompression obtained through corpectomy. Heading towards to posterior approaches. / Evolución morfométrica de descompresión obtenida tras corpectomía. Dirigiéndonos hacia abordajes posteriores.

INTRODUCTION: We analysed the decompression obtained by dorsal or dorsolumbar corpectomy measured by Cobb angle and the spinal area prior to and after surgery and compared the evolution of the technique over the last five years of the study. MATERIAL AND METHOD: A retrospective review of patients operated between 2005 and 2015 through anterior or posterior approaches was performed. RESULTS: 24 patients were studied and a significant improvement was observed between the preoperative and postoperative morphometrical measurement (4.18° correction of the kyphosis and an increase of 130.8mm2 in the spinal canal, p<.001 in both cases) and in clinical parameters (45.8% of patients improved in ASIA, and Karnofsky showed 13 points of improvement, p<.001 in both cases). However, there was no correlation between clinical and morphological parameters. We also observed that in the last five years of the study posterior approaches were more frequently used with good results. CONCLUSIONS: Dorsal corpectomy allows significant spinal decompression, with neurological improvement but this does not correlate with the measurement of decompression. Thanks to technical improvements, less invasive techniques (posterior approaches and MISS) allow good clinical results, which are similar to those obtained by anterior techniques.

Validation of Grading Scores and Outcome Prognostic Factors in Intracranial Meningiomas in Elderly Patients.

OBJECTIVE: Meningiomas are the most frequent benign intracranial tumors and they are becoming more frequent because of the aging population and advances in diagnostics and neurosurgical treatment. Therefore, there will be an increase of this disease in the coming years. METHODS: We performed a retrospective analysis of patients older than 70 years who underwent surgery for intracranial meningiomas, and we established risk factors related to outcome, morbidity, and mortality. We compared 3 previously described scores (Geriatric Scoring System [GSS], Clinico-Radiological Grading System [CRGS], and Sex, Karnofsky, ASA, Location and Edema [SKALE] score). RESULTS: We identified 110 patients older than 70 years. In the univariate analysis, postoperative Karnofsky Performance Status (KPS) was related to the presence of edema (P = 0.036), tumor size (P = 0.043), previous neurologic impairment (P = 0.012), and preoperative American Society of Anesthesiologists (ASA) physical status classification (P = 0.029). In the multivariable logistic regression model, ASA classification (odds ratio, 0.324; P = 0.04) and preoperative KPS (odds ratio, 1.042; P = 0.05) were also statistically significant. In all cases, better survival curves in the Kaplan-Meier survival test appear in patients with lower scores (CRGS, P = 0.015; GSS, P = 0.014; SKALE, P < 0.001). Also, morbidity measured as postoperative KPS correlated with these scores (CRGS, P < 0.001; SKALE, P < 0.001; GSS, P < 0.001). However, only SKALE correlated with perioperative morbidity, mortality, and 1-year mortality. CONCLUSIONS: Meningioma resection in patients older than 70 years is safe, with an acceptable rate of mortality and morbidity. Patients who should undergo surgery must be selected in relation to their comorbidities, such as ASA classification or preoperative KPS. However, SKALE could be a useful tool as an initial approach.

Image guidance in transdiscal fixation for high-grade spondylolisthesis in adults with correct spinal balance.

OBJECTIVE Spondylolisthesis is a prevalent spine disease that recent studies estimate could be detected in 9% of the population. High-grade spondylolisthesis (HGS), however, is much less frequent, which makes it difficult to develop a general recommendation for its treatment. Posterior transdiscal fixation was proposed in 1994 for HGS, and the use of spine navigation could make this technique more accessible and reduce the morbidity associated with the procedure. The purpose of this study was to present a case series involving adult patients with HGS and correct spinal alignment who were treated with transdiscal pedicle screw placement guided with neuronavigation and compare the results to those achieved previously without image guidance. METHODS The authors reviewed all cases in which adult patients with correct spinal alignment were treated for HGS with posterior transdiscal instrumentation placement guided with navigation between 2014 and 2016 at their institution. The authors compared preoperative and postoperative spinopelvic parameters on standing radiographs as well as Oswestry Disability Index (ODI) scores and visual analog scale (VAS) scores for low-back pain. Follow-up CT and MRI studies and postoperative radiographs were evaluated to identify any screw malplacement or instrumentation failure. Any other intraoperative or postoperative complications were also recorded. RESULTS Eight patients underwent posterior transdiscal navigated instrumentation placement during this period, with a mean duration of follow-up of 16 months (range 9-24 months). Six of the patients presented with Meyerding grade III spondylolisthesis and 2 with Meyerding grade IV. In 5 cases, L4-S1 instrumentation was placed, while in the other 3 cases, surgery consisted of transdiscal L5-S1 fixation. There was no significant difference between preoperative and postoperative spinopelvic parameters. However, there was a statistically significant improvement in the mean VAS score for low-back pain (6.5 ± 1.5 vs 4 ± 1.7) and the mean ODI score (49.2 ± 19.4 vs 37.7 ± 22) (p = 0.01 and p = 0.012, respectively). Six patients reduced their use of pain medication. There were no intraoperative or postoperative complications during the hospital stay, and as of the most recent follow-up, no complications related to pseudarthrosis or hardware failure had been observed. CONCLUSIONS Treatment with posterior transdiscal pedicle screws with in situ fusion achieved good clinical and radiological outcomes in patients with HGS and good sagittal spinal balance. The use of navigation and image guidance was associated with improved results in this technique, including a reduction in postoperative and intraoperative complications related to screw malplacement, pseudarthrosis, and instrumentation failure.

Review of Cortical Bone Trajectory: Evidence of a New Technique.

This article summarizes recent evidence on the cortical bone trajectory (CBT) obtained from published anatomical, biomechanical, and clinical studies. CBT was proposed by Santoni in 2009 as a new trajectory that can improve the fixation of pedicle screws in response to screw loosening in osteoporotic patients. Recently, research interest has been growing with increasing numbers of published series and frequent reports of new applications. We performed an online database search using the terms "cortical bone trajectory," "pedicle screw," "CBT spine," "CBT fixation," "MISS CBT," and "traditional trajectory." The search included the PubMed, Ovid MEDLINE, Cochrane, and Google Scholar databases, resulting in an analysis of 42 articles in total. These covered three aspects of CBT research: anatomical studies, biomechanical parameters, and clinical cases or series. Compared to the traditional trajectory, CBT improves pullout strength, provides greater stiffness in cephalocaudal and mediolateral loading, and shows superior resistance to flexion/extension; however, it is inferior in lateral bending and axial rotation. CBT seems to provide better immediate implant stability. In clinical studies, CBT has shown better perioperative results for blood loss, length of stay in hospital, and surgery time; similar or better clinical postoperative scores; and similar comorbidity, without any major fixation system complications due to instrumentation failure or screw misplacement. In addition, advantages such as less lateral exposure allow it to be used as a minimally invasive technique. However, most of the clinical studies were retrospective case series or case-control studies; prospective evidence on this technique is scarce, making a definitive comparison with the traditional trajectory difficult. Nevertheless, we can conclude that CBT is a safe technique that offers good clinical results with similar biomechanical and perioperative parameters to those of the traditional trajectory. In addition, new applications can improve its results and make it useful for additional pathologies.

Usefulness of Reintervention in Recurrent Glioblastoma: An Indispensable Weapon for Increasing Survival.

BACKGROUND: Glioblastoma is the most frequent primary brain tumor and despite of complete treatment survival is still poor. The aim of this study is to define the utility of reoperation for improving survival in patients with recurrent glioblastoma, and determine other prognostic factors associated with longer survival. METHODS: We performed a retrospective analysis of those patients who underwent surgery and compared those who were operated two or more times and those who received surgery only once. We studied overall survival (OS), progression-free survival (PFS), and clinical variables that could be related with higher survival. RESULTS: A total of 121 patients were eligible for the study, of whom 31 (25%) underwent reoperation. The reoperation group had a mean and median increase survival of 10.5 and 16.4 months in OS and 3.5 and 2.7 months for PFS compared with the non-reoperation group (P < 0.001 and 0.01, respectively). Although complications were higher in patients that underwent reintervention (19.3%) there was no statistical difference with complication rate in first surgery (12.4%, χ2 = 1.86; P = 0.40). Cox multivariable analysis revealed that age (hazard ratio [HR] 1.03; 95% confidence interval [CI], 1.006-1.055; P = 0.013), reoperation (HR, 0.48; 95% CI, 0.285-0.810; P = 0.006), extent of resection >95% (HR, 0.547; 95% CI, 0.401-0.748; P < 0.001), and complete adjuvant therapy (HR, 0.389; 95% CI, 0.208-0.726; P = 0.003) were correlated with a higher OS. CONCLUSIONS: Reoperation and the extent of resection (EOR) are the only surgical variables that neurosurgeons can modify to improve survival in our patients. Higher EOR and reoperation rates in patients who can be candidates for second surgery, will increase OS and PFS.