How I do it? Lumbar cortical bone trajectory fixation with image-guided neuronavigation.

BACKGROUND: Cortical bone trajectory was described in 2009 to reduce screw loosening in osteoporotic patients. Since then, it has demonstrated improvements in biomechanical and perioperative results compared to pedicle screws, and it have been described as a minimally invasive technique. METHOD: We describe our experience with the technique assisted by 3D neuronavigation and review some of the complications and tools to avoid them together with limitations and pitfalls. CONCLUSION: Cortical bone trajectory guided by 3D neuronavigation helps to reduce the need for radiation and incidence of complications.

Network Substrates of Centromedian Nucleus Deep Brain Stimulation in Generalized Pharmacoresistant Epilepsy.

Deep brain stimulation (DBS), specifically thalamic DBS, has achieved promising results to reduce seizure severity and frequency in pharmacoresistant epilepsies, thereby establishing it for clinical use. The mechanisms of action are, however, still unknown. We evidenced the brain networks directly modulated by centromedian (CM) nucleus-DBS and responsible for clinical outcomes in a cohort of patients uniquely diagnosed with generalized pharmacoresistant epilepsy. Preoperative imaging and long-term (2-11 years) clinical data from ten generalized pharmacoresistant epilepsy patients (mean age at surgery = 30.8 ± 5.9 years, 4 female) were evaluated. Volume of tissue activated (VTA) was included as seeds to reconstruct the targeted network to thalamic DBS from diffusion and functional imaging data. CM-DBS clinical outcome improvement (> 50%) appeared in 80% of patients and was tightly related to VTAs interconnected with a reticular system network encompassing sensorimotor and supplementary motor cortices, together with cerebellum/brainstem. Despite methodological differences, both structural and functional connectomes revealed the same targeted network. Our results demonstrate that CM-DBS outcome in generalized pharmacoresistant epilepsy is highly dependent on the individual connectivity profile, involving the cerebello-thalamo-cortical circuits. The proposed framework could be implemented in future studies to refine stereotactic implantation or the parameters for individualized neuromodulation.

Deep brain stimulation for aggressiveness: long-term follow-up and tractography study of the stimulated brain areas.

OBJECTIVE: Initial studies applying deep brain stimulation (DBS) of the posteromedial hypothalamus (PMH) to patients with pathological aggressiveness have yielded encouraging results. However, the anatomical structures involved in its therapeutic effect have not been precisely identified. The authors' objective was to describe the long-term outcome in their 7-patient series, and the tractography analysis of the volumes of tissue activated in 2 of the responders. METHODS: This was a retrospective study of 7 subjects with pathological aggressiveness. The findings on MRI with diffusion tensor imaging (DTI) in 2 of the responders were analyzed. The authors generated volumes of tissue activated according to the parameters used, and selected those volumes as regions of interest to delineate the tracts affected by stimulation. RESULTS: The series consisted of 5 men and 2 women. Of the 7 patients, 5 significantly improved with stimulation. The PMH, ventral tegmental area, dorsal longitudinal fasciculus, and medial forebrain bundle seem to be involved in the stimulation field. CONCLUSIONS: In this series, 5 of 7 medication-resistant patients with severe aggressiveness who were treated with bilateral PMH DBS showed a significant long-lasting improvement. The PMH, ventral tegmental area, dorsal longitudinal fasciculus, and medial forebrain bundle seem to be in the stimulation field and might be responsible for the therapeutic effect of DBS.

Subcutaneous tissue metastasis from glioblastoma multiforme: A case report and review of the literature. / Metástasis en tejido celular subcutáneo de glioblastoma multiforme: caso clínico y revisión de la literatura.

Glioblastoma multiforme is the most common primary brain tumor, despite an aggressive clinical course, less than 2% of patients develop extraneural metastasis. We present a 72-year-old male diagnosed with a right temporal glioblastoma due to headache. He underwent total gross resection surgery and after that the patient was treated with adyuvant therapy. Five months after the patient returned with trigeminal neuralgia, and MRI showed an infratemporal cranial mass which infiltrates masticator space, the surrounding bone, the temporal muscle and superior cervical and parotid lymph nodes. The patient underwent a new surgery reaching partial resection of the temporal lesion. After that the patient continued suffering from disabling trigeminal neuralgia, that's why because of the bad clinical situation and the treatment failure we decided to restrict therapeutic efforts. The patient died 3 weeks after the diagnosis of extracranial metastasis.

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.

[Chronic subdural haematomas. The internal architecture of the haematoma as a predictor of recurrence]. / Hematomas subdurales cronicos. Arquitectura interna del hematoma como predictor de recidiva.

INTRODUCTION: The internal architecture of a chronic subdural haematoma (CSDH) is an important factor that must be taken into account as a predictor of recurrence. AIM: To analyse the factors that are possibly associated to the recurrence of CSDH, with special emphasis on the above-mentioned architecture. PATIENTS AND METHODS: We reviewed 147 patients treated between 2010 and 2013. The CSDH were classified into four types, in accordance with Nakaguchi's classification published in 2001. Moreover, we gathered different clinical characteristics and they were submitted to a statistical analysis in order to evaluate the possible association between them and the rate of recurrence of CSDH. RESULTS: The rate of recurrence was 14.75% and the mortality rate was 4.76%. Treatment with anticoagulants, the type of haematoma and not using subdural drainage were statistically significant risk factors for the recurrence of CSDH. In terms of the internal architecture, the rate of recurrence was 36.36% for the separated type, 15.90% for the laminar type, 8.82% for the homogenous and 0% for the trabecular type. This rate was significantly higher in the separated type with respect to the homogenous and trabecular types. CONCLUSIONS: We have observed that treatment with anticoagulants and not using subdural drainage are risk factors for the recurrence of CSDH. Furthermore, dividing CSDH up in accordance with Nakaguchi's classification can be useful for predicting the risk of relapse, since the rate of recurrence of the separated type was significantly greater than that of the other types.

TITLE: Hematomas subdurales cronicos. Arquitectura interna del hematoma como predictor de recidiva.Introduccion. La arquitectura interna del hematoma subdural cronico (HSDC) es un factor muy importante que se debe tener en cuenta como predictor de recidiva. Objetivo. Analizar los factores posiblemente asociados a la recidiva de los HSDC, prestando especial atencion a dicha arquitectura. Pacientes y metodos. Hemos revisado 147 pacientes tratados desde 2010 hasta 2013. Dividimos los HSDC en cuatro tipos de acuerdo con la clasificacion de Nakaguchi de 2001. Ademas, hemos recogido diferentes caracteristicas clinicas y las hemos sometido a analisis estadistico para evaluar su posible asociacion con la tasa de recidiva de los HSDC. Resultados. La tasa de recidiva fue del 14,75% y la de mortalidad, del 4,76%. El tratamiento con anticoagulantes, el tipo de hematoma y el no usar drenaje subdural fueron factores de riesgo estadisticamente significativos para la recurrencia del HSDC. Segun la arquitectura interna, la tasa de recidiva fue del 36,36% para el tipo separado, del 15,90% para el laminar, del 8,82% para el homogeneo y del 0% para el trabecular. Dicha tasa fue significativamente mayor en el tipo separado respecto al homogeneo y trabecular. Conclusiones. El tratamiento con anticoagulantes y el no usar drenaje subdural son factores de riesgo de recurrencia de HSDC. Ademas, la division de los HSDC de acuerdo con la clasificacion de Nakaguchi puede ser util para predecir el riesgo de recurrencia, ya que la tasa de recidiva del tipo separado fue significativamente mayor que la del resto de tipos.

[Neurophysiological assisted transsulcal approach to a high grade glioma without affect neither motor nor somatosensory function]. / Mapeo neurofisiológico en un glioma de alto grado intervenido mediante abordaje transulcal en la región rolándica.

INTRODUCTION: Intraoperative mapping and neuronavigation permitted a safe approach through the rolandic sulcus, minimizing the impact onto the motor or somatosensory functions. Fluorescence-guide resection defines a limit that allows a total resection without exceed the border of the tumor. CASE REPORT: A 39-year-old man who was operated by a tumor placed into the rolandic area. With the patient anesthetized (propofol+remyfentanil), we performed cortical mapping, neuronavigation and fluorescence-guide resection with 5-aminolevulinic acid. Post-resection neurophysiologic assessment showed a minor and highly localized effect onto the somato-sensory system. CONCLUSION: Rolandic area surgery can be safely performed in anesthetized patients when extensive neurophysiological, anatomical and biological assessments are performed.

[Intracerebral neurenteric cysts in newborn infants]. / Quistes neuroentericos intracerebrales en neonatos.

INTRODUCTION: Intracranial neurenteric cysts are very infrequent congenital lesions. Within the nervous system, they are most commonly located in the rachis. Another frequent site is the craniocervical junction. Few cases of supratentorial location have been reported. A differential diagnosis is required to distinguish them from other cysts. They are not often diagnosed in the paediatric age. The clinical features they give rise to are due to the mass effect or episodes of chemical meningitis. Magnetic resonance imaging is the best diagnostic method although on many occasions they cannot be distinguished from arachnoid cysts. Treatment consists in surgery with complete resection of the membranes in order to prevent recurrences. CASE REPORTS: We report two cases of infants who, in the last weeks of gestation, presented supratentorial intracerebral cystic lesions that resembled arachnoid cysts. A neonatal magnetic resonance scan confirmed the existence of such supratentorial cysts with septae inside them. After presenting an increase in the cranial perimeter, surgical treatment was undertaken with a neuronavigation-guided craniotomy and debridement of the cysts. The cysts contain mucus and have thick membranes. Pathological study results are consistent with a neurenteric cyst. One of the patients presented complete resolution after the intervention with good cerebral expansion. In the second case, there was persistence of an adjoining arachnoid cyst, in which placement of a cyst-peritoneal shunt was necessary with full resolution. CONCLUSIONS: Most intracranial cysts are arachnoid cysts, but there are other cystic lesions that must be treated by surgical means so that they can be completely excised and sent for pathological analyses.

[Hemispheric transcranial electrical stimulation: clinical results]. / Estimulación eléctrica transcraneal hemisférica en cirugía supratentorial: resultados clínicos.

INTRODUCTION: Transcranial electrical stimulation (TES) is a technique widely used in intraoperative neurophysiological monitoring. However, there are theoretical limitations to their use in supratentorial surgery. AIM: To test the usefulness of hemispheric TES (C3/C4-Cz) in supratentorial surgery. PATIENTS AND METHODS: Hemispheric TES was conducted in a group of 15 patients operated on supratentorial region with possible compromise of the inner capsule. In all cases orbicularis oris, extensor digitorum, abductor of V finger, anterior tibialis and abductor hallucis brevis contralateral to stimulation were recorded. We used trains of 4-6 pulses of 50 micro-seconds at 500 Hz. RESULTS: The intensity of the movements induced by hemispheric TES did not interfere with the microsurgical dissection. We have used 78.5 +/- 11.2 trains per patient, with the voltage of 235 +/- 21 V and the equivalent current 370 +/- 37 mA. Stimulation resulted in response in facial region in 80% of cases, 100% in arm/hand and 66.7% in leg/foot. In eight patients, there was no change in latency and/or amplitude during resection. In six patients we observed retardation, decreased amplitude or both in any of the region studied. In these patients no neurologic injury was observed. In one patient a sharp decrease and complete absence of motor response was observed. In this case there was a post-surgical neurologic injury. CONCLUSIONS: The hemispheric TES have high sensitivity and specificity monitoring the inner capsule in supratentorial neurosurgery.

[Differential contribution of preoperatory studies to diagnosis in temporal lobe epilepsy surgery]. / Contribución diferencial de los estudios preoperatorios al diagnostico en la cirugia de la epilepsia temporal.

INTRODUCTION: It is necessary to know the degree of concordance of preoperative studies in temporal lobe epilepsy (TLE). AIM. To analyze the relative importance of different preoperative tests (vEEG, EEG, SPECT and MRI), the degree of agreement between them, and to develop a Bayesian probability model for diagnosis. PATIENTS AND METHODS: We analyzed 73 patients operated by TLE, with a minimum postoperative follow-up of two years. To analyze the localization capability of different test, we used only patients with an Engel's grade I outcome during all the follow-up time (n = 60). RESULTS: Engel's grades percentages at 2 years were 87.7/8.2/3.0/0.0 (I/II/III/IV, respectively). The preoperative correlation was < 50% for three tests and 33% for the four. MRI studies were found normal in 33.3% of cases. According to the localization index, the arrange was vEEG > RM > SPECT > EEG. The conditional probability of correct localization for a test was vEEG (0.950) > EEG (0.719) > SPECT (0.717) > RM (0.683). Concordance for more than two tests, was = 0.587 (vEEG + MRI). The probability of obtaining a priori correct localization was vEEG (0.983) > RM (0.414) > EEG (0.285) > SPECT (0.209). The Bayesian model is highly reliable. CONCLUSIONS: Probably it is not always possible to obtain a high degree of agreement among preoperative test, despite this, it is possible to obtain a good functional result. The most effective test is the vEEG.