Resonancia intraoperatoria de alto campo: cómo optimizar su uso en nuestro modelo sanitario / Intraoperative high-field resonance: how to optimize its use in our healthcare system

Antecedentes y objetivo: La RM intraoperatoria (RMio) consiste en la realización de una resonancia durante la cirugía de una lesión cerebral o espinal. Es una técnica segura y útil, aunque está disponible en pocos hospitales y algunos aspectos no están perfectamente definidos ni estandarizados, por lo que cada centro elabora sus propias soluciones. Nuestro objetivo es describir la técnica utilizada para la realización de RMio, evaluar los cambios que se han realizado para optimizar su uso desde el comienzo y facilitar la puesta en marcha de una resonancia intraoperatoria en otros departamentos de neurocirugía. Material y métodos: Estudio prospectivo de pacientes intervenidos consecutivamente con RMio, describiendo el tipo de tumor, datos clínicos, tiempo y secuencias de RMio, empleo de neurofisiología intraoperatoria, volumen tumoral preoperatorio, tras la RMio, y postoperatorio, y complicaciones observadas. Resultados: Se realizó RMio en 38 pacientes seleccionados de los 425 tumores cerebrales (9%) operados en este intervalo. Los tipos tumorales fueron: 11 glioblastomas, 8 astrocitomas anaplásicos, 5 astrocitomas difusos, 4 meningiomas, 3 oligodendrogliomas, 2 metástasis, 2 quistes epidermoides, 1 astroblastoma, 1 quiste aracnoideo y 1 adenoma hipofisario.La edad media fue de 45 años. El volumen tumoral preoperatorio medio fue 45,22 cc, tras la RMio de 5,08 cc y el postoperatorio de 1,28 cc.En el 76% se amplió la resección tras la RMio. En 15 pacientes se consiguió una resección completa y en 8 se objetivó un resto menor de 1cc. En 13 pacientes se dejó un resto intencional en área elocuente o regiones de base de cráneo (volumen medio 7cc).En un 5% se detectaron complicaciones de sangrado e isquemia de forma precoz en la RMio.La realización de la RMio requirió una media de 47 minutos...(AU)

Background and aims: Intraoperative MRI (ioMRI) consists of performing a MRI during brain or spinal surgery. Although it is a safe and useful technique, it is available in a few hospitals. This means some aspects are not perfectly defined or standardized, forcing each center to develop its own solutions. Our goal is to describe the technique, evaluate the changes made to optimize its use and thus be able to facilitate the intraoperative resonance implementation in other neurosurgery departments. Methods: A prospective analysis of patients consecutively operated using high-field ioMRI guidance was carried out, describing the type of tumor, clinical data, time and sequences of ioMR, use of intraoperative neurophysiology, preoperative tumor volume, after ioMR, and postoperative, as well as complications. Resultsio: MR was performed in 38 patients selected from among 425 brain tumors (9%) operated on in this interval. The tumor types were: 11 glioblastomas, 8 anaplastic astrocytomas, 5 diffuse astrocytomas, 4 meningiomas, 3 oligodendrogliomas, 2 metastases, 2 epidermoid cysts, 1 astroblastoma, 1 arachnoid cyst and 1 pituitary adenoma.The mean age was 45 years. The mean preoperative tumor volume was 45.22cc, after the ioMR 5.08cc and postoperative 1.28cc. Resection was extended after ioMR in 76%. Gross total resection was achieved in 15 patients and residual tumor of less than 1cc was observed in 8. An intentional tumor tissue was left in an eloquent brain region (mean volume 7cc) in 13 patients.Bleeding and ischemia complications were detected early on ioMR in 5%.MRI length was 47minutes on average. Conclusions: Intraoperative MRI was a useful and safe technique, and no associated complications were registered. (AU)

Intraoperative high-field resonance: How to optimize its use in our healthcare system.

BACKGROUND AND AIMS: Intraoperative MRI (ioMRI) consists of performing a MRI during brain or spinal surgery. Although it is a safe and useful technique, it is available in a few hospitals. This means some aspects are not perfectly defined or standardized, forcing each center to develop its own solutions. Our goal is to describe the technique, evaluate the changes made to optimize its use and thus be able to facilitate the intraoperative resonance implementation in other neurosurgery departments. METHODS: A prospective analysis of patients consecutively operated using high-field ioMRI guidance was carried out, describing the type of tumor, clinical data, time and sequences of ioMR, use of intraoperative neurophysiology, preoperative tumor volume, after ioMR, and postoperative, as well as complications. RESULTS: ioMR was performed in 38 patients selected from among 425 brain tumors (9%) operated on in this interval. The tumor types were: 11 glioblastomas, 8 anaplastic astrocytomas, 5 diffuse astrocytomas, 4 meningiomas, 3 oligodendrogliomas, 2 metastases, 2 epidermoid cysts, 1 astroblastoma, 1 arachnoid cyst and 1 pituitary adenoma. The mean age was 45 years. The mean preoperative tumor volume was 45.22cc, after the ioMR 5.08cc and postoperative 1.28cc. Resection was extended after ioMR in 76%. Gross total resection was achieved in 15 patients and residual tumor of less than 1cc was observed in 8. An intentional tumor tissue was left in an eloquent brain region (mean volume 7cc) in 13 patients. Bleeding and ischemia complications were detected early on ioMR in 5%. MRI length was 47 min on average. CONCLUSIONS: Intraoperative MRI was a useful and safe technique, and no associated complications were registered.

La importancia de la resección amigdalar en el tratamiento quirúrgico de la epilepsia temporal mesial / The importance of amygdala removal in the surgical treatment of mesial temporal lobe epilepsy

Pese a que desde hace tiempo se conoce que lesiones amigdalares en animales de experimentación producen un modelo de epilepsia, la participación de la amígdala en el complejo de la esclerosis temporal mesial es poco conocida y casi toda la atención se centra en el hipocampo. Este trabajo tiene como propósito enfatizar el papel de la resección de la amígdala para conseguir que el paciente quede sin crisis. Para ello presentamos dos casos de pacientes mujeres de 50 y 42 años con crisis desde la infancia y diagnosticadas de esclerosis temporal mesial. Ambas fueron intervenidas por nosotros en el año 2000 mediante amigdalohipocampectomía con resección parcial amigdalar más lobectomía temporal izquierda y derecha respectivamente. Las dos pacientes no presentaron nuevas crisis parciales complejas durante los primeros 6 años, empeorando posteriormente por lo que fueron reintervenidas para monitorización con electrodos subdurales y profundos. En ambas se evidenció un inicio ictal compatible con el electrodo situado en la amígdala. La subsiguiente resección del tejido donde se situó el electrodo amigdalar dejó a las dos pacientes libres de crisis. En estas dos pacientes fue preciso completar la resección amigdalar para conseguir que quedaran libres de crisis. La resección amigdalar es parte importante de la técnica quirúrgica en la epilepsia temporal mesial. Es posible que la amígdala tenga un papel mucho más relevante de lo actualmente considerado en el origen de las crisis

Even though amygdalar lesions are a known epilepsy model in laboratory animals, the role of the amygdala in mesial temporal sclerosis is not well-known. To date, most interest has been paid to the role of the hippocampal formation. The aim of this article is to emphasize the role of the amygdala in order to render a patient seizure free. Two patients are presented who were 50 and 42 years old at the time of surgery. They suffered from seizures since childhood and were diagnosed with mesial temporal sclerosis. A temporal lobectomy with hippocampectomy and partial amygdalectomy was performed on both patients in the year 2000, with one patient operated on the right side and the other one on the left side. Both patients were seizure free after surgery for 6 years, but presented again with seizures after that time. They were evaluated again for surgery, and subdural grids were placed, together with a deep electrode in the remnants of the amygdala. The amygdalar electrode showed to be the seizure onset in the two cases, and its resection rendered both patients seizure free. These two patients show that a complete amygdalar resection is necessary to render some patients seizure free. It might be the amygdala has a greater role than previously thought

[The importance of amygdala removal in the surgical treatment of mesial temporal lobe epilepsy]. / La importancia de la resección amigdalar en el tratamiento quirúrgico de la epilepsia temporal mesial.

Even though amygdalar lesions are a known epilepsy model in laboratory animals, the role of the amygdala in mesial temporal sclerosis is not well-known. To date, most interest has been paid to the role of the hippocampal formation. The aim of this article is to emphasize the role of the amygdala in order to render a patient seizure free. Two patients are presented who were 50 and 42 years old at the time of surgery. They suffered from seizures since childhood and were diagnosed with mesial temporal sclerosis. A temporal lobectomy with hippocampectomy and partial amygdalectomy was performed on both patients in the year 2000, with one patient operated on the right side and the other one on the left side. Both patients were seizure free after surgery for 6 years, but presented again with seizures after that time. They were evaluated again for surgery, and subdural grids were placed, together with a deep electrode in the remnants of the amygdala. The amygdalar electrode showed to be the seizure onset in the two cases, and its resection rendered both patients seizure free. These two patients show that a complete amygdalar resection is necessary to render some patients seizure free. It might be the amygdala has a greater role than previously thought.

Acute human brain responses to intracortical microelectrode arrays: challenges and future prospects.

The emerging field of neuroprosthetics is focused on the development of new therapeutic interventions that will be able to restore some lost neural function by selective electrical stimulation or by harnessing activity recorded from populations of neurons. As more and more patients benefit from these approaches, the interest in neural interfaces has grown significantly and a new generation of penetrating microelectrode arrays are providing unprecedented access to the neurons of the central nervous system (CNS). These microelectrodes have active tip dimensions that are similar in size to neurons and because they penetrate the nervous system, they provide selective access to these cells (within a few microns). However, the very long-term viability of chronically implanted microelectrodes and the capability of recording the same spiking activity over long time periods still remain to be established and confirmed in human studies. Here we review the main responses to acute implantation of microelectrode arrays, and emphasize that it will become essential to control the neural tissue damage induced by these intracortical microelectrodes in order to achieve the high clinical potentials accompanying this technology.

Transvenous Onyx embolization of a subependymal deep arteriovenous malformation with a single drainage vein: technical note.

Cerebral arteriovenous malformations (AVMs) are uncommon. Treatment options include embolization, radiosurgery and surgery, separately or combined, the final goal being complete occlusion of the malformation. We describe the case of a symptomatic small subependymal AVM with a single deep drainage vein previously treated unsuccessfully by radiosurgery and transarterial embolization. The AVM was successfully embolized transvenously using Onyx, achieving complete occlusion in a single treatment session.

Transvenous Onyx embolization of a subependymal deep arteriovenous malformation with a single drainage vein: technical note.

Cerebral arteriovenous malformations (AVMs) are uncommon. Treatment options include embolization, radiosurgery and surgery, separately or combined, the final goal being complete occlusion of the malformation. We describe the case of a symptomatic small subependymal AVM with a single deep drainage vein previously treated unsuccessfully by radiosurgery and transarterial embolization. The AVM was successfully embolized transvenously using Onyx, achieving complete occlusion in a single treatment session.

Tailored resections in occipital lobe epilepsy surgery guided by monitoring with subdural electrodes: characteristics and outcome.

PURPOSE: Occipital lobe epilepsy is uncommon in epilepsy surgery series and often difficult to assess due to rapid seizure propagation, misleading seizure semiology and confounding interictal epileptiform activity. Ictal recordings with surface electrodes may not define properly the seizure onset zone in surgical evaluation for intractable occipital epilepsy. Specially in dysplastic lesions, the extension of the epileptogenic zone is not well defined by neuroimaging techniques, therefore, implantation of intracranial electrodes is often indicated. In this study we present our experience with individually tailored resections of occipital lobe epileptic foci guided by monitoring with subdural electrodes. METHODS: Data from interictal and ictal surface and intracranial recordings, neuroimaging, surgical treatment, pathology and outcome of seven patients are presented. RESULTS: The most common seizure type (6/7 patients) was complex partial with temporal lobe semiology, five patients experienced visual auras as part of their complex partial seizures or as separate simple partial seizures. Two patients had seizures suggesting supplementary motor area involvement. One patient had temporal as well as frontal seizure propagation. Neuroimaging showed lesions in 6/7 patients. Pathological studies revealed cortical dysplasia and tumors as the most common causes. Intracranial recordings (6/7 patients) revealed focal onset in 2 patients, regional onset in 2, and diffuse onset in 2. Surgery was performed according to intracranial recordings restricting resections in cases with focal seizure onset (even in large dysplastic lesions) and performing wider resections in patients with regional or diffuse onset. Five of seven patients are seizure free after 12-55 months (mean 24.3). The two remaining patients may be classified as Engel 2b and 3a. CONCLUSIONS: This series of occipital lobe epilepsy surgery shows that, even in patients with cortical dysplasias, restricted resections may have a good outcome and that intracranial monitoring is usually necessary in order to design an individually tailored resection.

Effects of fibroblast growth factor and glial-derived neurotrophic factor on akinesia, F-DOPA uptake and dopamine cells in parkinsonian primates.

Parkinson's disease (PD) is a common neurodegenerative disorder that produces progressive disability despite symptomatic treatment. Several strategies, including stereotaxic brain lesions, deep brain stimulation, transplants of dopamine cells and administration of neurotrophic factors, have been proposed to improve efficacy and to counteract the progression of the disease. We here report the effects of repetitive intracerebral infusion of basic fibroblast growth factor (bFGF) and glial-derived neurotrophic factor, up to 1 year, in Cynomolgus monkeys with long standing asymmetric parkinsonism produced by unilateral intracarotid injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The treatment with neurotrophic factors was initiated when the parkinsonian deficits were stable, 6 months after the administration of MPTP. The evaluation of the response to the neurotrophic factors was performed by blind observers using: clinical scales that measured global motor deficit, motor ability in both hands, apomorphine-induced rotation, determination of the levels of monoamine metabolites in cerebrospinal fluid, and 6-F18-fluoro-l-DOPA (F-DOPA) uptake in the striatum and histology. Both factors, but bFGF more so, improve motor behavior, dopamine metabolism, striatal F-DOPA uptake, and the number of dopamine neurons. The procedure is well tolerated and provides a strong background for efficacy and safety of this treatment in patients with PD.