[Treatment of intrinsic brain tumors located in motor eloquent areas. Results of a protocol based in navigation, tractography and neurophysiological monitoring of cortical and subcortical structures]. / Tratamiento de los tumores cerebrales intrínsecos de áreas motoras elocuentes. Resultados de un protocolo basado en la navegación, tractografía y monitorización neurofisiológica de estructuras corticales y subcorticales.

OBJECTIVES: The role of the microsurgical management of intrinsic brain tumors is to maximize the volumetric resection of the tumoral tissue minimizing the postoperative morbidity. The purpose of our paper has been to study the benefits of an original protocol developed for the microsurgical treatment of tumors located in eloquent motor areas where the navigation and electrical stimulation of motor subcortical pathways have been implemented. MATERIALS AND METHODS: A total of 17 patients operated on for resection of cortical or subcortical tumors in motor areas were included in the series. Preoperative planning for multimodal navigation was done integrating anatomic studies, motor functional MRI (f-MRI) and subcortical pathways volumes generated by diffusion tensor imaging (DTI). Intraoperative neuromonitorization included motor mapping by direct cortical and subcortical electrical stimulation (CS and sCS) and localization of the central sulcus using cortical multipolar electrodes and the N20 wave inversion technique. The location of all cortical and subcortical stimulated points with positive motor response was stored in the navigator and correlated with the cortical or subcortical motor functional structures defined preoperatively. RESULTS: The mean tumoral volumetric resection was 89.1±14.2% of the preoperative volume, with a total resection (≥100%) in twelve patients. Preoperatively a total of 58.8% of the patients had some motor deficit, increasing 24 hours after surgery to 76.5% and decreasing to 41.1% a month later. There was a great correlation between anatomic and functional data, both cortically and subcortically. However, in six cases it was not possible to identify the central sulcus and in many cases fMRI gave contradictory information. A total of 52 cortical points submitted to CS had positive motor response, with a positive correlation of 83.7%. Also, a total of 55 subcortical points had positive motor response, being in these cases 7.3±3.1 mm the mean distance from the stimulated point to the subcortical tract. CONCLUSIONS: The integration of preoperative and intraoperative anatomic and functional studies allows a safe functional resection of the brain tumors located in eloquent areas, compared to the tumoral resection based on anatomic imaging studies. Multimodal navigation allows the integration and correlation among preoperative and intraoperative anatomic and functional data. Cortical motor functional areas are anatomically and functionally located preoperatively thanks to MRI and fMRI and subcortical motor pathways with TDI and tractography. Intraoperative confirmation is done with CS and N20 inversion wave for cortical structures and with sCS for subcortical pathways. With this protocol we achieved a mean of 90% of volumetric resection in cortical and subcortical tumors located in eloquent motor areas with an increase of neurological deficits in the immediate postoperative period that significantly decreased one month later. Ongoing studies will define the safe limits for functional resection taking into account the intraoperative brain shift. Finally, it must be demonstrated if this protocol has any benefit for patients concerning disease free or overall survival.

Tratamiento de los tumores cerebrales intrínsecos de áreas motoras elocuentes. Resultados de un protocolo basado en la navegación, tractografía y monitorizaciónneurofisiológica de estructuras corticales y subcorticales / Treatment of intrinsic brain tumors located in motor eloquent areas. results of a protocol based in navegation, tractography and neurophysiological monitoring of cortical and subcortical structures

Objetivos. El papel actual del tratamiento microquirúrgicode los tumores cerebrales intrínsecos se basaen alcanzar la máxima resección volumétrica del tumorminimizando la morbilidad postoperatoria. El propósitodel trabajo es estudiar los beneficios de un protocolodiseñado para tratar tumores localizados en áreaselocuentes motoras, en el que se incluye la navegación yla estimulación de tractos motores subcorticales.Material y métodos. Se han incluido 17 pacientescon tumores corticales y subcorticales de área motoratratados quirúrgicamente. Para la planificación preoperatoriase fusionaron en el sistema de navegaciónestudios anatómicos, de resonancia funcional motora(RNM-f) y los tractos subcorticales generados porestudios de tensor de difusión (DTI). La monitorizaciónintraoperatoria incluía el mapeo motor por estimulacióncortical y subcortical directa (ECD y EsCD) e identificacióndel surco central por inversión de la onda N20con electrodos corticales multipolares. La localizaciónde los puntos con respuesta positiva a la ECD o EsCD secorrelacionaba con las áreas corticales o tractos funcionalesmotores definidos en los estudios preoperatoriosgracias al navegador.Resultados. La resección volumétrica tumoral mediafue del 89.1±14.2% del volumen tumoral calculado enlos estudios preoperatorios, con resección total (≥100%)en doce pacientes. En el preoperatorio había focalidadneurológica deficitaria motora en el 58.8% de lospacientes, que aumentó al 76.5% a las 24 horas de lacirugía y se redujo a los 30 días al 41.1%. Hubo una (..) (AU)

Objectives. The role of the microsurgical managementof intrinsic brain tumors is to maximize the volumetricresection of the tumoral tissue minimizing thepostoperative morbidity. The purpose of our paper hasbeen to study the benefits of an original protocol developedfor the microsurgical treatment of tumors locatedin eloquent motor areas where the navigation and electricalstimulation of motor subcortical pathways havebeen implemented.Materials and methods. A total of 17 patients operatedon for resection of cortical or subcortical tumors inmotor areas were included in the series. Preoperativeplanning for multimodal navigation was done integratinganatomic studies, motor functional MRI (f-MRI)and subcortical pathways volumes generated by diffusiontensor imaging (DTI). Intraoperative neuromonitorizationincluded motor mapping by direct corticaland subcortical electrical stimulation (CS and sCS) andlocalization of the central sulcus using cortical multipolarelectrodes and the N20 wave inversion technique.The location of all cortical and subcortical stimulatedpoints with positive motor response was stored in thenavigator and correlated with the cortical or subcorticalmotor functional structures defined preoperatively.Results. The mean tumoral volumetric resection (..) (AU)

[Applications of functional magnetic resonance imaging in pre-surgical patients: motor, mnemonic and linguistic functions]. / Aplicaciones de la resonancia magnética funcional en pacientes prequirúrgicos: funciones motora, de memoria y lingüística.

AIMS: This paper reviews and describes cases involving useful protocols for pre-surgical evaluation in functional magnetic resonance imaging (fMRI) of the motor, mnemonic and linguistic functions. DEVELOPMENT: The application of fMRI in pre-surgical evaluation allows us to pinpoint the anatomical location of a function in relation to the lesion. This technique therefore appears as an alternative to the classical intraoperative tests, which are more aggressive and costly. The paper describes aspects and considerations of fMRI with regard to the methodology and procedure employed in its application, as well as the control of contaminating variables that can affect results. The language protocols are described in terms of lateralisation and localisation, and are divided into expressive and receptive language protocols, together with linguistic protocols for overall stimulation that allow the localisation of both expressive and receptive areas. Concerning the motor protocols, we describe the procedures for patients with and without difficulties in their movement. Lastly, we review and describe the memory protocols that give rise to bilateral stimulation in the mesial temporal areas, which allows both lateralisation and localisation of the hippocampal and parahippocampal areas that are functionally significant for the patients' memory. Each of the protocols is illustrated with cases carried out by our work team. CONCLUSIONS: The development of new protocols for pre-surgical evaluation must be guided by greater delimitation and consistency in functional stimulation, as well as analysis of the behaviour displayed.

Aplicaciones de la resonancia magnética funcional en pacientes prequirúrgicos: funciones motora, de memoria y lingüística / Applications of functional magnetic resonance imaging in pre-surgical patients: motor, mnemonic and linguistic functions

Objetivo. Este artículo revisa y presenta casos sobre protocolos útiles de evaluación prequirúrgica en resonancia magnética funcional (RMf) de las funciones motoras, mnésicas y lingüísticas. Desarrollo. La aplicación de la RMf en la evaluación prequirúrgica permite referenciar la localización anatómica de una función en relación con la lesión. En este sentido, esta técnica se plantea como alternativa a las pruebas clásicas intraoperatorias, que son más invasivas y costosas. El artículo reseña aspectos y consideraciones propias de la RMf en relación con su metodología y procedimiento de aplicación, además del control de variables contaminantes que pueden afectar a los resultados. Los protocolos de lenguaje se describen en términos de lateralización y localización, y se distinguen protocolos de lenguaje expresivo y receptivo, además de protocolos lingüísticos de activación global que permiten localizar tanto áreas expresivas como receptivas. En relación con los protocolos motores, se describen los procedimientos para pacientes con y sin dificultades de movimiento. En último lugar, se revisan y describen los protocolos de memoria que producen una activación bilateral en las áreas temporales mesiales, que permiten tanto la lateralización como la localización de las áreas hipocampales y parahipocampales funcionalmente elocuentes para la memoria de los pacientes. Cada uno de los protocolos se ilustra con casos llevados a cabo por nuestro equipo de trabajo. Conclusiones. La mayor delimitación y consistencia en la activación funcional, así como el análisis de la conducta manifiesta, deben guiar el desarrollo de nuevos protocolos de evaluación prequirúrgica (AU)

Aims. This paper reviews and describes cases involving useful protocols for pre-surgical evaluation in functional magnetic resonance imaging (fMRI) of the motor, mnemonic and linguistic functions. Development. The application of fMRI in presurgical evaluation allows us to pinpoint the anatomical location of a function in relation to the lesion. This technique therefore appears as an alternative to the classical intraoperative tests, which are more aggressive and costly. The paper describes aspects and considerations of fRMI with regard to the methodology and procedure employed in its application, as well as the control of contaminating variables that can affect results. The language protocols are described in terms of lateralisation and localisation, and are divided into expressive and receptive language protocols, together with linguistic protocols for overall stimulation that allow the localisation of both expressive and receptive areas. Concerning the motor protocols, we describe the procedures for patients with and without difficulties in their movement. Lastly, we review and describe the memory protocols that give rise to bilateral stimulation in the mesial temporal areas, which allows both lateralisation and localisation of the hippocampal and parahippocampal areas that are functionally significant for the patients’ memory. Each of the protocols is illustrated with cases carried out by our work team. Conclusions. The development of new protocols for pre-surgical evaluation must be guided by greater delimitation and consistence in functional stimulation, as well an analysis of the behaviour displayed (AU)

[Assessment of the degree of resection of high grade supratentorial gliomas with early postoperative magnetic resonance]. / Valoración del grado de resección de los gliomas supratentoriales de alto grado con resonancia magnética postoperatoria precoz.

UNLABELLED: In this paper we report the results of a prospective study in which we evaluate the degree of tumor removal of 25 supratentorial high grade gliomas by means of an MRI performed in the early postoperative period. In all cases, there was preoperative enhancement 8 patients had been previously operated on while the others had their first operation. In all cases the postoperative early MRI was performed within the first week and in 15 within the first 3 days. In order to evaluate the degree of tumor removal the presence or not of enhancement was considered and if it existed, classified as linear or nodular. RESULTS: To avoid postsurgical artifacts it is important to perform the MRI as soon as possible after surgery, especially within the first 3 days. Generally, linear enhancement disappeared on subsequent follow-up examinations, showing that it probably does no represent residual, tumor while nodular enhancement usually does. Survival with the high-grade tumors was slightly higher in the group without postoperative enhancement or linear one than in the group with nodular enhancement but the difference was not significant.