Gliomas difusos en áreas elocuentes: avances diagnósticos y terapéuticos / Diffuse gliomas within eloquent areas: diagnostic and therapeutic advances

Objetivo: presentar los avances diagnósticos, moleculares y radiológicos, así como en las estrategias terapéuticas para gliomas difusos en los últimos 5 años (2018-2023) en la Fundación Universitaria de Ciencias de la Salud (FUCS), Bogotá D.C., Colombia. Materiales y métodos: se describen las técnicas diagnósticas y terapéuticas utilizadas para gliomas difusos con casos ilustrativos. Resultados: se muestran los avances de las herramientas diagnósticas y terapéuticas para el manejo de gliomas difusos. Discusión: en los últimos 5 años se ha avanzado en la clasificación, diagnóstico y tratamiento de los gliomas difusos, gracias a los avances tecnológicos como los marcadores moleculares, la tractografía y la fusión de imágenes para la neuronavegación y las técnicas de estimulación cortical. Esto ha permitido que el tratamiento de los pacientes con dichos tumores mejore la tasa de morbilidad, la calidad de vida libre de enfermedad y la supervivencia global. Conclusiones: las técnicas de diagnóstico como la tractografía, la fusión integral de imágenes intraoperatorias y el mapeo cerebral electrofisiológico con estimulación cortical y subcortical han mejorado el diagnóstico y tratamiento de los gliomas difusos.

Objective: to present the diagnostic, molecular, radiological, and therapeutic advances, to address diffuse gliomas, made at Fundación Universitaria de Ciencias de la Salud (FUCS), Bogotá D.C., Colombia, in the last 5 years (2018-2023). Materials and methods: diagnostic and therapeutic techniques to address diffuse gliomas are described through illustrative cases. Results: the advances in diagnostic and therapeutic tools for managing diffuse gliomas, are shown. Discussion: in the last 5 years progress in characterizing, diagnosing, and treating diffuse gliomas, thanks to technological breakthroughs, such as molecular markers, tractography, image fusion for neuronavigation, and cortical stimulation techniques, has been achieved. This has allowed improving morbidity rate, disease-free quality of life and overall survival through the treatment provided to patients afflicted with gliomas. Conclusions: Diagnostic techniques based on tractography, comprehensive intraoperative image fusion, and electrophysiological brain mapping with cortical and subcortical stimulation, have improved the diagnostic and therapeutic approaches for diffuse gliomas.

Practical aspects of functional mri in clinical examinations / Aspectos práticos de rm funcional em exames clínicos / Aspectos prácticos de la rm funcional en los exámenes clínicos

The eloquent cerebral cortices are involved in movement, sensation, speech, vision, and higher cortical functions. Functional magnetic resonance imaging (fMRI) allows the evaluation of brain function, aiding in neurosurgical planning by mapping eloquent cortical areas. Considering the high cost of the hardware involved, the purpose of this work is to present a more affordable, in-house alternative for these studies that can provide adequate results in a clinical setting. We also present some practical information on how to perform these exams. We describe an affordable in-house hardware solution used by an imaging center, and examples of fMRI paradigms used to evaluate motor and language tasks. The fMRI studies show robust activations in eloquent areas consistent with the tasks performed on the exam. Images of post-processed studies illustrate clinical cases. The fMRI have well-established applications, mapping eloquent cortical areas in patients with brain lesions. In the case of surgical planning, it allows the surgeon to maximize the resection area while minimizing sequelae. More affordable hardware can reduce the cost of these exams, making them more accessible to the general public.

O córtex cerebral eloquente está envolvido nas atividades motora, sensação, fala, visão e funções corticais superiores. A ressonância magnética funcional (RMf) permite a avaliação da função cerebral, ajudando no planejamento neurocirúrgico através do mapeamento de áreas corticais eloquentes. Considerando o elevado custo do hardware envolvido, o objetivo deste trabalho é apresentar uma alternativa mais acessível para estes estudos, que possa fornecer resultados adequados em um ambiente clínico. Também apresentamos algumas informações práticas sobre a realização destes exames. Descrevemos uma solução de hardware acessível utilizada por um centro de imagens, e exemplos de paradigmas de RMf usados para avaliar tarefas motoras e relacionadas à fala. Os estudos de RMf mostram ativações em áreas eloquentes, consistentes com as tarefas realizadas no exame com imagens de estudos pós-processados ilustrando casos clínicos. A RMf tem aplicações bem estabelecidas, mapeando áreas corticais eloquentes em pacientes com lesões cerebrais. No caso do planejamento cirúrgico, permite que o cirurgião maximize a área de ressecção enquanto minimiza potenciais sequelas. Equipamentos mais acessíveis podem reduzir o custo destes exames, podendo aumentar a disponibilização ao público em geral.

La corteza cerebral elocuente está implicada en las actividades motoras, la sensibilidad, el habla, la visión y las funciones corticales superiores. La resonancia magnética funcional (RMf) permite la evaluación de la función cerebral, ayudando en la planificación neuroquirúrgica mediante el mapeo de las áreas corticales elocuentes. Teniendo en cuenta el elevado coste del hardware implicado, el objetivo de este artículo es presentar una alternativa más asequible para estos estudios que pueda proporcionar resultados adecuados en un entorno clínico. También presentamos información práctica sobre cómo realizar estos exámenes. Describimos una solución de hardware asequible utilizada por un centro de diagnóstico por imagen, y ejemplos de paradigmas de RMf utilizados para evaluar tareas motoras y relacionadas con el habla. Los estudios de RMf muestran activaciones en áreas elocuentes, coherentes con las tareas realizadas en el examen, con imágenes de estudios postprocesados que ilustran casos clínicos. La RMf tiene aplicaciones bien establecidas en el mapeo de áreas corticales elocuentes en pacientes con lesiones cerebrales. En el caso de la planificación quirúrgica, permite al cirujano maximizar el área de resección minimizando las posibles secuelas. Un equipo más asequible puede reducir el coste de estas exploraciones, aumentando potencialmente su disponibilidad para el público en general.

Intraoperative brain mapping during awake surgery in symptomatic supratentorial cavernomas / Mapeo cerebral intraoperatorio con paciente despierto en la cirugía de cavernomas supratentoriales sintomáticos

Background Complete resection of symptomatic supratentorial cavernoma (SCA) and removal of the surrounding gliotic area is recommended to minimize the risk of persistent seizures or (re)bleeding. Surgery of SCA located in an eloquent area, can carry out severe postoperative neurological morbidity. We report a study aimed to assess feasibility, extent of resection and outcome after surgical removal of CA by cortico-subcortical intraoperative brain stimulation (ioBS) in the awake patient. Methods Six patients diagnosed of symptomatic SCA located on an eloquent area and operated on while awake under local anaesthesia ioBS, were included. Preoperative planning included neuropsychologic assessment of language-related functions, sociocognitive functions and executive functions. Intraoperatively, we recorded the results achieved in the planned neuropsychological tasks when stimulation was applied (cortical and subcortical). Postoperative control 3D MRI was scheduled at 1 month after surgery to calculate extent of resection. Neuropsychological assessment at 6 months after surgery was performed in all cases. Results Six patients (5 females, 1 male) aged 24–48 years were included in our study. Locations of the lesions were right insular (n=1), left insular (n=1), left temporo-insular (n=1), left temporal (n=2) and left frontal (n=1). In all patients, positive findings were obtained during ioBS. In 5 patients, complete surgical resection was achieved. Two patients had postoperative transient neurological deficits, one case of hemiparesis, one case of dysnomia, both cleared over a 6-month period. Clinical follow-up revealed that all patients experienced complete recovery from preoperative symptoms within a year and five patients with seizures showed marked improvement and eventually quit antiepileptic drugs. Neuropsychological assessment at 6 months provided normal results compared to preoperative baseline in all domains (AU)

Antecedentes y objetivo La resección completa de los cavernomas supratentoriales (SCA) sintomáticos, incluyendo el área gliótica perilesional, es el tratamiento de elección para evitar la persistencia de crisis y el resangrado. La cirugía de los SCA localizados en áreas elocuentes puede asociar graves complicaciones neurológicas. Presentamos un estudio cuyo objetivo es documentar la viabilidad de la estimulación corticosubcortical intraoperatoria (ioBS) en el paciente despierto y su impacto en el grado de exéresis y el resultado clínico final. Materiales y métodos Incluimos 6 pacientes diagnosticados de SCA sintomático localizado en área elocuente, que fueron intervenidos mediante ioBS en el paciente despierto. El estudio preoperatorio incluyó una valoración neuropsicológica de funciones lingüísticas, sociocognitivas y ejecutivas. Durante la realización de la ioBS en el paciente despierto registramos los resultados obtenidos por los pacientes en las tareas neuropsicológicas planificadas. El grado de exéresis se estimó en una RM realizada un mes tras la cirugía. A los 6 meses de la cirugía se realizó una evaluación neuropsicológica de control. Resultados Cinco mujeres y un hombre con edades comprendidas entre los 24 y 48 años fueron incluidos en el estudio. Las localizaciones de los cavernomas fueron insular derecha (n=1), insular izquierda (n=1), temporo-insular izquierda (n=1), temporal izquierda (n=2) y frontal izquierda (n=1). En todos los pacientes se encontraron hallazgos tras la ioBS. Se obtuvo una exéresis completa en 5 casos. Dos pacientes presentaron déficit neurológico transitorio, un caso de hemiparesia y un caso de disnomia, que mejoró a los 6 meses (AU)

Intraoperative brain mapping during awake surgery in symptomatic supratentorial cavernomas.

BACKGROUND: Complete resection of symptomatic supratentorial cavernoma (SCA) and removal of the surrounding gliotic area is recommended to minimize the risk of persistent seizures or (re)bleeding. Surgery of SCA located in an eloquent area, can carry out severe postoperative neurological morbidity. We report a study aimed to assess feasibility, extent of resection and outcome after surgical removal of CA by cortico-subcortical intraoperative brain stimulation (ioBS) in the awake patient. METHODS: Six patients diagnosed of symptomatic SCA located on an eloquent area and operated on while awake under local anaesthesia ioBS, were included. Preoperative planning included neuropsychologic assessment of language-related functions, sociocognitive functions and executive functions. Intraoperatively, we recorded the results achieved in the planned neuropsychological tasks when stimulation was applied (cortical and subcortical). Postoperative control 3D MRI was scheduled at 1 month after surgery to calculate extent of resection. Neuropsychological assessment at 6 months after surgery was performed in all cases. RESULTS: Six patients (5 females, 1 male) aged 24-48 years were included in our study. Locations of the lesions were right insular (n=1), left insular (n=1), left temporo-insular (n=1), left temporal (n=2) and left frontal (n=1). In all patients, positive findings were obtained during ioBS. In 5 patients, complete surgical resection was achieved. Two patients had postoperative transient neurological deficits, one case of hemiparesis, one case of dysnomia, both cleared over a 6-month period. Clinical follow-up revealed that all patients experienced complete recovery from preoperative symptoms within a year and five patients with seizures showed marked improvement and eventually quit antiepileptic drugs. Neuropsychological assessment at 6 months provided normal results compared to preoperative baseline in all domains. CONCLUSIONS: Our study suggests that ioBS in the awake surgery of symptomatic SCA located in eloquent areas, allows to increase the rate of complete resection, minimizing postoperative neurological and neuropsychological deficit, and improving postoperative seizures control.

Intraoperative brain mapping during awake surgery in symptomatic supratentorial cavernomas.

BACKGROUND: Complete resection of symptomatic supratentorial cavernoma (SCA) and removal of the surrounding gliotic area is recommended to minimize the risk of persistent seizures or (re)bleeding. Surgery of SCA located in an eloquent area, can carry out severe postoperative neurological morbidity. We report a study aimed to assess feasibility, extent of resection and outcome after surgical removal of CA by cortico-subcortical intraoperative brain stimulation (ioBS) in the awake patient. METHODS: Six patients diagnosed of symptomatic SCA located on an eloquent area and operated on while awake under local anaesthesia ioBS, were included. Preoperative planning included neuropsychologic assessment of language-related functions, sociocognitive functions and executive functions. Intraoperatively, we recorded the results achieved in the planned neuropsychological tasks when stimulation was applied (cortical and subcortical). Postoperative control 3D MRI was scheduled at 1 month after surgery to calculate extent of resection. Neuropsychological assessment at 6 months after surgery was performed in all cases. RESULTS: Six patients (5 females, 1 male) aged 24-48 years were included in our study. Locations of the lesions were right insular (n=1), left insular (n=1), left temporo-insular (n=1), left temporal (n=2) and left frontal (n=1). In all patients, positive findings were obtained during ioBS. In 5 patients, complete surgical resection was achieved. Two patients had postoperative transient neurological deficits, one case of hemiparesis, one case of dysnomia, both cleared over a 6-month period. Clinical follow-up revealed that all patients experienced complete recovery from preoperative symptoms within a year and five patients with seizures showed marked improvement and eventually quit antiepileptic drugs. Neuropsychological assessment at 6 months provided normal results compared to preoperative baseline in all domains. CONCLUSIONS: Our study suggests that ioBS in the awake surgery of symptomatic SCA located in eloquent areas, allows to increase the rate of complete resection, minimizing postoperative neurological and neuropsychological deficit, and improving postoperative seizures control.

Neuropsychological management of the awake patient surgery: A protocol based on 3-year experience with glial tumors. / Protocolo de intervención neuropsicológica en la cirugía del paciente despierto: experiencia de 3 años con tumores gliales.

INTRODUCTION: Glial brain tumours usually require neurosurgical treatment and they are associated with cognitive, emotional and behavioural impairments. Awake intraoperative brain mapping is the gold standard technique used to optimize the onco-functional balance. Neuropsychological assessment and intervention have relevance in this type of procedures. Currently, there is a lack of protocolled structure for the neuropsychological intervention being able to satisfy patient needs. METHOD: A retrospective descriptive study of 52 patients was performed, all of them with a diagnosis of glial tumour. The structure of the protocol developed in our centre is reported, also data of neuropsychological evaluation, comparing baseline performance with both immediate posterior performance, and long term performance. RESULTS: We describe our experience in each step of the intervention, highlighting the development of eight neurocognitive protocols for intraoperative brain mapping. The results of the neuropsychological examination objectify deficits in the immediate after surgery assessment which are reduced in the long-term assessment. CONCLUSIONS: We emphasize the need of providing and structuring the cognitive and emotional aspects of patients suffering from any pathology that entails acquired brain damage in hospital environment. This type of approach is aimed at increasing the quality of life of cancer patients by structuring and optimizing tasks during their surgical intervention and attending to the neuropsychological difficulties they suffer.

Awake surgery with cortical-subcortical mapping in diffuse gliomas adjacent to central lobe. Report of two cases and literature review.

INTRODUCTION: Diffuse gliomas are brain neoplasms with an infiltrative growing pattern to cortical and subcortical structures, frequently adjacent to eloquent areas; direct cortical and subcortical stimulation in awake craniotomy is a useful tool to achieve a gross total resection with the least neurological deficit. PRESENTATION OF CASES: A 24 years old male presented with tonic-clonic seizures. The magnetic resonance imaging (MRI) showed a left parietal glioma. Awake craniotomy was performed using neuronavigation system and brain mapping with cortical and subcortical stimulation. Functional areas were found at the rostral margin of the tumor; however, the rest of the tumor was almost totally resected. Patient was discharged without neurological deficit. A 29 years old male presented in two occasions generalized tonic-clonic seizures, with right hemiparesis. The MRI showed a left parietal glioma. Awake craniotomy was performed using neuronavigation system and brain mapping with cortical and subcortical stimulation, achieving a gross total resection. Patient was discharged without neurological deficit. CONCLUSIONS: Awake craniotomy with brain mapping by cortical and subcortical stimulation and neuronavigation, are the best assets to treat diffuse gliomas and achieve a gross total resection, ensuring the major disease-free interval and preserving the function of eloquent areas.

INTRODUCCIÓN: Los gliomas difusos son neoplasias cerebrales con un patrón de crecimiento infiltrativo, frecuentemente adyacentes a áreas elocuentes. El mapeo cerebral con estimulación cortico-subcortical con el paciente despierto es una herramienta útil para lograr la mayor resección con el menor déficit posoperatorio. PRESENTACIÓN DE CASOS: Varón de 24 años con crisis tónico-clónicas. La resonancia magnética (RM) mostró un glioma parietal izquierdo. Se realizó cirugía con el paciente despierto y mapeo cerebral por estimulación cortical y subcortical directa. Se obtuvo una resección casi total, ya que se encontraron áreas fucionales en el borde rostral del tumor. El paciente egresó sin déficit neurológico. Varón de 29 años que presenta crisis tónico-clónicas generalizadas, acompañadas de hemiparesia derecha. La RM reportó un glioma parietal izquierdo. Se realizó cirugía con el paciente despierto y mapeo cerebral por estimulación cortical y subcortical directa. Se logró una resección total y el paciente egresó sin déficit. CONCLUSIONES: La cirugía con el paciente despierto con mapeo por estimulación directa y neuronavegación es la mejor opción en el tratamiento de los gliomas difusos, para lograr una resección máxima tumoral asegurando un mayor tiempo libre de enfermedad y la conservación de la función de áreas elocuentes.

[Neurophysiological monitoring options in brain tumour resections. Consensus statement from the Spanish Society of Neurosurgery's (SENEC) Neuro-oncology Working Group and the Spanish Society of Clinical Neurophysiology (SENFC)]. / Opciones de monitorización neurofisiológica en la resección de tumoraciones cerebrales. Documento de consenso entre el Grupo de Trabajo de Neurooncología de la Sociedad Española de Neurocirugía (SENEC) y la Sociedad Española de Neurofisiología Clínica (SENFC).

Brain tumours located in or in proximity to eloquent areas are a significant neurosurgical challenge. Performing this kind of surgery with neurophysiological monitoring to improve resections with reduced permanent focal neurological deficit has become widely accepted in the literature. However, how to conduct this monitoring, the exact definition of an eloquent area and whether to perform this surgery with the patient awake or asleep are still subject to rigorous scientific debate. Members of the Neuro-oncology Working Group (GTNO) of the Spanish Society of Neurosurgery (SENEC) and members of the Spanish Society of Clinical Neurophysiology (SENFC) have published a consensus statement to explain the different neurophysiological monitoring options currently available in awake and asleep patients to obtain better surgical resection without neurological deficits. An exhaustive review of the literature has also been conducted.

Valor pronóstico del mapeo cerebral en la recuperación funcional del paciente con enfermedad cerebrovascular isquémica / Pronostic value of brain mapping in the functional recovery of patients with ischemic cerebrovascular disease

Se efectuó un estudio descriptivo longitudinal y prospectivo de 22 pacientes con ictus isquémico, que fueron ingresados en el Hospital General Docente "Dr. Juan Bruno Zayas Alfonso" de Santiago de Cuba desde enero de 2010 hasta igual mes de 2011, con vistas a establecer un pronóstico de recuperación funcional a partir del mapeo cerebral. Se realizó la valoración neurofisiológica y funcional mediante el índice de Barthel. En la serie estudiada la edad media fue de 57,2 años y predominó el sexo masculino. El mapeo cerebral se caracterizó por la presencia de actividad lenta (theta, delta) y disminución de beta y alfa en regiones corticales ipsilaterales y contralaterales al territorio afectado por el foco isquémico; asimismo, la magnitud de estas alteraciones se correlacionó estrechamente con la ganancia funcional. La disminución de energía en las bandas alfa, asociada al incremento de esta en las bandas theta y delta, de tipo global, constituyeron índices de mal pronóstico rehabilitador.

A longitudinal and prospective descriptive study was made in 22 patients with ischemic ictus that were admitted to "Dr. Juan Bruno Zayas Alfonso" Teaching General Hospital in Santiago de Cuba from January, 2010 to the same month of 2011, aimed at establishing a prognosis of functional recovery from the cerebral mapping. A neurophysiological and functional evaluation was carried out by means of Barthel index. In the studied series the mean age was 57.2 years and the male sex prevailed. Cerebral mapping was characterized by the presence of slow activity (theta, delta) and beta and alpha decreases in cortical ipsilateral and contralateral regions to the territory affected by the ischemic focus; likewise, the magnitude of these changes was closely correlated with the functional gain. The energy decrease in the alpha bands associated with its increment in the theta and delta bands, of global type, constituted rates of bad rehabilitation prognosis.

Valor pronóstico del mapeo cerebral en la recuperación funcional del paciente con enfermedad cerebrovascular isquémica / Pronostic value of brain mapping in the functional recovery of patients with ischemic cerebrovascular disease

Se efectuó un estudio descriptivo longitudinal y prospectivo de 22 pacientes con ictus isquémico, que fueron ingresados en el Hospital General Docente Dr Juan Bruno Zayas Alfonso de Santiago de Cuba desde enero de 2010 hasta igual mes de 2011, con vistas a establecer un pronóstico de recuperación funcional a partir del mapeo cerebral. Se realizó la valoración neurofisiológica y funcional mediante el índice de Barthel. En la serie estudiada la edad media fue de 57,2 años y predominó el sexo masculino. El mapeo cerebral se caracterizó por la presencia de actividad lenta (theta, delta) y disminución de beta y alfa en regiones corticales ipsilaterales y contralaterales al territorio afectado por el foco isquémico; asimismo, la magnitud de estas alteraciones se correlacionó estrechamente con la ganancia funcional. La disminución de energía en las bandas alfa, asociada al incremento de esta en las bandas theta y delta, de tipo global, constituyeron índices de mal pronóstico rehabilitador(AU)

A longitudinal and prospective descriptive study was made in 22 patients with ischemic ictus that were admitted to Dr Juan Bruno Zayas Alfonso Teaching General Hospital in Santiago de Cuba from January, 2010 to the same month of 2011, aimed at establishing a prognosis of functional recovery from the cerebral mapping. A neurophysiological and functional evaluation was carried out by means of Barthel index. In the studied series the mean age was 57.2 years and the male sex prevailed. Cerebral mapping was characterized by the presence of slow activity (theta, delta) and beta and alpha decreases in cortical ipsilateral and contralateral regions to the territory affected by the ischemic focus; likewise, the magnitude of these changes was closely correlated with the functional gain. The energy decrease in the alpha bands associated with its increment in the theta and delta bands, of global type, constituted rates of bad rehabilitation prognosis(AU)

Resección de lesiones cerebrales con asistencia de mapeo cortical intraoperatorio / Intraoperative cortical mapping in surgery for brain lesions

Introducción: Se ha demostrado que la resección extensa de tumores intracraneanos intra-axiales malignos mejora la sobrevida. Esto no siempre es posible dada la eventual ubicación de estos tumores en o cercanos a áreas elocuentes, como corteza motora primaria o de lenguaje. En estas circunstancias, el desafío es evitar secuelas neurológicas. Uno de los métodos para disminuir dicho riesgo es el mapeo cortical intraoperatorio (MCI). El presente trabajo describe la técnica de mapeo cortical intraoperatorio de áreas elocuentes, al igual que su factibilidad y complementariedad con otras técnicas de localización tumoral. Método: Se analizan 7 pacientes operados, portadores de lesiones cercanas a áreas elocuentes. Se utilizó neuronavegación y MCI (estimulación directa de corteza y registro de potenciales evocados somatosensoriales). Se analizó la localización, tamaño y tipo de la lesión, grado de resección y estado neurológico pre y postoperatorio. Resultados: En todos los pacientes el MCI fue efectivo en localizar corteza motora primaria. Hubo 6 pacientes en los que se pudo resecar el área tumoral no asociada a funcionalidad, logrando en 5 de ellos resección completa o superior al 90 por ciento. En un paciente la lesión correspondió a una malformación arteriovenosa profunda ubicada en corteza motora primaria en que el MCI permitió una vía de abordaje por corteza no elocuente para su resección completa. No hubo déficit neurológico agregado postoperatorio con seguimiento de 12 meses. Conclusión: El MCI es útil y localiza en forma efectiva, simple y reproducible áreas de corteza funcional, haciendo posible realizar resecciones extensas de tumores en áreas elocuentes. Esta técnica es complementaria a otros métodos de ubicación anatómica y fisiológica pudiendo contribuir a una cirugía más segura y efectiva.

Introduction: Extensive resection for malignant intraaxial intracranial tumors has been demonstrated to improve survival. This is not always possible due to potential tumor location in or next to eloquent brain regions, like primary motor cortex or speech areas. In this case, avoiding neurological deficits is challenging. One of the tools for minimizing that risk is intraoperative cortical mapping (ICM). This report describes the ICM technique of eloquent brain regions, feasibility and complementariness with other methods for tumor localization. Methods: Seven patients with brain lesions near eloquent regions operated on were analyzed. Frameless stereotaxis (neuronavigation) and intraoperative cortical mapping (direct cortical stimulation and monitoring of somatosensory evoked potentials) were used. The location, size, type of lesion, amount of resection, pre and postoperative neurological status were studied. Results: ICM was effective in localizing primary motor cortex in all patients. In 6 patients the tumor area without functionality was removed, achieving complete or greater than 90 percent resection in 5 of them. In one patient the lesion was a deep arteriovenous malformation located below the primary motor cortex. In this case ICM made feasible an approach from non-eloquent cortex to achieve total resection. No new postoperative deficit was found in a 12 month follow-up period. Conclusion: ICM is useful and localize functional cortical regions effectively, simply and reliably, making possible to perform extensive tumor resections in eloquent regions. This technique is complementary to other tools for anatomical or physiological localization and could contribute to a safer and more effective surgery.

Alteraciones neuroeléctricas en el estrabismo / Neuroelectric alterations in strabismus

Introducción: La neurometría mide cualitativa y cuantitativamente la actividad bioeléctrica cerebral obtenida a partir del mapeo cerebral digitalizado; permite conocer el desempeño de las vías de interconexión cortas y largas contenidas en la sustancia blanca mediante el análisis de las coherencias. Nuestro objetivo fue demostrar las alteraciones neurométricas en la corteza cerebral en el estrabismo esencial. Material y métodos: Estudio transversal, descriptivo y observacional en el que se analizaron 23 parámetros de la actividad eléctrica cerebral obtenidos a partir del examen neurométrico en 16 niños con estrabismo esencial; los resultados fueron comparados con los parámetros internacionales NeuroGuide. Resultados: Se observaron alteraciones neurométricas en todos los casos analizados: hipocoherencia intertemporal, incremento de las ondas lentas, disminución de la frecuencia en lóbulos temporales, hipersimetría en lóbulos occipitales, disminución y asimetría en el poder de ambos lóbulos frontales. Conclusiones: Los pacientes con estrabismo esencial tienen alteraciones en las vías de interconexión córtico-corticales, córtico-subcorticales intra e interhemisféricas. El estudio sugiere que las alteraciones se deben a cambios funcionales en la sustancia blanca probablemente relacionados con la fisiopatogenia de la enfermedad.

BACKGROUND: Neurometry measures bioelectrical cerebral activity qualitatively and quantitatively and is obtained from digital cerebral mapping. This methodology allows determination of the efficiency of short and long association tracts contained in the white matter through coherence analysis. Our objective was to demonstrate neurometric alterations in the cerebral cortex of subjects with essential strabismus. METHODS: We carried out a cross-sectional, descriptive and observational study. There were 23 parameters analyzed of the electrical activity of the cerebralcortex. These parameters were obtained using neurometric analysis of 16 children with essential strabismus. Results were compared with international standards of NeuroGuide. RESULTS: Neurometric alterations were observed in all cases analyzed: intertemporal hypocoherence, increase in slow waves, decrease in the frequency in temporal lobes, increase in symmetry in occipital lobes, and decline and asymmetry in the power of both frontal lobes. CONCLUSIONS: Strabismal patients have alterations in cortico-cortical, cortico-subcortical and interhemispheric interconnection pathways. The study suggests that the presence of these alterations is due to functional changes in the white matter and that these changes may be related to the pathophysiogenesis of disease.

Resección de lesiones cerebrales en area rolándica con mapeo cortical intraoperatorio* / Resection of brain lesions in rolandic area with intraoperative cortical mapping

Objetivo. Describir los resultados obtenidos con el mapeo cortical intraoperatorio en el tratamiento de los tumores rolándicos. Método. El estudio se realizó en 27 pacientes (mayo 2000 - mayo 2005) entre 27 y 78 años (16M-11F) con tumores intracraneanos ubicados en el área central. En todos los casos se efectuaron técnicas de localización funcional y se utilizaron potenciales evocados somatosensitivos intraoperatorios y estimulación cortical bipolar. Resultados. La resección fue total en 24 casos y subtotal en 3 casos. En los 23 pacientes que presentaban algún déficit motor previo a la cirugía se logró la mejoría en 17 de ellos, permaneciendo estables 5 y sólo 1 caso padeció un empeoramiento transitorio. Ningún paciente sin déficit previo lo padeció después. No se registraron complicaciones relacionadas con el procedimiento de localización. Conclusión. El mapeo cortical intraoperatorio es una técnica segura y confiable para la preservación de la corteza elocuente en la cirugía de tumores del área rolándica.

Objective: To describe the results obtained with intraoperative cortical mapping in the surgical treatment of rolandic tumors. Method: We studied 27 patients (may 2000-may 2005) between 27 and 78 years old (16 males-11 females) with intracranial tumors located in the rolandic area. In all cases we used techniques of functional localization and, intraoperative somatosensorial evoked potentials and bipolar cortical stimulation. Results: In 24 cases removal was total and in 3 cases was subtotal. Of the 23 cases with preoperative motor symptoms, postoperatively 17 were improved, 5 remained stable and 1 deteriorated transiently. No patient without preoperative deficits was worst. We did not have complications related to the localization procedure. Conclusion: Intraoperative cortical mapping is a safe and sound technique for the preservation of the eloquent cortex during surgery of rolandic tumors.

Participación y neuromodulación de la corteza extraestriada en estrabismo / Participation and neuromodulation of extrastriate cortex in strabismus

Introducción: algunas manifestaciones del estrabismo comparten con la epilepsia un origen cortical. Objetivo: correlacionar los hallazgos neurofuncionales y los cambios neuroadaptativos durante el manejo de una variedad de estrabismo concerniente a la presencia de un foco epileptógeno en fase ictal. Paciente y métodos: estudio prospectivo y observacional de una paciente con "síndrome estrábico de variabilidad angular" (SEVA), en quien se aplican diversos estudios neurofisiológicos en épocas distintas: mapeo cerebral digital, tomografía computada de emisión de fotón único (SPECT), electroculografía (EOG) y filmación infrarroja. Resultados: endotropia de rango variable y supresión, que durante el tratamiento cambia transitoriamente a desviación horizontal disociada (DHD) y finalmente a endoforia compensada. El primer mapeo mostró actividad lenta y paroxística, brotes de alto voltaje y mayor potencia temporal derecha; el segundo mostró asimetría de potencia y retraso en la electrogénesis y el tercero fue normal. El primer SPECT manifestó zona focal de hiperactividad metabólica epileptógena en fase ictal en región temporal derecha y zona de hipoperfusión focalizada frontoparietal izquierda, el segundo SPECT reveló disminución de la actividad en la zona hipermetabólica y del área de la zona hipometabólica. Los EOG y la filmación mostraron durante el tratamiento mejoría de la ganancia e incomitancia horizontal. Conclusiones: se evidenció la correlación entre actividad cortical ictal y esta variedad de estrabismo, además de algunos cambios neuroadaptativos que incluyeron disminución de la actividad epileptógena, la ganancia, la incomitancia horizontal y la coherencia interhemisférica, se observó también aumento en la frecuencia y la potencia hacia las regiones posteriores del cerebro.

Introduction: some strabismic manifestations share a cortical origen with epilepsy. Objective: prospective observational study of a patient with "variable angle strabismic syndrome" (VASS) in whom several neurophysiologic studies are conducted at different times: digital cerebral mapping: single photon emission computed tomography (DVD) and finally to compensated endoforia The first mapping showed slow and paroxistic activity; spikes of high voltage and higher right temporal potency. The second mapping showed potency asymetry and electrogenesis delay. Third mapping was normal. First SPECT showed a focal zone of epileptogenic metabolic hyper-activity in ictal phase at the right temporal region and a left frontoparietal focalized hypoperfresed zone. The second SPECT showed diminished activity in the hypermetabolic zone, and diminished area of the hypometabolic zone. EOG and films showed gain and horizontal inconsistence improvement. Conclusions: a correlation was found between cortical ictal activity and this type of strabismus, besides some neuroadaptative changes that included reduced epileptogenic activity, gain, horizontal incomitance and interhemispheric coherence. A rise in frequency and potency towards posterior regions of the brain was also observed.