Hemodynamic response function description in patients with glioma.

INTRODUCTION: Functional magnetic resonance imaging is a powerful tool that has provided many insights into cognitive sciences. Yet, as its analysis is mostly based on the knowledge of an a priori canonical hemodynamic response function (HRF), its reliability in patients' applications has been questioned. There have been reports of neurovascular uncoupling in patients with glioma, but no specific description of the Hemodynamic Response Function (HRF) in glioma has been reported so far. The aim of this work is to describe the HRF in patients with glioma. METHODS: Forty patients were included. MR images were acquired on a 1.5T scanner. Activated clusters were identified using a fuzzy general linear model; HRFs were adjusted with a double-gamma function. Analyses were undertaken considering the tumor grade, age, sex, tumor location, and activated location. RESULTS: Differences are found in the occipital, limbic, insular, and sub-lobar areas, but not in the frontal, temporal, and parietal lobes. The presence of a glioma slows the time-to-peak and onset times by 5.2 and 3.8 % respectively; high-grade gliomas present 8.1 % smaller HRF widths than low-grade gliomas. DISCUSSION AND CONCLUSION: There is significant HRF variation due to the presence of glioma, but the magnitudes of the observed differences are small. Most processing pipelines should be robust enough for this magnitude of variation and little if any impact should be visible on functional maps. The differences that have been observed in the literature between functional mapping obtained with magnetic resonance vs. that obtained with direct electrostimulation during awake surgery are more probably due to the intrinsic difference in the mapping process: fMRI mapping detects all recruited areas while intra-surgical mapping indicates only the areas indispensable for the realization of a certain task. Surgical mapping might not be the gold standard to use when trying to validate the fMRI mapping process.

Cortical mapping in glioma surgery: correlation of fMRI and direct electrical stimulation with Human Connectome Project parcellations.

OBJECTIVE: Noninvasive brain mapping with functional MRI (fMRI) and mapping with direct electrical stimulation (DES) are important tools in glioma surgery, but the evidence is inconclusive regarding the sensitivity and specificity of fMRI. The Human Connectome Project (HCP) proposed a new cortical parcellation that has not been thoroughly tested in a clinical setting. The main goal of this study was to evaluate the correlation of fMRI and DES mapping with HCP areas in a clinical setting, and to evaluate the performance of fMRI mapping in motor and language tasks in patients with glioma, using DES as the gold standard. METHODS: Forty patients with supratentorial gliomas were examined using preoperative fMRI and underwent awake craniotomy with DES. Functional activation maps were visualized on a 3D representation of the cortex, classified according to HCP areas, and compared with surgical mapping. RESULTS: Functional MRI was successful in identifying language and motor HCP areas in most cases, including novel areas such as 55b and the superior longitudinal fasciculus (SLF). Functional MRI had a sensitivity and specificity of 100% and 71%, respectively, for motor function in HCP area 4. Sensitivity and specificity were different according to the area and fMRI protocol; i.e., semantic protocols performed better in Brodmann area (BA) 55b/peri-sylvian language areas with 100% sensitivity and 20% specificity, and word production protocols in BAs 44 and 45 with 70% sensitivity and 80% specificity. Some compensation patterns could be observed, such as motor activation of the postcentral gyrus in precentral gliomas. CONCLUSIONS: HCP areas can be detected in clinical scenarios of glioma surgery. These areas appear relatively stable across patients, but compensation patterns seem to differ, allowing occasional resection of activating areas. Newly described areas such as 55b and SLF can act as critical areas in language networks. Surgical planning should account for these parcellations.

Angioma capilar espinal intradural: reporte de un caso y revisión de la literatura / Spinal cord capillary hemangioma: a case report and literature review

INTRODUCTION: Capillary angiomas are extremely rare in the spinal intradural space (being even less frequent in the intramedullary location)10-24. We analyze the characteristics of these lesions. METHODS: We present a case report of a patient with a symptomatic spinal-intradural capillary hemangioma at the thoracic level, followed by a review of the literature. RESULTS: We found a total of 41 patients reported with single angiomas, and three more patients with multiple lesions. Most patients were male (33/44 patients), and the mean age was 53,5 years. The localization of these lesions was mainly in the dorsal spine (24), cauda equina (15) and conus medullaris (6), with one case reported in the cervical spine 11. Most patients presented with back pain, mielopathy or radiculopathy. Contrary to the case of cavernous angiomas, we did not find cases of capillary angiomas presenting with subarachnoid or intramedullary hemorrhage. The imaging characteristics (isointense at T1WI, hyperintense at T2WI and with intense contrast enhancement) were constant in almost all the reports. CONCLUSIONS: Spinal intradural capillary angiomas are rare vascular lesions, frequently mistaken for intradural tumors. It affects mostly males in the fifth or sixth decade of life, and is preferentially located in the thoracolumbar spine. It can be occasionally associated with marked spinal cord edema, specially when there is a intramedullary component. These lesions have a good prognosis after surgical treatment, and must be taken into account in the differential diagnosis of intradural tumors of thoracolumbar spine and cauda equina.

Uso de simvastatina en la prevención de la isquemia cerebral en la hemorragia subaracnoídea aneurismática / Use of simvastatin in brain ischemia prevention in aneurysmal subarachnoid hemorrhage

Introducción: El vasoespasmo cerebral es una complicación temida y aun no resuelta en los pacientes que cursan con hemorragia subaracnoídea neurismática (HSA), y que significa una importante morbi-mortalidad en dichos pacientes. Material y métodos: Se revisaron los registros de 161 pacientes ingresados en el Hospital Carlos Van Buren de Valparaíso por HSA entre entre Mayo de 2007 y Agosto de 2009, comparando la aparición de complicaciones isquémicas y resultados funcionales, según fuesen o no tratados con Simvastatina (40 mg/día). Resultados: El grupo de pacientes tratados con Simvastatina presentó significativamente menos infartos cerebrales (9,30 por ciento vs. 24,58 por ciento, p=0,02) y menos mortalidad intrahospitalaria (1,24 por ciento vs. 11,80 por ciento, p=0,04). Conclusiones: Si bien el diseño del estudio impide atribuir las diferencias encontradas al uso de Simvastatina, dado el contexto del mismo, es muy probable que así sea. El uso de estatinas en la hemorragia subaracnoídea aneurismática, como profilaxis del vasoespasmo es aún un tema controversial y promisorio, que se encuentra en plena etapa de estudio y desarrollo.

Background: Vasospasm is a feared complication in patients who present with aneurysmal subarachnoid hemorrhage (SAH) and that means significant morbidity and mortality in these patients. Material and methods: We reviewed the records of 161 patients admitted to the Hospital Carlos Van Buren with SAH between May 2007 and August 2009, comparing the occurrence of ischemic complications and functional results as they were or not treated with simvastatin (40mg/day). Results: The patient group treated with simvastatin had significantly fewer strokes (p = 0.02) and fewer hospital mortality (p = 0.04). Conclusions: Although the study design precludes attributing the differences found when using simvastatin, given the context, it is likely to be so. The use of statins in aneurismal subarachnoid hemorrhage for vasospasm prophylaxis is still a controversial and promising topic, wich is under full development and study.

Extirpación de tumores de ovario por vía vaginal asistida por laparoscopía / Resection of ovarian neoplasms by laparoscopy assisted transvaginal cystectomy

En esta presentación, 9 pacientes con tumores anexiales sólidos o complejos son sometidos a quistectomía transvaginal asistida laparoscópicamente. La quistectomía fue realizada a través de colpotomía colocando el ovario en una bolsa introducida por laparoscopia, previniendo el derrame del contenido quístico. El promedio de edad de las pacientes fue de 30 años y el tamaño de los tumores varió entre 50 y 120 mm. El tiempo operatorio promedio fue de 61 minutos. Siete tumores fueron teratomas quísticos maduros, uno fue un cistoadenoma seroso y otro correspondió a un cuerpo lúteo hemorrágico. No hubo derrame de contenido quístico dentro de la cavidad pelviana y no hubo complicaciones