Development of robust discriminant equations for assessing subtypes of glioblastoma biopsies.

BACKGROUND: In the preceding decade, various studies on glioblastoma (Gb) demonstrated that signatures obtained from gene expression microarrays correlate better with survival than with histopathological classification. However, there is not a universal consensus formula to predict patient survival. METHODS: We developed a gene signature using the expression profile of 47 Gbs through an unsupervised procedure and two groups were obtained. Subsequent to a training procedure through leave-one-out cross-validation, we fitted a discriminant (linear discriminant analysis (LDA)) equation using the four most discriminant probesets. This was repeated for two other published signatures and the performance of LDA equations was evaluated on an independent test set, which contained status of IDH1 mutation, EGFR amplification, MGMT methylation and gene VEGF expression, among other clinical and molecular information. RESULTS: The unsupervised local signature was composed of 69 probesets and clearly defined two Gb groups, which would agree with primary and secondary Gbs. This hypothesis was confirmed by predicting cases from the independent data set using the equations developed by us. The high survival group predicted by equations based on our local and one of the published signatures contained a significantly higher percentage of cases displaying IDH1 mutation and non-amplification of EGFR. In contrast, only the equation based on the published signature showed in the poor survival group a significant high percentage of cases displaying a hypothesised methylation of MGMT gene promoter and overexpression of gene VEGF. CONCLUSION: We have produced a robust equation to confidently discriminate Gb subtypes based in the normalised expression level of only four genes.

[Intraoperative identification of the supplementary motor area in neurooncological surgery]. / Identificación intraoperatoria del área motora suplentaria en cirugía neurooncológica.

OBJECTIVES: The main objective of the present work was to identify, by means of intraoperative electrical stimulation, the supplementary motor area (SMA) region which is implicated in complex motor function. The functional prognostic relevance of the surgical preservation of this area was also analyzed. METHOD: Fifteen patients with tumors infiltrating the premotor cortex were selected. All patients were operated under awake conditions. Primary motor cortex was identified with intraoperative electrical stimulation (IES). To identify the SMA, patients were asked to do a finger opposition motor task with their hand contralateral to the lesion, that was blocked by electrically stimulating the premotor cerebral cortex. RESULTS: SMA was identified in all patients with IES. Complete surgical resection was achieved in 13 patients (86.6%) and subtotal in 2 patients (13.3%). SMA function was preserved in 14 patients (93.3%). In only one patient the SMA was partially resected because of tumor infiltration (6.6%). In the immediate postoperative period, 8 patients (53.3%) did not show changes in comparison to their preoperative clinical status, and 2 patients improved. At 6 months follow up, 5 patients (33.3%) were asymptomatic and 10 patients showed permanent deficits. In this last group, five patients (33.3%) showed mild deficits that did not interfere with a normal life. In the other 5 patients (33.3%), permanent deficits interfered with daily life activities: two patients presented severe hemiparesis 3/5 (same similar to their preoperative status with no improvement), one patient had motor aphasia, and two other patients (13.3%) showed permanent left SMA syndrome. In two patients with severe postoperative hemiparesis, tumor infiltration of primary motor cortex and piramidal pathway was observed; severe preoperative motor deficit (KPS <70) was associated with poor functional outcome. CONCLUSIONS: Intraoperative electrical cortical stimulation is useful to identify the SMA. Once identified, SMA preservation decreases the risk of postoperative symptoms and permanent SMA syndrome. When SMA is infiltrated by the tumor, radical resection may cause permanent neurological deficits, specially in the dominant hemisphere. Severe preoperative motor deficit was associated with poor outcome.

Intrasurgical mapping of complex motor function in the superior frontal gyrus.

A lesion to the superior frontal gyrus (SFG) has been associated with long-lasting deficits in complex motor functions. The aim of this study was to analyze the functional role of the SFG by means of electrical cortical stimulation. Direct intraoperative electrical stimulation was used in a group of 21 subjects with lesions within or close to the SFG while they performed three motor tasks that require high skills or bimanual synergy. The results were compared to functional magnetic resonance imaging (fMRI). Ninety-four of the 98 (94.9%) labels identified were located on the convexity surface of the SFG and only four (4.1%) labels were located on the middle surface of the SFG. Areas of blockage of the three tasks were identified in six of the 12 (50%) hemispheres with lesions that had infiltrated the SFG, compared to all 10 of the 10 hemispheres (100%) with lesions that spared the SFG. The difference between these two proportions was statistically significant (P=0.015). fMRI activation was mainly located on the medial aspect of the SFG. We show that the convexity surface of the SFG has an important role in bilateral control of complex movements and in bimanual coordination. The infiltration of the posterior part of the SFG by a lesion disturbs some of the complex hand motor functions, which may be assumed by the contralesional homologous area. Finally, the current study emphasizes the discrepancies between fMRI and intraoperative electrical stimulation maps in complex hand motor function.

Proton MR spectroscopy provides relevant prognostic information in high-grade astrocytomas.

BACKGROUND AND PURPOSE: There is a large range of survival times in patients with HGA that can only be partially explained by histologic grade and clinical aspects. This study aims to retrospectively assess the predictive value of single-voxel (1)H-MRS regarding survival in HGA. MATERIALS AND METHODS: Pretreatment (1)H-MRS in 187 patients with HGA produced 180 spectra at STE (30 ms) and 182 at LTE (136 ms). Patients were dichotomized into 2 groups according to survival better or worse than the median. The spectra of the 2 groups were compared using the Mann-Whitney U test. The points on the spectrum with the most significant differences were selected for discriminating patients with good and poor prognosis. Thresholds were defined with ROC curves, and survival was analyzed by using the Kaplan-Meier method and the Cox proportional hazards model. RESULTS: Four points on the spectrum showed the most significant differences: 0.98 and 3.67 ppm at STE; and 0.98 and 1.25 ppm at LTE (P between <.001 and .011). These points were useful for stratifying 2 prognostic groups (P between <.001 and .003, Kaplan-Meier). The Cox forward stepwise model selected 3 spectroscopic variables: the intensity values of the points 3.67 ppm at STE (hazard ratio, 2.132; 95% CI, 1.504-3.023), 0.98 ppm at LTE (hazard ratio, 0.499; 95% CI, 0.339-0.736), and 1.25 ppm at LTE (hazard ratio, 0.574; 95% CI, 0.368-0.897). CONCLUSIONS: (1)H-MRS is of value in predicting the length of survival in patients with HGA and could be used to stratify prognostic groups.

Non-invasive grading of astrocytic tumours from the relative contents of myo-inositol and glycine measured by in vivo MRS.

MRI and MRS are established methodologies for evaluating intracranial lesions. One MR spectral feature suggested for in vivo grading of astrocytic tumours is the apparent myo-lnositol (ml) intensity (ca 3.55 ppm) at short echo times, although glycine (gly) may also contribute in vivo to this resonance. The purpose of this study was to quantitatively evaluate the ml + gly contribution to the recorded spectral pattern in vivo and correlate it with in vitro data obtained from perchloric acid extraction of tumour biopsies. Patient spectra (n = 95) at 1.5T at short (20-31 ms) and long (135-136 ms) echo times were obtained from the INTERPRET MRS database (http://gabrmn.uab.eslinterpretvalidateddbl). Phantom spectra were acquired with a comparable protocol. Spectra were automatically processed and the ratios of the (ml + gly) to Cr peak heights ((ml + gly)/Cr) calculated. Perchloric acid extracts of brain tumour biopsies were analysed by high-resolution NMR at 9.4T. The ratio (ml + gly)/Cr decreased significantly with astrocytic grade in vivo between low-grade astrocytoma (A2) and glioblastoma multiforme (GBM). In vitro results displayed a somewhat different tendency, with anaplastic astrocytomas having significantly higher (ml + gly)/Cr than A2 and GBM. The discrepancy between in vivo and in vitro data suggests that the NMR visibility of glycine in glial brain tumours is restricted in vivo.

Intracranial meningiomatosis causing foster kennedy syndrome by unilateral optic nerve compression and blockage of the superior sagittal sinus.

The original description of the Foster Kennedy syndrome included the clinical triad of optic disc pallor in one eye, optic disc edema in the other eye, and reduced olfaction caused by space-occupying anterior fossa masses. The optic disc pallor was attributed to direct compression of the intracranial optic nerve, the optic disc edema to increased intracranial pressure from mass effect, and the reduced olfaction to direct compression of the olfactory nerve. We report a patient with the ophthalmic features of the Foster Kennedy syndrome from meningiomatosis. A meningioma compressed one optic nerve to cause impaired visual function. Convexity meningiomas compressed the superior sagittal sinus to impair cerebral venous drainage, increased intracranial pressure, and papilledema in the other eye. This is the first report of the Foster Kennedy syndrome caused by this mechanism.

Fibrinolytic therapy in spontaneous intraventricular haemorrhage: efficacy and safety of the treatment.

Intraventricular haemorrhage (IVH) is associated with a poor outcome. Simple external ventricular drainage has not modified the high morbidity and mortality of these patients. Our objective was to review our experience using intraventricular urokinase (UK) in treating patients with moderate to severe IVH. Prospective analysis of medical records of 14 patients diagnosed with spontaneous IVH who received ventriculostomy and intraventricular infusion of UK from January 2002 to December 2005. Patients with the following characteristics were included: 18-70 years of age, GCS between 5 and 14, and moderate to severe IVH (Graeb > or = 6) without simultaneous intraparenchymal haematoma > 30 ml. The final results were compared to historic control group (14 patients) treated between January 1999 to December 2001 with ventriculostomy alone. All 28 patients accomplished the inclusion criteria. Patient age, initial GCS and Graeb classification of IVH were similar in the two groups of treatment. There was higher ventriculostomy obstruction rate in the non-UK group (33.3 vs. 0%; p > 0.05), a higher rate of intracranial hypertension in the non-UK group (66.6 vs. 16.6%; p = 0.036) and a lower mortality rate in the UK group (25 vs. 58.3%, p > 0.05). There was no rebleeding associated with UK treatment. Intraventricular UK appears to be a safe treatment. It is effective in the prevention of catheter blockage, speeding the clearance of IVH, and it is associated with lower rate of intracranial hypertension and death.

Early post-operative ACTH and cortisol as predictors of remission in Cushing's disease.

AIM: To study the value of early (24 h) post-operative ACTH and serum cortisol as predictors of remission after transsphenoidal surgery in Cushing's disease. METHODS: We prospectively studied 44 patients who underwent transsphenoidal surgery for Cushing's disease between 1997 and 2005. The mean follow-up period of patients after surgery was 49 months (19-102 months). The predictive value of clinical characteristics, pre-operative hormonal studies, radiological, surgical and histological findings, and post-operative hormonal studies were analysed. For the post-operative hormonal study plasma ACTH and serum cortisol were determined at 8.00 a.m. the day after surgery. RESULTS: After surgery, Cushing's disease remitted in 39 patients (89%) and persisted in 5 patients (11%). Three patients relapsed during the follow-up period. Only three study variables were predictive of persistence of Cushing's disease after surgery: the non identification of the adenoma in histology (an adenoma was found in 87% of the patients in remission, and in 20% of treatment failures, p = 0.01), the early post-operative plasma ACTH (patients in remission: 2 pmol/L (1.1-10.8 pmol/L), treatment failures: 8.2 pmol/L (1.1-12 pmol/L), p = 0.019), and the early post-operative serum cortisol (patients in remission: 128.4 nmol/L (27.6-4644 nmol/L), treatment failures: 797 nmol/L (606-1037 nmol/L), p = 0.003). ROC curves indicated that plasma ACTH < or = 7.55 pmol/L distinguished patients in remission from treatment failures with 80% sensitivity and 97.4% specificity, and serum cortisol < or = 585 nmol/L with 100% sensitivity and 90% specificity. CONCLUSIONS: Twenty-four hours after transsesphenoidal surgery for Cushing's disease, and without glucocorticoids replacement, patients with serum cortisol concentrations higher than 585 nmol/L, and/or plasma ACTH higher than 7.55 pmol/L, and/or those in which an adenoma is not identified in the histological study, have a high risk of treatment failure.

Intracranial retrograde dissemination in filum terminale myxopapillary ependymomas.

Myxopapillary ependymomas (ME) are considered benign tumours (WHO grade I) of the central nervous system with long term survival rates and a tendency to local recurrence. However an aggressive course has occasionally been described, leading to CSF dissemination and even systemic metastases. We describe the case of a 23-year-old man diagnosed with intracranial subarachnoid dissemination of a filum terminale ME three years after the initial diagnosis. We have performed a careful review of the literature on CSF dissemination in ME and finally propose treatment of these cases.

[Complications of craniofacial resection in anterior skull base tumors]. / Complicaciones de la cirugía craneofacial en tumores de base craneal anterior

INTRODUCTION: The development of new radiographic techniques and the refinement of microsurgery and reconstructive surgery have been the responsible of the establishment of craniofacial resection (CFR) as the standard treatment of anterior skull base tumors. Overall complication rates varies from 24-56%, according to a review of recently published series. OBJECTIVES: To describe the complications of CFR in a series of 41 patients and to analyze the management and final outcome. MATERIAL AND METHODS: From 1990 to 2002, 41 patients underwent CFR for tumors involving the anterior cranial base. The extent of the tumor was always assessed with craniofacial CT-scan and MRI. The objective of the surgical treatment was to achieve "on block" removal of the tumor. RESULTS: The average age was 57 years with a male preponderance (63.4%). Squamous cell carcinoma was the most frequent histopathological type of tumor. The tumors were localized in paranasal sinuses in 78% of the cases. Bifrontal craniotomy was performed in 85.4% and unilateral orbitofrontal craniotomy in 14.6% of the cases. The area of facial resection included: ethmoidectomy (60.9%), ethmoido-sphenoidectomy (24.3%), maxillectomy (39%) and orbital exenteration (14.6%). The reconstruction of the floor of the anterior cranial fossa was performed using pedicled pericranial flap (100%), local (34.1%) or microvascular free flaps (21.9%) and split calvarian graft (19.5%). 20 patients (48.7%) developed post-operative complications, CSF leaks (12.1%) and meningitis (7.3%) being the most frequent major complications. The mortality rate was 7.3%. CONCLUSIONS: CFR has become the standard approach for anterior cranial base tumors. Despite its widespread application, the complication's rate ranges between 24-50% and the procedure carries a risk of significant morbidity and even mortality. Improvement of specific aspects of surgical technique and more refined reconstructive methods will decrease the number of complications.

Complicaciones de la cirugía craneofacial en tumores de base craneal anterior / Complications of craniofacial resection in anterior skull base tumors

Introducción. Los recientes avances en radiología, técnica microquirúrgica y de reconstrucción han permitido que la cirugía craneofacial (CCF) se haya convertido en el tratamiento de elección de la patología tumoral de fosa craneal anterior. A pesar de esto, continua asociándose a una incidencia de complicaciones considerable (24-56%). Objetivos. Revisión, análisis y manejo de las complicaciones de la CCF en una serie de 41 pacientes. Material y métodos. 41 pacientes diagnosticados de patología tumoral infiltrativa de base craneal anterior, fueron intervenidos mediante CCF, entre 1990 y 2002. La extensión tumoral fue valorada en todos los casos con TC y RMN de la región craneo-facial. Tras determinar el volumen y extensión tumoral se diseñó un tratamiento quirúrgico radical, con el objetivo de conseguir una resección tumoral "en bloque". Resultados. El 63.4% de los pacientes eran varones con una mediana de edad de 57 años (18-73). La histología más frecuente de los tumores fue carcinoma escamoso y la localización habitual fue en los senos paranasales en el 78% (32 de 41 casos). En el 85.4% delos pacientes se realizó una craneotomía bifrontal basaly en el 14.6% restante craneotomía frontoorbitaria unilateral, en un sólo colgajo óseo. El área de resección facial incluía: etmoidectomía (60.9%), etmoido-esfenoidectomía (24.3%), maxilectomía unilateral (39%) y exenteración orbitaria (14.6%). Para la reconstrucción se utilizó: colgajo pediculado pericraneal (100%),colgajos locales (34.1%), colgajos libres microvascularizados (21.9%) e injerto óseo autólogo (19.5%). 20 pacientes (48.7%) presentaron complicaciones postoperatorias, entre las que destacan, como complicaciones mayores la fístula de LCR (12.1%) y la meningitis (7.3%). La mortalidad global fue del 7.3%.Conclusiones. La CCF continua asociándose a una elevada tasa de complicaciones, en general de tipo infeccioso. El perfeccionamiento de las técnicas de reconstrucción permitirán reducir la incidencia de las complicaciones más frecuentes y peligrosas

Introduction. The development of new radiographic techniques and the refinement of microsurgery and reconstructive surgery have been the responsible of the establishment of craniofacial resection (CFR) as the standard treatment of anterior skull base tumors. Overall complication rates varies from 24-56%, according to a review of recently published series. Objectives. To describe the complications of CFR in a series of 41 patients and to analyze the management and final outcome. Material and methods. From 1990 to 2002, 41 patients underwent CFR for tumors involving the anterior cranial base. The extent of the tumor was always assessed with craniofacial CT-scan and MRI. The objective of the surgical treatment was to achive "on block" removal of the tumor. Results. The average age was 57 years with a male preponderance (63.4%). Squamous cell carcinoma was the most frequent histopathological type of tumor. The tumors were localized in paranasal sinuses in 78% of the cases. Bifrontal craniotomy was performed in 85.4% and unilateral orbitofrontal craniotomy in 14.6% of the cases. The area of facial resection included: ethmoidectomy (60.9%), ethmoido-sphenoidectomy (24.3%), maxillectomy (39%) and orbital exenteration (14.6%). The reconstruction of the floor of the anterior cranial fossa was performed using pedicled pericranial flap (100%), local (34.1%) or microvascular free flaps (21.9%) and split calvarian graft (19.5%). 20 patients (48.7%) developed post-operative complications, CSF leaks (12.1%) and meningitis (7.3%) being the most frequent major complications. The mortality rate was 7.3%. Conclusions. CFR has become the standard approach for anterior cranial base tumors. Despite its widespread application, the complication's rate ranges between 24-50% and the procedure carries a risk of significant morbidity and even mortality. Improvement of specific aspects of surgical technique and more refined reconstructive methods will decrease the number of complications

[Spinal epidural hematomas. Prognostic factors in a series of 22 cases and a proposal for management]. / Revisión de 22 casos de hematomas epidurales espinales. Factores pronósticos y manejo terapéutico.

INTRODUCTION: Spontaneous and non-spontaneous spinal epidural hematoma (SEH) is a rare condition in neurosurgical practice. It presents as an acute spinal cord compression and usually requires emergent surgical decompression. Recently non-surgical treatment (corticoid therapy) has been proposed in selected cases of SEH with good neurological recovery. OBJECTIVES: To identify the prognostic factors of this condition. A treatment management based upon our results is proposed. MATERIAL AND METHODS: Between 1985 and 2001, 22 patients suffering SEH were treated at our Department. Age, sex, initial neurological condition (evaluated using the Frankel grading scale), surgical timing, radiological data such as location, extension and degree of radiological cord compression, anticoagulation or antiplatelet therapy, epidural anesthesia and previous spinal surgery were analyzed in order to find prognostic factors. Finally, conservative or surgical treatment as well as final neurological condition were also considered for the analysis. RESULTS: The average age was 69 years with a male preponderance (72.7%). Surgical decompression was done in 17 cases, most of them (11 cases) presenting with high neurological deficit (Frankel A-B). Conservative treatment was used on 5 patients. Operated patients showed a larger degree of neurological recovery. The incidence of post-operative complications was of 13%. CONCLUSIONS: This study shows the efficiency of SEH surgical evacuation performed within the first 24 hours, particularly when the patient presents a severe neurological deficit (Frankel A-B). Patients presenting minimal neurological involvement (Frankel D-E) can be managed successfully with conservative treatment.

Assignment of the 2.03 ppm resonance in in vivo 1H MRS of human brain tumour cystic fluid: contribution of macromolecules.

MRI and MRS are established techniques for the evaluation of intracranial mass lesions and cysts. The 2.03 ppm signal recorded in their (1)H-MRS spectra is often assigned to NAA from outer volume contamination, although it has also been detected in non-infiltrating tumours and large cysts. We have investigated the molecular origin of this resonance in ten samples of cystic fluids from human brain tumours. The NMR detected content of the 2.03 ppm resonance in 136 ms echo time spectra, assuming an N- CH(3) origin, was 3.19 +/- 1.01 mM. Only one third (34 +/- 12%) of the N-acetyl containing compound (NAC) signal could be extracted by perchloric acid (PCA) indicating that most of it originated in a macromolecular PCA-insoluble component. Chemical analysis of the cyst fluids showed that sialic acid bound to macromolecules would account for 64.3% and hexuronic containing compounds for 29.2% of the NMR-detectable ex vivo signal, 93.4% of the signal at TE 136 ms. Lactate content measured by NMR (6.4 +/- 4.4 mM) and the predominance of NAC originating in sialic acid point to a major origin from tumour rather than from plasma for this 2.03 ppm resonance.

Estimulación cortical intraoperatoria en el tratamiento quirúrgico de los gliomas de bajo grado situados en áreas elocuentes / Intraoperative cortical mapping in the surgical resection of low-grade gliomas located in eloquent areas

Introducción. La selección de pacientes para cirugía en los gliomas de bajo grado, basada en criterios radiológicos, es, en ocasiones, insuficiente, dada la variabilidad individual en la localización de las áreas elocuentes y la preservación de función en el tejido cerebral infiltrado. Evaluamos la seguridad de la técnica de estimulación cortical intraoperatoria en un subgrupo de pacientes con tumores gliales de bajo grado, analizando en qué medida la aplicación de ésta modifica la posibilidad de resecciones completas y la aparición de déficits postquirúrgicos. Material y métodos. Veinticinco pacientes con gliomas de bajo grado (II/IV OMS) localizados en áreas cerebrales elocuentes fueron intervenidos para exéresis guiada con estimulación cortical intraoperatoria. La cirugía se efectuó bajo anestesia local y sedación o bajo anestesia general sin relajación muscular, en dependencia de la función a explorar. Todas las intervenciones se efectuaron desde una perspectiva oncológica, buscando la resección tumoral máxima, y deteniéndose al hallar tejido cerebral funcionante en la lesión o próximo a ella. Resultados. Se logró una exéresis completa o parcial máxima en 16 pacientes (64 por ciento); en cinco casos (20 por ciento) la resección fue parcial, y en el resto (16 por ciento), sólo pudo efectuarse biopsia. Los tumores de área motora suplementaria (AMS) y los de la región fronto-opercular, fueron los que con más frecuencia pudieron resecarse completamente. Trece pacientes (52 por ciento) presentaron un empeoramiento de su situación neurológica previa, pero en ocho de ellos se observó mejoría progresiva durante los días siguientes, con práctica resolución de la clínica a los 6 meses. Conclusiones. La estimulación cortical intraoperatoria permite optimizar el grado de resección minimizando las secuelas postoperatorias. La existencia de áreas funcionales y vías subcorticales en el seno de estos tumores es una realidad a tener en cuenta. La localización en región fronto-opercular izquierda y AMS permiten mayor grado de exéresis con menor morbilidad, mientras que las lesiones insulares continúan siendo un reto incluso con el apoyo de esta técnica (AU)

Incidentaloma hipofisario: evaluación y abordaje terapéutico en la actualidad / Pituitary incidentaloma: evaluation and current therapeutic approach

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Utility of proton MR spectroscopy in the diagnosis of radiologically atypical intracranial meningiomas.

Our aim was to evaluate the usefulness of proton MR spectroscopy ((1)H MRS) in the diagnosis of radiologically atypical brain meningiomas. We studied 37 patients with intracranial meningiomas with MRI and (1)H MRS (TE 136 ms). Their spectra were quantitatively assessed and compared with those of 93 other intracranial brain neoplasms: 15 low-grade and 14 anaplastic astrocytomas, 30 glioblastomas and 34 metastases. The most characteristic features of meningiomas were the presence of alanine, high relative concentrations of choline and glutamine/glutamate and low concentrations of creatine-containing compounds, N-acetyl-containing compounds and lipids. These resonances were assembled in algorithms for two-way differentiation between meningioma and the other tumours. The performance of the algorithms was tested in the 130 patients using the leave-one-out method, with 94% success in differentiating between meningioma and other tumour. Of the 37 meningiomas, five (14%) were thought atypical on MRI, and in only one of these, found to be malignant on histology, was a diagnosis other than meningioma suggested by the algorithm. The other four were correctly classified. We suggest that (1)H MRS provides information on intracranial meningiomas which may be useful in diagnosis of radiologically atypical cases.

[Intraoperative cortical mapping in the surgical resection of low-grade gliomas located in eloquent areas]. / Estimulación cortical intraoperatoria en el tratamiento quirúrgico de los gliomas de bajo grado situados en áreas elocuentes.

INTRODUCTION: Surgical selection of patients harboring low-grade gliomas based on radiological criteria may be insufficient due to individual variability in eloquent areas location and to the fact that function can be preserved within infiltrated brain tissue. Brain stimulation mapping safety for patients with low-grade gliomas is evaluated, analyzing whether this technique modifies the extent of resection and minimizes postoperative deficits. MATERIAL AND METHODS: Twenty-five patients with lowgrade gliomas (II/IV WHO) located in eloquent areas underwent tumor resection with the aid of intraoperative mapping. Patients underwent surgery under local or general anesthesia depending on the neurological function to be explored. All procedures were performed from an oncological point of view, trying to achieve a radical tumor resection but stopping removal whenever functional tissue was found within or near the lesion. RESULTS: Total or subtotal resection was achieved in 16 patients (64%); in five cases (20%) resection was partial, and in the remaining (16%) only a biopsy was obtained. Tumors located in the supplementary motor area (SMA) or in the operculum were those which could be more often totally resected. Thirteen patients (52%) experienced neurological worsening immediately after surgery but eight of them had almost completely recovered six months after the procedure. CONCLUSIONS: Intraoperative functional mapping can optimize extent of resection minimizing permanent morbidity. Functional tissue can be found within the infiltrated brain and this must be considered in the presurgical planning. SMA and opercular tumors allow radical resection with low morbidity whereas insular tumors remain a challenge even with the aid of this technique.

[Cushing's disease in the 90's: a review]. / La enfermedad de Cushing en los años 90. Una revisión.

Since 1932 when Cushing's disease has been described, several important advances have been made in diagnosis and management. However several points remain obscure and there is no general agreement among authors. An accurate biological diagnosis is one of the difficulties found when we face a patient with hypercortisolism. In addition, corticotropin dependent syndrome should be distinguished from the independent one, as well as identifying the source of ACTH hypersecretion. The main problem in Cushing's disease is to localise the secreting adenoma and at the moment there is not any diagnostic method with absolute sensibility and specificity. Magnetic Resonance Imaging shows a sensibility of 77% and 87% especificity; inferior petrosal sinus sampling may help in localising the side, where the adenoma lies, although an appropriate technique is mandatory. New developing techniques, such as intraoperative doppler and assessment of ACTH levels in the peripituitary veins may help us in localising the source of ACTH hypersecretion. Sometimes the adenoma cannot be identified and a surgical exploration of the pituitary is required. If an adenoma is found, a 89% probility of curation has been reported; on the contrary, incomplete tumor removal, no tumor found at surgery, or the presence of the so-called corticotrop hyperplasia where followed of bad results and may explain the failed surgery. Then, hypofisectomy, hemi-hypofisectomy, radiotherapy, photon knife or gamma knife, may be of help in the control of this condition. We reviewed the recent literature and analysed the diagnostic strategies and teatments currently available for this illness. In addition we propose an algohritm for diagnosis and treatment and analyze our results in a consecutive series of 38 patients.

Intraventricular mass lesions of the brain.

Intraventricular tumours represent a diverse group of lesions, some of them infrequent, with a wide variety of radiological features. Determination of their precise aetiology or origin can be difficult. Nevertheless, considering patient's age, location within the ventricles, and some specific radiological features, the radiologist should be able to narrow down the differential diagnosis. This paper reviews the characteristic radiological appearances of the diverse intraventricular lesions emphasising its differential diagnosis.