RESUMEN
We discuss the clinical, neuroradiologic and histopathologic features of a case not apparently associated with neurofibromatosis (type 2), reviewing the relevant literature.
Asunto(s)
Neoplasias Encefálicas/patología , Neurofibromatosis 2/patología , Neoplasias Encefálicas/diagnóstico por imagen , Hemangioma/patología , Humanos , Imagen por Resonancia Magnética , Masculino , Meningioma/patología , Persona de Mediana Edad , Neurofibromatosis 2/diagnóstico por imagen , RadiografíaRESUMEN
Central neurocytoma (CN) is a rare, benign tumour of neuronal differentiation which affects young patients and is generally found in the lateral or third ventricles. Its radiological features are non-specific and, in the past, these tumours were confused with other intraventricular lesions. Only recently, thanks to their characteristic features on immunohistochemistry and electron microscopy, have they been recognized as a separate entity. We present the clinico-pathological features of five cases of CN treated at our Institution between 1986 and 1994. The importance of diagnostic suspicion, total microsurgical excision and the role of radiotherapy is discussed.
Asunto(s)
Neoplasias del Ventrículo Cerebral/patología , Neurocitoma/patología , Adulto , Neoplasias del Ventrículo Cerebral/diagnóstico , Neoplasias del Ventrículo Cerebral/cirugía , Femenino , Estudios de Seguimiento , Humanos , Imagen por Resonancia Magnética , Masculino , Neurocitoma/diagnóstico , Neurocitoma/cirugía , Tomografía Computarizada por Rayos XRESUMEN
From a total of 78 patients surgically treated for a spinal dural arteriovenous fistula, in whom long-term follow-up was available, 25 have been reviewed. Their outcome at different postoperative stages and the long-term prognostic factors is discussed. Excision or coagulation of the nidus, as well as disconnection of the draining vein offers better results in the long-term than clipping of the draining vein alone. Prolonged duration of symptoms and poor functional status before surgical treatment adversely affect the long-term outcome. Age at the time of surgery did not influence outcome in this study. In the long-term all patients tended to show a moderate, but definite functional decline. This is unlikely to be due entirely to recanalization and may represent a more generalized haemodynamic abnormality of the cord together with the effects of age on the original damage.
Asunto(s)
Fístula Arteriovenosa/cirugía , Duramadre/irrigación sanguínea , Adulto , Factores de Edad , Anciano , Fístula Arteriovenosa/complicaciones , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Factores de Tiempo , Resultado del TratamientoRESUMEN
The purpose of this study was to examine the changes in extracellular CO32- and lactate concentration produced by ischemia, especially in relation to the occurrence of anoxic depolarization, and how some of these changes are altered by the inhibition of organic acid transport systems with probenecid. These data demonstrate that (i) the transmembrane mechanisms contributing to intracellular acid-base regulation (Na+/H+ and HCO3-/Cl- exchanges, and lactate/H+ cotransport) are markedly activated during ischemia; (ii) the efficacy of these mechanisms is abolished as the cellular membrane permeability to ions, including H+ and pH-changing anions, suddenly increases with anoxic depolarization; and (iii) efflux of intracellular lactate during ischemia, and its reuptake with reperfusion, mainly occur via a transporter. These findings imply that residual cellular acid-base homeostasis persists as long as cell depolarization does not occur, and strengthen the concept that anoxic depolarization is a critical event for cell survival during ischemia.
Asunto(s)
Equilibrio Ácido-Base , Encéfalo/fisiopatología , Ataque Isquémico Transitorio/fisiopatología , Lactatos/metabolismo , Equilibrio Ácido-Base/efectos de los fármacos , Animales , Carbonatos/metabolismo , Electroencefalografía , Espacio Extracelular/fisiología , Hipoxia Encefálica , Ataque Isquémico Transitorio/metabolismo , Masculino , Potenciales de la Membrana , Microdiálisis , Probenecid/farmacología , Ratas , Ratas Wistar , Factores de TiempoRESUMEN
Abscess formation in the spinal epidural space is a very rare lesion, occurring once in 10,000 admissions to a tertiary centre and often requiring emergency neurosurgical treatment commonly presenting late. We present our experience of ten cases of spinal epidural abscess treated at our institution between January 1984 and July 1994 and review the most recent literature.
Asunto(s)
Absceso/cirugía , Compresión de la Médula Espinal/cirugía , Enfermedades de la Columna Vertebral/cirugía , Absceso/diagnóstico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Espacio Epidural/patología , Espacio Epidural/cirugía , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Examen Neurológico , Compresión de la Médula Espinal/diagnóstico , Enfermedades de la Columna Vertebral/diagnósticoRESUMEN
A rare localization of adenocarcinoma in Meckel's cave is reported in a 58-year-old woman, who had a 5-month history of pain and altered sensation in the second division of the left trigeminal nerve. Removal of the lesion was achieved by a subtemporal route. Histology showed this to be an adenocarcinoma. The patient underwent investigations for a primary tumor; the investigations were all negative, and the patient was subsequently treated with a course of radiotherapy. At 4-month follow-up, there was no evidence of recurrence, and she remains symptomatically well. The various mechanisms of secondary localization are discussed.
Asunto(s)
Adenocarcinoma/patología , Neoplasias Encefálicas/patología , Encéfalo/patología , Adenocarcinoma/complicaciones , Adenocarcinoma/cirugía , Encéfalo/cirugía , Neoplasias Encefálicas/complicaciones , Neoplasias Encefálicas/cirugía , Enfermedades de los Nervios Craneales/etiología , Enfermedades de los Nervios Craneales/fisiopatología , Femenino , Humanos , Imagen por Resonancia Magnética , Persona de Mediana Edad , Nervio Trigémino/fisiopatologíaRESUMEN
An anomalous vessel is reported in a patient with an anterior circulation aneurysm. The presence of an accessory middle cerebral artery arising from the postcommunicating segment of the anterior cerebral artery is described. The clinical relevance and possible etiology of the anomaly are reviewed.
Asunto(s)
Arterias Cerebrales/anomalías , Angiografía Cerebral , Arterias Cerebrales/cirugía , Femenino , Humanos , Aneurisma Intracraneal/complicaciones , Aneurisma Intracraneal/diagnóstico por imagen , Aneurisma Intracraneal/cirugía , Persona de Mediana Edad , Hemorragia Subaracnoidea/etiologíaRESUMEN
Marked abnormalities of the magnetic resonance intensity of N-acetylaspartate (NAA) have been reported in patients with various neurological disorders, but the neurochemical consequences of these alterations are difficult to assess because the function of NAA remains speculative. The purpose of this study was to examine whether NAA plays a role in protecting neurons against osmotic stress. Intracerebral microdialysis was used to expose a small region of the rat dorsolateral striatum to an increasingly hyposmotic environment and to measure resulting changes in NAA extracellular concentrations. NAA changes in the extracellular fluid (ECF) were compared with those of the amino acids, in particular, taurine, known to be involved in brain osmoregulation. Stepped increases in cellular hydration produced by hyposmotic perfusion media induced a marked increase in ECF NAA, reflecting a redistribution of NAA from intra-to extracellular space. Parallel experiments showed that, of all the extracellular amino acids measured, only taurine markedly increased with hyposmolar perfusion medium, indicating that the ECF NAA increase associated with hyposmotic stress was a specific response and not passive leakage out of the cells. As NAA is predominantly neuronal, it may contribute to the protection of neurons against swelling (i.e., regulatory volume decrease). In conditions with impaired blood-brain barrier and cytotoxic oedema, efflux of intracellular NAA subsequent to sustained cellular swelling might lead to a reduction in total brain NAA detectable by magnetic resonance spectroscopy. Alternatively, redistribution of NAA from intra-to extracellular space implies changes in its chemical environment that may alter its magnetic resonance visibility.
Asunto(s)
Ácido Aspártico/análogos & derivados , Encéfalo/metabolismo , Equilibrio Hidroelectrolítico , Aminoácidos/metabolismo , Animales , Ácido Aspártico/fisiología , Masculino , Microdiálisis , Concentración Osmolar , Ratas , Ratas Sprague-Dawley , Taurina/metabolismoRESUMEN
Mycosis fungoides is a rare malignant T-cell lymphoma, involving mainly the skin. It can, in 50%-75% of cases, involve visceral organs and, in 11%-14% of cases, metastasize to the central nervous system. The prognosis is poor. A case with cerebral involvement is presented and the relevant literature reviewed.
Asunto(s)
Neoplasias Encefálicas/secundario , Micosis Fungoide , Neoplasias Cutáneas/patología , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Three cases of surgically verified intramedullary cavernous angioma (cavernoma) of the spinal cord are reported. Intramedullary cavernomas of the cord are quite uncommon and account for between 3 and 12% of all vascular lesions of the spinal cord. Little is known of their natural history, although their tendency to produce haemorrhage and episodic symptomatic worsening is recognized. Our series includes one male and two females whose ages ranged between 31 and 67 years. The most common presenting symptom was pain, which in all cases preceded weakness. In two of our cases, the typical progression of sudden paroxysmal worsening of symptoms accompanied by pain was noted. This was thought to be related to bleeding in the lesion. In this series, an average of 8 years had elapsed after the onset of symptoms before the patients came to surgery. Standard microsurgical technique facilitated removal of the lesions, following which all patients regained preoperative function.
Asunto(s)
Hemangioma Cavernoso/cirugía , Neoplasias de la Médula Espinal/cirugía , Adulto , Anciano , Femenino , Hemangioma Cavernoso/diagnóstico , Hemangioma Cavernoso/patología , Hemorragia/diagnóstico , Hemorragia/patología , Hemorragia/cirugía , Humanos , Laminectomía/métodos , Imagen por Resonancia Magnética , Masculino , Microcirugia/métodos , Persona de Mediana Edad , Examen Neurológico , Médula Espinal/patología , Médula Espinal/cirugía , Neoplasias de la Médula Espinal/diagnóstico , Neoplasias de la Médula Espinal/patologíaRESUMEN
Posterior fossa arteriovenous malformations are uncommon lesions accounting for between 7 and 18% of all intracranial arteriovenous malformations. They have a greater incidence of haemorrhage and a higher morbidity and mortality if untreated compared with those localized in the supratentorial compartment. We report our experience with 28 cases of posterior fossa arteriovenous malformations referred to the senior author between January 1971 and December 1993. The anatomy, symptomatology, treatment and results are discussed with regard to the most recent literature.
Asunto(s)
Malformaciones Arteriovenosas/complicaciones , Malformaciones Arteriovenosas/fisiopatología , Fosa Craneal Posterior/fisiopatología , Hemorragia Subaracnoidea/etiología , Hemorragia Subaracnoidea/fisiopatología , Adolescente , Adulto , Edad de Inicio , Anciano , Malformaciones Arteriovenosas/cirugía , Niño , Fosa Craneal Posterior/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias , Estudios Retrospectivos , Índice de Severidad de la EnfermedadRESUMEN
A 47-year-old man presented, in 1990, with a short history of left-sided cerebellar ataxia. In 1986 he had undergone excision of a glomus jugulare tumour. A magnetic resonance (MRI) scan demonstrated cerebellar herniation through a defect in his skull base. Surgical repair was undertaken with resolution of his symptoms.
Asunto(s)
Ataxia Cerebelosa/etiología , Tumor del Glomo Yugular/cirugía , Complicaciones Posoperatorias , Arterias Carótidas/diagnóstico por imagen , Enfermedades Cerebelosas/diagnóstico , Enfermedades Cerebelosas/etiología , Encefalocele/diagnóstico , Encefalocele/etiología , Tumor del Glomo Yugular/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , RadiografíaRESUMEN
The time course of changes in extracellular glutamic acid levels and their Ca2+ dependency were studied in the rat striatum during focal cerebral ischaemia, using microdialysis. Ischaemia-induced changes were compared with those produced by high K(+)-evoked local depolarization. To optimize time resolution, glutamate was analysed continuously as the dialysate emerged from the microdialysis probe by either enzyme fluorimetry or biosensor. The Ca2+ dependency of glutamate changes was examined by perfusing the probe with Ca(2+)-free medium. With normal artificial CSF, ischaemia produced a biphasic increase in extracellular glutamate, which started from the onset of ischaemia. During the first phase lasting approximately 10 min, dialysate glutamate level increased from 5.8 +/- 0.9 microM.min-1 to 35.8 +/- 6.2 microM where it stabilized for approximately 3 min. During the second phase dialysate glutamate increased progressively to its maximum (82 +/- 8 microM), reached after 55 min of ischaemia, where it remained for as long as it was recorded (3 h). The overall changes in extracellular glutamate were similar when Ca2+ was omitted from the perfusion medium, except that the first phase was no longer detectable and, early in ischaemia, extracellular glutamate increased at a significantly slower rate than in the control group (2.2 +/- 1 microM.min-1; p < 0.05). On the basis of these data, we propose that most of the glutamate released in the extracellular space in severe ischaemia is of metabolic origin, probably originating from both neurons and glia, and caused by altered glutamate uptake mechanisms.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Calcio/farmacología , Cuerpo Estriado/metabolismo , Espacio Extracelular/metabolismo , Glutamatos/metabolismo , Ataque Isquémico Transitorio/metabolismo , Potenciales de Acción , Animales , Arterias Cerebrales/fisiología , Cuerpo Estriado/efectos de los fármacos , Depresión de Propagación Cortical , Diálisis , Electroencefalografía , Ácido Glutámico , Cinética , Masculino , Potasio/farmacología , Ratas , Ratas Sprague-DawleyRESUMEN
The purpose of this study was to determine the extracellular concentrations of N-acetylaspartate (NAA) in the rat cerebral cortex, striatum, and hippocampus of halothane-anaesthetised rats by intracerebral microdialysis, and to examine the effects of high K(+)-induced local depolarisation, which provokes synchronous neurotransmitter release, cell swelling, and acid-base changes. Basal levels of NAA in the extracellular fluid (ECF) were determined by the zero net flux method. Tissue levels of NAA in the cortex, striatum, and hippocampus were 8.4, 5.7, and 7.2 mmol/kg, respectively. The corresponding extracellular concentrations of NAA were much lower (35.1, 83.7, and 23.0 microM). High tissue/ECF concentration ratios may suggest little release or leakage of NAA under basal conditions, and potent reuptake mechanisms for NAA in the cellular membrane of CNS cells. There was no change in ECF NAA during K(+)-induced local depolarising stimuli produced in the striatum, but NAA levels consistently increased after the K+ stimuli, irrespective of whether or not Ca2+ was present in the perfusion medium. These data confirm that NAA is not a neurotransmitter and suggest strongly that NAA is not directly involved in the release and reuptake or metabolism of neuroactive compounds. The increase of NAA in the ECF immediately after K+ stimulation may reflect an involvement in brain osmoregulation and/or acid-base homeostasis.
Asunto(s)
Ácido Aspártico/análogos & derivados , Encéfalo/metabolismo , Espacio Extracelular/metabolismo , Potasio/farmacología , Animales , Ácido Aspártico/metabolismo , Encéfalo/efectos de los fármacos , Encéfalo/fisiología , Corteza Cerebral/metabolismo , Cuerpo Estriado/metabolismo , Electrofisiología , Hipocampo/metabolismo , Masculino , Microdiálisis , Concentración Osmolar , Ratas , Ratas Sprague-DawleyRESUMEN
The purpose of this study was to establish whether excessive lactate production associated with local application of K+ is reflected at the extracellular level during or after the K+ challenge. Changes in extracellular lactate were continuously monitored by microdialysis coupled to on-line fluorimetric analysis. K(+)-induced changes in dialysate lactate were closely related to those of the direct current potential. High K+ evoked a large and sustained negative shift of direct current potential onto which were superimposed a variable number of transient peaks of further depolarisation. The initial negative shift in direct current potential was associated with a decrease in dialysate lactate, but after each transient depolarisation, the positive shift in direct current potential indicating cell repolarisation was associated with a marked increase in extracellular lactate. When repetitive transient depolarisations occurred during a stimulus, only a small increase after each depolarisation was observed. However, recordings consistently revealed a marked and rapid increase in extracellular lactate after the K+ stimulus. These data indicate that extracellular lactate mostly increased during periods of repolarisation. This suggests strongly that lactic acid transport out of brain cells may be impaired when their transmembrane ionic gradients are disrupted.
Asunto(s)
Cuerpo Estriado/metabolismo , Cuerpo Estriado/fisiología , Espacio Extracelular/metabolismo , Lactatos/metabolismo , Potasio/farmacología , Animales , Electrofisiología , Ácido Láctico , Masculino , Microdiálisis , Concentración Osmolar , Ratas , Ratas Sprague-Dawley , Factores de TiempoRESUMEN
Cavernoma and suprasellar meningioma are rarely associated. We describe a patient, whose recovery after removal of the meningioma was complicated by haemorrhage from the cavernoma. This occurrence has not been previously reported.
Asunto(s)
Neoplasias Encefálicas/cirugía , Hemorragia Cerebral/cirugía , Hemangioma Cavernoso/cirugía , Neoplasias Primarias Secundarias/cirugía , Complicaciones Posoperatorias/cirugía , Adulto , Neoplasias Encefálicas/diagnóstico , Hemorragia Cerebral/diagnóstico , Femenino , Hemangioma Cavernoso/diagnóstico , Humanos , Imagen por Resonancia Magnética , Neoplasias Primarias Secundarias/diagnóstico , Examen Neurológico , Complicaciones Posoperatorias/diagnóstico , Rotura Espontánea , Tomografía Computarizada por Rayos XRESUMEN
The direct cortical response (DCR) and associated local cerebral blood flow was recorded from the primate cerebral cortex during a period of focal ischaemia induced by middle cerebral artery occlusion (MCAO). The DCR was lost when local blood flow fell below 20 ml/100 g/min but began to recover as collateral flow increased. Hypercapnia demonstrated a loss of local vascular reactivity following MCAO, but isovolaemic haemodilution still proved effective in increasing blood flow to these areas. The reduction in blood oxygen content induced by haemodilution did not impair cerebral function but the reduction in whole blood viscosity did exacerbate cerebral susceptibility to hypercapnia-induced intra-cerebral steal.
Asunto(s)
Dióxido de Carbono/sangre , Corteza Cerebral/irrigación sanguínea , Infarto Cerebral/fisiopatología , Electroencefalografía , Hemodilución/métodos , Animales , Corteza Cerebral/fisiopatología , Dominancia Cerebral/fisiología , Potenciales Evocados Somatosensoriales/fisiología , Hematócrito , Masculino , Oxígeno/sangre , Papio , Flujo Sanguíneo Regional/fisiología , Resistencia Vascular/fisiologíaRESUMEN
Attempts at radical excision of craniopharyngioma has been made increasingly possible by the advent of neuroradiological imaging and the use of microscopic technique. Between 1977 and 1993, 62 patients of The National Hospital for Neurology and Neurosurgery, London, have undergone surgical excision of craniopharyngioma by the temporal route, with a small anterior temporal resection. Surgical mortality was 4%. Forty-eight patients (76%) remain well on average follow-up of 34 months. Twelve percent had major complications (hypothalamic damage, subdural haematoma, scalp collections requiring shunt drainage). There were four recurrences in patients where the initial operations were considered as complete microscopic excision. Maximal control of tumour recurrence by removal of all tumour accessible and visible to the surgical microscope is best achieved by radical excision at the first operation.
Asunto(s)
Craneofaringioma/cirugía , Hipofisectomía/métodos , Microcirugia/métodos , Neoplasias Hipofisarias/cirugía , Adolescente , Adulto , Causas de Muerte , Niño , Preescolar , Craneofaringioma/diagnóstico , Craneofaringioma/mortalidad , Femenino , Estudios de Seguimiento , Humanos , Lactante , Masculino , Recurrencia Local de Neoplasia/diagnóstico , Recurrencia Local de Neoplasia/mortalidad , Recurrencia Local de Neoplasia/cirugía , Pruebas de Función Hipofisaria , Neoplasias Hipofisarias/diagnóstico , Neoplasias Hipofisarias/mortalidad , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/mortalidad , Complicaciones Posoperatorias/cirugía , Reoperación , Tasa de Supervivencia , Hueso Temporal/cirugíaRESUMEN
A retrospective study of 61 patients with glomus jugulare tumours treated at the National Hospital for Neurology and Neurosurgery, and at the Royal National Throat, Nose and Ear Hospital, London. The average age at presentation was 41.7 years. The patients were mainly treated by a posterolateral combined otoneurosurgical approach. 42/61 of the patients had total or subtotal excision of their tumours, 7/61 had partial removal and the remaining 11/61 had no operation. Only one case required a 2-staged procedure. There were two deaths in the postoperative period, one from intracerebral haemorrhage and the other from the left hemisphere infarction. Postoperative radiotherapy was given to 5/7 of the patients who had partial removal. 3/40 of the patients with total removal had postoperative radiotherapy, and a further 3/40 had received radiotherapy pre-operatively. Of the 11 patients who did not undergo surgery, 7/11 were treated with radiotherapy and 4/11 had embolisation only.
Asunto(s)
Tumor del Glomo Yugular/cirugía , Adulto , Hemorragia Cerebral/diagnóstico , Hemorragia Cerebral/mortalidad , Infarto Cerebral/diagnóstico , Infarto Cerebral/mortalidad , Terapia Combinada , Irradiación Craneana , Diagnóstico por Imagen , Estudios de Seguimiento , Tumor del Glomo Yugular/diagnóstico , Tumor del Glomo Yugular/mortalidad , Tumor del Glomo Yugular/radioterapia , Humanos , Examen Neurológico , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/mortalidad , Radioterapia Adyuvante , Estudios Retrospectivos , Tasa de SupervivenciaRESUMEN
The effect of a previous K+ stimulation on striatal extracellular monoamine levels during global ischaemia, under simulated penumbral conditions, was investigated. Rats were implanted with microdialysis probes in both striata, monoamine release was stimulated unilaterally by adding K+ (100 mM, 20 min) to the artificial CSF perfused through one probe, and bilateral partial ischaemia was imposed after monoamine levels had returned to basal values or below. Resultant increases in dialysate levels of dopamine and 5-hydroxytryptamine were markedly and significantly greater on the side previously exposed to K+, even though electrophysiological measurements indicated similarly severe ischaemia on both sides. Associated monoamine metabolite changes did not differ significantly between the two sides. There was no evidence of greater neuronal loss in the K(+)-stimulated striata 7 days after ischaemia. However, striatal tissue probably exposed to the highest concentrations of K+ could not be examined because of extensive gliosis around the probe.