How well do radiologists diagnose intracerebral tumour histology on CT? Findings from a prospective multicentre study

The management of patients with intracranial tumours relies on accurate diagnosis of tumour type. To assess the accuracy with which tumour histology could be diagnosed from brain CT we reviewed data from a prospective, population-based study from three Scottish neuroscience centres. Between October 1997 and April 1999 all patients from the Edinburgh, Aberdeen and Dundee Neuroscience Centres with a CT-diagnosis of a solitary, supratentorial intra-cerebral tumour were recruited. General and neuroradiologists were asked to give their best guess tumour diagnosis. Biopsy confirmed neuropathological tumour type was available for comparison with best guess CT-diagnosis in 221 of 324 patients. Histological diagnosis was either malignant glioma, low grade glioma or metastasis in 199 cases. The accuracy of CT lesional diagnosis for these three categories was 60% (95% confidence interval 54-67%), 85% (80-89%) and 82% (77-88%), respectively. The diagnostic accuracy of an intra-cerebral tumour was 0.81 with a positive predictive value of 0.93. There was no significant difference between histological diagnostic accuracy of neuroradiologists and general radiologists. In 10% of patients the initial CT scan was reported as negative for intracranial tumour, with 62% of these scans having been carried out without contrast. Based on CT alone radiologists are good at identifying an intra-cerebral tumour, but not so good at distinguishing between different tumour types. The implications of the findings for patient management are discussed.

Glioma tumourgenicity is decreased by iNOS knockout: experimental studies using the C6 striatal implantation glioma model

Nitric oxide synthase (NOS) has recently been shown to be an important pathophysiological regulator in experimental implantation glioma since manipulation of NOS can significantly alter tumoural blood flow and inhibit tumour growth. In this study we investigated the role of iNOS (inducible NOS) in glioma tumourogenisis using the rodent C6 striatal implantation model. We produced genetically engineered C6 clones that do not express iNOS activity even after stimulation with a mixture of lipopolysaccaride (LPS) and tumour necrosis factor (TNF)-alpha. These iNOS knockout cells showed a similar growth rate to control cells in vivo at 5 days. We then performed an in vivo implantation glioma study using either the iNOS knockout clone or two genetically engineered control C6 clones. There was a significant reduction (p < 0.01) of tumour mass with the iNOS knockout clone 28 days after the implantation. Immunocytochemistry indicated infiltrates of CD3 positive T cells and macrophages in the controls and the iNOS knockout group. These studies indicate that iNOS expression by tumour parenchymal cells is a critical factor for tumour growth with this model. The mechanisms that cause failure of tumour growth need clarification prior to considering that specific iNOS inhibitors might be candidates for adjuvant treatment of malignant glioma.

Impact of early endovascular aneurysmal occlusion on outcome of patients in poor grade after subarachnoid haemorrhage: a prospective, consecutive study

Patients in poor grade (WFNS IV and V) after aneurysmal subarachnoid hemorrhage (SAH) often have a bad outcome. To evaluate early GDC embolisation on such patients a prospective observational study, with comparison to a historical cohort was performed. From January 1996 to December 1998 113 patients were admitted to the Department of Clinical Neurosciences in poor grade after SAH (45 WFNS IV and 68 WFNS V). Eighty-one patients were managed actively with endovascular occlusion of the aneurysm (n = 42) where possible and delayed clipping (n = 16) where not. On an intention to treat basis, 46% had a favourable outcome (Glasgow Outcome Score IV or V) and 48% had died by 3 months. Compared to an historical cohort managed in the same unit between 1992 and 1995 (n = 62, 52% favourable outcome) these results suggest that early GDC aneurysmal occlusion has had a minimal impact on overall outcome.

Highly unsaturated fatty acid induced tumour regression in glioma pharmacodynamics and bioavailability of gamma linolenic acid in an implantation glioma model: effects on tumour biomass, apoptosis and neuronal tissue histology

Highly unsaturated fatty acids (HUFAs) are naturally occurring anti-tumour agents. HUFAs act as intracellular signalling molecules in cell proliferation and death. In human glioma, HUFAs may stimulate tumour regression and apoptosis. An implantation glioma model, using the C6 glioma cell line, was used to investigate the bioactivity of locally infused n-6 HUFA gamma linolenic acid (GLA). Rat brains (15 normal and 37 C6 tumour bearing) were infused with vehicle or GLA 200 microM-2 mM. The most active local concentration of GLA for anti-tumour activity was 2 mM, infused at 1 microl/h over 7 days. Tumour regression, increased apoptosis and decreased proliferation were observed in tumours of rats infused with this concentration of GLA. Little effect on normal neuronal tissue was detected. The intraparenchymal route was an effective method of GLA administration in the treatment of glioma. These studies provide further insights into the potential role of HUFAs as anti-glioma agents.

Management of patients aged >60 years with malignant glioma: good clinical status and radiotherapy determine outcome

Many clinical trials have shown that the most important prognostic variable in patients with malignant glioma is advanced age. However, can some patients aged >60 years still have relatively good outcomes with conventional surgical and radiotherapeutic treatment? A previous audit of practice (1983-89) suggested that functional status was an important prognostic variable in the elderly. We have reviewed a further cohort (1989-96) to evaluate changes in practice and outcomes given advances in neuroimaging, neurosurgery and radiotherapy. The major findings in this series of 80 patients aged over 60 years with a histological diagnosis of supratentorial malignant glioma were: (i) There was a relationship between management undertaken and clinical status of the patients (p < 0.01), i.e. patients in good grade generally had tumour debulking and radiotherapy, whilst those in poor grade generally had only biopsy. (ii) There was a significant increase in survival of patients in the second period who received surgical debulking and post-operative radiotherapy (from a median of 23 to 41 weeks (p < 0.05). (iii) It is likely that case selection accounted for much of this improvement since there was a direct relationship between median survival time and good clinical grade using the WHO performance scale. (iv) A shorter radiotherapy course (30 Gy in six fractions) was as efficacious as a conventional course (60 Gy in 30 fractions), and those patients having radiotherapy survived significantly longer than those not having this treatment (p = 0.001). This study has again demonstrated the importance of preoperative clinical grade and radiotherapy treatment in determining outcomes in patients >60 years. To put these data in a societal context a recent prospective multicentre audit of patients with malignant glioma in Scotland, and another audit from our unit, showed that between 24 and 65% of patients aged >60 years, with a CT diagnosis of malignant glioma do not undergo either surgery or radiotherapy. Advanced age per se should not be a bar to interventional treatment in patients aged >60 years with suspected malignant glioma.

A prospective study of thalamic deep brain stimulation for the treatment of movement disorders in multiple sclerosis

The place for neurosurgical management of movement disorders in multiple sclerosis is unclear. To evaluate the potential benefits of unilateral thalamic deep brain stimulation (DBS) a prospective study was performed. Fifteen patients with confirmed MS and chronic, severe, drug-resistant movement disorders underwent stereotactic surgery to implant a thalamic DBS electrode using CT image guidance and intra-operative neurophysiological testing. The primary outcome measures were reduction in tremor severity and improvement in tests of hand function when the DBS electrode was turned on, 12 months after surgery. Secondary outcome measures included indices of disability, handicap, neuropsychological function and independence. Thirty-seven patients were assessed for treatment, but only 15 underwent surgery. In the 10 patients in whom implantation of the complete DBS system was carried out there was a significant reduction in the severity of tremor (p = 0.02) and improvement in hand function (p = 0.02). There were no benefits in any of the secondary outcome measures. Two patients had thalamocapsular haemorrhages at the site of electrode implantation and two had seizures in the follow-up period. Thalamic stimulation significantly reduced the tremor associated with MS and improved hand function in the targeted upper limb. However, there can be difficulties with identifying an optimal implantation site during operation, significant procedural morbidity and difficulty in predicting immediate outcome. It is also likely that the insignificant benefits of DBS on disability and handicap reflect persisting cerebeller dysmetria, and both the severity and diffuse nature of the disease process in this patient cohort.

Microtubule-associated protein 2 (MAP-2) is expressed in low and high grade diffuse astrocytomas

The expression of neuronal antigens in diffuse astrocytomas has not been thoroughly evaluated. We have investigated the expression of microtubule associated protein 2 (MAP-2), synaptophysin and non-phosphorylated epitopes of neurofilament protein (NFP) by immunohistochemistry in 15 low grade diffuse astrocytomas and 15 glioblastomas. MAP-2 was strongly expressed in 97% of cases, using an antibody to both low and high molecular weight isoforms. An antibody specific to high molecular weight isoforms of MAP-2 (hmw-MAP-2) revealed weaker, focal staining in 60% of cases with greater expression in the glioblastomas (P=0.027). NFP was expressed in 50% of cases, but was generally weak and focal. There was little evidence of synaptophysin expression. We conclude that MAP-2 expression in astrocytomas is due predominantly to low molecular weight isoforms, which may be expressed in astrocytes as well as neurons. Focal expression of hmw-MAP-2 and NFP, however, suggest that neuronal antigens may be expressed, particularly in high grade astrocytomas. Immunopositivity for these antigens should not preclude the diagnosis of diffuse astrocytoma.

Surgical decompression for cerebral oedema in acute ischaemic stroke

BACKGROUND

The high mortality that follows a large cerebral infarction is in part due to brain oedema. Oedema causes mass-effect with raised intracranial pressure and herniation. Medical therapies are used to reduce intracranial pressure but outcome is poor in spite of treatment. Decompressive surgical techniques that attempt to relieve high intracranial pressure due to oedema have been described, but their efficacy in reducing case fatality and disability is uncertain.

OBJECTIVES

To compare medical therapy plus decompressive surgery with medical therapy alone on the outcomes death and 'death or dependency' in patients with an acute ischaemic stroke complicated by clinical and radiologically confirmed cerebral oedema.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (4 October 2001). In addition, we searched the following electronic databases: the Cochrane Controlled Trials Register (Cochrane Library, issue 3, 2001), MEDLINE (1966 - April 2002), EMBASE (1980 - April 2002), and SCISEARCH (to April 2002). We also searched the reference lists of all relevant articles retrieved and contacted individual investigators and experts in the field.

SELECTION CRITERIA

Randomised controlled studies comparing the outcome of treatment with decompressive surgical intervention with treatment not involving surgery. We aimed to include only those studies with low or moderate risk of bias.

DATA COLLECTION AND ANALYSIS

Titles retrieved by searching were assessed for relevance by one author. Data were extracted independently by two authors with discussion to resolve differences. Relevant sub-group analyses were planned and we planned to calculate Peto odds ratios with 95% confidence intervals.

MAIN RESULTS

Over 9000 citations were retrieved and inspected for relevance. We identified no randomised-controlled trials to include in a meta-analysis. Five observational studies reporting comparative data were found along with a number of small series and single case reports. Two ongoing randomised-controlled trials were identified.

REVIEWER'S CONCLUSIONS

There is no evidence from randomised-controlled trials to support the use of decompressive surgery for the treatment of cerebral oedema in acute ischaemic stroke. Evidence from randomised-controlled trials is needed to accurately assess the effect of decompressive surgery.

Antitumour and pro-apoptotic actions of highly unsaturated fatty acids in glioma

The highly unsaturated fatty acids (HUFA) of the n-6 and n-3 series are involved in cell signalling in normal and transformed cells and have recently been associated with pathways leading to tumour cell death. The antitumour activity of three HUFA (arachidonic acid, gamma linolenic acid and eicosapentaenoic acid) were studied in glioma cells and tissue. Using five glioma models, including primary cell suspensions prepared from 46 human glioma samples and an in vivo rat C6 glioma model, we obtained evidence that, following exposure to HUFA, either administered into the medium surrounding human glioma cells or in 16 preparations of multicellular spheroids derived from human and rodent glioma cell lines (C6, MOG, U87, U373) or administered intra-tumourally by infusion using osmotic mini-pumps in 48 rats, glioma regression and apoptosis were detected. Additionally, synergy between gamma irradiation and HUFA administration was observed in 13 experiments analyzing C6 glioma cell apoptosis in vitro. These pro-apoptotic and antiproliferative activities were observed using both C18 and C20 fatty acids of the n-6 and n-3 series, but not when saturated and monounsaturated C18 and C20 fatty acid preparations were used. In the glioma infusion model, in addition to the apoptosis detected in glioma tissue infused with HUFA for 3-7 days, preservation of normal neural tissue and vasculature in adjacent brain was observed. Also, there was little evidence of acute inflammatory infiltration in regressing tumours. Our findings suggest that intraparenchymal infusion of HUFA may be effective in stimulating glioma regression.

Heme oxygenase (HO) isoforms in experimental C6 glioma: an immunocytochemical study

Abstract Because of their potential to regulate tumoural blood flow and interactions with nitric oxide the expression of the type 1 and 2 isoforms of heme oxygenase (HO-1 and HO-2) were evaluated in implanted C6 striatal gliomas. Immunocytochemistry using antibodies specific for HO-1 and HO-2 were used in 20 C6 glioma tumours. The bulk of the tumour parenchyma and endothelium was negative for both HO isoforms. Isolated, but weak staining for HO-1 was seen in most tumours with focally increased expression in perinecrotic regions. Cells morphologically resembling macrophages stained with both HO-1 and HO-2, but were not numerous. These findings suggest that carbon monoxide, unlike nitric oxide, does not have a major role in regulating tumoural blood flow in this experimental glioma model. These findings once again demonstrate the differences between human malignant glioma and experimental implantation glioma models.

Chronic posttraumatic movement disorder alleviated by insertion of meso-diencephalic deep brain stimulating electrode

Incapacitating and drug-resistant posttraumatic movement disorders have successfully been treated by stereotactic thalamotomy. We describe the case of a young man with a posttraumatic hemiballismoid type movement disorder of the left arm, persistent for 2 years, who was selected for treatment with a thalamic deep brain stimulator. However, placement of the stimulating electrode tip at the junction of the zona incerta and subthalamic regions caused abolition of the movement disorder, and the pulse generator was not required. Reassessment over a 44-month period using multiple clinical and functional tests has confirmed continued benefit. This case adds to the reports of alleviation of movement disorders following either stereotactic thalamic mapping or placement of stimulating electrodes without macroscopic thalamic lesioning.

Gliosarcoma with areas of primitive neuroepithelial differentiation and extracranial metastasis

We report a case of gliosarcoma with areas of primitive neuroepithelial differentiation arising in the temporal lobe of a 53-year-old man. The sarcomatous component of this tumor was perivascular in its distribution and showed expression of factor VIII-related antigen, smooth muscle actin and CD34. The primitive neuroepithelial component possessed a small cell morphology and showed expression of neuronal antigens. Strong expression of p53 was demonstrated throughout the tumor with only focal weak expression of epidermal growth factor receptor. The tumor developed widespread extraneural metastases 5 months after surgical resection of the primary tumor. Histological examination of the liver metastases showed them to consist predominantly of the primitive neuroepithelial component. We believe this to be a novel pattern of differentiation in a gliosarcoma which in this case was associated with an aggressive metastatic potential.

Mechanisms of peritumoural brain dysfunction: metabolic and neuroreceptor findings in striatal C6 glioma

The aetiology of the peritumoural brain dysfunction that is rectified by steroids is unknown. To determine potential aspects of its pathophysiological basis we performed metabolic, histochemical and neuroreceptor studies in rodents with striatal C6 glioma. This model is known to cause focal neurobehavioural and electrophysiological dysfunction. The fully quantitative [(14)C]-2-deoxyglucose autoradiographic technique of measuring local cerebral metabolism of glucose (LCMRglu) showed raised LCMRglu (22-29%) in the pallidum, substantia nigra and endopeduncular nucleus. Acetylcholinesterase (AChE) histochemistry and a range of ligand binding studies for dopamine type 1 and 2, and serotonergic 5-HT(2)receptors were negative in the tumour and normal in peritumoural brain. 5-HT uptake sites and strong peripheral benzodiazepine receptor expression were present in the tumour. There was extensive up-regulation of peripheral benzodiazepine receptor expression in the peritumoural brain. These studies show there is metabolic dysregulation in brain regions functionally connected to, but anatomically distant from the striatum. There is also a peritumoural region of up-regulated receptors that have many, predominantly inhibitory, functions. The relationship of these findings to peritumoural brain dysfunction is discussed.

The development of necrosis and apoptosis in glioma: experimental findings using spheroid culture systems

Cell death in gliomas may occur either by apoptosis, or, in the case of high grade tumours, by necrosis, but questions remain as to the pathogenesis and relationship between these processes. The development of cell death was investigated in multicellular glioma spheroid cultures. Spheroids model the development of cell death due to diffusion gradients in a three-dimensional system without confounding influences of immune response, pressure gradients, etc. Spheroid cultures were established from four malignant glioma cell lines: U87, U373, MOG-G-CCM and A172; harvested from culture at weekly intervals and stained with Haematoxylin and Eosin (H&E), TdT-mediated dUTP-X nick end labelling (TUNEL) and by immunohistochemistry for vimentin, Glial Fibrillary Acidic Protein (GFAP) and Ki67. Annexin V flow cytometry and counts of apoptotic cells on H & E stained sections were performed to assess levels of apoptosis. Modes of cell death were also characterized by electron microscopy. Spatially separate zones of proliferation, differentiation and central cell death developed with increasing spheroid diameter. Central cell death developed at a predictable radius (300-400 microm) for each cell line. Ultrastructural examination showed this to be necrotic in type. Apoptosis was most reliably assayed by morphological counts using H & E. Basal levels of apoptosis were low (< 0.5%), but increased with increasing spheroid diameter (> 2% in U87). In particular, levels of apoptosis rose following development of central necrosis and apoptoses were most abundant in the peri-necrotic zone. There were quantitative differences in the levels of apoptosis and necrosis between glioma cell lines. The predictable onset of necrosis in the spheroids will allow us to investigate the pathogenesis of necrosis and events in prenecrotic cells. There is a relationship between the development of necrosis and apoptosis in this model and these processes can be separately assayed. Further in vitro and genetic studies will enable us to study these events and interactions in greater detail than is possible using other cell culture and in vivo systems.

Nitric oxide and glioma: a target for novel therapy?

The biological activities of nitric oxide (NO) include vasodilatation, inhibition of platelet aggregation, neurotransmission, neural plasticity, and modulation of inflammatory and immunological functions. NO synthase (NOS), which is the enzyme that produces NO, has been detected in resected human glioma specimens, and both human and rodent glioma cell lines. NO production in gliomas can alter several important pathophysiological processes, such as local host immune response, tumour cell apoptosis, tumour invasion/metastasis, free radical injury to tumour cells and adjacent normal brain tissues, tonic vasodilatation of tumour vessels, vascular permeability and neovascularization. Recently, some therapeutic strategies for gliomas using NO manipulation have been proposed, and evaluated both experimentally and indirectly in preliminary clinical trials. These include NO manipulation designed to modify tumour cell oncogenesis, tumour blood flow and disposition of anti-cancer drugs in tumour tissue. This review will discuss the biological role of NO in the central nervous system and gliomas and its current and future possibilities in neuro-oncology.

The effects of dexamethasone therapy on permeability, blood flow and iNOS expression in experimental glioma

Most studies of dexamethasone (DXN) effects on experimental glioma have used doses 10-500 higher (on mg/kg basis) than those used for patients with brain tumour. The relevance of findings to patients with glioma are therefore uncertain. In order to evaluate the effects of clinical doses of DXN (0.22 mg kg(-1)day(-1)) on the pathophysiology of an experimental glioma we have treated rodents with established C6 gliomas for 3 days. The effects of therapy on local cerebral blood flow (LCBF), tumour blood flow (TBF), tumour capillary permeability (TCP), and inducible nit ric oxide synthase (iNOS) mRNA expression were evaluated. DXN caused a significant reduction in TCP (21 +/- 1.9 to 7.7 +/- 2.2 ml.gm(-1)min(-1)10(-3)) and iNOS mRNA production within and around tumour, but no significant change in either TBF or LCBF. The reduction in TCP was identical to that reported after higher doses of DXN and is probably mediated by glucocorticoid receptors. Further in vivo stud ies using either behavioural or neuropathological paradigms in rodents with established cerebral glioma should be treated with similar doses of DXN to optimise clinical relevance.

The effects of chronic nitric oxide synthase suppression on glioma pathophysiology

Nitric oxide synthase (NOS) is strongly expressed in glioma and has an important role in tumour blood flow (TBF) regulation. Whether manipulation of NOS function within a tumour can have any therapeutic effect is unknown. This study therefore evaluated the pathophysiological effects of chronic systemic NOS inhibition on experimental rodent glioma blood flow, growth and necrosis. To determine the duration and pathophysiological effects of systemic NOS inhibition, Ng-nitro-L-arginine methyl ester (L-NAME) was given to rats bearing C6 glioma acutely (single dose i.v., 30 mg kg) or for either 4 or 7 days (i.p. 75 mg kg day) prior to study. TBF and local cerebral blood flow (LCBF) were measured using C14-iodoantipyrine quantitative autoradiography. Tumour volume, tumoural necrosis and tumoural NOS were measured using conventional neuropathology and immunocytochemistry. Acute and 4-day L-NAME administration produced significant TBF reductions (-48 and -39%, respectively) with less marked changes in LCBF (-35 and -15%, respectively). Seven-day L-NAME administration reduced tumour volume (p = 0.12), increased tumoural necrosis (p < 0.05), but immunohistochemistry showed no difference in tumoural NOS expression. These results confirm that NOS has a significant role in the pathophysiology of experimental glioma, and that in this glioma model the effects of chronic systemic NOS inhibition are, for the period under study, predominately anti-tumoural. Whether chronic NOS inhibition is useful as an adjunct in glioma therapy or provides the opportunity for novel therapeutic approaches requires further study.

The significance of intratumoural neurones and neuronal differentiation in diffuse gliomas: a case series

We describe four patients, ranging from 26-40 years of age, who presented with seizures and large, poorly circumscribed cerebral tumours on magnetic resonance imaging. The resected tumours demonstrated a histopathology similar to low-grade glioma, but with admixed mature neurones. Immunohistochemistry demonstrated expression of putative neuronal antigens in the neuronal component as well as in tumour cells which did not show neuronal morphology. These tumours did not have the usual radiological and pathological features typical of gangliogliomas, but demonstrated an infiltrative pattern of growth and subsequent progressive behaviour. The term ganglioglioma, with its implication of good prognosis, is therefore inappropriate for tumours of this type. The expression of "neuronal" antigens by astrocytomas requires further investigation.

Expression of poly(ADP-ribose) polymerase and distribution of poly(ADP-ribosyl)ation in glioblastoma and in a glioma multicellular tumour spheroid model

Development of necrosis is a characteristic feature of glioblastoma but its pathogenesis remains poorly understood. The process of poly(ADP-ribosyl)ation in response to DNA damage is mediated by poly(ADP-ribose) polymerase (PARP) and results in NAD+ depletion. The consequent ATP and energy depletion may result in cell necrosis. Therefore PARP activation is a potential candidate for a regulatory role in the pathogenesis of necrosis in glioblastoma. This study investigated whether there might be a relationship between both PARP expression and poly(ADP-ribosyl)ation, and necrosis in glioblastoma. The pattern of expression of PARP and of poly(ADP-ribose) groups in an archival series of glioblastoma was examined using immunohistochemistry. These parameters were also studied in multicellular tumour spheroids, derived from human glioma cell lines in which central necrosis develops with increasing spheroid diameter. Poly(ADP-ribose) groups were expressed in peri-necrotic tumour cells in glioblastoma. In the spheroid model poly(ADP-ribosyl)ation was seen centrally in pre-necrotic and necrotic cells with increasing spheroid diameter. PARP was widely expressed in viable tumour cells in the glioblastoma sections. In the spheroids, PARP expression, which was initially diffuse, became confined to the outer proliferative zone with increasing diameter. The pattern of expression of poly(ADP-ribose) groups in the spheroids and in glioblastoma raises the possibility that poly(ADP-ribosyl)ation may play a role in the development of necrosis in glioma. The high basal PARP expression in both glioblastoma and the spheroids suggests that this enzyme may have additional roles in glioma cell biology.

Experimental evaluation of the Spiegelberg intracranial pressure and intracranial compliance monitor. Technical note

The goal of this study was to compare the Spiegelberg intraventricular intracranial pressure (ICP)/intracranial compliance monitoring device, which features an air-pouch balloon catheter, with existing gold-standard methods of measuring ICP and intracranial compliance. A Spiegelberg intraventricular catheter, a standard intraventricular catheter, and a Codman intraparenchymal ICP microsensor were placed in five sheep, which previously had been given anesthetic and paralytic agents, to allow comparative measurement of ICP at incremental levels (range 5-50 mm Hg). Intracranial pressure measured using the Spiegelberg intraventricular air-pouch balloon catheter displayed a linear correlation with ICP measured using the standard intraventricular fluid-filled catheter (r2 = 0.9846, p < 0.001; average bias -0.74 mm Hg), as well as with ICP measured using the Codman intraparenchymal strain-gauge sensor (r2 = 0.9778, p < 0.001; average bias 0.01 mm Hg). Automated measurements of intraventricular compliance obtained using the Spiegelberg compliance device were compared with compliance measurements that were made using the gold-standard manual cerebrospinal fluid bolus injection technique at ICPs ranging from 5 to 50 mm Hg, and a linear correlation was demonstrated between the two methods (r2 = 0.7752, p < 0.001; average bias -0.019 ml/mm Hg). The Spiegelberg air-pouch ICP/compliance monitor provides ICP and compliance data that are very similar to those obtained using both gold-standard methods and an intraparenchymal ICP monitor over a range of pathophysiological ICPs. The automated closed Spiegelberg system offers practical advantages for the measurement of intraventricular compliance. Assessment of the clinical utility and robustness of the Spiegelberg system, together with the development of an intraparenchymal device, would enhance the clinical utility of automated compliance measurement and expand the range of its applications.

The pathogenesis of tumour associated epilepsy

Tumour associated epilepsy (TAE) is a poorly understood manifestation of many gliomas, meningiomas and metastatic brain tumours that has important clinical and social implications. Etiological mechanisms underlying tumour associated epilepsy include theories invoking peritumoural amino acid disturbances, local metabolic imbalances, cerebral oedema, pH abnormalities, morphological changes in the neuropil, changes in neuronal and glial enzyme and protein expression and altered immunological activity. It has also been suggested that the pathology involves perturbations in distribution and function of the NMDA subclass of glutamate receptors. The often capricious response of the seizure disorder following removal of the causative neoplasms suggests multiple factors are involved. Further understanding about the pathogenesis of TAE will await the development and characterisation of suitable animal models that demonstrate the clinical manifestations and physiological changes comparable to those seen in human cerebral tumours. With such a model it is hoped that progress may one day be made in understanding and subsequently treating this debilitating clinical problem.

Effects of N-6 essential fatty acids on glioma invasion and growth: experimental studies with glioma spheroids in collagen gels

OBJECT

Intracranial infusions of gamma-linolenic acid (GLA), an essential fatty acid, have been used as an adjuvant therapy following malignant glioma resection; however, little is known about the dose response of glioma cells to this therapy. In this in vitro study the authors address this important pharmacological question.

METHODS

Glioma spheroids derived from U87, U373, MOG-G-CCM, and C6 cell lines were grown in collagen gel and exposed to a range of GLA concentrations (0-1 mM) for 5 days. The diameter of glioma spheroids was measured, the apoptotic index was assessed using both the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling technique and cell morphological testing, and the levels of proliferating cell nuclear antigen were also measured.

CONCLUSIONS

The dose-response patterns were similar for all four glioma spheroids. Low concentrations of GLA (<100 microM) increased both apoptosis and proliferation with a net increase in tumor growth and invasion, whereas high-dose GLA (>100 microM) significantly impaired spheroid cell growth. The proliferative effects of low-dose GLA could be a hazard in the clinical treatment of malignant glioma; however, because of the low toxicity of GLA against normal cells, local delivery of millimolar doses of GLA could significantly reduce tumor size.

Expression of Bcl-2 and Bax in oligodendrogliomas and their relationship to apoptosis

Apoptotic bodies are frequently found in oligodendrogliomas, particularly in the anaplastic subtype. A range of proteins, such as those of the Bcl family, are implicated in the control of apoptosis. The ratio of antagonists of apoptosis, such as Bcl-2, to agonists, such as Bax, is thought to determine the outcome for a particular cell. This study aimed to determine the expression of Bcl-2 and Bax proteins in a series of oligodendrogliomas and to relate the expression of these to measures of apoptosis. Immunohistochemistry was used to detect the expression of Bcl-2 and Bax in an archival series of 32 oligodendrogliomas. The results were scored semiquantitatively for the extent and intensity of tumour staining. Apoptosis indices were determined by counting apoptotic bodies on haematoxylin and eosin staining and the percentage of cells showing a positive reaction with the TdT-mediated dUTP-biotin nick end-labelling technique (TUNEL). Granular cytoplasmic staining for Bcl-2 was seen in tumour cells in 81% of cases. Cases with a strong intensity (but not extent) of staining showed a lower TUNEL index (P=0.038). Bcl-2 expression was identified in the walls of intratumoural blood vessels in 55% of cases and in peri-tumoural neurones (where present) in 87%. Bax expression was detected in tumour cells in 69% of cases but no relationship to TI was detected. Bax positivity was seen in blood vessels in 44% of cases and peri-tumoural neurones in 60%. Bcl-2 and Bax were concluded to be expressed in a high proportion of oligodendrogliomas, suggesting that they may exert a regulatory role in cell death in these tumours.

Dsyembryoplastic neuroepithelial tumour with discrete bilateral multifocality: further evidence for a germinal origin

We report the case of a middle aged woman who developed refractory complex partial seizures in her early twenties. She had a right coloboma and neurological examination was normal. Neuropsychological assessments revealed mild impairments of non-verbal memory, and visuospatial and constructional difficulties. Serial CT and MRI showed multiple nodular abnormalities in her mid-brain, diencephalon, subependymal region and both mesial temporal lobes. EEG recording revealed a right medial temporal focus. She underwent en bloc temporal lobectomy. The surgical pathology revealed mesial temporal dysembryoplastic neuroepithelial tumour (DNET) in association with extensive, contiguous neocortical dysplasia. The proliferation marker MIB-1 revealed up to 2% labelling in tumour areas resembling conventional oligodendroglioma. In the two years since surgery she has been seizure free and the remaining MR brain abnormalities have not changed. The very unusual centripetal MRI pattern of discrete multifocal lesions with the characteristic T1 and T2 features of DNET would support the dysembyroplastic germinal origin that was proposed by Daumas-Duport et al. (1988) in their original description of the lesion. The neuroradiological, neuropathological and clinical features of this case are compared with the two previous cases of multifocal DNET.

Mood disorders in patients after treatment for primary intracranial tumours

The frequency of mood disorder was studied in a cohort of patients with treated intracranial glioma or meningioma, where psychological morbidity was related to physical and neuropsychological functioning and to the patients' knowledge of their disease. Forty patients were assessed on a range of physical, psychological and neuropsychological measures, with additional interview of a relative to obtain supplementary information regarding each patients' knowledge of their disease. Two (5%) of the 40 patients had clinically significant levels of anxiety, six (15%) clinically significant levels of depression and 92% full or intermediate knowledge about their prognosis. Psychological morbidity was associated with high levels of physical disability and also with cognitive dysfunction, but was not related to the grade of the patient's tumour or the extent to which the patient was aware of the nature of his or her disease. A proportion of patients with intracranial tumours suffer levels of psychological distress sufficient to warrant psychological and/or pharmacological intervention.

Tentative novel mechanism of the bystander effect in glioma gene therapy with HSV-TK/GCV system

Although many works support gap junctional intercellular communication (GJIC) having a close relation to bystander cell killing in herpes simplex virus thymidine kinase (HSV-TK) gene and ganciclovir (GCV) treatment, our previous work suggested that other factors involved in bystander effect besides GJIC exist. To confirm our primary work, we evaluated the mode of the bystander cell (C6) co-cultured with TK-positive cells (TF10.2) in our designed "insert plates" in which two cell lines could be separated but share the same medium. Another method that we used was adding the supernatant from the medium of GCV-treated TF10.2 cells to the wild type C6. Growth inhibition of the bystander cells was observed despite the absence of GJIC. In addition, apoptotic cell death of TK+ cells and bystander cells was obvious. These studies suggested that other pathways besides cell-cell contacts may play a role in bystander cell killing; the factors released from TK-positive cells could induce apoptosis of bystander cells.

The use of diffusion tensor imaging in quantifying the effect of dexamethasone on brain tumours

The role of dexamethasone in the treatment of patients with brain tumours remains poorly understood. In this study the self-diffusion parameters of extracellular water within primary intracranial tumours and peritumoural tissue, and their response to dexamethasone, have been measured using MR diffusion tensor imaging. Maps of the mean diffusivity <D> and two measures of diffusion anisotropy were obtained from six patients before, and typically 48-72h after, commencing dexamethasone treatment. A significant decrease in <D> of either tumour (p < 0.02) or oedematous brain (p < 0.04) was observed in three patients. No significant changes were noted in either of the two calculated diffusion anisotropy indices before and after steroid treatment in any of the six patients.

Platinum distribution in malignant glioma following intraoperative intravenous infusion of carboplatin

The objective of this paper was to determine the time course and extent of platinum uptake into human malignant glioma tissue. An intraoperative, intravenous infusion of carboplatin was given to nine patients (seven glioblastoma and two anaplastic glioma) undergoing tumour excision. Carboplatin dosage was calculated individually to achieve a target systemic free carboplatin exposure. Tumour and peritumoural tissue was harvested at timed intervals following carboplatin administration. Plasma and tumour platinum concentrations were measured by graphite furnace flameless atomic absorption spectrophotometry. Histological examination was also performed on a piece of each tissue sample. The mean carboplatin dose administered was 783, SEM 56 mg (range 485-903). Plasma pharmacokinetics showed a typical elimination curve. The mean peak plasma platinum concentration was 44, SEM 5 micrograms/ml (range 27-74). The mean total elemental plasma platinum area under the curve (AUC) was 9.0, SEM 1.4 mg/ml/min. Platinum was detected in 61 tumour samples, the mean peak concentration being 13 SEM 2 micrograms/g (range 5-21). Platinum was also detected in peritumoural brain and necrotic tumour. No correlation was apparent between the degree of necrosis in each tumour specimen and tumour platinum concentration. Platinum concentrations achieved in tumour were similar to levels that would be cytotoxic for glioma cells in vitro. The results of this study have implications for future studies using capillary permeability modifying agents as adjuncts to brain tumour chemotherapy.

Dynamics of reactive oxygen intermediate production in human glioma: n-6 essential fatty acid effects

BACKGROUND

Reactive oxygen intermediates (ROIs) are important signals controlling cell growth and cell death. Local essential fatty acid (EFA) deficiencies in tumour cells may limit tumour ROI generation. This deficiency may be rectified by the addition of exogenous EFA.

MATERIALS AND METHODS

The n-6 EFA effects on tumour ROIs were analysed in terms of kinetics, dose-response and individual cell type responses using flow cytometry of intracellular 2',7'-dichlorofluorescin oxidation. ROI formation in 30 gliomas and five paired samples of normal brain tissue, > 500 000 cells per specimen, was analysed every 10 s for 0-25 min.

RESULTS

Tumour cell basal ROI was lower than normal brain tissue ROI from the same subjects (P < 0.00002). Normal and tumour cell ROIs were stimulated by 4-40 micromol L-1 n-6 EFAs, arachidonic acid (AA) and gamma-linolenic acid (GLA). The stimulated ROI rate was exponential, with the maximum dependent on EFA concentration and tumour grade.

CONCLUSIONS

EFAs stimulated tumour cells more than normal cells (P < 0.0000017, n = 71) and increased ROIs in glial fibrillary acidic protein-positive cells in tumours. This indicated high sensitivity of glioma cell ROIs to n-6 EFAs.

Anxiety and depression in patients with an intracranial neoplasm before and after tumour surgery

The aims of this prospective study were to investigate levels of anxiety and depression in patients with a solitary intracranial neoplasm before and after surgery, and to determine if relationships exist between high levels of anxiety or depression and the hemispheric location of the tumour, the tumour type or patient gender. Patients aged between 17 and 79 years with a solitary intracranial neoplasm completed the Hospital Anxiety and Depression Scale (HAD) before and after biopsy or resective tumour surgery. A control group of non-brain-damaged subjects also completed the HAD before and after lumbar spinal surgery. Of the 109 patients with a brain tumour 30 and 16% demonstrated the likely presence of anxiety and depression, respectively, according to HAD scoring criteria. A greater proportion of females with a left hemisphere tumour reported higher levels of emotional disturbance than any other group of patients; relationships between dysphasia and levels of anxiety or depression were not significant. Patients with a meningioma had higher levels of anxiety and depression as measured by the HAD than those with any other tumour types. Levels of both anxiety and depression were significantly lower after tumour surgery according to the HAD. There were no significant differences in HAD scores between (a) left and right hemispheric tumour groups, and (b) the tumour and control (n = 20) groups. This study has found that anxiety and depression as measured by the HAD are relatively uncommon in patients with an intracranial neoplasm, and that levels of mood disturbance do not differ significantly from those in patients undergoing lumbar spinal surgery. Levels of anxiety and depression become lower after surgery in patients with a brain tumour. Patterns of anxiety and depression in patients with a brain tumour appear to differ from those reported in stroke.

Apoptosis in human primary brain tumours

Apoptosis, or programmed cell death, has been recognized for nearly three decades as occurring in many organs in response to different pathophysiological stimuli. It is now recognized as one of the fundamental cellular biological processes. In human glioma it was initially identified as 'shrinkage necrosis'. This review outlines the characteristics of apoptosis in the various types of primary human brain tumours. The significance of apoptosis is reviewed in relation to normal and tumour cell dynamics, cellular susceptibility to normal and oncogenic signals and to potential therapeutic advances. On a practical level, methods which are currently used to analyse different aspects of the apoptotic process are introduced. These techniques for analysing apoptosis are critically evaluated and compared. Current developments elucidating the diverse pathways of apoptosis signalling are also reviewed. The potential of pro-apoptotic therapy for the treatment of gliomas is discussed.

Assessment of communication impairment and the effects of resective surgery in solitary, right-sided supratentorial intracranial tumours: a prospective study

To assess the effects of solitary, right-sided supratentorial intracranial tumours on language and communication function patients were assessed preoperatively using the Western Aphasia Battery (WAB) and Boston Naming Test (BNT). The impact of resective tumour surgery was evaluated prospectively by a comparison of test scores obtained at pre- and postoperative assessments. The WAB scores in 33 patients revealed that 21% were by definition dysphasic (i.e. Aphasia Quotient < 93.8) and 35% obtained an abnormal Language Quotient. Performance was particularly variable on the written picture description and word fluency WAB subtests. Using the BNT 21% of 47 patients were anomic. The tumours were evenly distributed throughout the frontal, temporal and parietal lobes, but none were in the occipital lobe. Reassessment approximately 6 days after excisional tumour surgery showed that mean scores for the BNT, Aphasia Quotient, and the WAB spontaneous speech and comprehension subtests had improved significantly despite a significant reduction in dexamethasone therapy. This study has demonstrated that right-sided intracranial tumours produce subtle, but specific language deficits of a type more usually associated with left-sided brain dysfunction. The pathophysiological basis of these deficits is unclear, but they are not attributable to either limited education or pre-existing dyslexia. Further studies using a discriminating and comprehensive assessment of language in the right hemisphere are required.

Rater reliability of Fahn's tremor rating scale in patients with multiple sclerosis

OBJECTIVE

Assessment of movement disorders in patients with multiple sclerosis (MS) is difficult because of the complex nature of the movement disorders. The aim of this study was to determine the reliability of Fahn's Tremor Rating Scale (FTRS) in assessing movement disorders in patients with MS.

METHOD

Videos were made of 10 patients with MS showing their rest, postural, action/intention, and goal-related movement disorders as well as their performance of spirometry, a volumetric task, and timed functional tasks. Ratings of tremor were carried out by one rater on two occasions 3 months apart and by 8 raters on one occasion using FTRS.

RESULTS

Intrarater reliability was generally very good, with no significant "drift" in ratings over time. Interrater reliability was generally good, with some variation in interpretation of scoring criteria that may reflect raters' backgrounds.

CONCLUSION

The FTRS is a reliable and potentially useful tool with which to assess movement disorders in patients with MS.

Neuropathological findings after intracerebral implantation of microdialysis catheters

The neuropathological and immunocytochemical changes in the sheep forebrain following 7 days of microdialysis, using a catheter approved for human use, are described. There was no behavioural dysfunction and light microscopy revealed mild astrogliosis and patchy macrophage infiltration immediately adjacent to the catheter track. The surrounding neuropil was normal. There was one small subcortical haemorrhage (10 x 1.5 mm). These findings are similar to those following microdialysis in rodents and suggest that the risk of significant damage to the human brain is low, that neuropathological changes in the brain around the catheter should not interfere with local brain metabolism, and that the catheter should be affixed in such a way as to minimize movement-induced damage to the brain.

Effects of nitric oxide modulation on tumour blood flow and microvascular permeability in C6 glioma

C6 glioma strongly express nitric oxide synthase. Rats bearing C6 tumours were pre-treated with i.v. Ng-nitro-L-arginine methyl ester (L-NAME), 3-morpholinosydnonimine (SIN-1) or saline before local cerebral blood flow (LCBF) or tumour capillary permeability (TCP) was measured by the [14C]iodoantipyrine autoradiographic or [14C]alpha-amino-isobutyric acid techniques. L-NAME and SIN-1 caused significant TBF alterations (-44% and +136%, respectively) with less marked (-15% and +33%) alterations in normal brain. Calculated cerebrovascular resistance changes within tumour were indeed selective. Baseline TCP was increased compared with normal brain (20-fold). L-NAME and SIN-1 administration did not alter TCP. These effects have significant implications for human malignant glioma management. Selective i.v. manipulation of LCBF, without significant changes in TCP, could increase the efficacy of chemotherapy, radiotherapy or provide better peritumoural oedema control.

Application of the MRC brain tumour prognostic index to patients with malignant glioma not managed in randomised control trial

OBJECTIVES

The MRC brain tumour prognostic index, which uses clinical variables to place patients in different outcome categories, has not been evaluated on a cohort outside a randomised controlled trial. The aims of this study were to (a) determine in a large cohort of patients, derived solely from one centre and not in a clinical trial, whether the MRC prognostic index stratified patients for outcome; (b) compare actual outcomes with those obtained in the original studies; and (c) examine whether neuropathological diagnosis was an independent prognostic variable.

METHODS

The MRC prognostic index was calculated for 236 patients with either glioblastoma or anaplastic astrocytoma managed at a dedicated neuro-oncology clinic in Edinburgh between 1989 and 1995.

RESULTS

For this mixed population of malignant glioma the median survival was 8.6 months. Two year survival was 72.2% for patients with an MRC index score of 1-10; 36.3% for those with an index score of 11-15; 25.1% for those scoring 16-20; 20.4% with those scoring 21-25; 4.8% with those scoring 26-33; and 0% for those scoring 34-38. Exclusion of 79 patients who would not have been eligible for the MRC studies from which the index was derived, because they were either too old or did not receive radiotherapy, still resulted in a similar pattern of stratification but with significantly improved median survival times for the lowest two categories. Multivariate analysis of prognostic variables in the Edinburgh cohort showed that patients with anaplastic astrocytoma did significantly better than those with glioblastoma (p<0.001).

CONCLUSIONS

Although there were some differences in median survival times between the patients in the original MRC studies and the Edinburgh cohort in similar prognostic categories and a tendency to improved two year survivorship in the Edinburgh cohort these differences have arisen because (a) the Edinburgh cohort was accrued about 10 years later than the study has shown that even outside the setting of a prospective controlled trial and with relaxed inclusion criteria the Medical Research Council (MRC) prognostic index is a robust predictor of outcome in patients with malignant glioma. Survival clearly declines as the prognostic index increases. Moreover, the prognostic model can be substantially improved by the addition of histology data, although there is some evidence that this will require complex modelling procedures.

Pineal apoplexy: an occurrence with no diagnostic clinicopathological features

Symptomatic pineal apoplexy unlike pituitary apoplexy is uncommon. A patient with an apoplectic pineal cyst, identified preoperatively using MRI and confirmed histologically presented with episodic syncope, and features of raised intracranial pressure, but no localizing neuro-ophthalmological signs. This case prompted a review of the clinicopathological features of pineal apoplexy. There are no diagnostic clinical features and the neuropathological associations of pineal region haemorrhage are diverse. There is no consistent clinicopathological syndrome of pineal apoplexy.

Effects of resective surgery for left-sided intracranial tumours on language function: a prospective study

BACKGROUND

Although language disorders occur in about 50% of patients with a left hemispheric tumour and are a significant cause of morbidity, the effects of resective neurosurgery and their relation to tumour pathology are unclear. We report the immediate effects of resective surgery on language functions in a heterogeneous group of patients with left-sided intracranial tumours.

METHODS

40 patients were studied. The Western Aphasia Battery (WAB) and Boston Naming Test (BNT) were administered preoperatively and before discharge following resective neurosurgery. Dexamethasone dose at time of testing was recorded, as was time taken to complete the tests, and tumour neuropathology.

FINDINGS

15 patients with normal aphasia quotients and language quotients before resective surgery all had normal quotients postoperatively. 25 who were dysphasic (ie, aphasia quotient <93.8) preoperatively showed significant postoperative improvements in both their mean aphasia quotient (from 81.8 to 89.1, p=0.004) and their mean language quotient (from 73.4 to 85.4, p=0.001), though 13 remained dysphasic. Two of the 25 dysphasic patients had their WAB scores lowered by tumour resection. The findings and postoperative changes in BNT scores were almost identical to the pattern of those in WAB scores. At second assessment, dexamethasone therapy was significantly (p<0.01) lower than preoperative dose (reduction from mean 10.3 mg/day to 0.7 mg/day in the dysphasic group). Patients with glioblastoma were more likely to have lower aphasia quotients, language quotients, and BNT scores than patients with anaplastic glioma, metastasis, or meningioma. Although the glioblastoma group had the greatest improvements in WAB operative scores, 57% remained dysphasic after resective surgery. Two additional patients declined postoperative assessment.

INTERPRETATION

Resective surgery for left-sided intracranial tumours significantly improves language function in dysphasic patients, and is unlikely to impair language functions in non-dysphasic patients. Dysphasia and its response to resective surgery are related to the tumour neuropathology.

The costs of managing patients with malignant glioma at a neuro-oncology clinic

Malignant glioma (glioblastoma and anaplastic astrocytoma) remain incurable despite extensive resection, radiotherapy, chemotherapy and experimental therapies. Few studies have addressed either the costs of various treatments for malignant glioma or their cost effectiveness. The aims of this study were to identify direct hospital costs of treating patients with biopsy proven malignant glioma. The study was carried out within the setting of a dedicated neuro-oncology clinic at a university teaching hospital and included 236 patients treated between 1989 and 1995. The study used the unit costing of each item of treatment according to NHS National Costing Project. The cost of treatment was broken down into its various components: bed days, investigations, surgery, radiotherapy, chemotherapy and neuro-oncology out-patient follow-ups. The mean costs for each of the items based on 1995 figures for the 157 patients having surgery followed by radiotherapy were neuroradiological investigations (442 Pounds), neurosurgical bed days (2407 Pounds), neurosurgery (2068 Pounds), neuropathology (434 Pounds), radiotherapy (8832 Pounds), out-patients (1078 Pounds) and chemotherapy (440 Pounds). Total treatment costs per patient ranged from 1978 Pounds to 26,980 Pounds. Median costs of care decreased sequentially with worsening MRC Brain Tumour prognostic group. Management of patients with the best prognosis (MRC index score of 1-10) cost a median of 16,550 Pounds (range 4572-26,090 Pounds) whilst the median management cost of those in the worst prognostic group (MRC score 34-38) was 6514 Pounds (range 1978-18,360 Pounds). The median cost of each week of survival in the patients with the best outcome (MRC score 1-10) was < 150 Pounds compared to 232 Pounds for each week of survival for patients in the worst prognostic group (MRC score 34-38). This study made no attempt to collect costs of supportive or community-based care. Prospective studies are required to collect such data, as well as assessing the costs effectiveness of alternative treatment strategies.