Abstract: Teleradiology involving the transfer of vital patient information such as scan images is an important technology to facilitate effective and efficient provision of neurosurgical care in the setting of scarce resources and geographic isolation.
We review the implementation of teleradiology initiatives in the small city state of Singapore and its potential and need in the large province of Ontario and draw parallels in their strategic implementation. Although it may seem intuitive that teleradiology has greater applications in regions of vast geographical size, the technology has universal usefulness if applied appropriately in any neurosurgical or health care system.
Abstract: During early neurodevelopment, asymmetric segregation of Numb in mitotic progenitor cells influences the fate of daughter cells, whereby one daughter retains the progenitor phenotype while the other proceeds along a differentiation pathway. Numb has also been reported to function as a tumor suppressor in breast cancers and medulloblastomas. Given its role in maintaining neural progenitor pools in animal models and its reported role as a tumor suppressor, Numb could potentially contribute to astrocytoma oncogenesis. We characterized Numb expression in both human astrocytoma tissue samples and glioblastoma cell lines. We found that Numb is expressed in all grades of astrocytomas, being predominantly cytoplasmic in higher-grade astrocytomas but nuclear in pilocytic astrocytomas. Numb is also present in normal neurons, but not in normal astrocytes. In cultured glioblastoma cells, Numb concentrates in the perinuclear region and process tips. Numb expression in astrocytomas recapitulates that of progenitor cells during neurodevelopment, and suggests a role for Numb in astrocytoma oncogenesis.
Abstract: Cancer stem cells have been shown to initiate and sustain tumor growth. In many instances, clinical material is limited, compounded by a lack of methods to preserve such cells at convenient timepoints. Although brain tumor-initiating cells grown in spheroid manner have been shown to maintain their integrity through serial transplantation in immunecompromised animals, practically, it is not always possible to have access to suitably-aged animals to continuously maintain these cells. We therefore explored vitrification as a cryopreservation technique for brain tumor-initiating cells. Tumor neurospheres were derived from 5 patients with glioblastoma multiforme (GBM). Cryopreservation in 90% serum and 10% DMSO yields greatest viability and could be explored in future studies. Vitrification yields cells that maintain self-renewal and multipotentiality properties. Karyotypic analyses confirmed the presence of GBM hallmarks. Upon implantation into NOD-SCID mice, our vitrified cells re-form glioma masses that can be serially transplanted. Transcriptome analysis showed that the vitrified and non-vitrified samples in either the stem-like or differentiated states cluster together, providing evidence that vitrification does not change the genotype of frozen cells. Upon induction of differentiation, the transcriptomes of vitrified cells associate with the original primary tumors, indicating that tumor stem-like cells are a genetically distinct population from the differentiated mass, underscoring the importance of working with the relevant tumor-initiating population. Our results demonstrate that vitrification of brain tumor-initiating cells preserves the biological phenotype and genetic profiles of the cells. This should facilitate the establishment of a repository of tumorinitiating cells for subsequent experimental designs. ______________________________________________________________________________ Author contributions: Y.K.C.: Collection, assembly of data, data analysis and interpretation; T.B.T.: Collection, assembly of data, data analysis and interpretation; N.Z.: Collection of data; A.P.: Collection of data; S.H.L.: Collection, assembly of data, data analysis and interpretation; C.E.O.: Collection, assembly of data; Y.Y.: Collection, assembly of data; P.B.T.: Collection, assembly of data; S.J.S.: Provision of study material and patients; W.H.N.: Provision of study material and patients; I.N.: Provision of study material and patients; M.P.H.: Collection, assembly of data; O.L.K.: Collection, assembly of data, data analysis and interpretation; B.T.A.: Conception and design, financial support, provision of study material and patients, collection, assembly of data, data analysis and interpretation, manuscript writing, final approval of manuscript; C.T.: Conception and design, financial support, collection, assembly of data, data analysis and interpretation, manuscript writing, final approval of manuscript. Carol Tang, Beng-Ti Ang, Yuk-Kien Chong, and Tan-Boon Toh contributed equally to this work.
Abstract: PURPOSE: Central neurocytomas (CNCs) are rare neuronal tumors that have a favorable prognosis and lower rate of recurrence compared with other intraventricular neoplasms. Although it may be difficult to distinguish CNC on conventional neuroimaging, typical MR spectroscopy (MRS) features have been reported. We describe the MRI and MRS features of CNC. MATERIALS AND METHODS: Eight patients with CNC were reviewed. Three patients underwent presurgical in vivo single-voxel MRS at short echo time (TE, 35 ms) and multi-voxel MR spectroscopic imaging at long TE (144 ms). The surgically resected tumor specimen of one of these patients was also studied ex vivo using high-resolution magic angle spinning (HRMAS) nuclear magnetic resonance. RESULTS: All eight tumors were located in the lateral ventricles. In six patients, CNC extended into the third ventricle, and in two patients the tumor showed further contiguous intraventricular dissemination into the fourth ventricle. In all three patients who underwent MRS, a characteristic metabolite peak was detected at 3.55 parts per million (ppm) at both long and short TE. HRMAS confirmed the presence of elevated glycine (Gly) at 3.55 ppm, without increase in the concentration of myo-inositol found at the same chemical shift. Elevated choline (at 3.2 ppm) was also seen in all three patients. CONCLUSION: On MRS, CNCs have a typical appearance with a metabolite peak at 3.55 ppm due to increased Gly, and this feature may be helpful in presurgical diagnosis. Although they are rare benign intraventricular tumors, in atypical cases, CNCs can show extensive intraventricular dissemination into the fourth ventricle.
Abstract: OBJECTIVE: Benign extracerebral lesions such as meningiomas may cause hemiparesis by compression and deviation without infiltrating the white matter. We used magnetic resonance diffusion tensor imaging and diffusion tensor tractography to investigate the effects of benign extracerebral lesions on the corticospinal tract (CST). METHODS: Thirteen patients with extracerebral lesions (11 benign meningiomas and 2 benign cysts) underwent magnetic resonance diffusion tensor imaging and diffusion tensor tractography of the CST using fiber assignment by continuous tractography. The CST was reconstructed and assessed by comparing the ipsilateral and unaffected contralateral fibers. The tumor volume, relative fractional anisotropy, fiber deviation, relative fiber number, and relative fiber per voxel were compared between patients without and with temporary presurgical hemiparesis. RESULTS: Seven patients without hemiparesis and five patients with temporary hemiparesis were analyzed; one patient had permanent weakness and was excluded from analysis. There was no significant difference in the tumor volume, relative fractional anisotropy, presence of cerebral edema, or CST deviation between groups. In patients with temporary hemiparesis, the median relative fiber number (mean, 0.35 +/- 0.32) and relative fiber per voxel (mean, 0.49 +/- 0.14) were significantly reduced compared with patients without hemiparesis (0.92 +/- 0.55, P = 0.04; and 0.96 +/- 0.28, P < 0.01, respectively). CONCLUSION: In patients with benign extracerebral lesions, reduction in fiber number and fiber per voxel, but not fiber deviation, correlated with temporary hemiparesis. Clinical recovery was possible even if the CST fibers detected by diffusion tensor tractography were reduced by benign extracerebral lesions.
Abstract: Gliomas are heterogeneous brain tumors and prognosis and treatment are dependent on the highest histological grade present. Stereotactic biopsy is associated with an inherent risk of sampling error. Magnetic resonance spectroscopy (MRS) uses clinical MR scanners to provide chemical in addition to conventional information. MRS studies in brain tumors have found increased levels of choline-containing compounds (Cho) and decreased levels of N-acetylaspartate (NAA), creatine (Cr) and phosphocreatine (PCr) which are all associated with increased grade of glioma. We propose the use of MRS-guided stereotactic biopsy of astrocytomas to increase diagnostic yield and reduce the sampling error rate. MRS was performed on two patients undergoing stereotactic biopsy for suspected astrocytoma. Spectral peak heights of the metabolites Cho at 3.2 parts per million (ppm) chemical shift, NAA at 2.0 ppm and lipid (Lip) at 1.2 ppm, were measured. Biopsy targets were selected from the voxels with the highest Cho/NAA and normalised against Cho levels in the contralateral normal tissue, as well as those with highest lipid content. The biopsies were taken and tissue diagnosis was obtained via standard histological techniques. Histological grade was found to be different in one case: the region with a high Lip/Cr and Cho/NAA ratios showed glioblastoma, whereas the region with high Cho/NAA but low Lip/Cr ratios showed anaplastic astrocytoma. The second patient had high Cho/NAA ratio but low Lip/Cr ratio in both targets and the histology revealed anaplastic astrocytoma in both samples. MRS is a useful biomedical imaging tool for diagnosing and grading astrocytomas. Targeting regions with highest lipid content can potentially improve the diagnostic yield and minimize sampling error in stereotactic biopsy.
Abstract: BACKGROUND AND PURPOSE: Atypical and malignant meningiomas are uncommon tumors with aggressive behavior and higher mortality, morbidity, and recurrence compared with benign tumors. We investigated the utility of diffusion-weighted (DW) MR imaging to differentiate atypical/malignant from benign meningiomas and to detect histologic dedifferentiation to higher tumor grade. MATERIALS AND METHODS: We retrospectively compared conventional and DW MR images (b-value 1000 s/mm(2)) acquired on a 1.5T clinical scanner between 25 atypical/malignant and 23 benign meningiomas. The optimal cutoff for the absolute apparent diffusion coefficient (ADC) and normalized ADC (NADC) ratio to differentiate between the groups was determined by using receiver operating characteristic (ROC) analysis. RESULTS: Irregular tumor margins, peritumoral edema, and adjacent bone destruction occurred significantly more often in atypical/malignant than in benign meningiomas. The mean ADC of atypical/malignant meningiomas (0.66 +/- 0.13 x 10(-3) mm(2)/s) was significantly lower compared with benign meningiomas (0.88 +/- 0.08 x 10(-3) mm(2)/s; P < .0001). Mean NADC ratio in the atypical/malignant group (0.91 +/- 0.18) was also significantly lower than the benign group (1.28 +/- 0.11; P < .0001), without overlap between groups. ROC analysis showed that ADC and NADC thresholds of 0.80 x 10(-3) mm(2)/s and 0.99, respectively, had the best accuracy: at the NADC threshold of 0.99, the sensitivity and specificity were 96% and 100%, respectively. Two patients had isointense benign tumors on initial DW MR imaging, and these became hyperintense with the decrease in ADC and NADC below these thresholds when they progressed to atypical and malignant meningiomas on recurrence. CONCLUSIONS: ADC and NADC ratios in atypical/malignant meningiomas are significantly lower than in benign tumors. Decrease in ADC and NADC on follow-up imaging may suggest dedifferentiation to higher tumor grade.
Abstract: Unplanned migration of a deep brain stimulation (DBS) electrode after accurate placement at the intended target can result in a poor surgical outcome and added cost to the procedure. There are various fixation methods described in the literature. The authors describe the use of a modified burr-hole cover which serves as a simple and cost-effective method of fixation of the DBS lead with excellent results.
Abstract: BACKGROUND: This study aimed to evaluate 2 commonly used posterior approach entry points for ventricular cannulation and the ideal trajectories using 3-dimensional virtual reality technology. METHODS: Magnetic resonance imaging data of 10 patients without gross ventricular dilatation or distortion were retrieved and reconstructed. A stereoscopic 3-dimensional preoperative planning system was used to designate the entry points. Various trajectories were simulated. The ideal trajectory was determined as the one that provided direct entry into the atrium or body of the lateral ventricle en route to the ipsilateral frontal horn. RESULTS: Magnetic resonance imaging data sets from 10 patients were used. For the entry point 6 cm above and 4 cm lateral to the inion (Frazier's point), ideal cannulation was achieved for all 10 patients when the selected target was 4 cm above the contralateral medial canthus. When the contralateral medial canthus was targeted, 5 patients had successful outcomes. There were only 3 satisfactory outcomes each when the ipsilateral medial canthus and glabella were targeted. The target 2 cm above the glabella yielded 2 satisfactory outcomes. The entry point 3 cm above and 2 cm lateral to the inion (Dandy's point) had 10 satisfactory outcomes when the target point was 2 cm above the glabella. All the other target points, namely, ipsilateral medial canthus, contralateral medial canthus, 4 cm above the contralateral medial canthus and glabella yielded poor results. CONCLUSIONS: For satisfactory placement when entering via Frazier's point, the best trajectory target would be 4 cm above the contralateral medial canthus. When entering via Dandy's point, the best target would be 2 cm above the glabella.
Abstract: Pleomorphic xanthoastrocytoma (PXA) is a rare primary astrocytic tumour of the nervous system usually involving the superficial temporal cortex of children and young adults. Although the tumour may exhibit histological features of pleomorphism or cellular atypia, the overall prognosis is good compared with other glial tumours, with only 30% of PXA recurring and 20% undergoing anaplastic transformation. Increased mitotic activity, high MIB-1 and proliferating cell nuclear antigen labelling indices and necrosis are poor prognostic factors, whereas abundant lymphocytic infiltration is associated with more benign biological behaviour. Rarely, in older patients, PXA may have a poor prognosis as these patients tend to have intracranial hypertension and focal deficits, as well as histological features of mitosis, increased cellularity and necrosis. We report the case of a 76-year-old woman who presented with dysphasia and right hemiparesis. A left fronto-temporal lobe PXA was misdiagnosed as glioblastoma multiforme. Although a rare and benign tumour type, PXA in the elderly tend to be more malignant, may have the radiological appearance of a malignant tumour and have poor prognosis.
Abstract: INTRODUCTION: Glioblastoma is the most common primary brain tumour with poor overall survival. Surgical resection followed by radiation and chemotherapy is the mainstay of treatment. The role of aggressive resection in improving overall survival remains contentious, although there is evolving data to suggest this trend. Definitive evidence will necessitate a well-designed randomized prospective trial, although it is not likely that this will be possible or feasible. One possible advantage of aggressive tumour resection is a rapid reduction in oncological burden which may augment the effect of adjuvant chemotherapy. MATERIALS AND METHODS: Three glioblastoma cell lines were seeded in concentrations from 5000-20,000 cells per well onto 96-well plates. The cells were incubated for 24 hours before treatment with varying concentrations of 1,3-Bis(2- chloroethyl)-1-nitrosourea (BCNU) ranging from 25 to 175 microg/mL. After 24 hours of treatment with BCNU, the cells were then examined microscopically and subjected to a cell proliferation assay to determine cytotoxicity effects of BCNU. RESULTS: The drug concentration required to achieve greater than 90% growth inhibition (IC90) was taken as the reference for efficacy of chemotherapy dose. With tumour loading of 5000 cells per well, BCNU concentrations of 75-100 microg/mL resulted in greater than IC90, whereas BCNU concentration of 150-175 microg/mL was required with tumour loading of 20,000 cells per well. A higher concentration of chemotherapeutic agent is therefore required to bring about cell death in the presence of greater tumour burden. CONCLUSION: Higher glioblastoma loading confers chemoresistance to BCNU. This is possibly secondary to complex interactions between tumour cells and neighbouring cells acting via autocrine or paracrine signaling pathways.
Abstract: INTRODUCTION: Multi-voxel MR spectroscopic imaging (MRSI) provides chemical metabolite information that can supplement conventional MR imaging in the study of intracranial neoplasia. Our purpose was to use a robust semi-automated spectroscopic analysis to distinguish intracranial tumours from non-neoplastic disease. MATERIALS AND METHODS: Twenty intracranial tumours and 15 patients with non-neoplastic disease confirmed on histological examination or serial neuroimaging were studied with 2-dimensional MRSI using point-resolved spectroscopic (PRESS) imaging localisation. Using semi-automated post-processing software, spectra were analysed for peak heights of choline (Cho), creatine (Cr), N-acetyl aspartate (NAA), lactate (Lac) and lipid (Lip). Normalised Cho (nCho) ratios, computed by dividing maximum Cho in the lesion by the normal-appearing brain, were compared between intracranial tumours and non-neoplastic disease. RESULTS: Meningiomas displayed homogeneously elevated Cho. Malignant tumours, especially large glioblastoma multiforme, displayed inhomogeneity of metabolites within the tumour. All tumours had elevation of nCho >1 (mean 1.91 +/- 0.65), and non-neoplastic diseases had tumour nCho <1 (mean 0.91 +/- 0.46), which was significantly lower (P <0.05). Two patients with non-neoplastic lesions, one with subacute cerebral infarction and the other with cryptococcoma, had elevated Cho compared to normal tissue (false positive rate 13%). CONCLUSION: Using semi-automated MRSI method, a simplified normalised Cho algorithm provides a method to distinguish intracranial tumours from non-neoplastic disease.
Abstract: BACKGROUND: Neurosurgical emergencies constitute a significant proportion of workload of a tertiary neurosurgical service. Prompt diagnosis and emergent institution of definitive treatment are critical to reduce neurological mortality and morbidity. Diagnosis is highly dependent on accurate interpretation of scans by experienced clinicians. This expertise may not be readily available especially after office hours because many neurosurgical units are manned by middle-level neurosurgical staff with varying levels of experience in scan interpretation. Multimedia Messaging Service mobile phone technology offers a simple, cheap, quick, and effective solution to the problem of scan interpretation. An MMS takes only a few minutes to send and receive and allows senior doctors to view important images and make important clinical decisions to enhance patient management in an emergency situation. METHODS: A mobile phone (with VGA camera and MMS capabilities) was provided to the neurosurgery registrar on call. The on-call mobile phone is passed on to the corresponding registrar on-call the next day. All consultants had personal mobile phones that are MMS-enabled. Relevant representative CT/MRI images can be taken directly from the mobile phone from the PACS off the computer screen. When only hard copies are available, the images can be taken off the light box. After a 12-month trial period, a questionnaire was given to all staff involved in the project to ascertain the usefulness of the MMS teleradiology service. RESULTS: The survey on the use of the MMS service in a tertiary neurosurgical service demonstrated that the technology significantly improved the level of confidence of the senior-level staff in emergent clinical decision making. Significantly, the MMS images were of sufficient quality and resolution to obviate the need to view the actual scans. The impact of MMS is less pronounced in the middle-level staff, but there was a trend that most of the junior staff found the service more useful. CONCLUSION: The MMS technology is demonstrated to be a useful media for the transmission of high-quality images to assist in the diagnostic process and implementation of emergent clinical therapy. It is already in widespread use and can be seamlessly and rapidly implemented in the clinical arena to improve the quality of patient care.
Abstract: A review of dysembryoplastic neuroepithelial tumors (DNTs) in 14 patients over a 12-year period revealed four patients re-operated because of changes on magnetic resonance imaging (MRI) suggesting tumor recurrence or progression. In three of these, the histological features were identical to the initial DNT. In the fourth patient, persistent DNT was surrounded by WHO grade 2 oligoastrocytoma. In one of the other 10 patients, WHO grade 2 oligodendroglioma was present in white matter deep to and completely separate from a cortically based DNT. Fluorescence in situ hybridization showed codeletion of 1p and 19q in both the DNT and oligodendroglioma and oligoastrocytoma components. Deletions were not identified in any other tumor. Our findings corroborate other studies that 1p and 19q deletions are uncommon in DNT. These two unusual tumors also raise the possibility that rare DNTs may evolve into oligodendroglioma or oligoastrocytoma. DNTs with this altered biology can be identified by 1p and 19q deletion analysis.
Abstract: Ex-vivo and in-vitro nuclear magnetic resonance (NMR) spectroscopy techniques have been used for studying chemical metabolites in surgically resected specimens of human neoplasms, and may provide complementary information to in-vivo whole-body magnetic-resonance spectroscopy (MRS). We describe an ex-vivo NMR in water method for measurement of water-soluble metabolites in unprocessed normal rat brain tissue and human intracranial neoplasms. The NMR spectra obtained using the method described here were comparable to those obtained using high-resolution magic-angle spinning (HRMAS) NMR methods, with good correlation in metabolite concentrations relative to creatine (r2 = 0.7635). Improved spectral resolution and baseline were noted compared to HRMAS, but macromolecule resonances were not detected. Ex-vivo NMR of unprocessed tissue in water is rapid and technically simple to perform, and has the potential to be used for direct assessment of intracranial neoplasms.
Abstract: INTRODUCTION: Resection or even biopsy of an intra-axial mass lesion in close relationship to eloquent cortex carries a major risk of neurological deficit. We review the safety and effectiveness of craniotomy under local anaesthesia and monitored conscious sedation for resection of mass lesions involving eloquent cortex. MATERIALS AND METHODS: We performed a 3-year retrospective review of patients who underwent awake craniotomy under local anaesthesia at the National Neuroscience Institute, Singapore. All patients had tumours in close proximity to eloquent cortex, including speech areas in the dominant hemisphere as well as primary sensory and motor cortex in either hemisphere. Brain mapping was performed by direct cortical stimulation using the Ojemann stimulator to identify a safe corridor for surgical approach to the tumour. Intraoperative physiological monitoring was carried out by assessment of speech, motor and sensory functions during the process of surgical resection. All resections were evaluated and verified by postoperative imaging and reviewed by an independent assessor. Postoperative complications and neurological deficits, as well as extent of tumour resection, were evaluated. RESULTS: A total of 20 patients underwent stereotactic resection over a period of 3 years from July 2003 to August 2006. There were 7 male patients and 13 female patients, with a mean age of 39.8 years. The average length of stay was 5.5 days. There were no major anaesthetic complications and no perioperative deaths. Postoperative neurological deficits were seen in 6 patients (30%) and this was permanent in only 1 patient (5%). The degree of cytoreduction achieved was greater than 90% in 58% of patients and a further 21% had greater than 80% cytoreduction. CONCLUSION: Tumour surgery with conscious sedation in combination with frameless computer stereotactic guidance is a safe technique that allows maximal resection of lesions in close relationship to eloquent cortex and has a low risk of neurological deficit.
Abstract: INTRODUCTION: The aims of this article were to review the role of surgical resection in the management of high-grade gliomas and to determine whether there is any survival benefit from surgical resection. METHODS: A literature review of the influence of surgical resection on outcome was carried out. Relevant original and review papers were obtained through a PubMed search using the following keywords: glioma, resection, prognosis and outcome. RESULTS: Presently, there is a lack of evidence to support a survival benefit with aggressive glioma resection, but this should not detract patients from undergoing surgery as there are many other clinical benefits of glioma excision. In addition, limiting surgical morbidity through the use of adjuvant techniques such as intraoperative magnetic resonance imaging (MRI), functional MRI and awake craniotomy is becoming increasingly important. CONCLUSIONS: Ideally, a randomised controlled trial would be the best way to resolve the issue of whether (and to what extent) surgical resection leads to improvements in patient outcome and survival, but this would not be ethical. The second best option would be well-controlled retrospective studies with a multivariate analysis of all potential confounding factors.
Abstract: INTRODUCTION: The use of adjuvant temozolomide (TMZ) in patients managed with surgery and adjuvant radiation therapy (RT) for glioblastoma multiforme (GBM) has been demonstrated to improve median and 2-year survival in a recent large international multicentre study. To confirm this result in routine clinical practice, an audit of the management and outcome of patients with GBM at The Cancer Institute Radiation Oncology was performed. MATERIALS AND METHODS: All patients with GBM managed radically at The Cancer Institute Radiation Oncology from May 2002 to 2006 were entered into a prospective database. Patient, tumour and treatment factors were analysed for association with the outcome of median survival (MS). Survival was calculated using the Kaplan-Meier technique and correlation was assessed using Cox proportional hazards regression. RESULTS: Forty-one patients with GBM were managed with radical intent over the 4- year period. The median age was 54 years and 66% were Eastern Cooperative Oncology Group (ECOG) 0-1 performance status. Macroscopic, subtotal and biopsy alone procedures were performed in 61%, 29% and 10% of patients, respectively. The median time from surgery to RT was 26 days. Adjuvant TMZ was used in 44% of patients (n = 18). The MS of the total group was 13.6 months, with a 24% 2-year overall survival. The use of TMZ was associated with improved MS (19.6 versus 12.8 months; P = 0.035) and improved 2-year survival (43% versus 0%). A requirement of dexamethasone dose greater than 4 mg at the end of RT (P = 0.012) was associated with worse survival, but there was no association of MS with age, ECOG, tumour size or extent of surgery. CONCLUSION: The median and 2-year survival outcomes are comparable to the results of the European Multicentre Study and justify the continued use of TMZ in routine clinical practice.
Abstract: INTRODUCTION: There is increasing belief that a formal protocol-based multidisciplinary care model should be adopted as an optimal care model in oncology. However, there is minimal outcome evidence to demonstrate an improvement in patient care. The aim of this study was to compare clinical quality outcomes between patients with high-grade glioma managed at one hospital using a formal neuro-oncology multidisciplinary tumour clinic (MTC) and a second hospital with a traditional on-call referral pattern (non-MTC). MATERIALS AND METHODS: Patients with high-grade glioma managed radically with radiation therapy at 2 Singapore hospitals from May 2002 to May 2006 were entered into a prospective database. Patients were grouped into management via MTC or non-MTC. Four clinical quality indicators were chosen retrospectively to assess the variation in practice: a) Use of computed tomography (CT) or magnetic resonance (MR) imaging post-resection (POI) for assessment of residual disease; b) Commencement of radiation therapy (RT) within 28 days of surgery; c) Adjuvant chemotherapy use for glioblastoma multiforme (CTGBM) and d) Median survival. RESULTS: Sixty-seven patients were managed radically, with 47 by MTC and by 20 by non-MTC. MTC patients were more likely to have POI (P = 0.042), and CTGBM (P = 0.025). Although the RT start time was similar for the whole cohort (60% versus 45%: P = 0.296); for GBM patients, the RT start was earlier (63% vs 33% P = 0.024). The median survival for the MTC group was 18.7 months versus 11.9 months for the non-MTC group (P = 0.11). CONCLUSION: Clinical quality outcomes were significantly improved in patients with high-grade glioma managed in this neuro-oncology MTC.
Abstract: Oligodendroglioma is a relatively uncommon primary brain tumour. The occurrence of metastatic dissemination of oligodendroglioma is rare and usually occurs in patients with anaplastic oligodendroglioma. The dissemination of WHO Grade II oligodendroglioma can occur and we report a patient with an initial diagnosis of a left temporal oligodendroglioma who presented with disseminated disease in the left temporal lobe, sellar region, medulla oblongata, both frontal lobes and ventricles more than 8 years later. Histology at dissemination showed anaplastic oligodendroglioma. Similar reports of metastatic dissemination of oligodendrogliomas reveal that the tumours may remain as WHO Grade II or may progress to anaplastic oligodendroglioma at metastasis. However, regardless of the histological grade at metastasis, the prognosis of metastatic oligodendroglioma is poor.
Abstract: Metastatic dissemination of malignant glioma is rare. Metastatic disease usually occurs within the neuraxis but extracranial spread to the liver, spleen, lung, peritoneum and lymph nodes can also occur. In most cases of metastatic disease, the patient has previously undergone a craniotomy. The prognosis is uniformly poor. The vast majority of patients do not survive beyond six months from diagnosis of metastatic spread of a primary intracranial tumour. The pathophysiology and natural history of this condition is still not fully understood, hence well-designed prospective studies are needed.
Abstract: OBJECTIVE: Oligodendroglial tumors form an uncommon, but distinct, subgroup of gliomas with longer survival, better treatment response, and characteristic genetic alterations. Noninvasive grading of oligodendroglial tumors using functional and metabolic magnetic resonance imaging may be helpful in guiding the treatment approach and predicting malignant transformation of these tumors. We used perfusion-weighted magnetic resonance imaging and proton magnetic resonance spectroscopic imaging (MRSI) to predict the oligodendroglioma grade. METHODS: Twenty-four patients with pathologically confirmed oligodendrogliomas underwent dynamic contrast-enhanced perfusion-weighted magnetic resonance imaging and/or proton MRSI before surgery. We assessed the ability of tumor contrast enhancement, normalized cerebral blood volume, normalized choline, and the presence of either lactate or lipid metabolites to correctly predict the World Health Organization tumor grade. The accuracy of tumor grading using each method was also compared. RESULTS: Tumor contrast enhancement (P = 0.069) and normalized cerebral blood volume (P = 0.181) were not significantly different between low and high-grade oligodendrogliomas. The MRSI measurement of normalized choline was significantly higher in high-grade (2.82 +/- 0.64) than in low-grade (1.62 +/- 0.46) oligodendrogliomas (P < 0.001), and the presence of lactate or lipid metabolites also correctly predicted high-grade tumors (P = 0.014). The maximum accuracy of contrast enhancement, normalized cerebral blood volume, normalized choline, and lactate or lipid metabolites in grading oligodendroglioma was 71, 83, 90, and 85%, respectively. CONCLUSION: MRSI measurements are more accurate than perfusion-weighted magnetic resonance imaging or conventional contrast enhancement in differentiating oligodendroglial tumor grade. In these inherently vascular tumors, metabolic measurements of mitosis and necrosis may be better than measures of neovascularity in presurgical grading.
Abstract: Traumatic brain injury is a cause of high mortality and morbidity and is an area of intense research. Apoptosis plays a crucial role in the pathogenesis of head injury, and the inhibition of apoptosis can potentially reverse the deleterious effects and lead to better functional outcome. Elucidation of the apoptotic pathway and its role in traumatic brain injury will provide potential targets for therapeutic intervention. This article aims to review the current wealth of literature on apoptosis and traumatic head injury and explores the current status of therapeutic strategies available.
Abstract: Epidermoid cysts typically have images characteristic similar to cerebrospinal fluid (CSF). A case of a hyperdense epidermoid cyst on computed tomography (CT) scan mimicking meningioma is described and the possibility of unusual imaging characteristics of epidermoids is highlighted as a diagnostic problem.
Abstract: Epidural haematomas are usually associated with preceding head trauma. The entity of non-traumatic spontaneous acute epidural haematoma is rare and most commonly occurs in the presence of infectious disease. It can also occur in the presence of coagulopathy, vascular malformations of the dura mater and haemorrhagic tumours. Sickle cell disease, systemic lupus erythematosus, open heart surgery and haemodialysis have also been implicated as causative factors. The authors report two cases of spontaneous epidural haematomas (one of unknown aetiology and one from a coagulation disorder) and discuss the aetiological agents involved in this rarely described condition.
Abstract: A case of aneurysmal subarachnoid haemorrhage with associated haemorrhagic infarction of a growth hormone secreting pituitary macroadenoma is presented. The subarachnoid haemorrhage was not identifiable on CT, but was apparent on MRI. Angiography revealed a 7mm right posterior communicating aneurysm, a 3mm left A1 segment anterior cerebral aneurysm, and vasospasm. Surgery was performed through a right pterional/subfrontal approach, clipping both aneurysms and debulking the tumour. The left A1 aneurysm was the site of subarachnoid haemorrhage. There was evidence of haemorrhagic infarction of the pituitary tumour. Although rupture of an aneurysm into a pituitary tumour has been previously reported, this is the first case reported of aneurysmal subarachnoid haemorrhage with coexisting pituitary apoplexy where the aneurysm had not bled directly into the pituitary tumour. The literature regarding the association between pituitary tumours and aneurysm is reviewed.
Abstract: Lymphocytic hypophysitis is a rare but important cause of pituitary hypofunction which predominantly affects young women in the peripartum period. It is believed to be an autoimmune disorder with an association with other autoimmune disorders and expression of anti-pituitary cytosolic and anti-nuclear antibodies. Clinically, it presents most frequently with symptoms and signs attributable to pituitary hypofunction, headache, visual disturbance and amenorrhoea. It is difficult to distinguish lymphocytic hypophysitis from a pituitary adenoma on pre-operative imaging and definitive diagnosis rests on histology which classically demonstrates destruction of anterior pituitary acini by an inflammatory infiltrate rich in plasma cells and T lymphocytes. Surgical management therefore plays a crucial role to obtain a histological diagnosis and to relieve pressure effects on the optic apparatus in patients with visual disturbances.
Abstract: Lymphocytic hypophysitis is an uncommon disease with a variable presentation and unclear pathophysiology. We present the case of a 30 year old woman who presented with features typical of a pituitary macroadenoma. She underwent a transphenoidal resection of the mass and histopathological examination revealed lymphocytic hypophysitis. This case illustrates the difficulty in differentiating pituitary macroadenoma and lymphocytic hypophysitis and the variable presentations of lymphocytic hypophysitis.
Abstract: Spinal epidural haematoma is a rare cause of spinal cord compression. It is most commonly attributed to trauma and coagulation disorders. We report a case of a 64 year-old man with thrombocytopaenia who presented with a traumatic epidural haematoma who p resented with right hemiparesis which progressed to complete tetraplegia. MR of the cervical spine showed an epidural collection on the posterior aspect of the cord throughout the cervical spine. The patient underwent C1-C7 laminectomy and decompression. Postoperatively, the patient has improved gradually and has power of grade 3 (Medical Research Council classification of power) in all 4 limbs at 2-month follow-up. MRI is an important modality in the early diagnosis of spinal epidural haematomas and can facilitate emergent decompressive surgery which offers the best chance of neurological improvement.
Abstract: The authors report a case of tethered cord syndrome preceding the development of a syrinx, which subsequently resolved with detethering. This was shown conclusively with serial radiological imaging, although the patient did not improve clinically. The lack of clinical improvement is likely to be due to the delay in surgery caused by infections in this patient, and early detethering should therefore be the aim in patients with tethered cord syndrome.
Abstract: The authors describe a case of a 59 year-old Chinese lady with a history of spontaneous left caroticocavernous fistula in 1988 treated by left internal carotid artery clipping and muscle embolisation. She subsequently presented with a subarachnoid haemorrhage in November 1997 secondary to rupture of an unclippable giant right internal carotid artery aneurysm. This was treated satisfactorily with bilateral cervical carotid artery to proximal middle cerebral artery bypass followed by balloon occlusion. Postoperatively, the patient has no neurological deficit and CT angiogram shows good patency of both grafts 6 months after surgery.
Abstract: OBJECTIVE: Nitric oxide (NO) plays an important role in the pathogenesis of neuronal injury after brain ischemia, and decreased levels of NO have been implicated in the pathogenesis of vasospasm after subarachnoid hemorrhage (SAH). In this study, we measured the ventricular cerebrospinal fluid (CSF) NO levels in patients with SAH and correlated the levels with clinical grade and middle cerebral artery velocities measured with transcranial Doppler ultrasound. METHODS: All patients with spontaneous SAH documented on computed tomography and with an external ventricular drain inserted within 24 hours of hemorrhage were included in the study. A total of 16 patients were studied between August 1999 and August 2000. CSF was collected serially at the time of surgery and subsequently at daily intervals. It was collected during the time that the external ventricular drain remained patent and in situ. NO levels were measured by photometric analysis by using a nitrite/nitrate assay kit (Cayman Chemical, Ann Arbor, MI). RESULTS: The peak NO level in patients with SAH ranged from 9.96 to 168.16 micromol, with a median of 36.93 micromol. The levels were significantly elevated as compared with the control group (5.16 micromol, P < 0.05). The median NO level in patients with poor-grade SAH was 67.14 micromol as compared with 27.42 micromol in patients with good-grade hemorrhage (P < 0.05). No correlation was seen between CSF NO levels and middle cerebral artery velocities. The median NO level was 33.2 micromol in patients with a poor outcome as compared with 30.25 micromol in patients with a good outcome (P > 0.05). CONCLUSION: This study showed that NO levels are elevated after spontaneous SAH, and the degree of elevation is higher in patients with poor-grade SAH.
Abstract: Desmoid tumor of the breast is a clinician's dilemma as it is difficult to differentiate it from carcinoma clinically, mammographically, and cytologically. Histologically, it must be distinguished from fibrosarcoma. Current management favors wide excision with clear margins. Recurrence is relatively common and usually occurs within 3 years of excision. Adjuvant hormonal therapy does not reduce local recurrence rates; evidence indicates that postoperative radiotherapy can improve the 10-year recurrence-free survival rate.
Abstract: Neurosurgery is limited by the availability of highly trained professionals and resources. Interpretation of scan images is highly vital for accurate diagnosis and institution of appropriate treatment, which can have significant impact on patient care and outcome. Currently, there are various methods of transmitting important scan images to experienced medical staff for accurate interpretation. Multimedia messaging service (MMS) technology is a readily available, simple, and cost-effective method for the transmission of scan images. The use of MMS technology in emergency neurosurgery services has been effective in enhancing the confidence of neurosurgeons in clinical decision making, reducing the need for hospital call-back, and improving patient care.
