Cerebrospinal fluid white cell count to red cell count ratio as a predictor of ventriculitis in patients with external ventricular drains.

INTRODUCTION: External ventricular drain (EVD) associated ventriculitis is a complication of EVD placement associated with significant morbidity and mortality. Gold-standard for EVD associated bacterial ventriculitis diagnosis involves cerebrospinal fluid (CSF) sampling from the EVD with microscopy, culture and sensitivity testing. The ratio of white blood cells to red blood cells has anecdotally been considered a predictive factor in diagnosing EVD associated ventriculitis, however no study has been done demonstrating this. METHODS: A retrospective cross-sectional study was designed to assess whether the ratio of CSF white blood cells to red blood cells could be used to diagnose EVD associated ventriculitis. Data was collected for all patients undergoing EVD insertion at a major neurosurgical unit in Sydney, Australia. A receiver operator characteristics (ROC) curve was used to determine if this ratio was useful, and Youden's index was calculated to determine the appropriate cut-off point. RESULTS: This sample of n = 157 consecutive patients a total of 29 patients were diagnosed with ventriculitis. The area under the ROC curve was significant (0.706, P <0.001), and Youden's index demonstrated an appropriate cut-off point was a ratio of 1:106. DISCUSSION: CSF parameters have long been considered predictive of EVD associated ventriculitis. We demonstrated that using a component of routine testing it is possible to accurately predict a ventriculitis diagnosis. As the ratio is used, it enables discrimination in a raised white blood cell count due to local trauma with interventricular bleeding. CONCLUSION: CSF white blood cell to red blood cell ratio is an appropriate diagnostic test for ventriculitis.

Is neurotrauma training in rural New South Wales still required following the implementation of the New South Wales State Trauma Plan?

BACKGROUND: In New South Wales (NSW), Australia, trauma accounts for 6% of deaths. Trauma patients receiving definitive care in regional trauma centres are 34% more likely to have a fatal outcome compared to level 1 centres. Following the implementation of the NSW State Trauma Plan where patients with major trauma are fast tracked to regional trauma services, should NSW rural surgeons and retrieval doctors continue to receive surgical training in neurotrauma? METHODS: The study's primary objective was to ascertain which NSW regional and rural hospitals have the equipment to perform neurotrauma and when it was last used. The study also examined the outcome of those patients who had undergone an emergency neurosurgical procedure. RESULTS: Of the 149 regional and rural hospitals in NSW, 16 stored a Hudson brace, perforator, burr and Gigli saw sterile and ready to use in the operating theatre. Only one hospital utilised the equipment in the last year and 11 in the last 10 years. Of those patients who had undergone an emergency neurosurgical procedure, two patients died prior to transfer and three were confirmed deceased after transfer to a tertiary centre. CONCLUSION: The implementation of the NSW State Trauma Plan has streamlined the trauma triage process and transport of neurotrauma patients to regional and major trauma services. However, it is likely that knowledge of how to perform burr hole and craniectomy for the evacuation of extradural haematoma remains a useful skill for the rural surgeon and retrieval doctor if transport is delayed.

Transcranial Doppler-derived indices of cerebrovascular haemodynamics are independent of depth and angle of insonation.

Continuous measurement of cerebral blood flow velocity (CBFV) of the middle cerebral artery (MCA) using transcranial Doppler (TCD) and arterial blood pressure (ABP) monitoring enables assessment of cerebrovascular haemodynamics. Further indices describing cerebrovascular function can be calculated from ABP and CBFV, such as the mean index (Mxa) of cerebrovascular autoregulation, the 'time constant of the cerebral arterial bed' (tau), the 'critical closing pressure' (CrCP) and a 'non-invasive estimator of ICP' (nICP). However, TCD is operator-dependent and changes in angle and depth of MCA insonation result in different readings of CBFV. The effect of differing CBFV readings on the calculated secondary indices remains unknown. The aim of this study was to investigate variation in angle and depth of MCA insonation on these secondary indices. In eight patients continuous ABP and ipsilateral CBFV monitoring was performed using two different TCD probes, resulting in four simultaneous CBFV readings at different angles and depths per patient. From all individual recordings, the K-means clustering algorithm was applied to the four simultaneous longitudinal measurements. The average ratios of the between-clusters, sum-of-squares and total sum-of-squares were significantly higher for CBFV than for the indices Mxa, tau and CrCP (p < 0.001, p = 0.007 and p = 0.016) but not for nICP (p = 0.175). The results indicate that Mxa, tau and CrCP seemed to be not affected by depth and angle of TCD insonation, whereas nICP was.

Dynamic myelopathy as a result of C1 posterior arch aplasia and os odontoideum. A case report.

The atlas (C1) and axis (C2) have distinct morphologies to support the skull and facilitate head rotation and neck flexion. Congenital defects of C1 posterior arch are rare. We present a case of a 59-year-old man with both an absent C1 posterior arch with concomitant os odontoideum. The patient presented with neck crepitus, moderate neck pain and progressive worsening upper limbs paraesthesia and pain. Computed tomography (CT) revealed non-union between the odontoid process and body of axis as well as absence of C1 posterior arch. An occiput C0-C3 fusion was performed. The patient's symptoms improved significantly, and he is functioning well at 12 months. CT showed solid fusion without implant migration. Concomitant os odontoideum with aplastic C1 posterior arch is rare with limited evidence to guide management. Posterior fixation and fusion may be a potential solution to prevent dynamic compression, thereby preventing further myelopathy and related complications.

Expression of Components of the Renin-Angiotensin System by the Putative Stem Cell Population Within WHO Grade I Meningioma.

Aim: We have recently demonstrated a putative stem cell population within WHO grade I meningioma (MG) that expressed embryonic stem cell (ESC) markers OCT4, NANOG, SOX2, KLF4 and c-MYC, localized to the endothelial and pericyte layers of the microvessels. There is increasing recognition that the renin-angiotensin system (RAS) plays a critical role in stem cell biology and tumorigenesis. This study investigated the expression of components of the RAS: pro-renin receptor (PRR), angiotensin converting enzyme (ACE), angiotensin II receptor 1 (ATIIR1), and angiotensin II receptor 2 (ATIIR2) on the putative stem cell population on the microvessels of WHO grade I MG. Methods: 3,3-Diaminobenzidine (DAB) immunohistochemical (IHC) staining was performed on WHO grade I MG tissue samples from 11 patients for PRR, ACE, ATIIR1, and ATIIR2. Two of the MG samples subjected to DAB IHC staining underwent immunofluorescence (IF) IHC staining to investigate co-expression of each of these components of the RAS in using combinations of CD34 and ESC marker SOX2 or OCT4. NanoString mRNA expression analysis and Western blotting (WB), were performed on six snap-frozen MG tissue samples to confirm mRNA and protein expression of these proteins, respectively. Results: DAB IHC staining demonstrated expression of PRR, ACE, ATIIR1, and ATIIR2 within all 11 MG tissue samples. WB and NanoString mRNA analyses, confirmed protein and mRNA expression of these proteins, respectively. IF IHC staining showed PRR, ATIIR1 and ATIIR2 were localized to the OCT4+ and SOX2+ endothelium and the pericyte layer of MG while ACE was localized to the OCT4+ endothelium of the microvesels. Conclusion: The novel finding of the expression of PRR, ACE, ATIIR1, and ATIIR2 on the putative stem cell population on the microvessels of WHO grade I MG, suggests that these stem cells may be a potential therapeutic target by manipulation of the RAS.

Expression of Embryonic Stem Cell Markers on the Microvessels of WHO Grade I Meningioma.

Aim: The presence of cells within meningioma (MG) that express embryonic stem cell (ESC) markers has been previously reported. However, the precise location of these cells has yet to be determined. Methods: 3,3-Diaminobenzidine (DAB) immunohistochemical (IHC) staining was performed on 11 WHO grade I MG tissue samples for the expression of the ESC markers OCT4, NANOG, SOX2, KLF4 and c-MYC. Immunofluorescence (IF) IHC staining was performed to investigate the localization of each of these ESC markers. NanoString and colorimetric in situ hybridization (CISH) mRNA expression analyses were performed on six snap-frozen MG tissue samples to confirm transcriptional activation of these proteins, respectively. Results: DAB IHC staining demonstrated expression of OCT4, NANOG, SOX2, KLF4, and c-MYC within all 11 MG tissue samples. IF IHC staining demonstrated the expression of the ESC markers OCT4, NANOG, SOX2, KLF4, and c-MYC on both the endothelial and pericyte layers of the microvessels. NanoString and CISH mRNA analyses confirmed transcription activation of these ESC markers. Conclusion: This novel finding of the expression of all aforementioned ESC markers in WHO grade I MG infers the presence of a putative stem cells population which may give rise to MG.

An unusual presentation of cerebellar lymphoma.

We report a case of a 40 year old female who presented with a three month history of headaches with a background of Myasthenia Gravis (MG), treated with azathioprine. MRI brain demonstrated a rim-enhancing lesion in the left posterior fossa. CT scan of the chest abdomen and pelvis revealed no other lesion. The patient was taken for resection of the lesion via left retrosigmoid approach. Histologically the neoplasm was a large B-cell lymphoma, Epstein-Barr virus (EBV) positive, with clonality confirmed by IGH gene rearrangement studies. To the best of our knowledge this is the first case of primary central nervous system (CNS) EBV-positive diffuse large B-cell lymphoma of the posterior fossa in a patient with MG treated with azathioprine.

Tumour stem cells in meningioma: A review.

Meningioma is a common intracranial and intraspinal neoplasm accounting for 25-30% of all primary neurological tumours. It is associated with high rates of recurrence especially in higher-grade tumours and lesions located at the skull base. Cancer stem cells are increasingly recognised as the origin of cancer and are attributed to loco-regional recurrence, metastasis and treatment resistance. This review presents the accumulating evidence of the presence of tumour stem cells within meningioma and the stem cell markers being used to characterise this putative primitive population within this common tumour.

Metastatic thymoma presenting as spontaneous epidural lumbar haematoma.

We report the case of a 44-year-old man who was found to have metastatic thymoma to his lumbar spine presenting as a spontaneous epidural haematoma. The man presented with back pain and cauda equina like symptoms in the absence of trauma, antiplatelet or anticoagulant agents. Following a laminectomy and excision of the epidural collection he made a full neurological recovery. Histopathology of the haematoma demonstrated metastatic thymoma. To the best of our knowledge, this is the first such case of metastatic thymoma to the lumbar spine presenting as a spontaneous epidural collection. We believe, in all patients with spontaneous spinal epidural haematoma and a background of malignancy, histopathological analysis should be sought.

Spinal intradural myxoid chondrosarcoma.

The authors present a rare case of intradural extramedullary spinal chondrosarcoma. This 38-year-old man presented with urinary retention and lower-limb weakness. Magnetic resonance imaging demonstrated a thoracic intradural extramedullary spinal tumor, which was resected. Histopathology revealed a meningeal myxoid chondrosarcoma. Despite adjuvant radiotherapy, the patient had multiple recurrences and metastases and died 18 months following his first surgery. The management of the rare entity of spinal canal chondrosarcoma is discussed.

Using smart phone video to supplement communication of radiology imaging in a neurosurgical unit: technical note.

BACKGROUND: The use of smart phones within medicine continues to grow at the same rate as mobile phone technology continues to evolve. One use of smart phones within medicine is in the transmission of radiological images to consultant neurosurgeons who are off-site in an emergency setting. In our unit, this has allowed quick, efficient, and safe communication between consultant neurosurgeon and trainees, aiding in rapid patient assessment and management in emergency situations. OBJECTIVE: To describe a new means of smart phone technology use in the neurosurgical setting, where the video application of smart phones allows transfer of a whole series of patient neuroimaging via multimedia messaging service to off-site consultant neurosurgeons. METHOD/TECHNIQUE: Using the video application of smart phones, a 30-second video of an entire series of patient neuroimaging was transmitted to consultant neurosurgeons. With this information, combined with a clinical history, accurate management decisions were made. RESULTS: This technique has been used on a number of emergency situations in our unit to date. Thus far, the imaging received by consultants has been a very useful adjunct to the clinical information provided by the on-site trainee, and has helped expedite management of patients. CONCLUSION: While the aim should always be for the specialist neurosurgeon to review the imaging in person, in emergency settings, this is not always possible, and we feel that this technique of smart phone video is a very useful means for rapid communication with neurosurgeons.

Use of a synthetic dural substitute to prevent ventral retethering in the management of diastematomyelia.

Diastematomyelia is a congenital condition where the spinal cord is split by a bony or cartilaginous septum. Neurological signs and symptoms arise when this septum tethers the spinal cord. Surgical detethering often improves symptoms; however, recurrent tethering of the cord is increasingly recognised as a long-term complication. In order to prevent retethering many techniques have been used, including early patient mobilisation and sectioning of the cord. Dorsal expansile duroplasty, using synthetic grafts, is a commonly used technique to prevent recurrent dorsal tethering. We present a 31-year-old woman with recurrent ventral tethering of the cord where we used expanded polytetrafluoroethylene (Gore Preclude MVP Dura Substitute; WL Gore and Associates, Flagstaff, AZ, USA) to cover the ventral dural surface, separating the cord from its dural site of tethering. This technique may be useful to prevent ventral retethering in diastematomyelia.

Luteal phase defect: part of the infertility zeitgeist or relic from the past?

Luteal phase defect (LPD) or short luteal phase is a controversial entity that has been variously defined over the years. There are a number of potential causes for LPD all of which are associated with inadequate progesterone secretion throughout the luteal phase which impairs endometrial development and is thus thought to cause infertility. However, the relationship between LPD and infertility is complex, with LPD found in both fertile and infertile women. Attempts have been made at treating LPD with a number of regimens including progesterone supplementation and ovulation induction using clomiphene citrate, however, problems with study design have prevented conclusive evidence for the efficacy of these treatments being drawn. Practically, with the more interventionalist and aggressive approaches to managing couples with unexplained infertility, LPD may have become an irrelevant entity.