Aneurysmal subarachnoid haemorrhage in Maori and European New Zealanders - A comparative study.

A retrospective analysis of 358 patients admitted to the neurosurgical unit at a tertiary referral centre in Aotearoa New Zealand between 2010 and 2017 was undertaken to describe the relationship of ethnicity to demographic, disease characteristic and outcome data in Maori and European New Zealanders experiencing aneurysmal subarachnoid haemorrhage (aSAH). Maori had a higher incidence (RR 1.38, p = 0.01; 95 % CI 1.08-1.77) and presented at a younger age (mean age difference of 5 years). Higher rates of smoking and hypertension were observed in the Maori population studied. However, these do not fully explain any other differences observed. There was no significant difference in clinical grade at presentation. However, despite experiencing lower rates of posterior circulation aneurysms (adjusted OR 0.33, p = 0.05) and radiological findings predicting highest risk of vasospasm i.e., Modified Rankin Scale 4 (OR 0.54, p = 0.02), Maori had a higher incidence of clinical vasospasm (adjusted OR 1.40, p = 0.048, 95 % CI 1.01-1.98). While there was no observed difference in mortality, Maori may experience lower rates of excellent neurological recovery and survive with greater disability compared to European New Zealanders. Overall, this study is suggestive of inequities between Maori and European New Zealanders and highlights the need for further investigation in this area.

Craniectomy for acute disseminated encephalomyelitis.

A 17-year-old girl underwent emergency bifrontal craniectomy for severely raised intracranial pressure with brainstem compression, having developed acute disseminated encephalomyelitis (ADEM) following Epstein-Barr virus infection. We discuss the current evidence for craniectomy in both ADEM and infective encephalitis and propose an approach to management.

Expression of Cathepsins B, D, and G in WHO Grade I Meningioma.

Aim: We have recently demonstrated the presence of putative tumor stem cells (TSCs) in World Health Organization (WHO) grade I meningioma (MG) localized to the microvessels, which expresses components of the renin-angiotensin system (RAS). The RAS is known to be dysregulated and promotes tumorigenesis in many cancer types, including glioblastoma. Cathepsins B, D, and G are isoenzymes that catalyze the production of angiotensin peptides, hence providing bypass loops for the RAS. This study investigated the expression of cathepsins B, D, and G in WHO grade I MG in relation to the putative TSC population we have previously demonstrated. Methods: 3,3-Diaminobenzidine (DAB) immunohistochemical (IHC) staining with antibodies for cathepsins B, D, and G was performed on WHO grade I MG tissue samples from 10 patients. Three of the MG samples subjected to DAB IHC staining underwent immunofluorescence (IF) IHC staining to investigate co-expression of each of these cathepsins using combinations of smooth muscle actin (SMA) and embryonic stem cell marker OCT4. NanoString mRNA expression (n = 6) and Western blotting (WB; n = 5) analyses, and enzyme activity assays (EAAs; n = 3), were performed on snap-frozen WHO grade I MG tissue samples to confirm transcriptional activation, protein expression, and functional activity of these proteins, respectively. Results: DAB IHC staining demonstrated expression of cathepsins B, D, and G in all 10 MG samples. NanoString mRNA expression and WB analyses showed transcriptional activation and protein expression of all three cathepsins, although cathepsin G was expressed at low levels. EAAs demonstrated that cathepsin B and cathepsin D were functionally active. IF IHC staining illustrated localization of cathepsin B and cathepsin D to the endothelium and SMA+ pericyte layer of the microvessels, while cathepsin G was localized to cells scattered within the interstitium, away from the microvessels. Conclusion: Cathepsin B and cathepsin D, and to a lesser extent cathepsin G, are expressed in WHO grade I MG. Cathepsin B and cathepsin D are enzymatically active and are localized to the putative TSC population on the microvessels, whereas cathepsin G was localized to cells scattered within the interstitium, These results suggest the presence of bypass loops for the RAS, within WHO grade I MG.

Expression of cancer stem cell markers in metastatic melanoma to the brain.

We have recently characterized cancer stem cell (CSC) subpopulations in different types of cancer. This study aimed to identify and characterize CSCs within metastatic melanoma (MM) to the brain. 3, 3-diaminobenzidine (DAB) immunohistochemical (IHC) staining of ten samples of MM to the brain demonstrated the expression of the embryonic stem cell (ESC) markers OCT4, NANOG, SALL4, SOX2 and pSTAT3. Protein expression of all five ESC markers except SALL4 were confirmed by Western blotting on five samples and transcriptional activation of all five markers was demonstrated using NanoString mRNA analysis on four samples. Immunofluorescence IHC staining suggested the presence of CSCs that stained for OCT4, SALL4, SOX2 or NANOG. Some of these cells also stained for Melan-A. Also, a pSTAT3+/CD34+ primitive subpopulation was detected on the endothelium of microvessels. These CSCs may be a novel therapeutic target for MM to the brain.

Decompressive hemicraniectomy after malignant middle cerebral artery infarction: does hospital of origin matter?

Decompressive hemicraniectomy (DHC) has been shown to reduce mortality in malignant middle cerebral artery (MCA) infarction. Our primary objective was to compare 1-year mortality between patients receiving DHC for malignant MCA infarction at our institution based on hospital of origin. We retrospectively reviewed the medical records of all patients treated for malignant MCA infarction with DHC at our institution over a 3-year period. One-year mortality rates and time to surgery were comparable regardless of whether the patient first attended the tertiary referral centre or a peripheral centre.

Endoscopic neuroendoscopy using a novel ventricular access port.

BACKGROUND: Hydrocephalus remains an important aspect of neurosurgical care and in select circumstances, the endoscopic third ventriculostomy (ETV) continues to remain an important treatment. In our initial experience of ETV using the commercially available plastic ventricular ports we found them both restrictive and expensive. Following this experience, we developed a stainless steel ventricular access port (VAP). We present our novel method of access involving this non-disposable ventricular port. METHOD: We have developed a series of custom-made, 316-grade stainless steel VAPs designed specifically for our ventricular endoscopes. Following a standard Burr-hole, cannulation of the lateral ventricle is performed inserting this port and removing the trocar allowing free access using a standard ventriculoscope without the requirement for disposable plastic ports. Since 2008 our unit has used a standard method of ventricular access using this device. We present our long-term experience of cases of endoscopic ventriculoscopy and ventriculostomy using this method of ventricular access. RESULTS: From December 2008 to January 2016, 56 patients underwent an endoscopic third ventriculostomy using the stainless steel ventricular port. Two 2 patients (3.6%) had a recorded complication in the form of minor self-limiting intraventricular haemorrhage. No cases of infection or mortality were noted in this patient series. CONCLUSION: We demonstrate our long-term experience with a non-disposable VAP for ventricular access. This method remains safe with results that are comparable to published series. We suggest this method may be a less expensive and safe alternative to standard disposable methods of ventricular access.

Brain mushroom: A case of osteolytic intraosseous meningioma with transcalvaria herniation.

A 61-year-old male presented with primary intraosseous osteolytic meningioma and transcalvaria herniation. This is an extremely rare condition with only 16 case reports of osteolytic intraosseous meningioma. This case is unique because it was accompanied by a transcalvaria herniation.

Light at the end of the tunnel: the learning curve associated with endoscopic transsphenoidal skull base surgery.

Endoscopic transsphenoidal resection of skull base lesions has been introduced widely as an alternative to microscopic transmucosal approaches. We report the introduction of this technique to our unit, including the learning curve recognized for this procedure, comparing techniques in a concurrent case-control fashion. All patients operated on for sellar, suprasellar, or clival lesions were considered for endoscopic surgery, with 51 patients undergoing endoscopic surgery and 46 having microscopic surgery with the operating method determined by the availability of the ear, nose, and throat surgeon involved with the procedures. Endoscopic surgery compared favorably with microscopic surgery with respect to endocrine control, length of stay, diabetes insipidus, and cerebrospinal fluid leakage. A learning curve was found with a significant fall in complication rates between the first third and most recent third of the cohort. Endoscopic skull base surgery has superior results to microscopic approaches once the initial learning curve is overcome, but this can be done quickly and safely.