Cough-Induced Extracranial Internal Carotid Artery Dissection.

BACKGROUND: Coughing due to respiratory tract infections may lead to internal carotid artery (ICA) dissection. AIM: We are presenting a patient with an unusual cough-induced ICA dissection. CASE REPORT: A 42-year-old health care worker presented with bilateral hand numbness which resolved spontaneously. This initial episode was followed 9 days later with intermittent episodes of right hand and leg weakness with speech difficulty. Two days later, he had another episode of speech difficulty. One week prior to the first presentation, he had upper respiratory tract infection with ongoing strong bouts of coughing. Magnetic resonance imaging (MRI), diffusion-weighted imaging (DWI), and apparent diffusion coefficient (ADC) of the brain showed early ischaemic changes at the left frontal and left parietal regions. MR angiography (MRA) showed high signal intensity at the left proximal ICA and poor flow beyond the left carotid bulb. Cerebral angiography revealed left ICA dissection. CONCLUSION: Proper identification of cough-induced extracranial ICA dissection is important because this is treatable.

Expression of osteopontin, matrix metalloproteinase-2 and -9 proteins in vascular instability in brain arteriovenous malformation.

BACKGROUND: Matrix metalloproteinase (MMP)-2 and -9 are Osteopontin (OPN) dependent molecules implicated in the destabilization of blood vessels. OPN and MMPs have been studied in brain arteriovenous malformation (BAVM) patients' tissues and blood samples before intervention. In this study, we compared the serum level of these markers before and after treatment, as well as assessed their protein expressions in BAVM tissues to evaluate their roles in this disease. METHODOLOGY: Serum samples from six BAVM patients and three control subjects were analyzed using enzyme-linked immunoabsorbent assay (ELISA) for OPN. A total of 10 BAVM patients and five control subjects were analyzed using Multiplex ELISA for MMPs. A total of 16 BAVM tissue samples and two normal brain tissue samples were analyzed using immunohistochemistry. RESULT: MMP-2 and -9 were significantly higher in the serum of BAVM patients before and after treatment than in control patients. There were no significant differences of OPN and MMP-9 serum level in BAVM patients before and after treatment. MMP-2 showed a significant elevation after the treatment. Expression of OPN, MMP-2 and -9 proteins were seen in endothelial cells, perivascular cells and brain parenchyma of BAVM tissues. CONCLUSION: Findings revealed that the level of MMP-2 and -9 in the serum correlated well with the expression in BAVM tissues in several cases. Knockdown studies will be required to determine the relationships and mechanisms of action of these markers in the near future. In addition, studies will be required to investigate the expression of these markers' potential applications as primary medical therapy targets for BAVM patients.

Malignant Transformation of a Rosette-Forming Glioneuronal Tumor with IDH1 Mutation: A Case Report and Literature Review.

BACKGROUND: Rosette-forming glioneuronal tumor (World Health Organization grade I) is considered as a benign tumor with very low potential for progression. The potential for malignant transformation of this tumor is not known and has never been reported before in literature. CASE DESCRIPTION: We report a 42-year-old man, diagnosed with rosette-forming glioneuronal tumor of the fourth ventricle with a positive isocitrate dehydrogenase 1 mutation, progressed to glioblastoma after 6 years from diagnosis. We discuss the clinical history, radiological findings, and histopathological characteristic with immunohistochemistry findings observed in this unique case. CONCLUSIONS: Despite being acceptable as benign, based on our observations in this case, there is a potential for malignant transformation of rosette-forming glioneuronal tumor. The role of isocitrate dehydrogenase 1 mutation leading to malignant transformation could not be established as our finding is novel and further prospective studies are required to prove this association.

Effects of immunonutrition on biomarkers in traumatic brain injury patients in Malaysia: a prospective randomized controlled trial.

BACKGROUND: Head injury is one of the top three diagnosis leading to intensive care unit (ICU) admission in Malaysia. There has been growing interest in using immunonutrition as a mode of modulating the inflammatory response to injury or infection with the aim of improving clinical outcome. The aim of the present study was to evaluate the effect of an immunonutrition on biomarkers (IL-6, glutathione, CRP, total protein and albumin) in traumatic brain injury patients. METHODS: Thirty six patients with head injury admitted to neurosurgical ICU in University Malaya Medical Centre were recruited for this study, over a 6-month period from July 2014 to January 2015. Patients were randomized to receive either an immunonutrition (Group A) or a standard (Group B) enteral feed. Levels of biomarkers were measured at day 1, 5 and 7 of enteral feeding. RESULTS: Patients in Group A showed significant reduction of IL-6 at day 5 (p < 0.001) with concurrent rise in glutathione levels (p = 0.049). Patients in Group A also demonstrated a significant increase of total protein level at the end of the study (day 7). CONCLUSION: These findings indicate the potential of immunonutrition reducing cytokines and increasing antioxidant indices in patients with TBI. However, further studies incorporating patient outcomes are needed to determine its overall clinical benefits. TRIAL REGISTRATION: National Medical Research Register (NMRR) ID: 14-1430-23,171. ClinicalTrials.gov identifier: NCT03166449 .

Evaluation of the carotid artery stenosis based on minimization of mechanical energy loss of the blood flow.

BACKGROUND: Internal carotid artery stenosis requires an accurate risk assessment for the prevention of stroke. Although the internal carotid artery area stenosis ratio at the common carotid artery bifurcation can be used as one of the diagnostic methods of internal carotid artery stenosis, the accuracy of results would still depend on the measurement techniques. The purpose of this study is to propose a novel method to estimate the effect of internal carotid artery stenosis on the blood flow based on the concept of minimization of energy loss. METHODS: Eight internal carotid arteries from different medical centers were diagnosed as stenosed internal carotid arteries, as plaques were found at different locations on the vessel. A computational fluid dynamics solver was developed based on an open-source code (OpenFOAM) to test the flow ratio and energy loss of those stenosed internal carotid arteries. For comparison, a healthy internal carotid artery and an idealized internal carotid artery model have also been tested and compared with stenosed internal carotid artery in terms of flow ratio and energy loss. RESULTS: We found that at a given common carotid artery bifurcation, there must be a certain flow distribution in the internal carotid artery and external carotid artery, for which the total energy loss at the bifurcation is at a minimum; for a given common carotid artery flow rate, an irregular shaped plaque at the bifurcation constantly resulted in a large value of minimization of energy loss. Thus, minimization of energy loss can be used as an indicator for the estimation of internal carotid artery stenosis.

Measuring competence development for performing high flow extracranial-to-intracranial bypass.

We report our experience with competence development in the performance of high flow extracranial-to-intracranial (HF EC-IC) bypass surgery because of the infrequency of, and hence potential exposure to, this challenging surgery. We reviewed the National Hospital Morbidity Database for the incidence of EC-IC bypass surgery as well as a prospectively collected database (institutional experience). The following were recorded from the institutional experience: graft occlusion, stenosis, disruption, distal ischaemia, surgical complications of the bypass leading to a modified Rankin Scale (mRS) score >2, and intraoperative cross-clamping time. The cross-clamping time was considered the total time that circulation may have been impaired, which included both the distal and proximal cross-clamping periods. The Australian national EC-IC bypass rate (of all bypass types) averaged 1.9 cases per 1,000,000 head of population annually. The institutional experience (170 cases) of high flow EC-IC bypass in this series was associated with 14.7% (95% confidence interval [CI] 10.1-20.9) of graft complications. Graft-specific complications leading to a mRS score >2 were 5.9% (95% CI 3.1-10.6). For the 83 patients where the cross-clamping time was known, the time of cross-clamping was 44 ± 14 min. We concluded that HF EC-IC bypasses are rarely performed procedures that challenge the development of surgical competence. Novel ways of developing and maintaining surgical skills are necessary, including simulation and laboratory experience.

Proposition of an outflow boundary approach for carotid artery stenosis CFD simulation.

The purpose of this study was to propose an innovative approach of setting outlet boundary conditions for the computational fluid dynamics (CFD) simulation of human common carotid arteries (CCAs) bifurcation based on the concept of energy loss minimisation at flow bifurcation. Comparisons between this new approach and previously reported boundary conditions were also made. The results showed that CFD simulation based on the proposed boundary conditions gave an accurate prediction of the critical stenosis ratio of carotid arteries (at around 65%). Other boundary conditions, such as the constant external pressure (P = 0) and constant outflow ratio, either overestimated or underestimated the critical stenosis ratio of carotid arteries. The patient-specific simulation results furthermore indicated that the calculated internal carotid artery flow ratio at CCA bifurcation (61%) coincided with the result obtained by clinical measurements through the use of Colour Doppler ultrasound.

High flow extracranial-to-intracranial brain bypass surgery.

High flow extracranial to intracranial (HF EC-IC) cerebral revascularisation may be necessary in the management of complex skull base tumours and intracranial aneurysms. Vascular reconstruction techniques, in addition to direct clip reconstruction, have been described since the first successful bypass more than 50 years ago. Bypass grafting can be considered high flow when a radial artery or the saphenous vein is interposed between the extracranial carotids arteries and intracranial vessels. The decision as to whether to use a low flow or high flow bypass is determined by the anticipated cerebral blood flow needed and the availability of a supply source. In this review, we consider the indications, diagnostic evaluation strategies and long-term graft patency of HF EC-IC bypass surgery.

Mean arterial pressure required for maintaining patency of extracranial-to-intracranial bypass grafts: an investigation with computational hemodynamic models-case series.

BACKGROUND: Maintaining flow in a newly established high-flow bypass into the intracranial circulation may be threatened by low blood pressure. OBJECTIVE: To identify mean arterial blood pressure below which early graft failure may ensue. METHODS: Computational fluid dynamic blood flow simulation and Doppler ultrasound-derived velocities were combined to study 12 patients with common carotid-to-intracranial (internal carotid artery in 9 and middle cerebral artery in 3) arterial brain bypass with interposition of the saphenous vein. Patients underwent carotid duplex and high-resolution computed tomography angiography to obtain the necessary data. A mean time-averaged pressure gradient across both anastomoses of the graft was then calculated. RESULTS: The bypass graft mean blood flow±SD was 180.3±76.2 mL/min (95% confidence interval: 132-229). The mean time-averaged pressure gradient±SD across the bypass graft was 10.2±8.7 mm Hg (95% confidence interval: 4.6-15.7). This compared with a mean pressure gradient±SD on the contralateral carotid of 21.7±13.8 mm Hg. From these data, the minimum mean±SD systemic pressure necessary to maintain graft flow of at least 40 mL/min was 61.6±2.31 mm Hg, and the mean peak wall shear stress±SD at the proximal anastomosis was 0.8±0.7 Pa (95% confidence interval: 0.3-1.2). CONCLUSION: Early postoperative mean arterial pressure less than approximately 60 mm Hg may induce blood flow in the bypass to decrease to less than 40 mL/min, a flow below which low shear stress may lead to early graft occlusion.

Comparative patency between intracranial arterial pedicle and vein bypass surgery.

BACKGROUND: Long-term patency of extracranial-to-intracranial (EC-IC) vein bypass is poorly understood. OBJECTIVE: We report our experience of patency of arterial pedicle grafts and interposition vein grafts for the purpose of EC-IC bypass. METHODS: We analyzed 294 consecutive patients who underwent 178 intracranial arterial pedicle bypass procedures and 152 intracranial vein bypass procedures. Bypass patency was assessed by digital subtraction angiography, computed tomographic angiography, and/or Doppler ultrasound. The modified Rankin Scale (mRS) was assigned for clinical grading at the last follow-up consultation. RESULTS: The main indication for arterial pedicle bypass surgery was internal carotid artery occlusion (79 cases); for vein bypass surgery, it was giant aneurysms (61 cases). Procedure-related complications due to surgery occurred in 3 cases (1.7%; 95% CI: 0.4-5.1%) of arterial pedicle bypass surgery and 12 cases (7.9%; 95% CI: 4.5-13.4%) of vein bypass surgery. The patency rate at 6 weeks was 98% (95% CI: 95.0-99.7%) for arterial pedicle bypass and 93% (95% CI: 87.4-96%) for vein bypass, with almost all graft failures occurring within the first week following surgery. Beyond the first week, bypass patency was similar for both groups, with both arterial pedicle grafts and vein bypass grafts that were patent at 1 week having a long-term patency of 99%. There was no statistically significant difference in early, late, and overall patency between the 2 bypass groups. CONCLUSION: The surgical complication rate was greater for vein bypass. Both arterial pedicle and vein bypass have good long-term patency.

Protuberant fibro-osseous lesion of the temporal bone: "Bullough lesion".

Primary tumors of the calvarium are infrequent, and with the exception of osteoma, lesions confined to the surface of the skull are very rare. The differential diagnosis includes benign and malignant matrix forming tumors, other mesenchymal tumors, and reactive lesions. Fibro-osseous lesions are characteristically centered within bone and surface fibro-osseous lesions always prompt consideration of parosteal osteosarcoma, which is rare but well documented in the calvarium. We present 2 cases of a distinctive lesion of the temporal bone intimately related to the occipito-mastoid suture and typically presenting as a retroauricular soft tissue mass with calcific densities, confined to the soft tissues on the outer table of the skull without intraosseous involvement. The lesion is characterized histologically by rounded and ovoid zones of ossification within a bland fibrous stroma. The first 2 cases were documented in 1999 as "Protuberant fibroosseous lesion of the temporal bone.:" We present a further 2 cases, 1 of 2 years duration and the other with a 10-year history. This distinctive entity, which must be distinguished from other fibro-osseous lesions, including subtle low-grade parosteal osteosarcoma, seems to behave in a benign fashion and thus far recurrence is not documented. Local excision seems adequate. The pathologic features in the original report were documented by Prof Peter Bullough. As these cases were recognized by him alone we propose calling this entity "Bullough lesion" or, better still, "Bullough's Bump!"

A new expandable cannula system for endoscopic evacuation of intraparenchymal hemorrhages.

The authors describe a newly developed expandable cannula to enable a more efficient use of an endoscope in removing intraparenchymal spontaneous hypertensive intracerebral hematomas. The cannula is introduced like a conventional brain cannula, using neuronavigation techniques to reach the targeted hematoma accurately, and, once deployed, conventional microsurgical techniques are used under direct endoscopic visualization. This method was used in 6 patients, and, based on the results of intraoperative intracranial pressure monitoring and postoperative CT scanning, the authors were able to achieve good hematoma removal. They found that by using the expandable cannula, efficient endoscopic surgery in the brain parenchyma was possible.