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Background: Tubular retractors are FDA approved and in the Neurosurgical marketplace, but adaptation has been hampered by lack of evidence showing superiority over traditional retractors when performing subcortical surgery. This study examines brain injury associated with traditional brain retractors versus tubular retractors. Methods: Nine porcine models underwent a simulated neurosurgical operation. Retractors were inserted for four hours after which the porcine model was euthanized. The en-bloc extracted porcine brain was fixed in 10% formalin, paraffin embedded, sectioned at 4 um and stained with hematoxylin and eosin (H&E) using standard laboratory protocols. Computer algorithms were generated to calculate areas of cerebral edema and hemorrhage adjacent to retractor surfaces. Results: Using a two-tailed t-test with a significance level of 0.05, traditional brain retractors were associated with statistically significantly greater cerebral edema when compared to tubular retractors (17.36 um2 vs. 12.42 um2; p = 0.0038). There was no statistically significant difference in mean areas of hemorrhage between traditional brain retractors and tubular retractors noted (3.43 um2 vs 3.60 um2; p = 0.8297). Conclusions: Tubular retractors are associated with significantly less edema in surrounding brain than traditional retractors. On histopathological merits, this study supports the application of tubular retractors over traditional retractors.
Background: Ruptured Intracranial Infected Aneurysms (IIAs) are relatively rare, but they portend high mortality. To our knowledge, there are no Canadian case-series on IIA, as well there is a relative paucity of international published experiences. Our purpose is to share the experience of a single Canadian tertiary centre in managing ruptured IIA and to conduct a systematic review. Methods: We did a retrospective case review series of adult patients with ruptured IIA treated at our institution. Secondly, we conducted a systematic review of literature on ruptured IIA between 2011-2021 inclusive. Results: At our institution, of a total 8 cases with ruptured IIA, 4 were treated endovascularly and 2 by surgical bypass. For the systematic review, we included 9 non-comparative studies with a total of 509 patients (318 males) and at least 437 ruptured IIA aneurysms. Favourable outcome was specified for 63.3% of patients (n=57). Regarding ruptured IIA, favourable clinical outcome was described in 59.3% (n=16). Conclusions: This study highlights a single Canadian tertiary centre experience in the management of IIA and compares it to the global trends of the last 10 years in a systematic review.
Background: Ruptured Intracranial Infected Aneurysms (IIAs) are a relatively rare phenomenon, but they portend high mortality. To our knowledge, there are no Canadian studies on IIA with paucity of data on experiences as well. Our purpose is to share experience of a single Canadian tertiary centre in managing ruptured IIA and to conduct a systematic review. Methods: Retrospective case series review of adult patients with ruptured IIA treated at our institution. Secondly, we conducted a systematic review of literature on ruptured IIA between 2011-2021 inclusive. Results: At our institution, with a total 8 cases with ruptured IIA, 4 patients were treated endovascularly and 2 by surgical bypass. For the systematic review, we included 12 non-comparative studies with a total of 547 patients with IIA. Median percentage of ruptured IIA was at least 65.2%, cases that required intervention was 23.7% for surgical cases, and 50% for endovascular cases. The overall median percentage of complications was 5.3%. Conclusions: This study highlights a single Canadian tertiary centre experience in the management of IIA and compares it to the global trends of the last 10 years in a systematic review.
Background: Tubular retractors are FDA approved and in the Neurosurgical marketplace, but adaptation has been hampered by lack of evidence showing superiority over traditional retractors when performing subcortical surgery. This study examines brain injury associated with traditional brain retractors versus tubular retractors. Methods: Nine porcine models underwent a simulated neurosurgical operation. Retractors were inserted for four hours after which the porcine model was euthanized. The en-bloc extracted porcine brain was fixed in 10% formalin, paraffin embedded, sectioned at 4 um and stained with hematoxylin and eosin (H&E) using standard laboratory protocols. Computer algorithms were generated to calculate areas of cerebral edema and hemorrhage adjacent to retractor surfaces. Results: Using a two-tailed t-test with a significance level of 0.05, traditional brain retractors were associated with statistically significant greater areas of cerebral edema when compared to tubular retractors (17.36 um2 vs. 12.42 um2; p = 0.0038). There was no statistically significant difference in mean areas of hemorrhage between traditional brain retractors and tubular retractors (3.43 um2 vs 3.60 um2; p = 0.8297). Conclusions: Tubular retractors are associated with significantly less edema in surrounding brain than traditional retractors. On histopathological merits, this study supports the application of tubular retractors over traditional retractors.
Correct diagnosis of cause of death is necessary to suggest the most effective management interventions to reduce perinatal lamb mortality. Haemorrhage on the surface of the brain has been used as a field diagnostic tool to allocate lambs to a cause of death category, but the usefulness of this method was unclear. This study aimed to evaluate whether gross pathology was related to neuronal death and whether haemorrhage of the central nervous system (CNS) was distinct between differing causes of death, enabling indicators to be used in field diagnoses. Lambs dying from natural causes (n = 64) and from euthanasia (n = 7) underwent postmortem examination, then the brain and spinal cord were extracted and examined histologically. Histological changes consistent with neuronal death were not detected in any lamb. Haemorrhage of the meninges and/or parenchyma of the CNS occurred in all lambs. The age of the haemorrhage indicated that it occurred near the time of death in most lambs. Dilation of blood vessels varied in severity but appeared to be unrelated to causal diagnosis, severity of subcutaneous oedema, breathing or milk status. Moderate or severe dilation of blood vessels and haemorrhage of the CNS did not occur in all lambs with alternative clear indicators of dystocia and occurred in all death classifications, so it could not be used as diagnostic indicators for classification of cause of death. Dilation and haemorrhage were unrelated to neuronal damage and may have been artefactual. In conclusion, haemorrhage of the CNS was not indicative of neuronal damage and could not be used to distinguish between lambs with clear indicators of differing causes of death, so it is not recommended as a field diagnostic tool.
Background: Persistent fetal carotid-vertebrobasilar anastomoses are rare, with an incidence of <1%. The most common anomaly seen in this group is a persistent primitive trigeminal artery; others such as a persistent hypoglossal artery account for less than 15% of all persistent fetal anastomoses, making this finding exceedingly rare. Methods: We present the case of a 32-year-old-female with Poland syndrome (right-sided), who presented with thunderclap headache and reduced level of consciousness secondary to diffuse subarachnoid hemorrhage and hydrocephalus. CT and catheter angiography demonstrated an aneurysm of the V4 segment of the right vertebral artery arising from a persistent right hypoglossal artery, with an absent ipsilateral vertebral artery proximal to the anomaly. Results: Hydrocephalus was treated with an EVD, followed by a successful embolization of the V4 aneurysm with Axium coils. Subsequent MR studies demonstrated minimal recanalization of the aneurysm, and small foci of possible infarcts in the hippocampi. Four months later, the patient has some persistent short term memory difficulties but is otherwise neurologically intact. Conclusions: We present a rare finding of a persistent fetal hypoglossal artery with an associated vertebral aneurysm. The aneurysm was successfully treated endovascularly through coil embolization with minimal residual -neurological deficit. This vascular anomaly was ipsilateral to her Poland Syndrome defects.
Internet cognitive–behavioural therapy (iCBT) for panic disorder of up to 10 lessons is well established. The utility of briefer programmes is unknown.
To determine the efficacy and effectiveness of a five-lesson iCBT programme for panic disorder.
Study 1 (efficacy): Randomised controlled trial comparing active iCBT (n=27) and waiting list control participants (n=36) on measures of panic severity and comorbid symptoms. Study 2 (effectiveness): 330 primary care patients completed the iCBT programme under the supervision of primary care practitioners.
iCBT was significantly more effective than waiting list control in reducing panic (g=0.97, 95% CI 0.34 to 1.61), distress (g=0.92, 95% CI 0.28 to 1.55), disability (g=0.81, 95% CI 0.19 to 1.44) and depression (g=0.79, 95% CI 0.17 to 1.41), and gains were maintained at 3 months post-treatment (iCBT group). iCBT remained effective in primary care, but lower completion rates were found (56.1% in study 2 v. 63% in study 1). Adherence appeared to be related to therapist contact.
The five-lesson Panic Program has utility for treating panic disorder, which translates to primary care. Adherence may be enhanced with therapist contact.
Transitional cell carcinoma (TCC) of the renal pelvis is a rare urological malignancy, with only a handful of cases of metastases to the brain reported in literature. We aim to present a case of intracranial metastasis in a female patient with history of renal pelvic carcinoma, and review existing literature of brain metastases from renal pelvic TCC. Methods: We searched PubMed, EMBASE, and MEDLINE from 1966 to January 2016 for published case reports written in English. Results: Five published case reports describe intracranial metastases from renal pelvic TCC. Our case is a 56-year-old woman with known high grade renal pelvic carcinoma and pulmonary metastases, who presented nine years after her initial diagnosis with mild left side weakness and headaches. She was found to have two lesions in the right cerebral hemisphere and underwent surgical resection of the larger right frontal lobe mass. Her neurologic symptoms improved postoperatively. She declined whole brain radiotherapy and remains stable at 6 months’ follow-up. This is the first published case of presentation of brain metastases from pelvic TCC more than 12 months after diagnosis of the primary cancer. Conclusion: There is minimal literature of renal pelvic TCC metastasizing to the brain. However, as systemic chemotherapy leads to improved survival from the primary cancer, it is possible for more cases to appear, necessitating increased awareness from the healthcare team.
Background: Abciximab is used for the treatment of thromboembolism occuring during endovascular procedures, however the experience with intra-arterial infusion is limited. The objective is to evaluate its safety and effectiveness during coiling complications. Methods: From an aneurysm coiling database, patients treated with intra-arterial abciximab due to thrombotic complications were selected. Patient were classified either as non-ruptured aneurysm for elective coiling or presenting with subarachnoid hemorrhage. They all had preand post-procedure cerebral angiography performed at our institution as part of routine work-up. Success rate was based on recanalization seen on cerebral angiography. Complications of using abciximab were reported. Results: 35 of 441 coiling patients had a thrombotic complication. 13 of them were treated using intra-arterial infusion of abciximab. 2 patients were male, median age 59. 6 patients presented with sub-arachnoid haemorrhage. 84 % of patients had at least partial recanalization, while 38 % experienced complete recanalization of the parent vessel. 45 % of patients had complications, none severe. 2 patients had aneurysm recanalization, 3 distal migration of thrombus and 1 had haemorrhage (non ruptured aneurysm). Conclusions: Inspite of being considered a safer alternative, use of intrarterial abciximab has potential risks, including hemorrhage, distal thromboembolism and aneurysm recanalization.
Background: Closed cell carotid stent fracture is rare. From our literature review, we present the first reported case in English literature of a carotid stent fracture post angioplasty for an in-stent stenosis. Methods: Case Report Results: 72-year-old male underwent left carotid stenting for symptomatic ulcerated stenosis of the proximal aspect of left ICA (71% stenosis with post-stenting 55% residual stenosis). His right ICA and right vertebral artery were occluded. 2 months later, he presented with TIA’s and severe in-stent stenosis in the proximal left ICA measuring 1 mm in diameter. Satisfactory balloon (5×40 mm) angioplasty was done with residual stenosis measuring 2.5 mm in diameter. 8 months later he presented with symptoms of compromised cerebral perfusion. Workup showed a stent fracture distally at the site of severe ICA stenosis secondary to atherosclerotic calcified plaque causing blood flow changes. His PSV (peak systolic velocity) in the left ICA was 383 m/s. As such he underwent left ICA re-stenting for symptomatic severe left ICA stenosis of 70% with 40% residual stenosis following stent deployment. Conclusions: Carotid stent fracture post balloon angioplasty for recurrent stenosis is rare but of paramount importance. We demonstrate re-stenting as a viable treatment modality when patient profile is not amenable to a surgical revascularization procedure.
All explosive volcanic eruptions generate volcanic ash, fragments of rock that are produced when magma or vent material is explosively disintegrated. Volcanic ash is then convected upwards within the eruption column and carried downwind, falling out of suspension and potentially affecting communities across hundreds, or even thousands, of square kilometres. Ash is the most frequent, and often widespread, volcanic hazard and is produced by all explosive volcanic eruptions. Although ash falls rarely endanger human life directly, threats to public health and disruption to critical infrastructure services, aviation and primary production can lead to potentially substantial societal impacts and costs, even at thicknesses of only a few millimetres. Communities exposed to any magnitude of ash fall commonly report anxiety about the health impacts of inhaling or ingesting ash (as well as impacts to animals and property damage), which may lead to temporary socio-economic disruption (e.g. evacuation, school and business closures, cancellations). The impacts of any ash fall can therefore be experienced across large areas and can also be long-lived, both because eruptions can last weeks, months or even years and because ash may be remobilised and re-deposited by wind, traffic or human activities.
Given the potentially large geographic dispersal of volcanic ash, and the substantial impacts that even thin (a few mm in thickness) deposits can have for society, this chapter elaborates upon the ash component of the overviews provided in Chapters 1 and 2. We focus on the hazard and associated impacts of ash falls; however, the areas affected by volcanic ash are potentially much larger than those affected by ash falling to the ground, as fine particles can remain aloft for extended periods of time. For example, large portions of European airspace were closed for upto five weeks during the eruption of Eyjafjallajökull, Iceland, in 2010 because of airborne ash (with negligible associated ash falls outside of Iceland). The distance and area over which volcanic ash is dispersed is strongly controlled by wind conditions with distance and altitude from the vent, but also by the size, shape and density of the ash particles, and the style and magnitude of the eruption. These factors mean that ash falls are typically deposited in the direction of prevailing winds during the eruption and thin with distance. Forecasting ash dispersion and the deposition ‘footprint' is typically achieved through numerical simulation.
Background: Endometrial carcinoma (EC) is a rare cause of central nervous system metastases, with only 115 cases reported in the literature. There have only been 4 cases reported in the literature for the serous carcinoma subtype. This case study describes a new case of serous carcinoma metastasizing to the brain and demonstrates some of the potential characteristics of this subset. Case: A 77 year old female presented to the emergency department with a 2 week history of progressive left sided weakness and speech difficulties, and a known history of EC diagnosed approximately 3 years earlier. Imaging showed a right temporoparietal tumour. She underwent debulking of this tumour and was found to have a metastasis from her previously known serous carcinoma. Results: In comparing the serous subtype to the 115 known cases, many characteristics show similar patterns to EC as a whole; there could be a predominance to infratentorial lesions with the serous subtype, as 2/4 known metastases were cerebellar compared to only 25% of all endometrial carcinomas. Conclusions: There are possibly different characteristics of metastasizing of various EC subtypes. Before any conclusions can be drawn about the characteristics of any subtype, more data needs to be available for accurate interpretation.
The aims of the present study were to determine compliance with current advice on vitamin D and to assess the influence of season, dietary intake, supplement use and deprivation on vitamin D status in pregnant mothers and newborns in the north of Scotland where sunlight exposure is low. Pregnant women (n 1205) and their singleton newborns were studied in the Aberdeen Maternity Hospital (latitude 57°N) between 2000 and 2006. Plasma 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3 were measured at 19 weeks of gestation in mothers and at delivery in newborns. During pregnancy, 21·0 (95 % CI 18·5, 23·5) % of women took vitamin D supplements. The median intake was 5 μg/d and only 0·6 (95 % CI 0·1, 1·0) % took the recommended 10 μg/d. Supplement use, adjusted for season, dietary intake and deprivation, significantly increased maternal 25-hydroxyvitamin D (25(OH)D) by 10·5 (95 % CI 5·7, 15·2) nmol/l (P< 0·001); however, there was no significant effect on cord 25(OH)D (1·4 (95 % CI − 1·8, 4·5) nmol/l). The biggest influence on both maternal and cord 25(OH)D was season of birth (P< 0·001). Compared with the least deprived women (top three deciles), the most deprived pregnancies (bottom three deciles) were characterised by a significantly lower seasonally adjusted 25(OH)D ( − 11·6 (95 % CI − 7·5, − 15·7) nmol/l in the mother and − 5·8 (95 % CI − 2·3, − 9·4) nmol/l in the cord), and a lower level of supplement use (10 (95 % CI 4, 17) v. 23 (95 % CI 20, 26) %). More should be done to promote vitamin D supplement use in pregnancy but the critical importance of endogenous vitamin D synthesis, and known adaptations of fat metabolism specific to pregnancy, suggest that safe sun advice may be a useful additional strategy, even at high latitude.
Positioning in the urban environment using GNSS is hampered by poor satellite availability due to signal obstruction created by both man-made and natural features of the urban environment. In addition, range measurement to satellites for positioning and for navigation is severely degraded by the multipath effect. The arrival and continuous enhancement of computerised geometric city models makes it possible to tackle these problems through modelling. In this paper description is given of a method for determining the local multipath environment, defined by the surfaces within a city model that will cause disruptive signal reflections to be presented to a receiver. An example simulation is performed, and graphical and numerical results are produced.
Although approximately 95% of disease caused by nontyphoidal salmonella is transmitted by foodborne vehicles, four documented salmonella outbreaks in the 1990s have been traced to contact with young poultry. No environmental studies of source hatcheries were completed. This case-control study was performed by comparing culture-confirmed Salmonella Infantis in Michigan residents, identified between May and July 1999, with two age- and neighbourhood-matched controls. Eighty environmental and bird tissue samples were collected from an implicated hatchery; all salmonella isolates underwent pulsed-field gel electrophoresis (PFGE) analysis. The study included 19 case-patients sharing the same PFGE subtype and 37 matched controls. Within 5 days before illness onset, 74% of case-patients resided in households raising young poultry compared with 16% of controls (matched OR 19.5; 95% CI 2.9, 378.1). Eight hatchery samples yielded Salmonella Infantis with PFGE subtypes matching the patients' isolates. This investigation identified birds from a single hatchery as the source of human illness and confirmed the link by matching PFGE patterns from humans, birds and the hatchery environment. Subsequent public health interventions reduced, but did not eliminate, transmission of poultry-associated salmonellosis. Five additional PFGE-linked cases were identified in Spring 2000, necessitating quarantine of the hatchery for depopulation, cleaning and disinfection.
The streptozotocin (STZ)-diabetic rat, the most commonly employed model of experimental diabetic
neuropathy, is characterised by a reduction in nerve conduction velocity, pain threshold and blood flow.
Whether or not structural abnormalities underlie these functional abnormalities is unclear. 10 adult male
Sprague–Dawley STZ-diabetic rats (diabetes duration 27 d) and 10 age-matched (23 wk) control animals
were studied. Motor nerve conduction velocity (m s−1) was significantly reduced in diabetic
(41.31±0.8) compared with control (46.15±1.5) animals (P<0.001). The concentration of sciatic nerve glucose
(P<0.001), fructose (P<0.001) and sorbitol (P<0.001) was elevated, and myoinositol (P<0.001) was reduced
in diabetic compared with control animals. Detailed morphometric studies demonstrated no significant
difference in fascicular area, myelinated fibre density, fibre and axon areas as well as unmyelinated fibre
density and diameter. Endoneurial capillary density, basement membrane area and endothelial cell profile
number did not differ between diabetic and control animals. However, luminal area (P<0.03) was increased
and endothelial cell area (P<0.08) was decreased in the diabetic rats. We conclude there is no detectable
structural basis for the reduction in nerve conduction velocity, pain threshold or blood flow, observed in the
streptozotocin diabetic rat.
The retinal vasculature of postmortem normal human and diabetic
eyes was studied using an
immunohistochemical technique in conjunction with confocal laser scanning
microscopy. The technique,
which stained for von Willebrand factor, allowed both large areas of the
retinal vasculature to be visualised
and abnormalities to be studied in detail without disturbing the tissue
architecture. Only one
microaneurysm, defined as any focal capillary dilation, was observed in
10 normal eyes but numerous
microaneurysms were seen in 4 out of 5 diabetic retinas; counts varied
between 0 and 26 per 0.41 mm2
sample area. Microaneurysms were classified into 3 categories according
to morphology: saccular, fusiform
and focal bulges. Most were saccular, these having no preferred orientation.
The majority of
microaneurysms were associated with just 2 vessels suggesting they were
unlikely to develop at vascular
junctions. The majority were observed to originate from the inner nuclear
layer and were therefore in the
deeper part of the inner retinal capillary plexus. Variation in the staining
of microaneurysms may correlate
with endothelial dysfunction seen clinically as dye leakage during fluorescein
An acutely stressful stimulus such as relocation from a familiar strawed pen to an unfamiliar farrowing crate during birth has been shown to interrupt the birth process and inhibit oxytocin secretion (Lawrence et al, 1992). Both of these departures from normal parturition could be prevented by administration of the Î¼ opioid antagonist naloxone. A likely site of action for this effect is presynaptic Î¼ receptors on noradrenergic nerve terminals in the hypothalamus (Onaka et al, 1995). Such a neuro-endocrine control system, if active in the day prior to birth, might influence the timing of the onset of parturition and its subsequent efficiency even in the absence of a stressful stimulus. This experiment tested this hypothesis.
Organic-inorganic hybrids, with tailorable properties via control of their chemistries, offer great potential for many optical, electrical and mechanical applications. PDMS-based materials have been fabricated, having low optical losses of < 0.15 dB/cm but the dielectric properties of these hybrids have rarely been explored or reported. In the present study, the dielectric properties of PDMS:SiO2:TiO2 films are explored as a function of composition and curing temperature using an impedance analyzer. Dielectric spectroscopy was also performed to investigate the dielectric relaxation and dispersion behaviors. Results indicate that εr at 1 MHz ranges from 3 to 5. Residual hydroxyl and alkoxy species in the films contribute to the overall polarizabilities especially at low frequencies ( < 100 kHz).