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Dive into the research topics where Julian Spears is active.

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Featured researches published by Julian Spears.


Neurology | 2015

The unruptured intracranial aneurysm treatment score A multidisciplinary consensus

Nima Etminan; Robert D. Brown; Kerim Beseoglu; Seppo Juvela; Jean Raymond; Akio Morita; James C. Torner; Colin P. Derdeyn; Andreas Raabe; J. Mocco; Miikka Korja; Amr Abdulazim; Sepideh Amin-Hanjani; Rustam Al-Shahi Salman; Daniel L. Barrow; Joshua B. Bederson; Alain Bonafe; Aaron S. Dumont; David Fiorella; Andreas Gruber; Graeme J. Hankey; David Hasan; Brian L. Hoh; Pascal Jabbour; Hidetoshi Kasuya; Michael E. Kelly; Peter J. Kirkpatrick; Neville Knuckey; Timo Koivisto; Timo Krings

Objective: We endeavored to develop an unruptured intracranial aneurysm (UIA) treatment score (UIATS) model that includes and quantifies key factors involved in clinical decision-making in the management of UIAs and to assess agreement for this model among specialists in UIA management and research. Methods: An international multidisciplinary (neurosurgery, neuroradiology, neurology, clinical epidemiology) group of 69 specialists was convened to develop and validate the UIATS model using a Delphi consensus. For internal (39 panel members involved in identification of relevant features) and external validation (30 independent external reviewers), 30 selected UIA cases were used to analyze agreement with UIATS management recommendations based on a 5-point Likert scale (5 indicating strong agreement). Interrater agreement (IRA) was assessed with standardized coefficients of dispersion (vr*) (vr* = 0 indicating excellent agreement and vr* = 1 indicating poor agreement). Results: The UIATS accounts for 29 key factors in UIA management. Agreement with UIATS (mean Likert scores) was 4.2 (95% confidence interval [CI] 4.1–4.3) per reviewer for both reviewer cohorts; agreement per case was 4.3 (95% CI 4.1–4.4) for panel members and 4.5 (95% CI 4.3–4.6) for external reviewers (p = 0.017). Mean Likert scores were 4.2 (95% CI 4.1–4.3) for interventional reviewers (n = 56) and 4.1 (95% CI 3.9–4.4) for noninterventional reviewers (n = 12) (p = 0.290). Overall IRA (vr*) for both cohorts was 0.026 (95% CI 0.019–0.033). Conclusions: This novel UIA decision guidance study captures an excellent consensus among highly informed individuals on UIA management, irrespective of their underlying specialty. Clinicians can use the UIATS as a comprehensive mechanism for indicating how a large group of specialists might manage an individual patient with a UIA.


World Neurosurgery | 2013

Subarachnoid Hemorrhage International Trialists Data Repository (SAHIT)

R. Loch Macdonald; Michael D. Cusimano; Nima Etminan; Daniel Hänggi; David Hasan; Don Ilodigwe; Blessing N. R. Jaja; Hector Lantigua; Peter D. Le Roux; Benjamin Lo; Ada Louffat-Olivares; Stephan A. Mayer; Andrew Molyneux; Audrey Quinn; Tom A. Schweizer; Thomas Schenk; Julian Spears; Michael M. Todd; James C. Torner; Mervyn D.I. Vergouwen; George Kwok Chu Wong

The outcome of patients with aneurysmal subarachnoid hemorrhage (SAH) has improved slowly over the past 25 years. This improvement may be due to early aneurysm repair by endovascular or open means, use of nimodipine, and better critical care management. Despite this improvement, mortality remains at about 40%, and many survivors have permanent neurologic, cognitive, and neuropsychologic deficits. Randomized clinical trials have tested pharmacologic therapies, but few have been successful. There are numerous explanations for the failure of these trials, including ineffective interventions, inadequate sample size, treatment side effects, and insensitive or inappropriate outcome measures. Outcome often is evaluated on a good-bad dichotomous scale that was developed for traumatic brain injury 40 years ago. To address these issues, we established the Subarachnoid Hemorrhage International Trialists (SAHIT) data repository. The primary aim of the SAHIT data repository is to provide a unique resource for prognostic analysis and for studies aimed at optimizing the design and analysis of phase III trials in aneurysmal SAH. With this aim in mind, we convened a multinational investigator meeting to explore merging individual patient data from multiple clinical trials and observational databases of patients with SAH and to create an agreement under which such a group of investigators could submit data and collaborate. We welcome collaboration with other investigators.


Stroke | 2015

The VASOGRADE: A Simple Grading Scale for Prediction of Delayed Cerebral Ischemia After Subarachnoid Hemorrhage

Airton Leonardo de Oliveira Manoel; Blessing N. R. Jaja; Menno R. Germans; Han Yan; Winnie Qian; Ekaterina Kouzmina; Tom R. Marotta; David Turkel-Parrella; Tom A. Schweizer; R. Loch Macdonald; Nima Etminan; Daniel Hänggi; David Hasan; S. Claiborne Johnston; Peter D. Le Roux; Stephan Mayer; Andrew Molyneux; Adam Noble; Audrey Quinn; Thomas Schenk; Julian Spears; Michael M. Todd; James C. Torner; Ming Tseng; William van den Bergh; Mervyn D.I. Vergouwen; George Kwok Chu Wong; Ming-Yuan Tseng

Background and Purpose— Patients are classically at risk of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage. We validated a grading scale—the VASOGRADE—for prediction of DCI. Methods— We used data of 3 phase II randomized clinical trials and a single hospital series to assess the relationship between the VASOGRADE and DCI. The VASOGRADE derived from previously published risk charts and consists of 3 categories: VASOGRADE-Green (modified Fisher scale 1 or 2 and World Federation of Neurosurgical Societies scale [WFNS] 1 or 2); VASOGRADE-Yellow (modified Fisher 3 or 4 and WFNS 1–3); and VASOGRADE-Red (WFNS 4 or 5, irrespective of modified Fisher grade). The relation between the VASOGRADE and DCI was assessed by logistic regression models. The predictive accuracy of the VASOGRADE was assessed by receiver operating characteristics curve and calibration plots. Results— In a cohort of 746 patients, the VASOGRADE significantly predicted DCI (P<0.001). The VASOGRADE-Yellow had a tendency for increased risk for DCI (odds ratio [OR], 1.31; 95% CI, 0.77–2.23) when compared with VASOGRADE-Green; those with VASOGRADE-Red had a 3-fold higher risk of DCI (OR, 3.19; 95% CI, 2.07–4.50). Studies were not a significant confounding factor between the VASOGRADE and DCI. The VASOGRADE had an adequate discrimination for prediction of DCI (area under the receiver operating characteristics curve=0.63) and good calibration. Conclusions— The VASOGRADE results validated previously published risk charts in a large and diverse sample of subarachnoid hemorrhage patients, which allows DCI risk stratification on presentation after subarachnoid hemorrhage. It could help to select patients at high risk of DCI, as well as standardize treatment protocols and research studies.


Biomedical Optics Express | 2012

Endovascular optical coherence tomography intensity kurtosis: visualization of vasa vasorum in porcine carotid artery

Kyle H. Y. Cheng; Cuiru Sun; Barry Vuong; Kenneth K. C. Lee; Adrian Mariampillai; Thomas R. Marotta; Julian Spears; Walter Montanera; Peter R. Herman; Tim-Rasmus Kiehl; Beau A. Standish; Victor X. D. Yang

Application of speckle variance optical coherence tomography (OCT) to endovascular imaging faces difficulty of extensive motion artifacts inherently associated with arterial pulsations in addition to other physiological movements. In this study, we employed a technique involving a fourth order statistical method, kurtosis, operating on the endovascular OCT intensity images to visualize the vasa vasorum of carotid artery in vivo and identify its flow dynamic in a porcine model. The intensity kurtosis technique can distinguish vasa vasorum from the surrounding tissues in the presence of extensive time varying noises and dynamic motions of the arterial wall. Imaging of vasa vasorum and its proliferation, may compliment the growing knowledge of structural endovascular OCT in assessment and treatment of atherosclerosis in coronary and carotid arteries.


Journal of the Neurological Sciences | 2013

Long-term consequences of subarachnoid hemorrhage: examining working memory.

Signy Sheldon; R. Loch Macdonald; Michael D. Cusimano; Julian Spears; Tom A. Schweizer

Working memory impairments are prevalent among survivors of aneurysmal subarachnoid hemorrhage (SAH), but few studies have examined specifically these impairments. Such an examination is important because working memory processes are vital for daily cognitive functioning. In the current study, patients with SAH and healthy control participants were administered the word-span and alpha-span test - experimental tests of working memory. In the word-span test, participants recalled increasingly longer word-lists, requiring the maintenance of information in mind. In the alpha-span test, participants recalled the word-lists in alphabetical order, requiring both the maintenance and manipulation of information. Patients with SAH were no different from healthy controls on a battery of standard neuropsychological measures or on the word-span test. They were, however, significantly impaired on the alpha-span test, suggesting a deficit in the manipulation components of working memory. That is, impairment resulting from SAH is present when a working memory task requires additional executive processing demands. This deficit in patients with SAH does not appear to be influenced by aneurysm location, suggesting that some of the effects of SAH on cognition are from diffuse rather than focal pathology; however, a larger sample size is needed to reinforce this claim.


Canadian Journal of Neurological Sciences | 2014

Safety of Early Pharmacological Thromboprophylaxis after Subarachnoid Hemorrhage

Airton Leonardo de Oliveira Manoel; David Turkel-Parrella; Menno Germans; Ekaterina Kouzmina; Priscila da Silva Almendra; Thomas R. Marotta; Julian Spears; Simon Abrahamson

OBJECTIVEnThe recent guidelines on management of aneurysmal subarachnoid hemorrhage (aSAH) advise pharmacological thromboprophylaxis (PTP) after aneurysm obliteration. However, no study has addressed the safety of PTP in the aSAH population. Therefore, the aim of this study was to assess the safety of early PTP after aSAH.nnnMETHODSnRetrospective cohort of aSAH patients admitted between January 2012 and June 2013 in a single high-volume aSAH center. Traumatic SAH and perimesencephalic hemorrhage patients were excluded. Patients were grouped according to PTP timing: early PTP group (PTP within 24 hours of aneurysm treatment), and delayed PTP group (PTP started > 24 hours).nnnRESULTSnA total of 174 SAH patients (mean age 56.3±12.5 years) were admitted during the study period. Thirty-nine patients (22%) did not receive PTP, whereas 135 patients (78%) received PTP after aneurysm treatment or negative angiography. Among the patients who received PTP, 65 (48%) had an external ventricular drain. Twenty-eight patients (21%) received early PTP, and 107 (79%) received delayed PTP. No patient in the early treatment group and three patients in the delayed PTP group developed an intracerebral hemorrhagic complication. Two required neurosurgical intervention and one died. These three patients were on concomitant PTP and dual antiplatelet therapy.nnnCONCLUSIONSnThe initiation of PTP within 24 hours may be safe after the treatment of a ruptured aneurysm or in angiogram-negative SAH patients with diffuse aneurysmal hemorrhage pattern. We suggest caution with concomitant use of PTP and dual antiplatelet agents, because it possibly increases the risk for intracerebral hemorrhage.


Journal of Biomedical Optics | 2012

Comprehensive data visualization for high resolution endovascular carotid arterial wall imaging

Kyle H. Y. Cheng; Cuiru Sun; Juan Pablo Cruz; Thomas R. Marotta; Julian Spears; Walter Montanera; Aman Thind; Brian Courtney; Beau A. Standish; Victor X. D. Yang

Carotid angioplasty and stenting is a minimally invasive endovascular procedure that may benefit from in vivo high resolution imaging for monitoring the physical placement of the stent and potential complications. The purpose of this pilot study was to evaluate the ability of optical coherence tomography to construct high resolution 2D and 3D images of stenting in porcine carotid artery. Four Yorkshire pigs were anaesthetized and catheterized. A state-of-the-art optical coherence tomography (OCT) system and an automated injector were used to obtain both healthy and stented porcine carotid artery images. Data obtained were then processed for visualization. The state-of-the-art OCT system was able to capture high resolution images of both healthy and stented carotid arteries. High quality 3D images of healthy and stented carotid arteries were constructed, clearly depicting vessel wall morphological features, stent apposition and thrombus formation over the inserted stent. The results demonstrate that OCT can be used to generate high quality 3D images of carotid arterial stents for accurate diagnosis of stent apposition and complications under appropriate imaging conditions.


Proceedings of SPIE | 2012

Feasibility of endovascular optical coherence tomography for high-resolution carotid vessel wall imaging

Kyle H. Y. Cheng; Cuiru Sun; Juan Pablo Cruz; Thomas R. Marotta; Julian Spears; Walter Montanera; Peter R. Herman; Aman Thind; Brian Courtney; Beau A. Standish; Victor X. D. Yang

Carotid Artery Stenting (CAS) is a procedure that treats carotid atherosclerosis which should be monitored by in vivo high resolution imaging for the quality of the procedure and potential complications. The purpose of this pilot study is to evaluate the ability of optical coherence tomography to construct high resolution two and three dimensional images of stenting in porcine carotid artery for high accuracy diagnostic purposes. Four Yorkshire pigs were anaesthetized and catheterized. A state-of-the-art optical coherence tomography (OCT) system (Lightlab Imaging, St. Jude Medical Inc.) and an automated injector were used to obtain both healthy and stented porcine carotid artery images. Data obtained were then processed for visualization. The state-of-the-art OCT system was able to capture high resolution images of both healthy and stented carotid arteries. High quality three dimensional images of stented carotid arteries were constructed, clearly depicting stent apposition and thrombus formation over different stents. The results demonstrated that current state-of-the-art OCT system can be used to generate high quality three dimensional images of carotid arterial stents for accurate diagnosis of stent apposition and complications under appropriate imaging conditions.


Polish Journal of Radiology | 2016

The Slowly Enlarging Ventriculus Terminalis

Joel Woodley-Cook; Magdalena Konieczny; Julian Spears

Summary Background A cerebral spinal fluid (CSF) cavity within the conus medullaris has been described by the term ventriculus terminalis (VT) or the fifth ventricle. The finding of a VT on MRI imaging of the lumbar spine is often incidental but may be found in patients with low back pain or neuromuscular deficits. These lesions, when identified, are thought to regress or remain stable in terms of size, although some have been described to enlarge in the presence of post-traumatic meningeal hemorrhages or deformities of the vertebral canal. Case Report We describe a case of a slowly growing VT in a patient with progressing lower limb weakness without any history or imaging findings of trauma or spinal canal abnormalities. Conclusions We present an intriguing case of a slowly growing VT in a woman with progressive neurological symptoms. Surgical fenestration provided complete symptomatic relief and follow-up imaging two years after surgery demonstrated no evidence of recurrence. This, to our knowledge, is the first described case of a slowly enlarging VT independent of any other imaging findings.


Case Reports | 2015

Flow diversion in vasculitic intracranial aneurysms? Repair of giant complex cavernous carotid aneurysm in polyarteritis nodosa using Pipeline embolization devices: first reported case

Jaime Martinez Santos; Zul Kaderali; Julian Spears; Laurence A. Rubin; Thomas R. Marotta

Intracranial aneurysms in polyarteritis nodosa (PAN) are exceedingly rare lesions with unpredictable behavior that pose real challenges to microsurgical and endovascular interventions owing to their inflammatory nature. We introduce a safe and effective alternative for treating these aneurysms using Pipeline embolization devices (PEDs). A 20-year-old man presented with diplopia, headaches, chronic abdominal pain, and weight loss. Diagnostic evaluations confirmed PAN, including bilateral giant cavernous carotid aneurysms. Cyclophosphamide and steroids achieved significant and sustained clinical improvement, with a decision to follow the aneurysms serially. Seven years later the left unruptured aneurysm enlarged, causing a sudden severe headache and a cavernous sinus syndrome. Treatment of the symptomatic aneurysm was pursued using flow diversion (PED) and the internal carotid artery was successfully reconstructed with a total of four overlapping PEDs. At 6u2005months follow-up, complete exclusion of the aneurysm was demonstrated, with symptomatic recovery. This is the first description of using a flow-diverting technique in an inflammatory vasculitis. In this case, PEDs not only attained a definitive closure of the aneurysm but also reconstructed the damaged and fragile arterial segment affected with vasculitis.

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Victor X. D. Yang

Sunnybrook Health Sciences Centre

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R. Loch Macdonald

Howard Hughes Medical Institute

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James C. Torner

University of Iowa Hospitals and Clinics

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