Publications by authors named "Patrick J Nicholson"

Introduction: Posterior cerebral artery (PCA) aneurysms represent up to 1% of all cerebral aneurysms. P1-P2 perforator aneurysms are thought to be even less prevalent and often require complex treatment strategies due to their anatomical and morphological characteristics, with risk of a perforator infarct. We studied the treatment of P1-P2 perforator aneurysms in a single-center cohort from a high-volume tertiary center, reporting clinical and anatomical characteristics, treatment strategies, and outcomes.

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Purpose: Spontaneous direct carotid-cavernous fistula (CCF) are usually caused by a ruptured carotid cavernous aneurysm. We studied treatment of spontaneous direct CCFs in a single-center cohort of a high-volume tertiary referral center, reporting anatomical details, technical approaches of treatment, and outcomes.

Methods: Adult patients with a spontaneous direct CCF treated between 2010-2022 with follow-up MRI and/or DSA imaging available were retrospectively analyzed.

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Background: Bilateral transverse venous sinus stenosis (TVSS) or stenosis of a dominant venous sinus has been found to be very sensitive radiological findings in patients with intracranial hypertension (IH), yet there is still an ongoing debate whether they constitute reversible or permanent phenomena. Thus, the purpose of this study was to investigate the reversibility of TVSS in patients with IH, including conservatively treated patients with signs of IH as defined by the presence of papilledema.

Methods: This was a retrospective chart review of all patients diagnosed with IH between 2016 and 2022, assessed from 2 tertiary university-affiliated neuro-ophthalmology practices.

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Purpose: Presented here is a strategy of sequential lateral decubitus digital subtraction myelography (LDDSM) followed closely by lateral decubitus CT (LDCT) to facilitate cerebrospinal fluid (CSF)-venous fistula (CVF) localization.

Materials And Methods: This is a retrospective analysis of patients referred to our institution for evaluation of CSF leak. Patients with Type 1 and Type 2 leaks, and those not displaying MR brain stigmata of intracranial hypotension were excluded.

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Purpose: Traditionally, in the work-up of patients for spontaneous intracranial hypotension, T1 post-contrast imaging is performed in order to assess for pachymeningeal enhancement. The aim of this study is to assess whether pachymeningeal hyperintensity can be identified on a non-contrast FLAIR sequence in these patients as a surrogate sign for pachymeningeal enhancement.

Methods: The patient cohort was identified from a prospectively maintained database of patients with a clinical diagnosis of intracranial hypotension.

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Purpose: Both CT myelogram (CTM) and digital-subtraction myelogram (DSM) can be used to evaluate patients for possible cerebrospinal fluid (CSF) leaks. DSM is a relatively new technique. No data exists on the radiation dose associated with this procedure, and how it compares with CTM.

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Objective: Coverage of the anterior spinal artery (ASA) ostia is a source of considerable consternation regarding flow diversion (FD) in vertebral artery (VA) aneurysms due to cord supply. The authors sought to assess the association between coverage of the ASA, posterior spinal artery (PSA), or lateral spinal artery (LSA) ostia when placing flow diverters in distal VAs and clinical outcomes, with emphasis on cord infarction.

Methods: A multicenter retrospective study of 7 institutions in which VA aneurysms were treated with FD between 2011 and 2019 was performed.

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Purpose: The transfemoral approach is widely used by neurointerventionalists for accessing the femoral artery in patients undergoing diagnostic and therapeutic endovascular procedures. In patients with more difficult anatomy, duplex ultrasonography (US) may be a valuable adjunct for femoral vascular access. We aimed to assess the evidence for the effectiveness of duplex US-guided femoral access within interventional neuroradiology.

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Introduction: To assess the early safety and efficacy of anterior cerebral artery (ACA) and anterior communicating artery (ACoA) aneurysm treatment with flow-diversion devices (FDDs), we performed a systematic review and meta-analysis for these aneurysms.

Evidence Acquisition: A literature search was performed by a reference librarian, and, after screening, eight case series were included for meta-analysis. We estimated from each study the cumulative incidence (event rate) and 95% confidence interval (CI) for each outcome.

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Objective: Twitter is a popular social media platform among physicians. Neurointerventionalists frequently document their lifesaving mechanical thrombectomy cases on Twitter with very favorable results. We fear that there may be some social media publication bias to tweeted mechanical thrombectomy cases with neurointerventionalists being more likely to tweet cases with favorable outcomes.

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Background: Orbital infarction syndrome (OIS) is a rare entity defined as ischemia of all intraorbital and intraoccular structures including the optic nerve, extraocular muscles, and orbital fat. This entity is rare due to rich anastomotic orbital vascularization from both the internal carotid artery and external carotid artery. We report a case of a patient who suffered emboli to previously nonaffected territories to the ophthalmic artery and external carotid artery, which resulted in orbital infarction syndrome, and describe techniques to avoid such complications.

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Purpose: To report on outcomes following the use of prophylactic internal iliac artery occlusion balloons in patients with abnormal placental implantation.

Methods: A retrospective analysis was undertaken of patients with abnormal placental implantation who underwent prophylactic iliac balloon placement prior to delivery in a University Maternity Hospital. Various clinical and technical factors were analysed, including technical success of balloon placement, blood loss and number of blood units transfused, duration of surgery, length of stay, hysterectomy rates, complications related to the balloon insertion, foetal pH and infant Apgar scores.

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Background: Carotid plaque imaging with MRI is becoming more commonplace, but practical challenges exist in performing plaque imaging with surface coils.

Purpose: To compare the diagnostic performance of a carotid plaque MRI protocol using a standard neurovascular coil (Neurovascular Coil Protocol) to a higher-resolution carotid plaque MRI using carotid surface coils (Surface Coil Protocol) in characterizing carotid plaque.

Study Type: Prospective study comparing two MR techniques in plaque characterization.

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Objective: To determine the yield of follow-up imaging in patients sustaining renal trauma at our level-1 trauma center and hence, whether the 2013 European Association of Urology guidelines are clinically applicable.

Methods: All patients who attended Cork University Hospital with a diagnosis of renal injury from 2000-2012 were identified. Review of all medical records and radiologic imaging was undertaken.

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Purpose: To evaluate the relationship between pulmonary and myocardial fibrosis in patients with systemic sclerosis (SS).

Materials And Methods: Eighteen patients with SS prospectively underwent cardiac magnetic resonance imaging (CMR) and high-resolution computed tomography (HRCT) of the chest. Cardiac biomarkers (N-terminal pro B-type natriuretic peptide) and quality-of-life measures (SF-36 and SS health assessment questionnaires) were assessed.

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