Citations

OBJECTIVEHypoplasia of the A1 segment of the anterior cerebral artery is frequently observed in patients with anterior communicating artery (ACoA) aneurysms. The effect of this anatomical variant on ACoA aneurysm morphology is not well understood.METHODSDigital subtraction angiography images were reviewed for 204 patients presenting to the authors' institution with either a ruptured or an unruptured ACoA aneurysm. The ratio of the width of the larger A1 segment to the smaller A1 segment was calculated. Patients with an A1 ratio greater than 2 were categorized as having A1 segment hypoplasia. The relationship of A1 segment hypoplasia to both patient and aneurysm characteristics was then assessed.RESULTSOf 204 patients that presented with an ACoA aneurysm, 34 (16.7%) were found to have a hypoplastic A1. Patients with A1 segment hypoplasia were less likely to have a history of smoking (44.1% vs 62.9%, p = 0.0410). ACoA aneurysms occurring in the setting of a hypoplastic A1 were also found to have a larger maximum diameter (mean 7.7 vs 6.0 mm, p = 0.0084). When considered as a continuous variable, increasing A1 ratio was associated with decreasing aneurysm dome-to-neck ratio (p = 0.0289). There was no significant difference in the prevalence of A1 segment hypoplasia between ruptured and unruptured aneurysms (18.9% vs 10.7%; p = 0.1605).CONCLUSIONSOur results suggest that a hypoplastic A1 may affect the morphology of ACoA aneurysms. In addition, the relative lack of traditional risk factors for aneurysm formation in patients with A1 segment hypoplasia argues for the importance of hemodynamic factors in the formation of ACoA aneurysms in this anatomical setting.

Abstract This book comprises a collection of case studies of patients with acute and critical neurological disease, along with pertinent discussion of approaches to each particular condition. Case studies provide a way to examine how difficult it is to approach these patients situated in the neurosciences intensive care unit. Some patients need close observation and management of emerging problems, others need a neurosurgical intervention or a neurointerventional procedure, a few patients are in extremis. The examples provided in this book are quintessential to the practice of neurocritical care. Some are less common conditions that need to be recognized and appropriately treated. Another purpose of this book is to introduce the reader to the field of neurocritical care and to show what goes on. The book shows the complexity of care and urgent decision-making involved in treating patients who deteriorate. Practical suggestions are included for each topic it covers. Not only is treatment of serious neurological disorders discussed but also prognostication in practice and end-of-life care discussions. In some ways this book summarizes the entire spectrum of presenting acute illness and how best to intervene.