Ahead of Print: Unruptured Intracranial Aneurysms in the Norwegian HUNT-study

Background: Rupture risk of unruptured intracranial aneurysms (UIA) has been investigated in studies observing the natural history of this condition. Such studies have been prone to selection bias that may influence the results.

Objective: To calculate the overall rupture risk from data of prevalence of UIA, which constitutes the population at risk, and the incidence of aneurysmal subarachnoid hemorrhage (aSAH) in the same population.

Methods: Data were collected from the Norwegian Nord-Trondelag Health Study (HUNT) study, a large population-based cohort study. Prevalence of UIA was estimated by performing MR angiography in 1006 randomly selected volunteers aged 50 – 65 years from this population cohort. The incidence of aSAH was investigated by searching national and hospital registers with thorough case ascertainment to avoid inclusion of non-aneurysmal SAH.

Free Article: Are We Underestimating the Burden of TBI?

Background: The epidemiology of traumatic brain injury (TBI) is often studied through the use of International Classification of Disease, ninth revision, clinical modification (ICD-9-CM), diagnosis codes from the Centers for Disease Control and Prevention TBI Surveillance System. Recent studies suggest that these codes may underestimate the burden of TBI because of inaccuracies and low sensitivity.

Objective: To determine the sensitivity and specificity of ICD-9-CM codes in a severe TBI population.

Methods: We retrospectively reviewed medical records of all hospital admissions including computed tomography of the head at a single center to identify severe blunt TBI patients, their injuries, and the neurosurgical procedures performed. We calculated sensitivity and specificity by comparing ICD-9-CM diagnosis and procedure codes assigned by hospital coders with medical records, the gold standard.

Ahead of Print: Cerebral Dural Arteriovenous Fistulae Natural History

Background: Hemorrhage from cerebral dural arteriovenous fistulae (dAVF) is a considerable source of neurologic morbidity and even mortality.

Objective: To evaluate the natural history of cerebral dAVF.

Methods: We reviewed our own cohort of 70 dAVF and incorporated results from the literature, synthesizing pooled hemorrhage rates and evaluating risk factors for 395 dAVF in 6 studies.

Editor Choice: The Association Between Weather and Spontaneous Subarachnoid Hemorrhage: An Analysis of 155 US Hospitals

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Cowperthwaite, Matthew C PhD; Burnett, Mark G MD

BACKGROUND: A seasonal and meteorological influence on the incidence of spontaneous subarachnoid hemorrhage (SAH) has been suggested, but a consensus in the literature has yet to emerge.

OBJECTIVE: This study examines the impact of weather patterns on the incidence of SAH using a geographically broad analysis of hospital admissions and represents the largest study of the topic to date.

METHODS: We retrospectively analyzed SAH admissions to 155 US hospitals during the calendar years 2004 to 2008 (N = 7758). Daily weather readings for temperature, pressure, and humidity were obtained for the same period from National Oceanic and Atmospheric Administration weather stations located near each hospital. The daily values of each weather variable were associated with the daily volume of SAH admissions using a combination of correlation and time-series analyses.

Free Editor Choice: Trends in Case-Fatality Rates in Hospitalized Nontraumatic Subarachnoid Hemorrhage: Results of a Population-Based Study in Dijon, France, From 1985 to 2006

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Biotti, Damien MD; Jacquin, Agnès MD; Boutarbouch, Mahjouba MD; Bousquet, Olivier MD; Durier, Jérôme PhD; Ben Salem, Douraïeb MD; Ricolfi, Frederic MD; Beaurain, Jacques MD; Osseby, Guy-Victor MD; Moreau, Thibault MD; Giroud, Maurice MD; Béjot, Yannick MD

BACKGROUND: Subarachnoid hemorrhage accounts for 2% to 5% of all strokes and is associated with high morbidity and mortality rates. Reports in the literature show that case-fatality rates vary with time and according to geographical area.

OBJECTIVE: The objective of the study was to evaluate the case-fatality rates in subarachnoid hemorrhage at 1 and 6 months and to determine trends in these rates over 22 years using a population-based registry.

METHODS: The Dijon Stroke Registry has enabled us to perform a comprehensive analysis of subarachnoid hemorrhage diagnosed in a population of >150 000 inhabitants hospitalized between 1985 and 2006 in the Dijon University Hospital, which has both a neurosurgery unit and a neuroradiology unit. Diagnosis was based on clinical and neuroimaging features and, when necessary, on lumbar puncture.