Evaluation of Ischemic Stroke Hybrid Segmentation in a Rat Model of Temporary Middle Cerebral Artery Occlusion using Ground Truth from Histologic and MR data

A segmentation method that quantifies cerebral infarct using rat data with ischemic stroke is evaluated using ground truth from histologic and MR data. To demonstrate alternative approach to rapid quantification of cerebral infarct volumes using histologic stained slices that requires scarifying animal life, a study with MR acquire volumetric rat data is proposed where ground truth is obtained by manual delineations by experts and automated segmentation is assessed for accuracy. A framework for evaluation of segmentation is used that provides more detailed accuracy measurements than mere cerebral infarct volume. Our preliminary experiment shows that ground truth derived from MRI data is at least as good as the one obtained from the histologic slices for evaluating segmentation algorithms for accuracy. Therefore we can develop and evaluate automated segmentation methods for rapid quantification of stroke without the necessitating animal sacrifice

Ground Truth for Evaluation of Ischemic Stroke Hybrid Segmentation in a Rat Model of Temporary Middle Cerebral Artery Occlusion

In vivo rodent models of focal cerebral ischemia have been developed to investigate stroke therapy. Typically these models require rapid quantification of cerebral infarct volumes using vital stains with tetrazolium salts to delineate the extent of neuronal death. To avoid animal sacrifice, we sought a study with MR acquired volumetric rata data where surrogate of ground truth is obtained by repeated manual delineation by experts, and an automated hybrid segmentation is evaluated for accuracy. We propose a rating system for the expert delineations that captures intra- and inter-expert discrepancy. Our preliminary results show that surrogate ground truth derived from MR data is at least as good as the one derived from histologic stained slices. Hence animal sacrifice is not necessary to evaluate ischemic stroke automated segmentation in a rat model of temporary middle cerebral artery occlusion

Anesthesia in Children: Perspectives From Nonsurgical Pediatric Specialists

The Pediatric Anesthesia NeuroDevelopment Assessment (PANDA) study investigates the potential neurotoxicity of anesthetics in the pediatric population. At a recent symposium, a panel of nonsurgical physicians from the disciplines of radiology, neurology, cardiology, and critical care discussed the role anesthesia plays in their respective practices. To execute diagnostic studies and/or therapeutic interventions in each of these disciplines, general anesthesia is oftentimes required for pediatric patients. Given recent publications in the literature suggesting the potential for neurotoxicity following anesthesia in pediatric patients, physicians, parents, and other stakeholders are now challenged to continue to balance safety with efficacy in caring for children. This paper summarizes the panelist presentations and the ensuing discussion at the 2014 PANDA symposium

THE IMPACT OF MICROSURGICAL FENESTRATION OF THE LAMINA TERMINALIS ON SHUNT-DEPENDENT HYDROCEPHALUS AND VASOSPASM AFTER ANEURYSMAL SUBARACHNOID HEMORRHAGE

Abstract OBJECTIVE Chronic hydrocephalus requiring shunt placement and cerebral vasospasm are common complications after aneurysmal subarachnoid hemorrhage. Recent publications have investigated the possibility that microsurgical fenestration of the lamina terminalis during aneurysm surgery may reduce the incidence of shunt-dependent hydrocephalus and cerebral vasospasm. We reviewed a single-surgeon series to compare postsurgical outcomes of patients who underwent fenestration of the lamina terminalis against those who did not. METHODS This study is a retrospective review of the medical records of 369 consecutive patients with aneurysmal subarachnoid hemorrhage admitted to Columbia University Medical Center between January 2000 and July 2006. All patients underwent craniotomy and clipping of at least one ruptured cerebral aneurysm by a single neurosurgeon (ESC). The incidences of shunt-dependent hydrocephalus, conversion from acute hydrocephalus on admission to chronic hydrocephalus, and clinical cerebral vasospasm were compared in patients who underwent fenestration of the lamina terminalis with those who did not. The patient cohort was thus divided into three subgroups: 1) patients whose operative records clearly indicated that they underwent fenestration of the lamina terminalis, 2) patients whose operative records clearly indicated that they did not undergo fenestration of the lamina terminalis, and 3) patients whose operative records did not indicate one way or another whether they received fenestration of the lamina terminalis. We performed two separate analyses by comparing the postsurgical outcomes in those patients who were fenestrated versus those who were definitively not fenestrated and comparing the postsurgical outcomes in those patients who were fenestrated versus those who were not plus those whose records did not document fenestration. To further control for any cohort differences, we performed a comparison between patients who were fenestrated and those who were not after matching 1:1 for presenting radiographic and clinical characteristics predictive of hydrocephalus and vasospasm. Outcomes were compared using logistic regression and multivariable analysis. RESULTS In the first model, fenestrated patients had a shunt rate, conversion rate, and rate of clinical vasospasm of 25, 50, and 23%, respectively, versus 20, 27, and 27% in nonfenestrated patients, respectively (P = 0.28, 0.21, and 0.32, respectively). In the second model, the nonfenestrated patients plus nondocumented patients had a shunt rate, conversion rate, and rate of clinical vasospasm of 16, 40, and 20%, respectively (P = 0.19, 0.33, and 0.60, respectively). In the matched cohort, fenestrated patients had a shunt rate, conversion rate, and rate of clinical vasospasm of 29, 67, and 20%, respectively, versus 20, 25, and 25% in nonfenestrated patients, respectively (P = 0.30, 0.24, and 0.20, respectively). CONCLUSION In contrast to other retrospective multisurgeon series, our retrospective single-surgeon series suggests that microsurgical fenestration of the lamina terminalis may not reduce the incidence of shunt-dependent hydrocephalus or cerebral vasospasm after aneurysmal subarachnoid hemorrhage. A prospective multicenter trial is needed to definitively address the use of this maneuver

Urgent endovascular revascularization for symptomatic intracranial atherosclerotic stenosis.

BACKGROUND: Endovascular revascularization for intracranial atherosclerotic stenoses is being increasingly performed at major medical centers and has been reported to be technically feasible and safe. The authors report their experience with patients who underwent such a procedure for impending stroke and neurologic instability. METHOD: All 18 patients (21 intracranial lesions) treated between 1997 and 2002 at the authors\u27 institution with endovascular revascularization were retrospectively reviewed. Each patient had failed maximal medical therapy and was thought to be at high risk for an imminent stroke. RESULTS: Endovascular revascularization was performed on eight distal internal carotid artery lesions, six middle cerebral artery lesions, four intracranial vertebral artery lesions, and three basilar artery lesions. Recanalization was complete in 5 arteries (Thrombolysis in Myocardial Infarction [TIMI] Grade III), partial in 14 arteries (TIMI Grade II), and complete occlusion (TIMI 0) developed in 1 artery. In a patient with a tight basilar stenosis, no angioplasty could be performed because of the inability to cross the stenosis with the guidewire. Major periprocedural complications occurred in 9 (50%) patients: intracranial hemorrhage in 3 (17%), disabling ischemic stroke in 2 (11%), and major extracranial hemorrhage in 4 (22%). Three patients died: one from intracerebral hemorrhage and two from cardiorespiratory failure. CONCLUSIONS: Endovascular revascularization of intracranial vessels is technically feasible and may be performed successfully. However, periprocedural complication and fatality rates in neurologically unstable patients are high. The results suggest that patient selection, procedure timing, and periprocedural medical management are critical factors to reduce periprocedural morbidity and mortality

Epidemiological trends in the neurological intensive care unit from 2000 to 2008

Intensive care units (ICU) specializing in the treatment of patients with neurological diseases (Neuro-ICU) have become increasingly common. However, there are few data on the longitudinal demographics of this patient population. Identifying admission trends may provide targets for improving resource utilization. We performed a retrospective analysis of admission logs for primary diagnosis, age, sex, and length of stay, for all patients admitted to the Neuro-ICU at Columbia University Medical Center (CUMC) between 2000 and 2008. From 2000 to 2008, inclusive, the total number of Neuro-ICU admissions increased by 49.9%. Overall mean patient age (54.6 ± 17.4 to 56.2 ± 18.0 years, p=0.041) and gender (55.9-50.3% female, p=0.005) changed significantly, while median length of stay (2 days) did not. When comparing the time period prior to construction of a larger Neuro-ICU (2000-2004) to that after completion (2005-2008), patient age (56.0 ± 17.6 compared to 56.9 ± 17.5 years, p=0.012) and median length of stay (1 compared to 2 days, p\u3c0.001) both significantly increased. Construction of a newer, larger Neuro-ICU at CUMC led to a substantial increase in admissions and changes in diagnoses from 2000 to 2008. Advances in neurocritical care, neurosurgical practices, and the local and global expansion and utilization of ICU resources likely led to differences in lengths of stay

Hippocampal and entorhinal atrophy in mild cognitive impairment: Prediction of Alzheimer disease

Objective: To evaluate the utility of MRI hippocampal and entorhinal cortex atrophy in predicting conversion from mild cognitive impairment (MCI) to Alzheimer disease (AD). Methods: Baseline brain MRI was performed in 139 patients with MCI, broadly defined, and 63 healthy controls followed for an average of 5 years (range 1 to 9 years). Results: Hippocampal and entorhinal cortex volumes were each largest in controls, intermediate in MCI nonconverters, and smallest in MCI converters to AD (37 of 139 patients converted to AD). In separate Cox proportional hazards models, covarying for intracranial volume, smaller hippocampal volume (risk ratio [RR] 3.62, 95% CI 1.93 to 6.80, p Ͻ 0.0001), and entorhinal cortex volume (RR 2.43, 95% CI 1.56 to 3.79, p Ͻ 0.0001) each predicted time to conversion to AD. Similar results were obtained for hippocampal and entorhinal cortex volume in patients with MCI with Mini-Mental State Examination (MMSE) scores Ն 27 out of 30 (21% converted to AD) and in the subset of patients with amnestic MCI (35% converted to AD). In the total patient sample, when both hippocampal and entorhinal volume were entered into an age-stratified Cox model with sex, MMSE, education, and intracranial volume, smaller hippocampal volume (RR 2.21, 95% CI 1.14 to 4.29, p Ͻ 0.02) and entorhinal cortex volume (RR 2.48, 95% CI 1.54 to 3.97, p Ͻ 0.0002) predicted time to conversion to AD. Similar results were obtained in a Cox model that also included Selective Reminding Test (SRT) delayed recall and Wechsler Adult Intelligence Scale–Revised (WAIS-R) Digit Symbol as predictors. Based on logistic regression models in the 3-year follow-up sample, for a fixed specificity of 80%, the sensitivities for MCI conversion to AD were as follows: age 43.3%, MMSE 43.3%, age ϩ MMSE 63.7%, age ϩ MMSE ϩ SRT delayed recall ϩ WAIS-R Digit Symbol 80.6% (79.6% correctly classified), hippocampus ϩ entorhinal cortex 66.7%, age ϩ MMSE ϩ hippocampus ϩ entorhinal cortex 76.7% (85% correctly classified), age ϩ MMSE ϩ SRT delayed recall ϩ WAIS-R Digit Symbol ϩ hippocampus ϩ entorhinal cortex 83.3% (86.8% correctly classified). Conclusions: Smaller hippocampal and entorhinal cortex volumes each contribute to the prediction of conversion to Alzheimer disease. Age and cognitive variables also contribute to prediction, and the added value of hippocampal and entorhinal cortex volumes is small. Nonetheless, combining these MRI volumes with age and cognitive measures leads to high levels of predictive accuracy that may have potential clinical application