Outcome of elective endovascular abdominal aortic aneurysm repair in nonagenarians

ObjectiveCompared with open repair of abdominal aortic aneurysms (AAA), endovascular repair (EVAR) is associated with decreased perioperative morbidity and mortality in a standard patient population. This study sought to determine if the advantage of EVAR extends to patients aged ≥90 years.MethodsThis was a retrospective review from a prospectively maintained computerized database. Of the 322 patients aged ≥80 treated with EVAR from January 1997 to November 2007, 24 (1.9%) were aged ≥90. Mean age was 91.5 ± 1.5 years (range, 90-95 years), and 83.3% were men. Mean aneurysm size was 6.8 cm (range, 5.2-8.7 cm).ResultsMean procedural blood loss was 490 mL (range, 100-4150 mL), and 20.8% required an intraoperative transfusion. Mean postoperative length of stay was 6.0 days, (median, 4 days; mode, 1 day; range, 1-42 days), with 33.3% of patients discharged on the first postoperative day. Amongst the 24 patients, there were 6 (25.0%) perioperative major adverse events, and 2 patients died, for a perioperative mortality rate of 8.3%. Mean follow-up was 20.5 months (range, 1-49 months). Overall, three patients (12.5%) required a secondary intervention, comprising thrombectomy, angioplasty, and proximal cuff extension. No patients required conversion to open repair. Two patients (8.3%) died of AAA rupture at 507 and 1254 days. Freedom from all-cause mortality was 83.3% at 1 year and 19.3% at 5 years. Freedom from aneurysm-related mortality was 87.5% at 1 year and 73.2% at 5 years. Endoleak occurred in five patients (20.8%), with three type I and two of indeterminate type; of these, two patients with type I endoleak underwent secondary intervention at 153 and 489 days after EVAR, of which one case was successful.ConclusionOur study supports that EVAR in nonagenarians is associated with acceptable procedural success and perioperative morbidity and mortality. The medium-term results suggest that EVAR may be of limited benefit in very carefully selected patients who are aged ≥90 years

Interobserver Agreement in the Diagnosis of Stroke Type

Interobserver Agreement is Essential to the Reliability of Clinical Data from Cooperative Studies and Provides the Foundation for Applying Research Results to Clinical Practice. in the Stroke Data Bank, a Large Cooperative Study of Stroke, We Sought to Establish the Reliability of a Key Aspect of Stroke Diagnosis: The Mechanism of Stroke. Seventeen Patients Were Evaluated by Six Neurologists. Interobserver Agreement Was Measured When Diagnosis Was based on Patient History and Neurologic Examination Only, as Well as When It Was based on Results of a Completed Workup, Including a Computed Tomographic Scan. Initial Clinical Impressions, based Solely on History and One Neurologic Examination, Were Fairly Reliable in Establishing the Mechanism of Stroke (Ie, Distinguishing among Infarcts, Subarachnoid Hemorrhages, and Parenchymatous Hemorrhages). Classification into One of Nine Stroke Subtypes Was Substantially Reliable When Diagnoses Were based on a Completed Workup. Compared with Previous Findings for the Same Physicians and Patients, the Diagnosis of Stroke Type Was Generally More Reliable Than Individual Signs and Symptoms. These Results Suggest that Multicentered Studies Can Rely on the Independent Diagnostic Choices of Several Physicians When Common Definitions Are Employed and Data from a Completed Workup Are Available. Furthermore, Reliability May Be Less for Individual Measurements Such as Signs or Symptoms Than for More-Complex Judgments Such as Diagnoses. © 1986, American Medical Association. All Rights Reserved

Interobserver Reliability in the Interpretation of Computed Tomographic Scans of Stroke Patients

Interobserver Reliability in Interpretation of Computed Tomographic Images Was Studied by Six Senior Neurologists Who Independently Evaluated on a Standardized Stroke Data Bank Form the Brain Lesions of 17 Patients. the Results Analyzed with K Statistics Yielded Moderate to Substantial Agreement on Most Items of Interest Including the Stroke Pathology and Anatomy. in General, the Levels of Agreement Were as High as Previously Reported for the Diagnosis of the Mechanism of the Stroke, and Much Higher Than on Many Stroke History Items and Items of Neurologic Examination. Excellent Agreement Was Obtained for the Detection of Infarcts and Intracerebral Hemorrhage, and Substantial Agreement Was Obtained on Whether the Computed Tomographic Images Were Normal or Indicative of Small Deep Infarcts, Superficial and Deep Infarcts, and Aneurysms. the Level of Agreement on Anatomy of the Lesions Was Best for the Frontal, Parietal, and Temporal Lobes, Putamen, Cerebellum, and Subarachnoid Space. Implications for Clinical Research and Diagnosis Are Discussed. © 1987 American Medical Association All Rights Reserved

Interobserver Variability in the Assessment of Neurologic History and Examination in the Stroke Data Bank

Interobserver Reliability in Obtaining Neurologic Histories and Examinations Was Investigated among Neurologists Collaborating in the Stroke Data Bank (SDB). Seventeen In-Hospital Stroke Patients Were Examined by Six Neurologists Experienced in Stroke over the Course of Three Days. Patients Were Examined Twice a Day for Two Successive Days, with Each Patient Seen by Four Different Neurologists. Data Were Recorded on SDB Forms, According to Definitions and Procedures Established for the SDB. Percent Agreement and Κ Coefficients Were Calculated to Assess the Levels of Agreement for Each Item. Important Differences in Levels of Agreement Were Found among Items on Both Neurologic History and Examination. Agreement among Neurologists Was Higher for Neurologic Examination Than for History. Patterns of Agreement for Items with Low Prevalence or with Numerous Unknown Ratings Are Discussed. Improvement in Interobserver Agreement Due to Data Editing for Intra-Observer Consistency Was Shown. © 1985, American Medical Association. All Rights Reserved

25th annual computational neuroscience meeting: CNS-2016

The same neuron may play different functional roles in the neural circuits to which it belongs. For example, neurons in the Tritonia pedal ganglia may participate in variable phases of the swim motor rhythms [1]. While such neuronal functional variability is likely to play a major role the delivery of the functionality of neural systems, it is difficult to study it in most nervous systems. We work on the pyloric rhythm network of the crustacean stomatogastric ganglion (STG) [2]. Typically network models of the STG treat neurons of the same functional type as a single model neuron (e.g. PD neurons), assuming the same conductance parameters for these neurons and implying their synchronous firing [3, 4]. However, simultaneous recording of PD neurons shows differences between the timings of spikes of these neurons. This may indicate functional variability of these neurons. Here we modelled separately the two PD neurons of the STG in a multi-neuron model of the pyloric network. Our neuron models comply with known correlations between conductance parameters of ionic currents. Our results reproduce the experimental finding of increasing spike time distance between spikes originating from the two model PD neurons during their synchronised burst phase. The PD neuron with the larger calcium conductance generates its spikes before the other PD neuron. Larger potassium conductance values in the follower neuron imply longer delays between spikes, see Fig. 17.Neuromodulators change the conductance parameters of neurons and maintain the ratios of these parameters [5]. Our results show that such changes may shift the individual contribution of two PD neurons to the PD-phase of the pyloric rhythm altering their functionality within this rhythm. Our work paves the way towards an accessible experimental and computational framework for the analysis of the mechanisms and impact of functional variability of neurons within the neural circuits to which they belong