Internal Carotid Artery Redundancy is Significantly Associated With Dissection.

BACKGROUND AND PURPOSE: Redundant internal carotid arteries have been considered a risk factor in tonsillectomy, adenoidectomy, and surgical treatment of peritonsillar abscess and also a potentially treatable cause of stroke. However, an association between internal carotid artery redundancy and spontaneous dissection has not yet been clearly demonstrated. METHODS: We reviewed, for spontaneous carotid artery dissection, records of all patients admitted to our institution during the period from 1986 through 1992 with the diagnosis of stroke or transient ischemic attack. We also reviewed 108 percutaneous cerebral arteriograms performed between September 1992 and December 1992 for presence of carotid artery redundancies. RESULTS: Thirteen patients exhibited spontaneous dissection. Of these, 8 of 13 (62%) patients and 13 of 20 (65%) internal carotid arteries, viewed to the siphon, had significant redundancies, kinks, coils, or loops. Of 108 consecutive arteriograms of patients without dissection, in which 187 internal carotid arteries were viewed to the siphon, there were 20 (19%) patients and 22 (12%) of 187 vessels with significant redundancy. Five patients in the dissection group and 2 in the nondissection group had bilateral internal carotid artery redundancy (P = .0019 and P = .0001, respectively). CONCLUSIONS: We found a significant correlation between internal carotid artery redundancy and dissection, particularly if redundancy is present bilaterally

The development and validation of a scoring tool to predict the operative duration of elective laparoscopic cholecystectomy

Background: The ability to accurately predict operative duration has the potential to optimise theatre efficiency and utilisation, thus reducing costs and increasing staff and patient satisfaction. With laparoscopic cholecystectomy being one of the most commonly performed procedures worldwide, a tool to predict operative duration could be extremely beneficial to healthcare organisations. Methods: Data collected from the CholeS study on patients undergoing cholecystectomy in UK and Irish hospitals between 04/2014 and 05/2014 were used to study operative duration. A multivariable binary logistic regression model was produced in order to identify significant independent predictors of long (> 90 min) operations. The resulting model was converted to a risk score, which was subsequently validated on second cohort of patients using ROC curves. Results: After exclusions, data were available for 7227 patients in the derivation (CholeS) cohort. The median operative duration was 60 min (interquartile range 45–85), with 17.7% of operations lasting longer than 90 min. Ten factors were found to be significant independent predictors of operative durations > 90 min, including ASA, age, previous surgical admissions, BMI, gallbladder wall thickness and CBD diameter. A risk score was then produced from these factors, and applied to a cohort of 2405 patients from a tertiary centre for external validation. This returned an area under the ROC curve of 0.708 (SE = 0.013, p  90 min increasing more than eightfold from 5.1 to 41.8% in the extremes of the score. Conclusion: The scoring tool produced in this study was found to be significantly predictive of long operative durations on validation in an external cohort. As such, the tool may have the potential to enable organisations to better organise theatre lists and deliver greater efficiencies in care

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study

Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation

Handbook of Multiple Sclerosis

X, 88 p. 29 illus. in color.online resource

Type III Intermittency: a Nonlinear Dynamic Model of EEG Burst Suppression.

Burst suppression electroencephalograms from 9 comatose patients have been studied using nonlinear dynamic techniques. These EEG records show many dynamical features characteristic of nonlinear systems, including sensitive dependence on initial conditions, self-organization, similarity across scales, and intermittency. Histograms of burst durations showed an asymmetric distribution with a decreasing tail of increasing duration. Interpreting the histograms from the standpoint of intermittency classifications of iterated dynamical maps, the absence of any conspicuous maximal cut-off duration suggests a type III intermittency. The power-law exponent of the decreasing tail is -3/2 for type III intermittency in the large scale sample size limit, and we have found the EEGs to be consistent with type III intermittency behavior. We have also developed a nonlinear algorithm which models burst suppression pattern based on a low dimensional return map. Burst suppression pattern appears to be the constrained activity of a nonlinear dynamical system at the transition to chaos