9 research outputs found
Conditional Deletion of Prnp Rescues Behavioral and Synaptic Deficits after Disease Onset in Transgenic Alzheimer's Disease
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Itemized NIHSS subsets predict positive MRI strokes in patients with mild deficits.
BACKGROUND: While imaging is useful in confirming the diagnosis of ischemic stroke, negative diffusion weighted imaging (DWI) is reported in up to 25% of patients. Our aim was to identify predictors of MRI-positive stroke from the itemized NIHSS. METHODS: Data were derived from the Stroke Warning Information and Faster Treatment study from February 2006 to February 2010 among patients with mild deficits (NIHSS 0-5) and a final diagnosis of stroke by a vascular neurologist. All MRI sequences were reviewed for the presence or absence of an acute infarct on DWI. Multivariate logistic regression assessed factors predicting DWI-positive strokes; p<0.05 was considered significant. RESULTS: 894 patients had a discharge diagnosis of stroke; 709 underwent MRI and 28.0% were DWI negative. All patients with visual field deficits or neglect were DWI positive. On multivariate analysis including total NIHSS (0-2 vs. 3-5) and itemized NIHSS score subsets, predictors of a positive DWI were NIHSS score of 3-5 (OR=3.3, 95% CI: 1.8-6.1), motor deficits (OR=1.7, 95% CI: 1.1-2.8), ataxia (OR=1.9, 95% CI: 1.0-3.5), and absence of sensory deficits (OR=1.7, 95% CI: 1.0-2.7). We developed the NIHSS-m score that predicts DWI positivity in patients with mild deficits in the absence of neglect or visual field deficits. CONCLUSION: NIHSS score subsets predict DWI positivity in mild strokes. The presence of neglect or visual field deficits on the NIHSS subsets is most likely to have an MRI correlate even in patients with low NIHSS
Variability in Motor and Language Recovery during the Acute Stroke Period
Background: Most stroke recovery occurs by 90 days after onset, with proportional recovery models showing an achievement of about 70% of the maximal remaining recovery. Little is known about recovery during the acute stroke period. Moreover, data are described for groups, not for individuals. In this observational cohort study, we describe for the first time the daily changes of acute stroke patients with motor and/or language deficits over the first week after stroke onset. Methods: Patients were enrolled within 24-72 h after stroke onset with upper extremity hemiparesis, aphasia, or both, and were tested daily until day 7 or discharge with the upper-extremity Fugl-Meyer Assessment of Motor Recovery after Stroke, the Boston Naming Test, and the comprehension domain from the Western Aphasia Battery. Discharge scores, and absolute and proportional changes were examined using t-tests for pairwise comparisons and linear regression to determine relative contributions of initial impairment, lesion volume, and age to recovery over this period. Results: Thirty-four patients were enrolled: 19 had motor deficits alone, 8 had aphasia alone, and 7 had motor and language deficits. In a group analysis, statistically significant changes in absolute scores were found in the motor (p Conclusions: Over the first week after stroke onset, recovery of upper extremity hemiparesis and aphasia were not predictable on the basis of initial impairment, lesion volume, or age. In addition, patients only achieved about 1/3 of their remaining possible recovery based on the anticipated 70% proportion found at 90 days. These findings suggest that the complex interaction between poststroke structural repair, regeneration, and functional reorganization during the first week after stroke has yet to be elucidated
Negative Impact of the UEFA European Soccer Championship on Central Hemodynamics and Arterial Stiffness: A Multicenter Study
(1) Background: watching sporting events may trigger cardiovascular events by elevating emotional stress levels. The underlying reasons and specific populations at risk are not well defined. (2) Methods: we conducted a multicenter prospective trial at three German sites during the UEFA Soccer EC 2012 and 2021 comprising 52 healthy participants (noCVD) and 18 patients hospitalized with cardiovascular disease (CVD). Subjects were studied during matches of the German national team (GP) as well as corresponding matches without German participation (noGP). Peripheral and central blood pressure (BP) and parameters of arterial stiffness were measured (Mobil-O-Graphâ„¢, I.E.M., Stolberg, Germany) before, during, and after the matches. (3) Results: in terms of CVD, peripheral as well as central BP and heart rate increased significantly during GP as well as noGP matches and remained elevated beyond the end of the matches. Likewise, arterial stiffness parameters and vascular resistance were higher during the matches and remained elevated after the matches. No consistent significant differences were found between GP and noGP matches. (4) Conclusions: this is the first study on real-life changes in hemodynamics during sport-associated emotional stress, with comparison between noCVD and CVD. We found that alterations were profound in CVD and remained elevated even after the matches
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The Association between Diffusion MRI-Defined Infarct Volume and NIHSS Score in Patients with Minor Acute Stroke.
BACKGROUND: Prior studies have shown a correlation between the National Institutes of Health Stroke Scale (NIHSS) and stroke volume on diffusion weighted imaging (DWI); data are more limited in patients with minor stroke. We sought to determine the association between DWI lesion(s) volume and the (1) total NIHSS score and (2) NIHSS component scores in patients with minor stroke. METHODS: We included all patients with minor stroke (NIHSS 0-5) enrolled in the Stroke Warning Information and Faster Treatment study. We calculated lesion(s) volume (cm3 ) on the DWI sequence using Medical Image Processing, Analysis, and Visualization (MIPAV, NIH, Version 7.1.1). We used nonparametric tests to study the association between the primary outcome, DWI lesion(s) volume, and the predictors (NIHSS score and its components). RESULTS: We identified 894 patients with a discharge diagnosis of minor stroke; 709 underwent magnetic resonance imaging and 510 were DWI positive. There was a graded relationship between the NIHSS score and median DWI lesion volume in cm3 : (NIHSS 0: 7.1, NIHSS 1: 8.0, NIHSS 2: 17.1, NIHSS 3: 11.6, NIHSS 4: 19.0, and NIHSS 5: 23.6, P < .01). The median lesion volume was significantly higher in patients with neglect (105.6 vs. 12.5, P = .025), language disorder (34.6 vs. 11.9, P < .001), and visual field impairment (185.6 vs. 11.6, P < .001). Other components of the NIHSS were not associated with lesion volume. CONCLUSION: In patients with minor stroke, the nature of deficit when used with the NIHSS score can improve prediction of infarct volume. This may have clinical and therapeutic implications
Silent Allosteric Modulation of mGluR5 Maintains Glutamate Signaling while Rescuing Alzheimer’s Mouse Phenotypes
Metabotropic glutamate receptor 5 (mGluR5) has been implicated in Alzheimer’s disease (AD) pathology. We sought to understand whether mGluR5’s role in AD requires glutamate signaling. We used a potent mGluR5 silent allosteric modulator (SAM, BMS-984923) to separate its well-known physiological role in glutamate signaling from a pathological role in mediating amyloid-β oligomer (Aβo) action. Binding of the SAM to mGluR5 does not change glutamate signaling but strongly reduces mGluR5 interaction with cellular prion protein (PrPC) bound to Aβo. The SAM compound prevents Aβo-induced signal transduction in brain slices and in an AD transgenic mouse model, the APPswe/PS1ΔE9 strain. Critically, 4 weeks of SAM treatment rescues memory deficits and synaptic depletion in the APPswe/PS1ΔE9 transgenic mouse brain. Our data show that mGluR5’s role in Aβo-dependent AD phenotypes is separate from its role in glutamate signaling and silent allosteric modulation of mGluR5 has promise as a disease-modifying AD intervention with a broad therapeutic window
Dentate granule cell recruitment of feedforward inhibition governs engram maintenance and remote memory generalization
Review of Solar Energetic Particle Models
Solar Energetic Particles (SEP) events are interesting from a scientific perspective as they are the product of a broad set of physical processes from the corona out through the extent of the heliosphere, and provide insight into processes of particle acceleration and transport that are widely applicable in astrophysics. From the operations perspective, SEP events pose a radiation hazard for aviation, electronics in space, and human space exploration, in particular for missions outside of the Earth’s protective magnetosphere including to the Moon and Mars. Thus, it is critical to imific understanding of SEP events and use this understanding to develop and improve SEP forecasting capabilities to support operations. Many SEP models exist or are in development using a wide variety of approaches and with differing goals. These include computationally intensive physics-based models, fast and light empirical models, machine learning-based models, and mixed-model approaches. The aim of this paper is to summarize all of the SEP models currently developed in the scientific community, including a description of model approach, inputs and outputs, free parameters, and any published validations or comparisons with data