Spatiotemporal characteristics of the neural representation of event concepts.

Events are a fundamentally important part of our understanding of the world. How lexical concepts denoting events are represented in the brain remains controversial. We conducted two experiments using event and object nouns matched on a range of psycholinguistic variables, including concreteness, to examine spatial and temporal characteristics of event concepts. Both experiments used magnitude and valence tasks on event and object nouns. The fMRI experiment revealed a distributed set of regions for events, including the angular gyrus, anterior temporal lobe, and posterior cingulate across tasks. In the EEG experiment, events and objects differed in amplitude within the 300-500 ms window. Together these results shed light into the spatiotemporal characteristics of event concept representation and show that event concepts are represented in the putative hubs of the semantic system. While these hubs are typically associated with object semantics, they also represent events, and have a likely role in temporal integration.

Rapid Arterial Occlusion Evaluation Scale Agreement between Emergency Medical Services Technicians and Neurologists.

BACKGROUND: Rapid arterial occlusion evaluation (RACE) scale is a valid prehospital tool used to predict large vessel occlusion of major cerebral arteries in patients with suspected acute stroke. RACE scale administered by Emergency medicine services (EMS) technicians in the prehospital setting correlates well with NIH Stroke Scale score after patient arrival at a hospital. Despite this, the RACE scale is often characterized as too difficult for EMS technicians to accurately utilize. There are no data examining RACE scale accuracy in the prehospital setting comparing EMS technicians with neurologists. We sought to examine agreement between RACE scores calculated by EMS technicians and stroke neurologists in the prehospital setting during telestroke consultation. METHODS: Data for this observational cohort study were prospectively collected and retrospectively analyzed. EMS technicians in person and stroke specialized neurologists via televideo connection independently assessed suspected stroke patients and calculated RACE scores in the prehospital setting. We used a linearly weighted Cohen's kappa (kw) to estimate the extent of agreement for RACE score between EMS technicians and stroke neurologists. RESULTS: Thirty-one patients with stroke symptoms were independently examined and assessed with the RACE scale by EMS technicians and stroke neurologists in the prehospital setting. Exact agreement on the RACE score was found in 24 of 31 (77%) patients. We found very good agreement between EMS technicians and stroke neurologists, kw = .818 (95% CI, .677-.960), P< .001. CONCLUSIONS: EMS technicians provide reliable RACE assessments in patients with suspected stroke, with agreement similar to stroke specialized neurologists in the prehospital setting.

Specific clinical phenotypes in relapsing multiple sclerosis: The impact of relapses on long-term outcomes.

OBJECTIVE: The impact of relapses on the disease course of relapsing MS remains to be determined. This study aims to identify and characterize clinical phenotypes of relapse onset MS in a longitudinally studied cohort. METHODS: We recorded the clinical course of MS during the first decade of disease, using five-year epochs. Patients were stratified as: no worsening due to relapse or secondary progression (type A), relapse with worsening seen without secondary progression (type B), secondary progression with no worsening due to relapse (type C), worsening due to relapses mixed with secondary progression (type D). RESULTS: Of 176 patients followed from diagnosis for 12.62 ± 4.18 years, 93.2% (164/176) had increased disability in their first 5-year epoch of MS and 52.2% (72/138) in the next. The phenotypes significantly differed by EDSS change during each epoch (p<0.001), final confirmed MSSS (p ≤ 0.002) and relapse rate (p<0.001). Type D fared worse than others by change in EDSS and MSSS. CONCLUSION: We identified multiple specific phenotypes of MS and temporal shifts between phenotypes according to relapse type and progression.

Relapsing multiple sclerosis patients treated with disease modifying therapy exhibit highly variable disease progression: a predictive model.

OBJECTIVE: To describe a "new natural history" of multiple sclerosis (MS), characterizing three patterns of progression in Relapsing MS (RMS) patients during the "treatment era," using newly developed definitions. By utilizing our simple model we intend to predict which patients are most likely to reach an EDSS of 6.0. METHODS: We stratified MS progression into three distinct patterns: aggressive MS (AMS), intermediate MS (IMS) and mild MS (MMS), based on Expanded Disability Status Scale (EDSS) score rate of change. These groups were compared for progression of EDSS before and after reaching these definitions. RESULTS: The three groups remained significantly different in terms of disability throughout their disease courses p ≤ 0.001; 98% of the patients used disease modifying treatments (DMTs). AMS patients represent a significantly more disabling and aggressive form of MS than the IMS group. CONCLUSIONS: Transition from relatively mild MS to aggressive course may begin at any time in the first 15 years, despite DMTs. Our definition for AMS is unique and identifies a group of patients who become permanently disabled within two years after a variable amount of time in a benign phase, despite treatment with modern DMTs.