Neuroscience

Studying and modifying brain function with non-invasive brain stimulation

Nature Neuroscience - 8 January 2018 - 12:00am

Studying and modifying brain function with non-invasive brain stimulation

Studying and modifying brain function with non-invasive brain stimulation, Published online: 08 January 2018; doi:10.1038/s41593-017-0054-4

Polanía, Nitsche and Ruff summarize the state of non-invasive brain stimulation research in humans, discuss some current debates about properties and limitations of these methods, and give recommendations for how these challenges may be addressed.
Categories: Neuroscience

Pretreatment Lesional Volume Impacts Clinical Outcome and Thrombectomy Efficacy

Annals of Neurology - 3 January 2018 - 4:40pm
Abstract

Objective: We aimed to characterize the association between pretreatment lesional volume measured on diffusion-weighted images and functional outcome, and estimate the impact on thrombectomy efficacy for ischemic stroke with anterior proximal intracranial arterial occlusion.

Methods: Anterior circulation ischemic stroke patients who had pretreatment diffusion-weighted imaging in the THRACE study were included. Lesional volume was semi-automatically segmented. Logistic regression was applied to model clinical outcome as a function of lesional volume. Outcomes included functional independence (modified Rankin Scale [mRS] 0-2), degree of disability (ordinal mRS 0-6), and mortality at 3 months.

Results: Of 298 included patients, with median lesional volume 17.2 mL (interquartile range [IQR] 9.2-51.8) and median mRS 2 (IQR 1-4), 51.0% achieved functional independence. Increased lesional volume was an independent predictor for a lower probability of functional independence (odds ratio [OR] 0.90 [95% CI 0.81-0.99] per 10 mL, p<0.001), a less favorable degree of disability (common OR [cOR] 0.86 [95% CI 0.81-0.90] per 10 mL, p<0.001), and a higher mortality rate (OR 1.21 [95% CI 1.08-1.37] per 10 mL, p<0.001). For additional thrombectomy, the number of patients needed to treat to achieve functional independence in 1 patient increased with lesional volume (10 for a volume of 80 mL; 15 for 135 mL). No significant treatment-by-dichotomized volume interaction for functional independence and mortality was observed.

Interpretation: Pretreatment lesional volume is an independent predictor for functional outcome in acute ischemic stroke with proximal intracranial occlusion. The clinical benefit of adding mechanical thrombectomy to thrombolysis decreased with the increase of lesional volume. This article is protected by copyright. All rights reserved.

Categories: Neuroscience

Association of prothrombin complex concentrates administration and hematoma enlargement in NOAC-related intracerebral hemorrhage

Annals of Neurology - 3 January 2018 - 4:40pm
Abstract

Objective: To investigate parameters associated with hematoma enlargement in non-vitamin-K-antagonist-anticoagulant(NOAC)-related intracerebral hemorrhage(ICH).

Methods: Retrospective cohort study including individual patient data of 190 patients with NOAC-associated ICH over a 5-year-period(2011-2015) at 19 Departments of Neurology across Germany. Primary outcome was the association of PCC-administration with hematoma enlargement. Subanalyses were calculated for blood-pressure management and its association with the primary outcome. Secondary outcomes include associations with in-hospital mortality and functional outcome at 3 months assessed using the modified Rankin scale.

Results: The study population for analysis of primary and secondary outcomes consisted of 146 NOAC-ICH-patients with available follow-up imaging. Hematoma enlargement occurred in 49/146(33.6%) patients with NOAC-related ICH. Parameters associated with hematoma enlargement were blood pressure above 160mmHg within 4hours and – in case of factor-Xa-inhibitor-ICH – anti-Xa-levels on admission. PCC-administration prior to follow-up imaging was not significantly associated with a reduced rate of hematoma enlargement neither in overall NOAC-related ICH nor in patients with factor-Xa-inhibitor intake (RR(95%CI):NOAC 1.150(0.632-2.090);factor-Xa-inhibitor: 1.057(0.565-1.977)), regardless of PCC-dosage given or time interval until imaging or treatment. Systolic blood pressure levels<160mmHg within 4 hours after admission were significantly associated with a reduction in the proportion of patients with hematoma enlargement (RR(95%CI):1.057(0.565-1.977)). PCC-administration had no effect on mortality and functional outcome neither at discharge nor at 3months.

Interpretation: In contrast to blood-pressure control, PCC-administration was not associated with a reduced rate of hematoma enlargement in NOAC-related ICH. Our findings support the need of further investigations exploring new hemostatic reversal strategies for patients with factor-Xa-inhibitor-related ICH. This article is protected by copyright. All rights reserved.

Categories: Neuroscience

Autoimmune Encephalitis Epidemiology and a comparison to Infectious Encephalitis

Annals of Neurology - 2 January 2018 - 4:10pm
Abstract

Objectives We evaluate incidence and prevalence of autoimmune encephalitis and compare the epidemiology of autoimmune and infectious encephalitis.

Methods We performed a population-based comparative study of the incidence and prevalence of autoimmune and infectious encephalitis in Olmsted County, USA. Autoimmune encephalitis diagnosis and subgroups were defined by 2016 diagnostic criteria and infectious encephalitis diagnosis required a confirmed infectious pathogen. Age- and sex-adjusted prevalence and incidence rates were calculated. Patients with encephalitis of uncertain etiology were excluded.

Results The prevalence of autoimmune encephalitis on January 1, 2014 of 13.7/100,000 was not significantly different from that of all infectious encephalitides (11.6/100,000; p=0.63) or the viral subcategory (8.3/100,000; p=0.17). The incidence rates (1995-2015) of autoimmune and infectious encephalitis were 0.8/100,000 and 1.0/100,000 person-years respectively (p=0.58). The number of relapses or recurrent hospitalizations was higher for autoimmune than infectious encephalitis (p=0.03). The incidence of autoimmune encephalitis increased over time from 0.4/100,000 person-years (1995-2005) to 1.2/100,000 person-years (2006-2015) (p=0.02), attributable to increased recognition of autoantibody-positive cases. The incidence (2.8 vs 0.7/100,000 person-years; p=0.01) and prevalence (38.3 vs 13.7/100,000; p=0.04) of autoimmune encephalitis was higher among African-Americans than Caucasians. The prevalence of specific neural autoantibodies was: myelin-oligodendrocyte-glycoprotein (MOG) (1.9/100,000); glutamic acid decarboxylase-65 (GAD65) (1.9/100,000); unclassified neural autoantibody (1.4/100,000); leucine-rich glioma-inactivated-protein-1 (LGI1) (0.7/100,000); collapsin response-mediator protein-5 (CRMP5) (0.7/100,000); N-methyl-D-aspartate-receptor (NMDAR) (0.6/100,000); anti-neuronal nuclear antibody-2 (ANNA-2/anti-Ri) (0.6/100,000) and glial fibrillary acidic protein-α (GFAPα) (0.6/100,000).

Interpretation This study shows that the prevalence and incidence of autoimmune encephalitis is comparable to infectious encephalitis and its detection is increasing over time. This article is protected by copyright. All rights reserved.

Categories: Neuroscience

Generalizable representations of pain, cognitive control, and negative emotion in medial frontal cortex

Nature Neuroscience - 1 January 2018 - 12:00am

Generalizable representations of pain, cognitive control, and negative emotion in medial frontal cortex

Generalizable representations of pain, cognitive control, and negative emotion in medial frontal cortex, Published online: 01 January 2018; doi:10.1038/s41593-017-0051-7

Assessing person-level human brain maps across 18 fMRI studies, the authors identify separable representations of pain, cognitive control, and negative emotion in the medial frontal cortex that generalize across different studies and tasks.
Categories: Neuroscience

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