The journal of neuroscience : the official journal of the Society for Neuroscience.

Additional co-authors: Endre Czeiter, Marek Czosnyka, Ramon Diaz-Arrastia, Jens P Dreier, Ann-Christine Duhaime, Ari Ercole, Thomas A van Essen, Valery L Feigin, Guoyi Gao, Joseph Giacino, Laura E Gonzalez-Lara, Russell L Gruen, Deepak Gupta, Jed A Hartings, Sean Hill, Ji-yao Jiang, Naomi Ketharanathan, Erwin J O Kompanje, Linda Lanyon, Steven Laureys, Fiona Lecky, Harvey Levin, Hester F Lingsma, Marc Maegele, Marek Majdan, Geoffrey Manley, Jill Marsteller, Luciana Mascia, Charles McFadyen, Stefania Mondello, Virginia Newcombe, Aarno Palotie, Paul M Parizel, Wilco Peul, James Piercy, Suzanne Polinder, Louis Puybasset, Todd E Rasmussen, Rolf Rossaint, Peter Smielewski, Jeannette Soderberg, Simon J Stanworth, Murray B Stein, Nicole von Steinbuchel, William Stewart, Ewout W Steyerberg, Nino Stocchetti, Anneliese Synnot, Braden Te Ao, Olli Tenovuo, Alice Theadom, Dick Tibboel, Walter Videtta, Kevin K W Wang, W Huw Williams, Kristine Yaffe for the InTBIR Participants and Investigators

/pdf/traumatic-brain-injury-integrated-approaches-to-improve-29obvlh2iu.pdf

Traumatic brain injury: integrated approaches to improve prevention, clinical care, and research

There is increasing concern that most current published research findings are false. The probability that a research claim is true may depend on study power and bias, the number of other studies on the same question, and, importantly, the ratio of true to no relationships among the relationships probed in each scientific field. In this framework, a research finding is less likely to be true when the studies conducted in a field are smaller; when effect sizes are smaller; when there is a greater number and lesser preselection of tested relationships; where there is greater flexibility in designs, definitions, outcomes, and analytical modes; when there is greater financial and other interest and prejudice; and when more teams are involved in a scientific field in chase of statistical significance. Simulations show that for most study designs and settings, it is more likely for a research claim to be false than true. Moreover, for many current scientific fields, claimed research findings may often be simply accurate measures of the prevailing bias. In this essay, I discuss the implications of these problems for the conduct and interpretation of research.

Why most published research findings are false

Transcranial direct current stimulation

1: Amartya Sen: Radical Needs and Moderate Reforms 2: Jean Dreze and Haris Gazdar: Uttar Pradesh: The Burden of Inertia 3: Sunil Sengupta and Haris Gazdar: Agrarian Politics and Rural Development in West Bengal 4: V.K. Ramachandran: On Kerala's Development Achievements 5: Mamta Murthi, Anne-Catherine Guio, and Jean Dreze: Mortality, Fertility and Gender Bias in India: A District Level Analysis

Indian Development: Selected Regional Perspectives

The present study investigated the neural correlates of cognitive fatigue in Multiple Sclerosis (MS), looking specifically at the relationship between self-reported fatigue and objective measures of cognitive fatigue. In Experiment 1, functional magnetic resonance imaging (fMRI) was used to examine where in the brain BOLD activity covaried with “state” fatigue, assessed during performance of a task designed to induce cognitive fatigue while in the scanner. In Experiment 2, diffusion tensor imaging (DTI) was used to examine where in the brain white matter damage correlated with increased “trait” fatigue in individuals with MS, assessed by the Fatigue Severity Scale (FSS) completed outside the scanning session. During the cognitively fatiguing task, the MS group had increased brain activity associated with fatigue in the caudate as compared with HCs. DTI findings revealed that reduced fractional anisotropy in the anterior internal capsule was associated with increased self-reported fatigue on the FSS. Results are discussed in terms of identifying a “fatigue-network” in MS.

/pdf/examination-of-cognitive-fatigue-in-multiple-sclerosis-using-31xjxovbfy.pdf

Examination of Cognitive Fatigue in Multiple Sclerosis using Functional Magnetic Resonance Imaging and Diffusion Tensor Imaging

A method for electroencephalography (EEG) - near-infrared spectroscopy (NIRS) based assessment of neurovascular coupling (NVC) during anodal transcranial direct current stimulation (tDCS). Anodal tDCS modulates cortical neural activity leading to a hemodynamic response, which was used to identify impaired NVC functionality. In this study, the hemodynamic response was estimated with NIRS. NIRS recorded changes in oxy-hemoglobin (HbO2) and deoxy-hemoglobin (Hb) concentrations during anodal tDCS-induced activation of the cortical region located under the electrode and in-between the light sources and detectors. Anodal tDCS-induced alterations in the underlying neuronal current generators were also captured with EEG. Then, a method for the assessment of NVC underlying the site of anodal tDCS was proposed that leverages the Hilbert-Huang Transform. The case series including four chronic (>6 months) ischemic stroke survivors (3 males, 1 female from age 31 to 76) showed non-stationary effects of anodal tDCS on EEG that correlated with the HbO2 response. Here, the initial dip in HbO2 at the beginning of anodal tDCS corresponded with an increase in the log-transformed mean-power of EEG within 0.5Hz-11.25Hz frequency band. The cross-correlation coefficient changed signs but was comparable across subjects during and after anodal tDCS. The log-transformed mean-power of EEG lagged HbO2 response during tDCS but then led post-tDCS. This case series demonstrated changes in the degree of neurovascular coupling to a 0.526 A/m2 square-pulse (0---30 s) of anodal tDCS. The initial dip in HbO2 needs to be carefully investigated in a larger cohort, for example in patients with small vessel disease.

/pdf/eeg-nirs-based-assessment-of-neurovascular-coupling-during-ocq3y5d9o3.pdf

EEG-NIRS Based Assessment of Neurovascular Coupling During Anodal Transcranial Direct Current Stimulation - a Stroke Case Series

India's Janani Suraksha Yojana: further review needed

India, the world’s second most populous country, is facing the emergence of a hitherto “hidden” epidemic: neurologic disability. The rapid economic, demographic, and social transformation of India in recent decades has already resulted in the double burden of unresolved epidemics of infectious diseases (e.g., malaria, tuberculosis) coupled with rising rates of chronic diseases (e.g., cardiovascular diseases). Neurologic disability is likely to join these public health concerns as a third epidemic, largely due to 3 emerging health trends: 1) an increase in traumatic brain injuries (TBI) from road traffic accidents (RTA); 2) an increase in the incidence of age-related dementia; and 3) an increase in the stroke incidence. Without adequate preparation, the treatment and long-term care for an increasing population of neurologically disabled people will strain India's health care system and economy in the coming years in unprecedented ways.

https://n.neurology.org/content/neurology/79/21/2146.full.pdf

Neurologic Disability: A Hidden Epidemic for India

Post-stroke fatigue (PSF) is a common and one of the most distressing symptoms in stroke survivors. However, little is known about the relationship between severity of fatigue and the overall impact it has on post-stroke disability and burden of care. We aimed to examine the role of PSF in post-stroke disability and burden of care among stroke survivors after their first-ever stroke.Methods: We prospectively recruited 163 subjects (35 females) from patients examined consecutively in a tertiary stroke care center in India, after their first-ever ischemic or hemorrhagic stroke (>3 months after event). In addition to demographic and clinical characteristics, the following assessments were done – SF-36 vitality domain (fatigue), Modified Rankin Scale (functional recovery), Hospital anxiety and depression scale (depression), Functional independence measure (disability and burden of care). We used path analysis to identify a model that will capture the interactions of fatigue, depression, and degree of function...

Abhijit Das

Papers

Examination of Cognitive Fatigue in Multiple Sclerosis using Functional Magnetic Resonance Imaging and Diffusion Tensor Imaging

EEG-NIRS Based Assessment of Neurovascular Coupling During Anodal Transcranial Direct Current Stimulation - a Stroke Case Series

India's Janani Suraksha Yojana: further review needed

Neurologic Disability: A Hidden Epidemic for India

Post-stroke Fatigue is an Independent Predictor of Post-stroke Disability and Burden of Care: A Path analysis Study