Search results for "Neurologic"

Intracranial measurement of current densities induced by transcranial magnetic stimulation in the human brain

2003

Transcranial magnetic stimulation (TMS) is a non-invasive technique that uses the principle of electromagnetic induction to generate currents in the brain via pulsed magnetic fields. The magnitude of such induced currents is unknown. In this study we measured the TMS induced current densities in a patient with implanted depth electrodes for epilepsy monitoring. A maximum current density of 12 microA/cm2 was recorded at a depth of 1 cm from scalp surface with the optimum stimulation orientation used in the experiment and an intensity of 7% of the maximal stimulator output. During TMS we recorded relative current variations under different stimulating coil orientations and at different points…

Negative and Positive Bias for Emotional Faces: Evidence from the Attention and Working Memory Paradigms

2021

Visual attention and visual working memory (VWM) are two major cognitive functions in humans, and they have much in common. A growing body of research has investigated the effect of emotional information on visual attention and VWM. Interestingly, contradictory findings have supported both a negative bias and a positive bias toward emotional faces (e.g., angry faces or happy faces) in the attention and VWM fields. We found that the classical paradigms—that is, the visual search paradigm in attention and the change detection paradigm in VWM—are considerably similar. The settings of these paradigms could therefore be responsible for the contradictory results. In this paper, we compare previou…

Some Necessary Revisions of the Neuronal Model Concept of the Orienting Response

1978

Sokolov's neural trace model as well as his entropy model of the orienting response are examined. Both seem inadequate for empirical and theoretical reasons. The role of the relevance aspect of a stimulus is stressed. It is proposed to consider the information transmitted by a stimulus as in some way being weighted by the relevance of the context to which it belongs. It is furthermore proposed to restrict the neural trace concept to the physical properties of the stimulus. Major theoretical gain is achieved by viewing information content of a stimulus and its physical properties independently and by breaking the motivation determining the strength of an orienting response into a situation-s…

Axons take a dive

2014

In the walls of the lateral ventricles of the adult mammalian brain, neural stem cells (NSCs) and ependymal (E1) cells share the apical surface of the ventricular-subventricular zone (V-SVZ). In a recent article, we show that supraependymal serotonergic (5HT) axons originating from the raphe nuclei in mice form an extensive plexus on the walls of the lateral ventricles where they contact E1 cells and NSCs. Here we further characterize the contacts between 5HT supraependymal axons and E1 cells in mice, and show that suprependymal axons tightly associated to E1 cells are also present in the walls of the human lateral ventricles. These observations raise interesting questions about the functio…

Pharmacotherapy, drug-drug interactions and potentially inappropriate medication in depressive disorders.

2021

Introduction The aim of this study was to describe the number and type of drugs used to treat depressive disorders in inpatient psychiatry and to analyse the determinants of potential drug-drug interactions (pDDI) and potentially inappropriate medication (PIM). Methods Our study was part of a larger pharmacovigilance project funded by the German Innovation Funds. It included all inpatients with a main diagnosis in the group of depressive episodes (F32, ICD-10) or recurrent depressive disorders (F33) discharged from eight psychiatric hospitals in Germany between 1 October 2017 and 30 September 2018 or between 1 January and 31 December 2019. Results The study included 14,418 inpatient cases.…

FOLLOW-UP 2003-2008 DEI NATI VERY LOW BIRTH WEIGHT: ESITI NEUROLOGICI

2009

Fast Estimation of Diffusion Tensors under Rician noise by the EM algorithm

2016

Diffusion tensor imaging (DTI) is widely used to characterize, in vivo, the white matter of the central nerve system (CNS). This biological tissue contains much anatomic, structural and orientational information of fibers in human brain. Spectral data from the displacement distribution of water molecules located in the brain tissue are collected by a magnetic resonance scanner and acquired in the Fourier domain. After the Fourier inversion, the noise distribution is Gaussian in both real and imaginary parts and, as a consequence, the recorded magnitude data are corrupted by Rician noise. Statistical estimation of diffusion leads a non-linear regression problem. In this paper, we present a f…

Robust Conditional Independence maps of single-voxel Magnetic Resonance Spectra to elucidate associations between brain tumours and metabolites.

2020

The aim of the paper is two-fold. First, we show that structure finding with the PC algorithm can be inherently unstable and requires further operational constraints in order to consistently obtain models that are faithful to the data. We propose a methodology to stabilise the structure finding process, minimising both false positive and false negative error rates. This is demonstrated with synthetic data. Second, to apply the proposed structure finding methodology to a data set comprising single-voxel Magnetic Resonance Spectra of normal brain and three classes of brain tumours, to elucidate the associations between brain tumour types and a range of observed metabolites that are known to b…

Griscelli-Syndrom: ein Fallbericht

2003

Background: Griscelli syndrome is a rare disorder with poor prognosis. It is characterized by silver-grey hair or strands of silver-grey hair in childhood, and variable cellular immunodeficiency. The course of the untreated disease is fatal. Recurrent episodes of fever and lymphohistocytic infiltration of organs lead to hepatosplenomegaly, lymphadenopathy, pancytopenia, and progressive neurological impairment. Prognosis on morbidity and lethality depends on an early diagnosis. Patient: The girl we report on suffers from Griscelli syndrome. She developed normally and only her grey strands of hair, grey eyebrows, and eyelids were conspicuous. With the age of 4 years she presented with a first…

Food of the Gods for the Treatment of Multiple Sclerosis Related Fatigue?

2019

In their JNNP paper, Coe et al report the preliminary results of a feasibility trial on flavonoid enriched cocoa for the treatment of multiple sclerosis (MS) related fatigue, showing promising results that encourage the conduction of a phase III clinical trial to confirm the results of possible clinical effects on MS related fatigue.1 As described in the paper,1 fatigue is the most common symptom reported by individuals affected by MS, affecting the majority of patients. It is often present even when neurological disability is low and in the early stages of the disease, but impacts significantly the quality of life in MS patients, diminishing independence in everyday activities. Fatigue sym…