0000000000161143

AUTHOR

Florian Müller-dahlhaus

Alpha-Synchronized Stimulation of the Dorsolateral Prefrontal Cortex (DLPFC) in Major Depression: A Proof-of-Principle EEG-TMS Study

High-frequency repetitive transcranial magnetic stimulation (rTMS) of the left dorsolateral prefrontal cortex (DLPFC) shows therapeutic potential in pharmaco-resistant patients with major depression. However, clinical efficacy is limited by high inter-individual variability and low response rates. One possible strategy to improve the effect size and consistency may be brain state dependent brain stimulation, i.e. coupling of TMS pulses to the endogenous brain states as reflected by the instantaneous oscillatory brain activity. Here we present findings from a proof-of-principle study of alpha-oscillation synchronized brain stimulation of the frontal cortex in patients with major depression (…

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GABA—from Inhibition to Cognition:Emerging Concepts

Neural functioning and plasticity can be studied on different levels of organization and complexity ranging from the molecular and synaptic level to neural circuitry of whole brain networks. Across neuroscience different methods are being applied to better understand the role of various neurotransmitter systems in the evolution of perception and cognition. GABA is the main inhibitory neurotransmitter in the adult mammalian brain and, depending on the brain region, up to 25% of the total number of cortical neurons are GABAergic interneurons. At the one end of the spectrum, GABAergic neurons have been accurately described with regard to cell morphological, molecular, and electrophysiological…

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Musical Sonification of Arm Movements in Stroke Rehabilitation Yields Limited Benefits.

Neurologic music therapy in rehabilitation of stroke patients has been shown to be a promising supplement to the often strenuous conventional rehabilitation strategies. The aim of this study was threefold: (i) replicate results from a previous study with a sample from one clinic (henceforth called Site 1; N = 12) using an already established recording system, and (ii) conceptually replicate previous findings with a less costly hand-tracking system in Site 2 (N = 30), and (iii) compare both sub-studies' outcomes to estimate the efficiency of neurologic music therapy. Stroke patients in both sites were randomly assigned to treatment or control groups and received daily training of guided sequ…

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Effects of antiepileptic drugs on cortical excitability in humans: A TMS-EMG and TMS-EEG study.

Brain responses to transcranial magnetic stimulation (TMS) recorded by electroencephalography (EEG) are emergent noninvasive markers of neuronal excitability and effective connectivity in humans. However, the underlying physiology of these TMS-evoked EEG potentials (TEPs) is still heavily underexplored, impeding a broad application of TEPs to study pathology in neuropsychiatric disorders. Here we tested the effects of a single oral dose of three antiepileptic drugs with specific modes of action (carbamazepine, a voltage-gated sodium channel (VGSC) blocker; brivaracetam, a ligand to the presynaptic vesicle protein VSA2; tiagabine, a gamma-aminobutyric acid (GABA) reuptake inhibitor) on TEP a…

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P 56 tDCS shows no effects on motor cortex excitability at rest

Introduction Transcranial direct current stimulation (tDCS) is a widely used technique in research and clinics. However, the underlying physiological mechanisms are not yet clear. Modeling studies suggest that the electric field during tDCS is dominated by a tangential component which predominantly modifies active synaptic connections ( Radman et al., 2007 ). We have previously shown that tDCS with an increased tangential compared to the conventional montage introduced by Nitsche and Paulus (2000) , suppresses the effects of paired associative stimulation of the supplementary motor area and the primary motor cortex (PASSMA-M1) independent of tDCS polarity (Faber et al., under submission). H…

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Early improvement of executive test performance during antidepressant treatment predicts treatment outcome in patients with Major Depressive Disorder

Executive dysfunctions frequently occur in patients with Major Depressive Disorder and have been shown to improve during effective antidepressant treatment. However, the time course of improvement and its relationship to treatment outcome is unknown. The aim of the study was to assess the test performance and clinical outcome by repetitive assessments of executive test procedures during antidepressant treatment. Executive test performance was assessed in 209 –patients with Major Depressive Disorder (mean age 39.3 ± 11.4 years) and 84 healthy controls five times in biweekly intervals from baseline to week 8. Patients were treated by a defined treatment algorithm within the early medication c…

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