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  1. Article ; Online: Clinical Neurophysiology: Quo vadis?

    Ziemann, Ulf

    Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology

    2023  Volume 156, Page(s) 247–248

    Language English
    Publishing date 2023-11-17
    Publishing country Netherlands
    Document type Editorial
    ZDB-ID 1463630-x
    ISSN 1872-8952 ; 0921-884X ; 1388-2457
    ISSN (online) 1872-8952
    ISSN 0921-884X ; 1388-2457
    DOI 10.1016/j.clinph.2023.11.005
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article: Pulsed Facilitation of Corticospinal Excitability by the Sensorimotor μ-Alpha Rhythm

    Bergmann, Til Ole / Ziemann, Ulf

    The journal of neuroscience, 50(39):10034-10043

    2019  

    Abstract: Alpha oscillations (8–14 Hz) are assumed to gate information flow in the brain by means of pulsed inhibition; that is, the phasic suppression of cortical excitability and information processing once per alpha cycle, resulting in stronger net suppression ... ...

    Institution Deutsches Resilienz Zentrum gGmbH
    Abstract Alpha oscillations (8–14 Hz) are assumed to gate information flow in the brain by means of pulsed inhibition; that is, the phasic suppression of cortical excitability and information processing once per alpha cycle, resulting in stronger net suppression for larger alpha amplitudes due to the assumed amplitude asymmetry of the oscillation. While there is evidence for this hypothesis regarding occipital alpha oscillations, it is less clear for the central sensorimotor μ-alpha rhythm. Probing corticospinal excitability via transcranial magnetic stimulation (TMS) of the primary motor cortex and the measurement of motor evoked potentials (MEPs), we have previously demonstrated that corticospinal excitability is modulated by both amplitude and phase of the sensorimotor μ-alpha rhythm. However, the direction of this modulation, its proposed asymmetry, and its underlying mechanisms remained unclear. We therefore used real-time EEG-triggered single- and paired-pulse TMS in healthy humans of both sexes to assess corticospinal excitability and GABA-A-receptor mediated short-latency intracortical inhibition (SICI) at rest during spontaneous high amplitude μ-alpha waves at different phase angles (peaks, troughs, rising and falling flanks) and compared them to periods of low amplitude (desynchronized) μ-alpha. MEP amplitude was facilitated during troughs and rising flanks, but no phasic suppression was observed at any time, nor any modulation of SICI. These results are best compatible with sensorimotor μ-alpha reflecting asymmetric pulsed facilitation but not pulsed inhibition of motor cortical excitability. The asymmetric excitability with respect to rising and falling flanks of the μ-alpha cycle further reveals that voltage differences alone cannot explain the impact of phase. SIGNIFICANCE STATEMENT: The pulsed inhibition hypothesis, which assumes that alpha oscillations actively inhibit neuronal processing in a phasic manner, is highly influential and has substantially shaped our understanding of these oscillations. However, some of its basic assumptions, in particular its asymmetry and inhibitory nature, have rarely been tested directly. Here, we explicitly investigated the asymmetry of modulation and its direction for the human sensorimotor μ-alpha rhythm. We found clear evidence of pulsed facilitation, but not inhibition, in the human motor cortex, challenging the generalizability of the pulsed inhibition hypothesis and advising caution when interpreting sensorimotor μ-alpha changes in the sensorimotor system. This study also demonstrates how specific assumptions about the neurophysiological underpinnings of cortical oscillations can be experimentally tested noninvasively in humans.
    Keywords alpha oscillation ; motor cortex ; motor evoked potential (MEP) ; short-interval intracortical inhibition (SICI) ; real-time EEG-TMS ; transcranial magnetic stimulation (TMS)
    Language English
    Document type Article
    Database Repository for Life Sciences

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  3. Article ; Online: I-waves in motor cortex revisited.

    Ziemann, Ulf

    Experimental brain research

    2020  Volume 238, Issue 7-8, Page(s) 1601–1610

    Abstract: I-waves represent high-frequency (~ 600 Hz) repetitive discharge of corticospinal fibers elicited by single-pulse stimulation of motor cortex. First detected and examined in animal preparations, this multiple discharge can also be recorded in humans from ...

    Abstract I-waves represent high-frequency (~ 600 Hz) repetitive discharge of corticospinal fibers elicited by single-pulse stimulation of motor cortex. First detected and examined in animal preparations, this multiple discharge can also be recorded in humans from the corticospinal tract with epidural spinal electrodes. The exact underpinning neurophysiology of I-waves is still unclear, but there is converging evidence that they originate at the cortical level through synaptic input from specific excitatory interneuronal circuitries onto corticomotoneuronal cells, controlled by GABAAergic interneurons. In contrast, there is at present no supportive evidence for the alternative hypothesis that I-waves are generated by high-frequency oscillations of the membrane potential of corticomotoneuronal cells upon initial strong depolarization. Understanding I-wave physiology is essential for understanding how TMS activates the motor cortex.
    MeSH term(s) Animals ; Evoked Potentials, Motor ; Humans ; Interneurons ; Membrane Potentials ; Motor Cortex/physiology ; Pyramidal Tracts ; Transcranial Magnetic Stimulation
    Language English
    Publishing date 2020-03-17
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 1201-4
    ISSN 1432-1106 ; 0014-4819
    ISSN (online) 1432-1106
    ISSN 0014-4819
    DOI 10.1007/s00221-020-05764-4
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Closed-Loop Brain Stimulation.

    Zrenner, Christoph / Ziemann, Ulf

    Biological psychiatry

    2023  Volume 95, Issue 6, Page(s) 545–552

    Abstract: In the same way that beauty lies in the eye of the beholder, what a stimulus does to the brain is determined not simply by the nature of the stimulus but by the nature of the brain that is receiving the stimulus at that instant in time. Over the past ... ...

    Abstract In the same way that beauty lies in the eye of the beholder, what a stimulus does to the brain is determined not simply by the nature of the stimulus but by the nature of the brain that is receiving the stimulus at that instant in time. Over the past decades, therapeutic brain stimulation has typically applied open-loop fixed protocols and has largely ignored this principle. Only recent neurotechnological advancements have enabled us to predict the nature of the brain (i.e., the electrophysiological brain state in the next instance in time) with sufficient temporal precision in the range of milliseconds using feedforward algorithms applied to electroencephalography time-series data. This allows stimulation exclusively whenever the targeted brain area is in a prespecified excitability or connectivity state. Preclinical studies have shown that repetitive stimulation during a particular brain state (e.g., high-excitability state), but not during other states, results in lasting modification (e.g., long-term potentiation) of the stimulated circuits. Here, we survey the evidence that this is also possible at the systems level of the human cortex using electroencephalography-informed transcranial magnetic stimulation. We critically discuss opportunities and difficulties in developing brain state-dependent stimulation for more effective long-term modification of pathological brain networks (e.g., in major depressive disorder) than is achievable with conventional fixed protocols. The same real-time electroencephalography-informed transcranial magnetic stimulation technology will allow closing of the loop by recording the effects of stimulation. This information may enable stimulation protocol adaptation that maximizes treatment response. This way, brain states control brain stimulation, thereby introducing a paradigm shift from open-loop to closed-loop stimulation.
    MeSH term(s) Humans ; Depressive Disorder, Major ; Brain/physiology ; Transcranial Magnetic Stimulation/methods ; Electroencephalography ; Long-Term Potentiation
    Language English
    Publishing date 2023-09-22
    Publishing country United States
    Document type Journal Article ; Review
    ZDB-ID 209434-4
    ISSN 1873-2402 ; 0006-3223
    ISSN (online) 1873-2402
    ISSN 0006-3223
    DOI 10.1016/j.biopsych.2023.09.014
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Seventy years of our journal.

    Ziemann, Ulf

    Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology

    2019  Volume 130, Issue 12, Page(s) 2255–2257

    MeSH term(s) Anniversaries and Special Events ; History, 20th Century ; History, 21st Century ; Neurology ; Neurophysiology ; Periodicals as Topic/history
    Language English
    Publishing date 2019-11-05
    Publishing country Netherlands
    Document type Editorial ; Historical Article
    ZDB-ID 1463630-x
    ISSN 1872-8952 ; 0921-884X ; 1388-2457
    ISSN (online) 1872-8952
    ISSN 0921-884X ; 1388-2457
    DOI 10.1016/j.clinph.2019.10.006
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Book: Der kryptogene Schlaganfall - moderne medizinische Konzepte

    Ziemann, Ulf / Meyer-Zürn, Christine Stefanie / Poli, Sven

    (UNI-MED Science)

    2018  

    Author's details Prof. Dr. Ulf Ziemann unter Mitarbeit von Prof. Dr. Christine Meyer-Zürn, Dr. Sven Poli
    Series title UNI-MED Science
    Keywords Embolischer Schlaganfall ungeklärter Ursache
    Subject ESUS ; Embolischer Infarkt ohne klare Quelle ; Embolic stroke of unknown source ; Embolic stroke of undetermined source
    Language German
    Size 77 Seiten, Illustrationen
    Edition 1. Auflage
    Publisher UNI-MED Verlag AG
    Publishing place Bremen
    Publishing country Germany
    Document type Book
    HBZ-ID HT019792380
    ISBN 978-3-8374-1563-6 ; 3-8374-1563-5
    Database Catalogue ZB MED Medicine, Health

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  7. Article: Das Konzept der homöostatischen Plastizität verhindert eine Dosis-Wirkungs-Beziehung

    Ziemann, U.

    Neurologie & Rehabilitation

    2017  Volume 23, Issue 1, Page(s) 57

    Language German
    Document type Article
    ZDB-ID 1314800-x
    ISSN 0947-2177
    Database Current Contents Medicine

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  8. Article ; Online: More invited reviews in clinical neurophysiology.

    Jääskeläinen, Satu K / Ziemann, Ulf

    Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology

    2022  Volume 136, Page(s) 39

    MeSH term(s) Electroencephalography ; Humans ; Neurophysiology
    Language English
    Publishing date 2022-01-29
    Publishing country Netherlands
    Document type Editorial
    ZDB-ID 1463630-x
    ISSN 1872-8952 ; 0921-884X ; 1388-2457
    ISSN (online) 1872-8952
    ISSN 0921-884X ; 1388-2457
    DOI 10.1016/j.clinph.2022.01.124
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Reflecting the causes of variability of EEG responses elicited by cerebellar TMS.

    Gaßmann, Lukas / Gordon, Pedro Caldana / Ziemann, Ulf

    NeuroImage

    2023  Volume 281, Page(s) 120368

    Abstract: Recently, Fong et al. published EEG responses in cerebral cortex elicited by cerebellar TMS (cbTMS) (Fong et al., 2023), which differ from our recently identified cbTMS-EEG responses (Gassmann et al., 2022). Fong et al. argued that this discrepancy is ... ...

    Abstract Recently, Fong et al. published EEG responses in cerebral cortex elicited by cerebellar TMS (cbTMS) (Fong et al., 2023), which differ from our recently identified cbTMS-EEG responses (Gassmann et al., 2022). Fong et al. argued that this discrepancy is due to coil placement unsuitable for eliciting cerebellar brain inhibition (CBI) in our study. However, we reliably elicited CBI in our subjects. Consequently, this leads to a compelling discussion on possible reasons for the observed discrepancies in cbTMS-evoked EEG responses. Reliably measuring cbTMS-evoked EEG responses could become an important neurophysiological tool to test effective cerebellum-to-cortex connectivity.
    MeSH term(s) Humans ; Transcranial Magnetic Stimulation ; Cerebral Cortex/physiology ; Cerebellum/physiology ; Neurophysiology ; Electroencephalography ; Evoked Potentials, Motor/physiology
    Language English
    Publishing date 2023-09-09
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1147767-2
    ISSN 1095-9572 ; 1053-8119
    ISSN (online) 1095-9572
    ISSN 1053-8119
    DOI 10.1016/j.neuroimage.2023.120368
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: Thirty years of transcranial magnetic stimulation: where do we stand?

    Ziemann, Ulf

    Experimental brain research

    2017  Volume 235, Issue 4, Page(s) 973–984

    Abstract: Transcranial magnetic stimulation (TMS) has been first described 30 years ago, and since then has gained enormous attention by neurologists, psychiatrists, neurosurgeons, clinical neurophysiologists, psychologists, and neuroscientist alike. In the early ... ...

    Abstract Transcranial magnetic stimulation (TMS) has been first described 30 years ago, and since then has gained enormous attention by neurologists, psychiatrists, neurosurgeons, clinical neurophysiologists, psychologists, and neuroscientist alike. In the early days, it was primarily used to test integrity of the corticospinal tract. Beyond further developments of TMS in diagnostics, mapping and monitoring of the motor system, major other applications expanded into using TMS as research tool in the cognitive neurosciences, and as therapeutic tool in neurological and psychiatric disease by virtue of inducing long-term change in excitability and connectivity of the stimulated brain networks. This mini-review will highlight these developments by reviewing the 10 most frequently cited TMS publications. Despite the tremendous popularity and success of TMS as a non-invasive technique to stimulate the human brain, several aims remain unresolved. This review will end with highlighting those 10 most frequently cited papers that have been published in 2014-2016 to indicate the currently hottest topics in TMS research and major avenues of development.
    MeSH term(s) Brain/physiology ; Databases, Bibliographic/statistics & numerical data ; Evoked Potentials, Motor/physiology ; History, 20th Century ; History, 21st Century ; Humans ; Transcranial Magnetic Stimulation/history
    Language English
    Publishing date 2017-04
    Publishing country Germany
    Document type Historical Article ; Journal Article ; Review
    ZDB-ID 1201-4
    ISSN 1432-1106 ; 0014-4819
    ISSN (online) 1432-1106
    ISSN 0014-4819
    DOI 10.1007/s00221-016-4865-4
    Database MEDical Literature Analysis and Retrieval System OnLINE

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