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Michaelis R, Knake S, Rosenow F, Grönheit W, Hamer H, Schmitz B, Accarie A, Dedeken P, Immisch I, Habermehl L, Zöllner JP, Mann C, Wehner T, Wellmer J, Cuny J, Gollwitzer S, Losch F, Krämer K, Voss KS, Heinen G, Strzelczyk A. A multicenter randomized controlled feasibility trial of a digital self-management intervention for adults with epilepsy. Epilepsia Open 2024. [PMID: 38689518 DOI: 10.1002/epi4.12933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 03/07/2024] [Accepted: 03/07/2024] [Indexed: 05/02/2024] Open
Abstract
OBJECTIVE Self-management interventions may enhance health-related quality of life (HRQoL) in epilepsy. However, several barriers often impair their implementation in the real world. Digital interventions may help to overcome some of these barriers. Considering this, the Helpilepsy Plus Prototype was developed as a prototype smartphone-delivered self-care treatment program for adults with epilepsy. METHODS The 12-week Helpilepsy Plus Prototype was evaluated through a randomized controlled feasibility trial with a waiting-list control (WLC) group. Outcome measurement at baseline and at 12 weeks assessed adherence to the prototype intervention and changes in epilepsy-related outcomes. The primary endpoint was patient autonomy measured with EASE, and secondary endpoints included HRQoL measured with QOLIE-31, health literacy measured with HLQ, anxiety, and depression symptoms measured with HADS. Semi-structured interviews were conducted with a heterogeneous sample of participants to assess user-friendliness and usefulness. The prototype program was delivered through the Neuroventis Platform (Neuroventis, BV, Overijse, Belgium), a certified medical device (under EU/MDD Class I, and EU/MDR grace period). RESULTS Ninety-two patients were included (46 in the intervention group, 46 in WLC). Most participants (63%, 58/92 women, median age 30 years) had pharmacoresistant epilepsy (61%, 56/92). Only 22% of participants (10/46) in the intervention group completed at least half of all intervention sessions. No significant differences between the intervention group and WLC were observed. Although there was a larger proportion of patients in the intervention group with meaningful improvements in HRQoL compared to WLC (19/46 versus 11/46), the difference was not significant (p = 0.119). Qualitative feedback showed that participants would appreciate more personalization, such as adaptation of the content to their current epilepsy knowledge level, a more interactive interface, shorter text sections, and interaction through reminders and notifications. SIGNIFICANCE Digital interventions should allow sufficient scope for personalization and interaction to increase patient engagement and enable benefits from self-care apps. Feedback loops allow the participatory development of tailored interventions. PLAIN LANGUAGE SUMMARY In this study, we investigated the effectiveness of an app-based self-help intervention. Study participants were either randomly assigned to a group that had access to the app or a group that received access to the app after the end of the study. Although a larger proportion of participants in the intervention group showed a relevant improvement in quality of life, the difference between the two groups was not statistically significant. Less than one-fifth of participants in the intervention group attended at least half of all intervention sessions; patient feedback showed that patients required more personalization and interactive options.
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Affiliation(s)
- Rosa Michaelis
- Ruhr-Epileptology, Department of Neurology, University Hospital Knappschaftskrankenhaus Bochum, Ruhr University Bochum, Bochum, Germany
| | - Susanne Knake
- Department of Neurology, Epilepsy Center Hessen, University Hospital and Philipps-University Marburg, Marburg, Germany
| | - Felix Rosenow
- Department of Neurology, Epilepsy Center Frankfurt Rhine-Main, Center of Neurology and Neurosurgery, University Hospital and Goethe-University Frankfurt, Frankfurt, Germany
| | - Wenke Grönheit
- Ruhr-Epileptology, Department of Neurology, University Hospital Knappschaftskrankenhaus Bochum, Ruhr University Bochum, Bochum, Germany
| | - Hajo Hamer
- Epilepsy Center, Department of Neurology, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Bettina Schmitz
- Stroke Unit, and Center for Epilepsy, Department of Neurology, Vivantes Humboldt-Klinikum Berlin, Berlin, Germany
| | | | | | - Ilka Immisch
- Department of Neurology, Epilepsy Center Hessen, University Hospital and Philipps-University Marburg, Marburg, Germany
| | - Lena Habermehl
- Department of Neurology, Epilepsy Center Hessen, University Hospital and Philipps-University Marburg, Marburg, Germany
| | - Johann Philipp Zöllner
- Department of Neurology, Epilepsy Center Frankfurt Rhine-Main, Center of Neurology and Neurosurgery, University Hospital and Goethe-University Frankfurt, Frankfurt, Germany
| | - Catrin Mann
- Department of Neurology, Epilepsy Center Frankfurt Rhine-Main, Center of Neurology and Neurosurgery, University Hospital and Goethe-University Frankfurt, Frankfurt, Germany
| | - Tim Wehner
- Ruhr-Epileptology, Department of Neurology, University Hospital Knappschaftskrankenhaus Bochum, Ruhr University Bochum, Bochum, Germany
| | - Jörg Wellmer
- Ruhr-Epileptology, Department of Neurology, University Hospital Knappschaftskrankenhaus Bochum, Ruhr University Bochum, Bochum, Germany
| | - Jeanne Cuny
- Epilepsy Center, Department of Neurology, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Stephanie Gollwitzer
- Epilepsy Center, Department of Neurology, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Florian Losch
- Stroke Unit, and Center for Epilepsy, Department of Neurology, Vivantes Humboldt-Klinikum Berlin, Berlin, Germany
| | - Kirsten Krämer
- Stroke Unit, and Center for Epilepsy, Department of Neurology, Vivantes Humboldt-Klinikum Berlin, Berlin, Germany
| | | | | | - Adam Strzelczyk
- Department of Neurology, Epilepsy Center Frankfurt Rhine-Main, Center of Neurology and Neurosurgery, University Hospital and Goethe-University Frankfurt, Frankfurt, Germany
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Losch F, Liedtke S, Vautz W, Weigend M. Evaluation of floral volatile patterns in the genus Narcissus using gas chromatography-coupled ion mobility spectrometry. Appl Plant Sci 2023; 11:e11506. [PMID: 36818782 PMCID: PMC9934524 DOI: 10.1002/aps3.11506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 10/19/2022] [Accepted: 10/20/2022] [Indexed: 06/18/2023]
Abstract
PREMISE Daffodils (Narcissus, Amaryllidaceae) are iconic ornamentals with a complex floral biology and many fragrant species; however, little is known about floral plant volatile organic compounds (pVOCs) across the genus and additional sampling is desirable. The present study investigates whether the floral scent of 20 species of Narcissus can be characterized using gas chromatography-coupled ion mobility spectrometry (GC-IMS), with the aim of building a comparative pVOC data set for ecological and evolutionary studies. METHODS We used a commercial GC-IMS equipped with an integrated in-line enrichment system for a fast, sensitive, and automated pVOC analysis. This facilitates qualitative and (semi)-quantitative measurements without sample preparation. RESULTS The GC-IMS provided detailed data on floral pVOCs in Narcissus with very short sampling times and without floral enclosure. A wide range of compounds was recorded and partially identified. The retrieved pVOC patterns showed a good agreement with published data, and five "chemotypes" were characterized as characteristic combinations of floral volatiles. DISCUSSION The GC-IMS setup can be applied to rapidly generate large amounts of pVOC data with high sensitivity and selectivity. The preliminary data on Narcissus obtained here indicate both considerable pVOC variability and a good correspondence of the pVOC patterns with infrageneric classification, supporting the hypothesis that floral scent could represent a considerable phylogenetic signal.
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Affiliation(s)
- Florian Losch
- Nees‐Institut für Biodiversität der Pflanzen, Mathematisch‐Naturwissenschaftliche FakultätRheinische Friedrich‐Wilhelmsuniversität Bonn53115BonnGermany
| | - Sascha Liedtke
- ION‐GAS GmbHKonrad‐Adenauer‐Allee 1144263DortmundGermany
| | - Wolfgang Vautz
- ION‐GAS GmbHKonrad‐Adenauer‐Allee 1144263DortmundGermany
- Leibniz‐Institut für Analytische Wissenschaften – ISAS – e.V.Bunsen‐Kirchhoff‐Straße 1144139DortmundGermany
| | - Maximilian Weigend
- Nees‐Institut für Biodiversität der Pflanzen, Mathematisch‐Naturwissenschaftliche FakultätRheinische Friedrich‐Wilhelmsuniversität Bonn53115BonnGermany
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Škopić MK, Losch F, McMillan AE, Willeke N, Malenica M, Bering L, Bode J, Brunschweiger A. Reagent-Based Scaffold Diversity for DNA-Encoded Library Design: Solid Phase Synthesis of DNA-Tagged sp 3-Rich Heterocycles by SnAP Chemistry. Org Lett 2022; 24:1383-1387. [PMID: 35113572 DOI: 10.1021/acs.orglett.2c00228] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Reactions that require strictly dry conditions are challenging to translate to a DNA-encoded library format. Controlled pore glass solid support-connected DNA oligonucleotide-aldehyde conjugates could be condensed with SnAP reagents and cyclized to various sp3-rich heterocycles. The Boc-group of products provided a handle for product purification, and its facile removal under acidic conditions was tolerated by a chemically stabilized barcode. The reaction provides reagent-based scaffold diversity with functionalities for further library synthesis.
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Affiliation(s)
- Mateja Klika Škopić
- TU Dortmund University, Faculty of Chemistry and Chemical Biology, Medicinal Chemistry, Otto-Hahn-Str. 6, 44227 Dortmund, Germany
| | - Florian Losch
- TU Dortmund University, Faculty of Chemistry and Chemical Biology, Medicinal Chemistry, Otto-Hahn-Str. 6, 44227 Dortmund, Germany
| | - Angus E McMillan
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
| | - Niklas Willeke
- TU Dortmund University, Faculty of Chemistry and Chemical Biology, Medicinal Chemistry, Otto-Hahn-Str. 6, 44227 Dortmund, Germany
| | - Mateo Malenica
- TU Dortmund University, Faculty of Chemistry and Chemical Biology, Medicinal Chemistry, Otto-Hahn-Str. 6, 44227 Dortmund, Germany
| | - Luis Bering
- TU Dortmund University, Faculty of Chemistry and Chemical Biology, Medicinal Chemistry, Otto-Hahn-Str. 6, 44227 Dortmund, Germany
| | - Jeffrey Bode
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
| | - Andreas Brunschweiger
- TU Dortmund University, Faculty of Chemistry and Chemical Biology, Medicinal Chemistry, Otto-Hahn-Str. 6, 44227 Dortmund, Germany
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Weissinger F, Losch F, Winter Y, Brecht S, Lendemans D, Kockelmann E. Effectiveness of eslicarbazepine acetate in dependency of baseline anticonvulsant therapy: Results from a German prospective multicenter clinical practice study. Epilepsy Behav 2019; 101:106574. [PMID: 31678808 DOI: 10.1016/j.yebeh.2019.106574] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 08/23/2019] [Accepted: 09/14/2019] [Indexed: 11/25/2022]
Abstract
Eslicarbazepine acetate (ESL) is a third-generation antiepileptic drug (AED) approved as monotherapy for partial-onset seizures in adults and as adjunctive therapy in patients aged above 6 years in the European Union (EU). The prospective observational Zebinix Effects in DEpendency of BAseline Conditions (ZEDEBAC) study aimed at investigating the effectiveness of ESL in clinical practice, with ESL being administered as monotherapy (mono group), as only add-on to a current monotherapy (1+ group), or as add-on to ≥2 baseline AEDs (≥2+ group). In total, 237 patients were included, 35 in the mono group, 114 in the 1+, and 88 in the ≥2+ group. Six-month retention rates were 93.9%, 78.0%, and 75.3% in the mono, 1+, and ≥2+ group. There were 90.5%, 77.6%, and 48.3% of patients in the mono, 1+, and ≥2+ groups who were responders (patients with a ≥50% reduction in seizure frequency at follow-up vs. baseline). Seizure freedom rates were 81.5%, 47.9%, and 23.4%, respectively. Adverse drug reactions (ADRs) occurred in 11.4% of patients of the mono, 19.3% of the 1+, and 28.4% of patients of the ≥2+ group. Hyponatremia was reported as ADR in 3.4% of all patients. Although baseline variables differed considerably, with most elderly patients with tumor-related and vascular etiologies in the mono group and most patients with refractory epilepsies with pronounced use of concomitant sodium channel blockers (SCBs) in the ≥2+ group, retention as a measure of real-life effectiveness turned out not to be substantially different and favorable in all groups.
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Affiliation(s)
- Florian Weissinger
- Epilepsy Centre, Department of Neurology, Vivantes Humboldt Hospital, Am Nordgraben 2, 13509 Berlin, Germany; Department of Neurology, Charité University Hospital, Charitéplatz 1, 10117 Berlin, Germany
| | - Florian Losch
- Epilepsy Centre, Department of Neurology, Vivantes Humboldt Hospital, Am Nordgraben 2, 13509 Berlin, Germany
| | - Yaroslav Winter
- Mainz Comprehensive Epilepsy Center, Department of Neurology, Johannes Gutenberg-University, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Silvia Brecht
- Eisai GmbH, Lyoner Str. 36, 60528 Frankfurt, Germany.
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Potowski M, Losch F, Wünnemann E, Dahmen JK, Chines S, Brunschweiger A. Screening of metal ions and organocatalysts on solid support-coupled DNA oligonucleotides guides design of DNA-encoded reactions. Chem Sci 2019; 10:10481-10492. [PMID: 32055372 PMCID: PMC7003951 DOI: 10.1039/c9sc04708e] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 10/17/2019] [Indexed: 12/27/2022] Open
Abstract
DNA-encoded compound libraries are widely used in drug discovery. Screening of catalysts for compatibility with solid phase-coupled DNA sequences guided the selection of encoded reactions, exemplified by a Zn(II)-mediated aza-Diels–Alder reaction.
DNA-encoded compound libraries are a widely used technology for target-based small molecule screening. Generally, these libraries are synthesized by solution phase combinatorial chemistry requiring aqueous solvent mixtures and reactions that are orthogonal to DNA reactivity. Initiating library synthesis with readily available controlled pore glass-coupled DNA barcodes benefits from enhanced DNA stability due to nucleobase protection and choice of dry organic solvents for encoded compound synthesis. We screened the compatibility of solid-phase coupled DNA sequences with 53 metal salts and organic reagents. This screening experiment suggests design of encoded library synthesis. Here, we show the reaction optimization and scope of three sp3-bond containing heterocyclic scaffolds synthesized on controlled pore glass-connected DNA sequences. A ZnCl2-promoted aza-Diels–Alder reaction with Danishefsky's diene furnished diverse substituted DNA-tagged pyridones, and a phosphoric acid organocatalyst allowed for synthesis of tetrahydroquinolines by the Povarov reaction and pyrimidinones by the Biginelli reaction, respectively. These three reactions caused low levels of DNA depurination and cover broad and only partially overlapping chemical space though using one set of DNA-coupled starting materials.
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Affiliation(s)
- Marco Potowski
- Department of Chemistry and Chemical Biology , TU Dortmund University , Otto-Hahn-Str. 6 , 44227 Dortmund , Germany .
| | - Florian Losch
- Department of Chemistry and Chemical Biology , TU Dortmund University , Otto-Hahn-Str. 6 , 44227 Dortmund , Germany .
| | - Elena Wünnemann
- Department of Chemistry and Chemical Biology , TU Dortmund University , Otto-Hahn-Str. 6 , 44227 Dortmund , Germany .
| | - Janina K Dahmen
- Department of Chemistry and Chemical Biology , TU Dortmund University , Otto-Hahn-Str. 6 , 44227 Dortmund , Germany .
| | - Silvia Chines
- Department of Chemistry and Chemical Biology , TU Dortmund University , Otto-Hahn-Str. 6 , 44227 Dortmund , Germany .
| | - Andreas Brunschweiger
- Department of Chemistry and Chemical Biology , TU Dortmund University , Otto-Hahn-Str. 6 , 44227 Dortmund , Germany .
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Potowski M, Kunig VBK, Losch F, Brunschweiger A. Synthesis of DNA-coupled isoquinolones and pyrrolidines by solid phase ytterbium- and silver-mediated imine chemistry. Medchemcomm 2019; 10:1082-1093. [PMID: 31391880 PMCID: PMC6644566 DOI: 10.1039/c9md00042a] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 02/21/2019] [Indexed: 12/16/2022]
Abstract
DNA-encoded libraries of chemically synthesized compounds are an important small molecule screening technology. The synthesis of encoded compounds in solution is currently restricted to a few DNA-compatible and water-tolerant reactions. Encoded compound synthesis of short DNA-barcodes covalently connected to solid supports benefits from a broad range of choices of organic solvents. Here, we show that this encoded chemistry approach allows for the synthesis of DNA-coupled isoquinolones by an Yb(iii)-mediated Castagnoli-Cushman reaction under anhydrous reaction conditions and for the synthesis of highly substituted pyrrolidines by Ag(i)-mediated 1,3-dipolar azomethine ylide cycloaddition. An encoding scheme for these DNA-barcoded compounds based on a DNA hairpin is demonstrated.
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Affiliation(s)
- Marco Potowski
- Department of Chemistry and Chemical Biology , TU Dortmund University , Otto-Hahn-Str. 6 , 44227 Dortmund , Germany .
| | - Verena B K Kunig
- Department of Chemistry and Chemical Biology , TU Dortmund University , Otto-Hahn-Str. 6 , 44227 Dortmund , Germany .
| | - Florian Losch
- Department of Chemistry and Chemical Biology , TU Dortmund University , Otto-Hahn-Str. 6 , 44227 Dortmund , Germany .
| | - Andreas Brunschweiger
- Department of Chemistry and Chemical Biology , TU Dortmund University , Otto-Hahn-Str. 6 , 44227 Dortmund , Germany .
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Kowski AB, Weissinger F, Gaus V, Fidzinski P, Losch F, Holtkamp M. Specific adverse effects of antiepileptic drugs--A true-to-life monotherapy study. Epilepsy Behav 2016; 54:150-7. [PMID: 26709103 DOI: 10.1016/j.yebeh.2015.11.009] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 10/20/2015] [Accepted: 11/08/2015] [Indexed: 11/17/2022]
Abstract
BACKGROUND In patients taking antiepileptic drugs (AEDs) for epilepsy, adverse effects (AEs) often lead to unfavorable quality of life, impaired adherence, and, eventually, discontinuation of pharmacological treatment. In a true-to-life sample of subjects from our academic epilepsy outpatient clinic, we aimed to identify predictors for overall high AE burden and for specific AEs focusing on patients on monotherapy. METHODS All patients ≥16years of age with epilepsy for ≥12months were routinely asked to complete the Liverpool Adverse Event Profile (LAEP) just before their appointment. Demographic, epilepsy, and treatment variables were derived from our comprehensive outpatient database. RESULTS Out of 841 patients, 438 (61% female, mean age: 44.7±17.1years) on monotherapy were included in this study. Levetiracetam (n=151), lamotrigine (n=167), valproic acid (n=73), or controlled-release carbamazepine (n=47) were the most commonly used antiepileptic drugs (AEDs). Independent predictors for general high AE burden (LAEP score≥45) were duration of epilepsy, lack of 12-month seizure freedom, and partial epilepsy, but none of the four individual AEDs. The most frequent LAEP-defined specific AEs were sleepiness, difficulty concentrating, tiredness, and memory problems. The three most frequent independent predictors for each of the 19 AEs were lack of 12-month seizure freedom (13/19 AEs), individual AED (7/19 AEs), and partial epilepsy (6/19 AEs). Levetiracetam was independently associated with anger/aggression, nervousness/agitation, upset stomach, depression, and sleep disturbance; lamotrigine with nervousness/agitation, upset stomach, and difficulty concentrating; and valproic acid with upset stomach and shaky hands. CONCLUSION Individual AEDs independently predicted some specific AEs, but not overall high AE burden. Our findings may help to characterize patients with epilepsy who are at high risk for specific AEs. Dose reduction or change to another AED may reduce LAEP score and potential nonadherence.
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Affiliation(s)
- Alexander B Kowski
- Epilepsy-Center Berlin-Brandenburg, Department of Neurology, Charité - Universitätsmedizin Berlin, Germany.
| | - Florian Weissinger
- Epilepsy-Center Berlin-Brandenburg, Department of Neurology, Charité - Universitätsmedizin Berlin, Germany
| | - Verena Gaus
- Epilepsy-Center Berlin-Brandenburg, Department of Neurology, Charité - Universitätsmedizin Berlin, Germany
| | - Pawel Fidzinski
- Epilepsy-Center Berlin-Brandenburg, Department of Neurology, Charité - Universitätsmedizin Berlin, Germany
| | - Florian Losch
- Epilepsy-Center Berlin-Brandenburg, Department of Neurology, Charité - Universitätsmedizin Berlin, Germany
| | - Martin Holtkamp
- Epilepsy-Center Berlin-Brandenburg, Department of Neurology, Charité - Universitätsmedizin Berlin, Germany
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Carlowitz-Ghori KV, Bayraktaroglu Z, Hohlefeld F, Losch F, Curio G, Nikulin V. Corticomuscular coherence in acute and chronic stroke. KLIN NEUROPHYSIOL 2014. [DOI: 10.1055/s-0034-1371233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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von Carlowitz-Ghori K, Bayraktaroglu Z, Hohlefeld FU, Losch F, Curio G, Nikulin VV. Corticomuscular coherence in acute and chronic stroke. Clin Neurophysiol 2013; 125:1182-91. [PMID: 24315544 DOI: 10.1016/j.clinph.2013.11.006] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 10/23/2013] [Accepted: 11/05/2013] [Indexed: 01/25/2023]
Abstract
OBJECTIVE Motor recovery after stroke is attributed to neuronal plasticity, however not all post-stroke neuronal changes relate to regaining fine motor control. Corticomuscular coherence (CMC) is a measure allowing to trace neuronal reorganizations which are functionally relevant for motor recovery. Contrary to previous studies which were performed only in chronic stage, we measured CMC in patients with stroke at both acute and chronic stroke stages. METHODS For the detection of CMC we used multichannel EEG and EMG recordings along with an optimization algorithm for the detection of corticomuscular interactions. RESULTS In acute stroke, the CMC amplitude was larger on the unaffected side compared to the affected side and also larger compared to the unaffected side in the chronic period. Additionally, CMC peak frequencies on both sides decreased in the acute compared to the chronic period and to control subjects. In chronic stage, there were no inter-hemispheric or group differences in CMC amplitude or frequency. CONCLUSIONS The changes in CMC parameters in acute stroke could result from a temporary decrease in inhibition, which normalizes in the course of recovery. As all patients showed very good motor recovery, the modulation of CMC amplitude and frequency over time might thus reflect the process of motor recovery. SIGNIFICANCE We demonstrate for the first time the dynamical changes of corticomuscular interaction both at acute and chronic stage of stroke.
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Affiliation(s)
- Katherina von Carlowitz-Ghori
- Neurophysics Group, Department of Neurology, Charité - University Medicine Berlin, Germany; Institute of Science and Ethics, University of Bonn, Germany; Department of Software Engineering and Theoretical Computer Science, Berlin Institute of Technology, Berlin, Germany
| | - Zubeyir Bayraktaroglu
- Neurophysics Group, Department of Neurology, Charité - University Medicine Berlin, Germany; Center for Stroke Research Berlin, Charité - University Medicine Berlin, Germany
| | - Friederike U Hohlefeld
- Neurophysics Group, Department of Neurology, Charité - University Medicine Berlin, Germany
| | - Florian Losch
- Neurophysics Group, Department of Neurology, Charité - University Medicine Berlin, Germany
| | - Gabriel Curio
- Neurophysics Group, Department of Neurology, Charité - University Medicine Berlin, Germany; Center for Stroke Research Berlin, Charité - University Medicine Berlin, Germany; Bernstein Center for Computational Neuroscience, Berlin, Germany
| | - Vadim V Nikulin
- Neurophysics Group, Department of Neurology, Charité - University Medicine Berlin, Germany; Center for Stroke Research Berlin, Charité - University Medicine Berlin, Germany; Bernstein Center for Computational Neuroscience, Berlin, Germany.
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Bayraktaroglu Z, Carlowitz-Ghori KV, Losch F, Nolte G, Curio G, Nikulin V. Rectification of surface EMG impairs cortico-muscular coherence estimation. KLIN NEUROPHYSIOL 2011. [DOI: 10.1055/s-0031-1272809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Gross S, Geldmacher A, Sharav T, Losch F, Walden P. Immunosuppressive mechanisms in cancer: consequences for the development of therapeutic vaccines. Vaccine 2009; 27:3398-400. [PMID: 19200836 DOI: 10.1016/j.vaccine.2009.01.070] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Recent investigations revealed strong immunosuppressive mechanisms in tumors that may block anti-tumor T cells and be responsible for failures of immunotherapies. Current attempts to overcome this immunosuppression include blockade of co-inhibitory factors on T cells. Reports from the respective trials indicate that the strategy can improve efficacy of therapeutic vaccination, but at the cost of severe inflammatory and autoimmune reactions. We tried to circumvent tumor-associated immunosuppression by mimotope vaccination to broaden reactive anti-tumor T cell repertoires to include T cells that have not been rendered anergic by the tumor. Initial clinical observations suggest that this strategy bears considerable promise.
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Affiliation(s)
- Stefanie Gross
- Department of Dermatology, Charité - Universitätsmedizin Berlin, Humboldt University, Germany
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Blankertz B, Losch F, Krauledat M, Dornhege G, Curio G, Müller KR. The Berlin Brain-Computer Interface: Accurate performance from first-session in BCI-naive subjects. IEEE Trans Biomed Eng 2008; 55:2452-62. [PMID: 18838371 DOI: 10.1109/tbme.2008.923152] [Citation(s) in RCA: 173] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Benjamin Blankertz
- Machine Learning Laboratory, Technical University of Berlin, Berlin, Germany.
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Krauledat M, Dornhege G, Blankertz B, Losch F, Curio G, Müller KR. Improving speed and accuracy of brain-computer interfaces using readiness potential features. Conf Proc IEEE Eng Med Biol Soc 2007; 2004:4511-5. [PMID: 17271309 DOI: 10.1109/iembs.2004.1404253] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
To enhance human interaction with machines, research interest is growing to develop a 'brain-computer interface', which allows communication of a human with a machine only by use of brain signals. So far, the applicability of such an interface is strongly limited by low bit-transfer rates, slow response times and long training sessions for the subject. The Berlin Brain-Computer Interface (BBCI) project is guided by the idea to train a computer by advanced machine learning techniques both to improve classification performance and to reduce the need of subject training. In this paper we present two directions in which brain-computer interfacing can be enhanced by exploiting the lateralized readiness potential: (1) for establishing a rapid response BCI system that can predict the laterality of upcoming finger movements before EMG onset even in time critical contexts, and (2) to improve information transfer rates in the common BCI approach relying on imagined limb movements.
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Losch F, Blankertz B, Krauledat M, Dornhege G, Curio G, Müller KR. Präzise Leistungen ab dem ersten Versuch: Das Berliner Brain-Computer-Interface. KLIN NEUROPHYSIOL 2007. [DOI: 10.1055/s-2007-976419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Losch F, Blankertz B, Müller KR, Curio G. „Aus Fehlern lernen“ – eine Meta-Analyse der Falschklassifikationen von Fingerbewegungen durch EEG-basierte nicht-invasive Brain-Computer-Interfaces. Akt Neurol 2007. [DOI: 10.1055/s-2007-987474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Dornhege G, Blankertz B, Krauledat M, Losch F, Curio G, Müller KR. Combined Optimization of Spatial and Temporal Filters for Improving Brain-Computer Interfacing. IEEE Trans Biomed Eng 2006; 53:2274-81. [PMID: 17073333 DOI: 10.1109/tbme.2006.883649] [Citation(s) in RCA: 278] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Brain-computer interface (BCI) systems create a novel communication channel from the brain to an output device by bypassing conventional motor output pathways of nerves and muscles. Therefore they could provide a new communication and control option for paralyzed patients. Modern BCI technology is essentially based on techniques for the classification of single-trial brain signals. Here we present a novel technique that allows the simultaneous optimization of a spatial and a spectral filter enhancing discriminability rates of multichannel EEG single-trials. The evaluation of 60 experiments involving 22 different subjects demonstrates the significant superiority of the proposed algorithm over to its classical counterpart: the median classification error rate was decreased by 11%. Apart from the enhanced classification, the spatial and/or the spectral filter that are determined by the algorithm can also be used for further analysis of the data, e.g., for source localization of the respective brain rhythms.
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Affiliation(s)
- Guido Dornhege
- Fraunhofer FIRST.IDA, Kekuléstr. 7, 12 489 Berlin, Germany.
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Blankertz B, Dornhege G, Krauledat M, Müller KR, Kunzmann V, Losch F, Curio G. The Berlin brain-computer interface: EEG-based communication without subject training. IEEE Trans Neural Syst Rehabil Eng 2006; 14:147-52. [PMID: 16792281 DOI: 10.1109/tnsre.2006.875557] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The Berlin Brain-Computer Interface (BBCI) project develops a noninvasive BCI system whose key features are 1) the use of well-established motor competences as control paradigms, 2) high-dimensional features from 128-channel electroencephalogram (EEG), and 3) advanced machine learning techniques. As reported earlier, our experiments demonstrate that very high information transfer rates can be achieved using the readiness potential (RP) when predicting the laterality of upcoming left- versus right-hand movements in healthy subjects. A more recent study showed that the RP similarily accompanies phantom movements in arm amputees, but the signal strength decreases with longer loss of the limb. In a complementary approach, oscillatory features are used to discriminate imagined movements (left hand versus right hand versus foot). In a recent feedback study with six healthy subjects with no or very little experience with BCI control, three subjects achieved an information transfer rate above 35 bits per minute (bpm), and further two subjects above 24 and 15 bpm, while one subject could not achieve any BCI control. These results are encouraging for an EEG-based BCI system in untrained subjects that is independent of peripheral nervous system activity and does not rely on evoked potentials even when compared to results with very well-trained subjects operating other BCI systems.
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Chakarov V, Hummel S, Losch F, Schulte-Mönting J, Kristeva R. Handwriting performance in the absence of visual control in writer's cramp patients: initial observations. BMC Neurol 2006; 6:14. [PMID: 16594993 PMCID: PMC1456986 DOI: 10.1186/1471-2377-6-14] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2005] [Accepted: 04/04/2006] [Indexed: 11/26/2022] Open
Abstract
Background The present study was aimed at investigating the writing parameters of writer's cramp patients and control subjects during handwriting of a test sentence in the absence of visual control. Methods Eight right-handed patients with writer's cramp and eight healthy volunteers as age-matched control subjects participated in the study. The experimental task consisted in writing a test sentence repeatedly for fifty times on a pressure-sensitive digital board. The subject did not have visual control on his handwriting. The writing performance was stored on a PC and analyzed off-line. Results During handwriting all patients developed a typical dystonic limb posture and reported an increase in muscular tension along the experimental session. The patients were significantly slower than the controls, with lower mean vertical pressure of the pen tip on the paper and they could not reach the endmost letter of the sentence in the given time window. No other handwriting parameter differences were found between the two groups. Conclusion Our findings indicate that during writing in the absence of visual feedback writer's cramp patients are slower and could not reach the endmost letter of the test sentence, but their level of automatization is not impaired and writer's cramp handwriting parameters are similar to those of the controls except for even lower vertical pressure of the pen tip on the paper, which is probably due to a changed strategy in such experimental conditions.
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Affiliation(s)
- Vihren Chakarov
- Neurological Clinic, University Freiburg, Breisacherstraße 64, 79106 Freiburg, Germany
- Center of Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Sibylla Hummel
- Neurological Clinic, University Freiburg, Breisacherstraße 64, 79106 Freiburg, Germany
| | - Florian Losch
- Neurological Clinic, University Freiburg, Breisacherstraße 64, 79106 Freiburg, Germany
- Universitätsklinikum Benjamin Franklin, Berlin, Germany
| | | | - Rumyana Kristeva
- Neurological Clinic, University Freiburg, Breisacherstraße 64, 79106 Freiburg, Germany
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Losch F, Blankertz B, Krauledat M, Müller K, Curio G. Brain state differences between calibration and application periods influence BCI classification accuracy. Akt Neurol 2006. [DOI: 10.1055/s-2006-953100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Kristeva R, Chakarov V, Losch F, Hummel S, Popa T, Schulte-Mönting J. Electroencephalographic spectral power in writer's cramp patients: evidence for motor cortex malfunctioning during the cramp. Neuroimage 2005; 27:706-14. [PMID: 16027007 DOI: 10.1016/j.neuroimage.2005.05.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2004] [Revised: 04/07/2005] [Accepted: 05/09/2005] [Indexed: 11/21/2022] Open
Abstract
We investigated cortical activation as reflected in task-related spectral power (TRPow) changes in 8 writer's cramp patients during writing on a digital board and during isometric contraction and compared them to those of 8 age-matched healthy subjects. Scalp EEG was recorded over the contralateral primary sensorimotor area (SM1(c)), and from the ipsilateral sensorimotor area (SM1(i)). The electromyogram (EMG) was recorded from the Extensor Digitorum Communis (Extensor), Flexor Digitorum Superficialis (Flexor), and First Dorsal Interosseous (FDI) muscles. We analyzed (1) handwriting performance, (2) changes in the TRPow confined to alpha and beta band, and (3) the EMG spectral power during both tasks, writing and isometric contraction. During writing, all patients developed writer's cramp. The handwriting in writer's cramp patients was associated with significantly less reduction of the beta-range TRPow and lower frequency of the TRPow reduction compared to controls. No significant differences between patients and controls for the alpha band TRPow reduction during handwriting were observed. During writing, the patients showed higher EMG spectral power than the controls but this difference was at the border of significance. The present results indicate disorder in the motor execution system, in writer's cramp patients, associated with impaired functional beta-network state of the contra- and ipsilateral sensorimotor cortices, most probably due to inadequate modulation of the intracortical inhibition associated with writing.
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Affiliation(s)
- Rumyana Kristeva
- Neurological Clinic, Albert-Ludwigs-University, Breisacher Strasse 64, 79106 Freiburg, Germany.
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Losch F, Blankertz B, Müller KR, Curio G. The Influence of Preceding Movements on Motor Cortical Activity in Finger-Tapping. KLIN NEUROPHYSIOL 2004. [DOI: 10.1055/s-2004-832081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Losch F, Blankertz B, Müller K, Curio G. Lateralisiertes Bereitschaftspotenzial und Ereignis-korrelierte Desynchronisation perizentraler my/beta-Rhythmen bei rasch repetierten Fingerbewegungen im Kontext des Berlin Brain-Computer Interface (BBCI). KLIN NEUROPHYSIOL 2003. [DOI: 10.1055/s-2003-816484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Blankertz B, Dornhege G, Schäfer C, Krepki R, Kohlmorgen J, Müller KR, Kunzmann V, Losch F, Curio G. Boosting bit rates and error detection for the classification of fast-paced motor commands based on single-trial EEG analysis. IEEE Trans Neural Syst Rehabil Eng 2003; 11:127-31. [PMID: 12899253 DOI: 10.1109/tnsre.2003.814456] [Citation(s) in RCA: 159] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Brain-computer interfaces (BCIs) involve two coupled adapting systems--the human subject and the computer. In developing our BCI, our goal was to minimize the need for subject training and to impose the major learning load on the computer. To this end, we use behavioral paradigms that exploit single-trial EEG potentials preceding voluntary finger movements. Here, we report recent results on the basic physiology of such premovement event-related potentials (ERP). 1) We predict the laterality of imminent left- versus right-hand finger movements in a natural keyboard typing condition and demonstrate that a single-trial classification based on the lateralized Bereitschaftspotential (BP) achieves good accuracies even at a pace as fast as 2 taps/s. Results for four out of eight subjects reached a peak information transfer rate of more than 15 b/min; the four other subjects reached 6-10 b/min. 2) We detect cerebral error potentials from single false-response trials in a forced-choice task, reflecting the subject's recognition of an erroneous response. Based on a specifically tailored classification procedure that limits the rate of false positives at, e.g., 2%, the algorithm manages to detect 85% of error trials in seven out of eight subjects. Thus, concatenating a primary single-trial BP-paradigm involving finger classification feedback with such secondary error detection could serve as an efficient online confirmation/correction tool for improvement of bit rates in a future BCI setting. As the present variant of the Berlin BCI is designed to achieve fast classifications in normally behaving subjects, it opens a new perspective for assistance of action control in time-critical behavioral contexts; the potential transfer to paralyzed patients will require further study.
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Klostermann F, Nolte G, Losch F, Curio G. Differential recruitment of high frequency wavelets (600 Hz) and primary cortical response (N20) in human median nerve somatosensory evoked potentials. Neurosci Lett 1998; 256:101-4. [PMID: 9853713 DOI: 10.1016/s0304-3940(98)00773-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Human median nerve somatosensory evoked potentials contain a burst of high-frequency (600 Hz) wavelets superimposed on the primary cortical response (N20). These presumably reflect highly-synchronized repetitive thalamic and/or intracortical population spike bursts and are diminished in non-REM sleep with N20 persisting. Here the burst/N20 relation in awake subjects was examined by using eight different intensities of electric median nerve stimuli. In all subjects the amplitude recruitment of both N20 and burst could be modeled adequately as a sigmoidal function of stimulus intensity. While 8/10 subjects showed a parallel recruitment, 2/10 subjects required significantly higher stimulation intensities for burst than for N20 recruitment. This dampened burst recruitment possibly reflects slight vigilance fluctuations in open-eyed awake subjects; a further increase of burst thresholds could explain the burst attenuation when entering shallow sleep.
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Affiliation(s)
- F Klostermann
- Department of Neurology, Klinikum Benjamin Franklin, Freie Universität, Berlin, Germany.
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