1
|
Ligneul C, Najac C, Döring A, Beaulieu C, Branzoli F, Clarke WT, Cudalbu C, Genovese G, Jbabdi S, Jelescu I, Karampinos D, Kreis R, Lundell H, Marjańska M, Möller HE, Mosso J, Mougel E, Posse S, Ruschke S, Simsek K, Szczepankiewicz F, Tal A, Tax C, Oeltzschner G, Palombo M, Ronen I, Valette J. Diffusion-weighted MR spectroscopy: Consensus, recommendations, and resources from acquisition to modeling. Magn Reson Med 2024; 91:860-885. [PMID: 37946584 DOI: 10.1002/mrm.29877] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 07/18/2023] [Accepted: 09/08/2023] [Indexed: 11/12/2023]
Abstract
Brain cell structure and function reflect neurodevelopment, plasticity, and aging; and changes can help flag pathological processes such as neurodegeneration and neuroinflammation. Accurate and quantitative methods to noninvasively disentangle cellular structural features are needed and are a substantial focus of brain research. Diffusion-weighted MRS (dMRS) gives access to diffusion properties of endogenous intracellular brain metabolites that are preferentially located inside specific brain cell populations. Despite its great potential, dMRS remains a challenging technique on all levels: from the data acquisition to the analysis, quantification, modeling, and interpretation of results. These challenges were the motivation behind the organization of the Lorentz Center workshop on "Best Practices & Tools for Diffusion MR Spectroscopy" held in Leiden, the Netherlands, in September 2021. During the workshop, the dMRS community established a set of recommendations to execute robust dMRS studies. This paper provides a description of the steps needed for acquiring, processing, fitting, and modeling dMRS data, and provides links to useful resources.
Collapse
Affiliation(s)
- Clémence Ligneul
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Chloé Najac
- C.J. Gorter MRI Center, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - André Döring
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, UK
- CIBM Center for Biomedical Imaging, Lausanne, Switzerland
| | - Christian Beaulieu
- Departments of Biomedical Engineering and Radiology, University of Alberta, Alberta, Edmonton, Canada
| | - Francesca Branzoli
- Paris Brain Institute-ICM, Sorbonne University, UMR S 1127, Inserm U 1127, CNRS UMR 7225, Paris, France
| | - William T Clarke
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Cristina Cudalbu
- CIBM Center for Biomedical Imaging, Lausanne, Switzerland
- Animal Imaging and Technology, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Guglielmo Genovese
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minnesota, Minneapolis, USA
| | - Saad Jbabdi
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Ileana Jelescu
- Department of Radiology, Lausanne University Hospital, Lausanne, Switzerland
- Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Dimitrios Karampinos
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany
| | - Roland Kreis
- MR Methodology, Department for Diagnostic and Interventional Neuroradiology, University of Bern, Bern, Switzerland
- Translational Imaging Center (TIC), Swiss Institute for Translational and Entrepreneurial Medicine, Bern, Switzerland
| | - Henrik Lundell
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital-Amager anf Hvidovre, Hvidovre, Denmark
- Department of Health Technology, Technical University of Denmark, Lyngby, Denmark
| | - Małgorzata Marjańska
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minnesota, Minneapolis, USA
| | - Harald E Möller
- NMR Methods & Development Group, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Jessie Mosso
- CIBM Center for Biomedical Imaging, Lausanne, Switzerland
- Animal Imaging and Technology, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- LIFMET, EPFL, Lausanne, Switzerland
| | - Eloïse Mougel
- Université Paris-Saclay, CEA, CNRS, MIRCen, Laboratoires des Maladies Neurodégénératives, Fontenay-aux-Roses, France
| | - Stefan Posse
- Department of Neurology, University of New Mexico School of Medicine, New Mexico, Albuquerque, USA
- Department of Physics and Astronomy, University of New Mexico School of Medicine, New Mexico, Albuquerque, USA
| | - Stefan Ruschke
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany
| | - Kadir Simsek
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, UK
- School of Computer Science and Informatics, Cardiff University, Cardiff, UK
| | | | - Assaf Tal
- Department of Chemical and Biological Physics, The Weizmann Institute of Science, Rehovot, Israel
| | - Chantal Tax
- University Medical Center Utrecht, Utrecht, The Netherlands
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Physics and Astronomy, Cardiff University, Cardiff, United Kingdom
| | - Georg Oeltzschner
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Maryland, Baltimore, USA
- F. M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Maryland, Baltimore, USA
| | - Marco Palombo
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, UK
- School of Computer Science and Informatics, Cardiff University, Cardiff, UK
| | - Itamar Ronen
- Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, Brighton, UK
| | - Julien Valette
- Université Paris-Saclay, CEA, CNRS, MIRCen, Laboratoires des Maladies Neurodégénératives, Fontenay-aux-Roses, France
| |
Collapse
|
2
|
Farkhani S, Demnitz N, Boraxbekk CJ, Lundell H, Siebner HR, Petersen ET, Madsen KH. End-to-end volumetric segmentation of white matter hyperintensities using deep learning. Comput Methods Programs Biomed 2024; 245:108008. [PMID: 38290291 DOI: 10.1016/j.cmpb.2024.108008] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 12/08/2023] [Accepted: 01/03/2024] [Indexed: 02/01/2024]
Abstract
BACKGROUND AND OBJECTIVES Reliable detection of white matter hyperintensities (WMH) is crucial for studying the impact of diffuse white-matter pathology on brain health and monitoring changes in WMH load over time. However, manual annotation of 3D high-dimensional neuroimages is laborious and can be prone to biases and errors in the annotation procedure. In this study, we evaluate the performance of deep learning (DL) segmentation tools and propose a novel volumetric segmentation model incorporating self-attention via a transformer-based architecture. Ultimately, we aim to evaluate diverse factors that influence WMH segmentation, aiming for a comprehensive analysis of the state-of-the-art algorithms in a broader context. METHODS We trained state-of-the-art DL algorithms, and incorporated advanced attention mechanisms, using structural fluid-attenuated inversion recovery (FLAIR) image acquisitions. The anatomical MRI data utilized for model training was obtained from healthy individuals aged 62-70 years in the Live active Successful Aging (LISA) project. Given the potential sparsity of lesion volume among healthy aging individuals, we explored the impact of incorporating a weighted loss function and ensemble models. To assess the generalizability of the studied DL models, we applied the trained algorithm to an independent subset of data sourced from the MICCAI WMH challenge (MWSC). Notably, this subset had vastly different acquisition parameters compared to the LISA dataset used for training. RESULTS Consistently, DL approaches exhibited commendable segmentation performance, achieving the level of inter-rater agreement comparable to expert performance, ensuring superior quality segmentation outcomes. On the out of sample dataset, the ensemble models exhibited the most outstanding performance. CONCLUSIONS DL methods generally surpassed conventional approaches in our study. While all DL methods performed comparably, incorporating attention mechanisms could prove advantageous in future applications with a wider availability of training data. As expected, our experiments indicate that the use of ensemble-based models enables the superior generalization in out-of-distribution settings. We believe that introducing DL methods in the WHM annotation workflow in heathy aging cohorts is promising, not only for reducing the annotation time required, but also for eventually improving accuracy and robustness via incorporating the automatic segmentations in the evaluation procedure.
Collapse
Affiliation(s)
- Sadaf Farkhani
- Danish Research Center for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital-Amager and Hvidovre, Kattegaard Alle 30, Hvidovre, Denmark.
| | - Naiara Demnitz
- Danish Research Center for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital-Amager and Hvidovre, Kattegaard Alle 30, Hvidovre, Denmark
| | - Carl-Johan Boraxbekk
- Danish Research Center for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital-Amager and Hvidovre, Kattegaard Alle 30, Hvidovre, Denmark; Institute for Clinical Medicine, Faculty of Medical and Health Sciences, University of Copenhagen, Denmark; Department of Neurology, Copenhagen University Hospital Bispebjerg and Frederiksberg, Copenhagen, Denmark; Institute of Sports Medicine Copenhagen (ISMC), Copenhagen University Hospital Bispebjerg and Frederiksberg, Copenhagen, Denmark
| | - Henrik Lundell
- Danish Research Center for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital-Amager and Hvidovre, Kattegaard Alle 30, Hvidovre, Denmark; Department of Health Technology, Technical University of Denmark, Lyngby, Denmark
| | - Hartwig Roman Siebner
- Danish Research Center for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital-Amager and Hvidovre, Kattegaard Alle 30, Hvidovre, Denmark; Institute for Clinical Medicine, Faculty of Medical and Health Sciences, University of Copenhagen, Denmark; Department of Neurology, Copenhagen University Hospital Bispebjerg and Frederiksberg, Copenhagen, Denmark
| | - Esben Thade Petersen
- Danish Research Center for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital-Amager and Hvidovre, Kattegaard Alle 30, Hvidovre, Denmark; Department of Health Technology, Technical University of Denmark, Lyngby, Denmark
| | - Kristoffer Hougaard Madsen
- Danish Research Center for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital-Amager and Hvidovre, Kattegaard Alle 30, Hvidovre, Denmark; Department of Applied Mathematics and Computer Science, Technical University of Denmark, Lyngby, Denmark
| |
Collapse
|
3
|
Ammitzbøll C, Dyrby TB, Börnsen L, Schreiber K, Ratzer R, Romme Christensen J, Iversen P, Magyari M, Lundell H, Jensen PEH, Sørensen PS, Siebner HR, Sellebjerg F. NfL and GFAP in serum are associated with microstructural brain damage in progressive multiple sclerosis. Mult Scler Relat Disord 2023; 77:104854. [PMID: 37418931 DOI: 10.1016/j.msard.2023.104854] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 06/04/2023] [Accepted: 06/22/2023] [Indexed: 07/09/2023]
Abstract
BACKGROUND The potential of neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) as biomarkers of disease activity and severity in progressive forms of multiple sclerosis (MS) is unclear. OBJECTIVE To investigate the relationship between serum concentrations of NfL, GFAP, and magnetic resonance imaging (MRI) in progressive MS. METHODS Serum concentrations of NfL and GFAP were measured in 32 healthy controls and 32 patients with progressive MS from whom clinical and MRI data including diffusion tensor imaging (DTI) were obtained during three years of follow-up. RESULTS Serum concentrations of NfL and GFAP at follow-up were higher in progressive MS patients than in healthy controls and serum NfL correlated with the EDSS score. Decreasing fractional anisotropy (FA) in normal-appearing white matter (NAWM) correlated with worsening EDSS scores and higher serum NfL. Higher serum NfL and increasing T2 lesion volume correlated with worsening paced autitory serial addition test scores. In multivariable regression analyses with serum GFAP and NfL as independent factors and DTI measures of NAWM as dependent factors, we showed that high serum NfL at follow-up was independently associated with decreasing FA and increasing MD in NAWM. Moreover, we found that high serum GFAP was independently associated with decreasing MD in NAWM and with decreasing MD and increasing FA in cortical gray matter. CONCLUSION Serum concentrations of NfL and GFAP are increased in progressive MS and are associated with distinct microstructural changes in NAWM and CGM.
Collapse
Affiliation(s)
- C Ammitzbøll
- Danish Multiple Sclerosis Center, Copenhagen University Hospital - Rigshospitalet, Valdemar Hansens Vej 17, Glostrup 2600, Denmark.
| | - T B Dyrby
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital - Amager and Hvidovre, Hvidovre, Denmark; Department of Applied Mathematics and Computer Science, Technical University of Denmark, Lyngby, Denmark
| | - L Börnsen
- Danish Multiple Sclerosis Center, Copenhagen University Hospital - Rigshospitalet, Valdemar Hansens Vej 17, Glostrup 2600, Denmark
| | - K Schreiber
- Danish Multiple Sclerosis Center, Copenhagen University Hospital - Rigshospitalet, Valdemar Hansens Vej 17, Glostrup 2600, Denmark
| | - R Ratzer
- Danish Multiple Sclerosis Center, Copenhagen University Hospital - Rigshospitalet, Valdemar Hansens Vej 17, Glostrup 2600, Denmark
| | - J Romme Christensen
- Danish Multiple Sclerosis Center, Copenhagen University Hospital - Rigshospitalet, Valdemar Hansens Vej 17, Glostrup 2600, Denmark
| | - P Iversen
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital - Amager and Hvidovre, Hvidovre, Denmark
| | - M Magyari
- Danish Multiple Sclerosis Center, Copenhagen University Hospital - Rigshospitalet, Valdemar Hansens Vej 17, Glostrup 2600, Denmark
| | - H Lundell
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital - Amager and Hvidovre, Hvidovre, Denmark
| | - P E H Jensen
- Danish Multiple Sclerosis Center, Copenhagen University Hospital - Rigshospitalet, Valdemar Hansens Vej 17, Glostrup 2600, Denmark
| | - P S Sørensen
- Danish Multiple Sclerosis Center, Copenhagen University Hospital - Rigshospitalet, Valdemar Hansens Vej 17, Glostrup 2600, Denmark
| | - H R Siebner
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital - Amager and Hvidovre, Hvidovre, Denmark; Department of Neurology, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark; Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - F Sellebjerg
- Danish Multiple Sclerosis Center, Copenhagen University Hospital - Rigshospitalet, Valdemar Hansens Vej 17, Glostrup 2600, Denmark; Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
4
|
von Essen MR, Talbot J, Hansen RHH, Chow HH, Lundell H, Siebner HR, Sellebjerg F. Intrathecal CD8 +CD20 + T Cells in Primary Progressive Multiple Sclerosis. Neurol Neuroimmunol Neuroinflamm 2023; 10:e200140. [PMID: 37369602 DOI: 10.1212/nxi.0000000000200140] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 05/15/2023] [Indexed: 06/29/2023]
Abstract
BACKGROUND AND OBJECTIVE Despite accumulating evidence of intrathecal inflammation in patients with primary progressive multiple sclerosis (PPMS), immunomodulatory and suppressive treatment strategies have proven unsuccessful. With this study, we investigated the involvement of CD20+ T cells and the effect of dimethyl fumarate on CD20+ T cells in PPMS. METHODS The main outcomes in this observational, case-control study were flow cytometry assessments of blood and CSF CD20+ T cells and ELISA measurements of myelin basic protein and neurofilament light chain in untreated patients with PPMS and patients treated for 48 weeks with dimethyl fumarate or placebo. MRI measures included new and enlarging T2-weighted lesions over 48 weeks and lesion, normal-appearing white matter, cortical, and thalamic volume. RESULTS Assessing CD20+ T cells in patients with PPMS and controls showed an increased percentage of CD20+ T cells in the blood of untreated patients and a strong enrichment in the CSF. In addition, a higher frequency of CD8+CD20+ T cells in the CSF correlated with a higher concentration of myelin basic protein and T2-weighted lesion volume and with a lower normal-appearing white matter and thalamus volume. Furthermore, CD8+CD20+ T cells were associated with the development of new T2 lesions. After 48 weeks of treatment with dimethyl fumarate, total T cells in CSF were reduced; however, CD20+ T cells were unaffected. DISCUSSION This study shows an association between intrathecal CD8+CD20+ T cells, white matter injury, and thalamic atrophy in PPMS, suggesting a role of CD8+CD20+ T cells in the immunopathogenesis of PPMS. The results also suggest that limited efficacy of dimethyl fumarate in PPMS may, at least partly, be a consequence of failure to suppress CD8+CD20+ T cells in CSF.
Collapse
Affiliation(s)
- Marina Rode von Essen
- From the Danish Multiple Sclerosis Center (M.R.E., J.T., R.H.H.H., H.H.C., F.S.), Department of Neurology, Copenhagen University Hospital - Rigshospitalet, Glostrup; Danish Research Centre for Magnetic Resonance (H.L., H.R.S.), Copenhagen University Hospital - Amager and Hvidovre; Department of Clinical Medicine (H.R.S.), University of Copenhagen; and Department of Neurology (H.R.S.), Copenhagen University Hospital - Bispebjerg and Frederiksberg, Denmark.
| | - Jacob Talbot
- From the Danish Multiple Sclerosis Center (M.R.E., J.T., R.H.H.H., H.H.C., F.S.), Department of Neurology, Copenhagen University Hospital - Rigshospitalet, Glostrup; Danish Research Centre for Magnetic Resonance (H.L., H.R.S.), Copenhagen University Hospital - Amager and Hvidovre; Department of Clinical Medicine (H.R.S.), University of Copenhagen; and Department of Neurology (H.R.S.), Copenhagen University Hospital - Bispebjerg and Frederiksberg, Denmark
| | - Rikke Holm Holm Hansen
- From the Danish Multiple Sclerosis Center (M.R.E., J.T., R.H.H.H., H.H.C., F.S.), Department of Neurology, Copenhagen University Hospital - Rigshospitalet, Glostrup; Danish Research Centre for Magnetic Resonance (H.L., H.R.S.), Copenhagen University Hospital - Amager and Hvidovre; Department of Clinical Medicine (H.R.S.), University of Copenhagen; and Department of Neurology (H.R.S.), Copenhagen University Hospital - Bispebjerg and Frederiksberg, Denmark
| | - Helene Højsgaard Chow
- From the Danish Multiple Sclerosis Center (M.R.E., J.T., R.H.H.H., H.H.C., F.S.), Department of Neurology, Copenhagen University Hospital - Rigshospitalet, Glostrup; Danish Research Centre for Magnetic Resonance (H.L., H.R.S.), Copenhagen University Hospital - Amager and Hvidovre; Department of Clinical Medicine (H.R.S.), University of Copenhagen; and Department of Neurology (H.R.S.), Copenhagen University Hospital - Bispebjerg and Frederiksberg, Denmark
| | - Henrik Lundell
- From the Danish Multiple Sclerosis Center (M.R.E., J.T., R.H.H.H., H.H.C., F.S.), Department of Neurology, Copenhagen University Hospital - Rigshospitalet, Glostrup; Danish Research Centre for Magnetic Resonance (H.L., H.R.S.), Copenhagen University Hospital - Amager and Hvidovre; Department of Clinical Medicine (H.R.S.), University of Copenhagen; and Department of Neurology (H.R.S.), Copenhagen University Hospital - Bispebjerg and Frederiksberg, Denmark
| | - Hartwig Roman Siebner
- From the Danish Multiple Sclerosis Center (M.R.E., J.T., R.H.H.H., H.H.C., F.S.), Department of Neurology, Copenhagen University Hospital - Rigshospitalet, Glostrup; Danish Research Centre for Magnetic Resonance (H.L., H.R.S.), Copenhagen University Hospital - Amager and Hvidovre; Department of Clinical Medicine (H.R.S.), University of Copenhagen; and Department of Neurology (H.R.S.), Copenhagen University Hospital - Bispebjerg and Frederiksberg, Denmark
| | - Finn Sellebjerg
- From the Danish Multiple Sclerosis Center (M.R.E., J.T., R.H.H.H., H.H.C., F.S.), Department of Neurology, Copenhagen University Hospital - Rigshospitalet, Glostrup; Danish Research Centre for Magnetic Resonance (H.L., H.R.S.), Copenhagen University Hospital - Amager and Hvidovre; Department of Clinical Medicine (H.R.S.), University of Copenhagen; and Department of Neurology (H.R.S.), Copenhagen University Hospital - Bispebjerg and Frederiksberg, Denmark
| |
Collapse
|
5
|
Kolmos M, Madsen MJ, Liu ML, Karabanov A, Johansen KL, Thielscher A, Gandrup K, Lundell H, Fuglsang S, Thade E, Christensen H, Iversen HK, Siebner HR, Kruuse C. Patient-tailored transcranial direct current stimulation to improve stroke rehabilitation: study protocol of a randomized sham-controlled trial. Trials 2023; 24:216. [PMID: 36949490 PMCID: PMC10035265 DOI: 10.1186/s13063-023-07234-y] [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: 02/11/2023] [Accepted: 03/09/2023] [Indexed: 03/24/2023] Open
Abstract
BACKGROUND Many patients do not fully regain motor function after ischemic stroke. Transcranial direct current stimulation (TDCS) targeting the motor cortex may improve motor outcome as an add-on intervention to physical rehabilitation. However, beneficial effects on motor function vary largely among patients within and across TDCS trials. In addition to a large heterogeneity of study designs, this variability may be caused by the fact that TDCS was given as a one-size-fits-all protocol without accounting for anatomical differences between subjects. The efficacy and consistency of TDCS might be improved by a patient-tailored design that ensures precise targeting of a physiologically relevant area with an appropriate current strength. METHODS In a randomized, double-blinded, sham-controlled trial, patients with subacute ischemic stroke and residual upper-extremity paresis will receive two times 20 min of focal TDCS of ipsilesional primary motor hand area (M1-HAND) during supervised rehabilitation training three times weekly for 4 weeks. Anticipated 60 patients will be randomly assigned to active or sham TDCS of ipsilesional M1-HAND, using a central anode and four equidistant cathodes. The placement of the electrode grid on the scalp and current strength at each cathode will be personalized based on individual electrical field models to induce an electrical current of 0.2 V/m in the cortical target region resulting in current strengths between 1 and 4 mA. Primary endpoint will be the difference in change of Fugl-Meyer Assessment of Upper Extremity (FMA-UE) score between active TDCS and sham at the end of the intervention. Exploratory endpoints will include UE-FMA at 12 weeks. Effects of TDCS on motor network connectivity and interhemispheric inhibition will be assessed with functional MRI and transcranial magnetic stimulation. DISCUSSION The study will show the feasibility and test the efficacy of personalized, multi-electrode anodal TDCS of M1-HAND in patients with subacute stroke patients with upper-extremity paresis. Concurrent multimodal brain mapping will shed light into the mechanisms of action of therapeutic personalized TDCS of M1-HAND. Together, the results from this trial may inform future personalized TDCS studies in patients with focal neurological deficits after stroke.
Collapse
Affiliation(s)
- Mia Kolmos
- Neurovascular Research Unit (NVRU), Department of Neurology, Copenhagen University Hospital -Herlev and Gentofte, Copenhagen, Denmark
- Danish Research Centre for Magnetic Resonance (DRCMR), Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Copenhagen, Denmark
| | - Mads Just Madsen
- Danish Research Centre for Magnetic Resonance (DRCMR), Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Copenhagen, Denmark
| | - Marie Louise Liu
- Danish Research Centre for Magnetic Resonance (DRCMR), Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Copenhagen, Denmark
| | - Anke Karabanov
- Department of Nutrition, Exercise and Sport (NEXS), Copenhagen University, Copenhagen, Denmark
| | - Katrine Lyders Johansen
- Department of Physiotherapy and Occupational Therapy, Copenhagen University Hospital Herlev and Gentofte, Copenhagen, Denmark
| | - Axel Thielscher
- Danish Research Centre for Magnetic Resonance (DRCMR), Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Copenhagen, Denmark
- Department of Health Technology, Technical University of Denmark, Kgs Lyngby, Denmark
| | - Karen Gandrup
- Department of Radiology, Copenhagen University Hospital Herlev and Gentofte, Copenhagen, Denmark
| | - Henrik Lundell
- Danish Research Centre for Magnetic Resonance (DRCMR), Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Copenhagen, Denmark
| | - Søren Fuglsang
- Danish Research Centre for Magnetic Resonance (DRCMR), Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Copenhagen, Denmark
| | - Esben Thade
- Danish Research Centre for Magnetic Resonance (DRCMR), Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Copenhagen, Denmark
- Department of Health Technology, Technical University of Denmark, Kgs Lyngby, Denmark
| | - Hanne Christensen
- Department of Neurology, Copenhagen University Hospital Bispebjerg and Frederiksberg, Copenhagen, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Helle Klingenberg Iversen
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Neurology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Hartwig Roman Siebner
- Danish Research Centre for Magnetic Resonance (DRCMR), Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Copenhagen, Denmark
- Department of Neurology, Copenhagen University Hospital Bispebjerg and Frederiksberg, Copenhagen, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Christina Kruuse
- Neurovascular Research Unit (NVRU), Department of Neurology, Copenhagen University Hospital -Herlev and Gentofte, Copenhagen, Denmark.
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| |
Collapse
|
6
|
Cerri S, Greve DN, Hoopes A, Lundell H, Siebner HR, Mühlau M, Van Leemput K. An open-source tool for longitudinal whole-brain and white matter lesion segmentation. Neuroimage Clin 2023; 38:103354. [PMID: 36907041 PMCID: PMC10024238 DOI: 10.1016/j.nicl.2023.103354] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 02/10/2023] [Accepted: 02/19/2023] [Indexed: 03/06/2023]
Abstract
In this paper we describe and validate a longitudinal method for whole-brain segmentation of longitudinal MRI scans. It builds upon an existing whole-brain segmentation method that can handle multi-contrast data and robustly analyze images with white matter lesions. This method is here extended with subject-specific latent variables that encourage temporal consistency between its segmentation results, enabling it to better track subtle morphological changes in dozens of neuroanatomical structures and white matter lesions. We validate the proposed method on multiple datasets of control subjects and patients suffering from Alzheimer's disease and multiple sclerosis, and compare its results against those obtained with its original cross-sectional formulation and two benchmark longitudinal methods. The results indicate that the method attains a higher test-retest reliability, while being more sensitive to longitudinal disease effect differences between patient groups. An implementation is publicly available as part of the open-source neuroimaging package FreeSurfer.
Collapse
Affiliation(s)
- Stefano Cerri
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, USA.
| | - Douglas N Greve
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, USA; Department of Radiology, Harvard Medical School, USA
| | - Andrew Hoopes
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, USA
| | - Henrik Lundell
- Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Amager and Hvidovre, Copenhagen, Denmark
| | - Hartwig R Siebner
- Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Amager and Hvidovre, Copenhagen, Denmark; Department of Neurology, Copenhagen University Hospital Bispebjerg and Frederiksberg, Copenhagen, Denmark; Institute for Clinical Medicine, Faculty of Medical and Health Sciences, University of Copenhagen, Denmark
| | - Mark Mühlau
- Department of Neurology and TUM-Neuroimaging Center, School of Medicine, Technical University of Munich, Germany
| | - Koen Van Leemput
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, USA; Department of Health Technology, Technical University of Denmark, Denmark
| |
Collapse
|
7
|
Højsgaard Chow H, Talbot J, Lundell H, Marstrand L, Gøbel Madsen C, Bach Søndergaard H, Bredahl Hansen M, Solberg Sørensen P, Siebner HR, Sellebjerg F. Dimethyl fumarate treatment of primary progressive multiple sclerosis: results of an open-label extension study. Mult Scler Relat Disord 2023; 70:104458. [PMID: 36586351 DOI: 10.1016/j.msard.2022.104458] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/02/2022] [Accepted: 12/07/2022] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Dimethyl fumarate treatment is approved in Europe for patients with relapsing-remitting multiple sclerosis (MS) and in the US for relapsing forms of MS. We recently published the results of the first randomized placebo-controlled trial of 48 weeks of treatment with dimethyl fumarate or placebo in primary progressive MS (PPMS) (clinicaltrial.gov NCT02959658). The placebo-controlled phase of the trial did not meet its primary endpoint (reduction in cerebrospinal fluid concentrations of neurofilament light chain [NFL]). AIM To investigate the effects of dimethyl fumarate treatment in the open-label extension phase of the trial (week 48-96), where all patients were treated with DMF. METHODS Reported data are from screening, week 48, and week 96 visits. Patients were clinically evaluated with Expanded Disability Status Scale (EDSS), 9-Hole Peg Test (9HPT), Timed 25-Foot Walk (T25FW) test, Symbol Digit Modalities Test (SDMT), California Verbal Learning Test, and Brief Visuospatial Memory-Revised. Serum NFL concentrations were measured by single-molecule array analysis. MRI was performed on a 3 tesla MRI scanner and included: new/enlarging lesions, volume of lesions, cortical grey matter, putamen, thalamus, and normal-appearing white matter, and additional diffusion tensor imaging and magnetization transfer ratio measures. RESULTS Forty-two patients entered the open-label treatment phase, and 33 patients (61%) had complete data sets at week 96. The remaining 39% did not complete the trial and were not evaluated at week 96. We found no evidence of differences in clinical and MRI measures between patients initially treated with dimethyl fumarate and patients initially treated with placebo from baseline to week 48 and from week 48-96, where all patients were treated with dimethyl fumarate. Serum NFL concentrations remained stable in both groups over 96 weeks. Assessed with either EDSS, T25FW, or 9HPT at week 96, progression was observed for 14 patients (45%). Interestingly, another 15 patients (46%) had improvement in one or more of these domains. Applying a cut-off of 8 points, 2 (6%) patients worsened on SDMT, 25 (78%) did not change, and 5 (16%) improved. CONCLUSIONS Dimethyl fumarate treatment showed no effects on neither clinical nor MRI outcomes or changes in serum concentrations of NFL. An expected number of patients showed evidence of progression on standard clinical scales; however, this was matched by an equal number of patients improving. The reasons for the physical improvement in an unexpectedly high proportion of patients must be addressed in future studies.
Collapse
Affiliation(s)
- Helene Højsgaard Chow
- Danish Multiple Sclerosis Center, Copenhagen University Hospital - Rigshospitalet, Nordre Ringvej 57, 2600 Glostrup, Denmark.
| | - Jacob Talbot
- Danish Multiple Sclerosis Center, Copenhagen University Hospital - Rigshospitalet, Nordre Ringvej 57, 2600 Glostrup, Denmark
| | - Henrik Lundell
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Copenhagen Denmark, Kettegård Alle 30, 2650 Hvidovre, Denmark
| | - Lisbet Marstrand
- Danish Multiple Sclerosis Center, Copenhagen University Hospital - Rigshospitalet, Nordre Ringvej 57, 2600 Glostrup, Denmark
| | - Camilla Gøbel Madsen
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Copenhagen Denmark, Kettegård Alle 30, 2650 Hvidovre, Denmark
| | - Helle Bach Søndergaard
- Danish Multiple Sclerosis Center, Copenhagen University Hospital - Rigshospitalet, Nordre Ringvej 57, 2600 Glostrup, Denmark
| | - Malene Bredahl Hansen
- Danish Multiple Sclerosis Center, Copenhagen University Hospital - Rigshospitalet, Nordre Ringvej 57, 2600 Glostrup, Denmark
| | - Per Solberg Sørensen
- Danish Multiple Sclerosis Center, Copenhagen University Hospital - Rigshospitalet, Nordre Ringvej 57, 2600 Glostrup, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Copenhagen, Denmark
| | - Hartwig Roman Siebner
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Copenhagen Denmark, Kettegård Alle 30, 2650 Hvidovre, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Copenhagen, Denmark; Department of Neurology, Copenhagen University Hospital Bispebjerg and Frederiksberg, Bispebjerg Bakke 23, 2400 Copenhagen, Denmark
| | - Finn Sellebjerg
- Danish Multiple Sclerosis Center, Copenhagen University Hospital - Rigshospitalet, Nordre Ringvej 57, 2600 Glostrup, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Copenhagen, Denmark
| |
Collapse
|
8
|
Just Madsen MA, Wiggermann V, Christiansen L, Povazan M, Lundell H, Puonti O, Christensen JR, Sellebjerg F, Siebner HR. The ipsilateral silent period and its link to cortical lesions in multiple sclerosis. Brain Stimul 2023. [DOI: 10.1016/j.brs.2023.01.578] [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: 02/17/2023] Open
|
9
|
Talbot J, Højsgaard Chow H, Mahler M, Buhelt S, Holm Hansen R, Lundell H, Vinther-Jensen T, Hellem MNN, Nielsen JE, Siebner HR, von Essen MR, Sellebjerg F. Relationship between cerebrospinal fluid biomarkers of inflammation and tissue damage in primary progressive multiple sclerosis. Mult Scler Relat Disord 2022; 68:104209. [PMID: 36257152 DOI: 10.1016/j.msard.2022.104209] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 10/01/2022] [Indexed: 11/05/2022]
Abstract
BACKGROUND AND OBJECTIVES It is unclear to what extent intrathecal inflammation contributes to the pathogenesis in primary progressive multiple sclerosis (PPMS). We conducted an exploratory study to investigate the degree of intrathecal inflammation and its association with biomarkers of disease activity and severity in patients with PPMS. METHODS We included patients with PPMS who participated in a randomized controlled trial conducted at the Danish Multiple Sclerosis Center, patients with relapsing-remitting multiple sclerosis (RRMS) and healthy controls. We analyzed concentrations of a panel of cytokines in CSF using electrochemiluminescence assays. We then explored the relationship between cytokines found in increased CSF concentrations in patients with PPMS (compared with healthy controls) with CSF concentrations of neurofilament light chain (NFL) and myelin basic protein (MBP), IgG-index, and magnetic resonance imaging (MRI) metrics (volume, magnetization transfer ratio and diffusion tensor imaging) from lesions, normal-appearing white matter, and cortical grey matter. RESULTS We included 59 patients with PPMS, 40 patients with RRMS, and 21 healthy controls. In patients with PPMS, CSF concentrations of CC chemokine ligand 3 (CCL-3), CXC chemokine ligand 8 (CXCL-8), CXCL-10, interleukin (IL)-10, IL-15, and vascular endothelial growth factor (VEGF)-A were increased compared with healthy controls and comparable with CSF concentrations in patients with RRMS. In addition, patients with PPMS had increased CSF concentrations of IL-12p40, IL-17A, tumor necrosis factor (TNF)-α, and lymphotoxin (LT)-α compared with healthy controls, but concentrations of these cytokines were even higher in patients with RRMS. For the remaining seven cytokines (CCL22, interferon-γ, IL-5, IL-7, IL-16, IL-22, IL-27), we found no difference between patients with PPMS and healthy controls. CSF concentrations of NFL and MBP correlated weakly with concentrations of IL-15, while the remaining proinflammatory cytokines were not associated with CSF concentrations of NFL or MBP. The IgG-index correlated with four cytokines (IL-10, IL-12p40, TNF-α, and LT-α). We did not observe any significant associations between MRI metrics and CSF biomarkers of inflammation. DISCUSSION In this exploratory study, we found few and weak associations between intrathecal inflammation and the extent of neuroaxonal damage and demyelination, and no associations between intrathecal inflammation and MRI metrics, in patients with PPMS. Our findings suggest that, for patients with PPMS, these measures of intrathecal inflammation are not associated with the extent of neuroaxonal injury, demyelination, and disease severity, and these processes may therefore have less relevance in PPMS than in relapsing forms of MS.
Collapse
Affiliation(s)
- Jacob Talbot
- Danish Multiple Sclerosis Center, Department of Neurology, Copenhagen University Hospital - Rigshospitalet, Valdemar Hansens Vej 17, 5, 7, Glostrup 2600, Denmark.
| | - Helene Højsgaard Chow
- Danish Multiple Sclerosis Center, Department of Neurology, Copenhagen University Hospital - Rigshospitalet, Valdemar Hansens Vej 17, 5, 7, Glostrup 2600, Denmark
| | - Mie Mahler
- Danish Multiple Sclerosis Center, Department of Neurology, Copenhagen University Hospital - Rigshospitalet, Valdemar Hansens Vej 17, 5, 7, Glostrup 2600, Denmark
| | - Sophie Buhelt
- Danish Multiple Sclerosis Center, Department of Neurology, Copenhagen University Hospital - Rigshospitalet, Valdemar Hansens Vej 17, 5, 7, Glostrup 2600, Denmark
| | - Rikke Holm Hansen
- Danish Multiple Sclerosis Center, Department of Neurology, Copenhagen University Hospital - Rigshospitalet, Valdemar Hansens Vej 17, 5, 7, Glostrup 2600, Denmark
| | - Henrik Lundell
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Copenhagen, Denmark
| | - Tua Vinther-Jensen
- The Neurogenetics Clinic, Danish Dementia Research Center, Copenhagen University Hospital -Rigshospitalet, Copenhagen, Denmark; Department of Neurology, Copenhagen University Hospital Bispebjerg and Frederiksberg, Copenhagen, Denmark
| | - Marie N N Hellem
- The Neurogenetics Clinic, Danish Dementia Research Center, Copenhagen University Hospital -Rigshospitalet, Copenhagen, Denmark
| | - Jørgen E Nielsen
- The Neurogenetics Clinic, Danish Dementia Research Center, Copenhagen University Hospital -Rigshospitalet, Copenhagen, Denmark
| | - Hartwig Roman Siebner
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Copenhagen, Denmark; Department of Neurology, Copenhagen University Hospital Bispebjerg and Frederiksberg, Copenhagen, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Marina R von Essen
- Danish Multiple Sclerosis Center, Department of Neurology, Copenhagen University Hospital - Rigshospitalet, Valdemar Hansens Vej 17, 5, 7, Glostrup 2600, Denmark
| | - Finn Sellebjerg
- Danish Multiple Sclerosis Center, Department of Neurology, Copenhagen University Hospital - Rigshospitalet, Valdemar Hansens Vej 17, 5, 7, Glostrup 2600, Denmark
| |
Collapse
|
10
|
Madsen MAJ, Wiggermann V, Marques MFM, Lundell H, Cerri S, Puonti O, Blinkenberg M, Christensen JR, Sellebjerg F, Siebner HR. Linking lesions in sensorimotor cortex to contralateral hand function in multiple sclerosis: a 7 T MRI study. Brain 2022; 145:3522-3535. [PMID: 35653498 PMCID: PMC9586550 DOI: 10.1093/brain/awac203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 01/04/2022] [Revised: 05/17/2022] [Accepted: 05/20/2022] [Indexed: 11/14/2022] Open
Abstract
Abstract
Cortical lesions constitute a key manifestation of multiple sclerosis and contribute to clinical disability and cognitive impairment. Yet it is unknown whether local cortical lesions and cortical lesion subtypes contribute to domain-specific impairments attributable to the function of the lesioned cortex.
In this cross-sectional study, we assessed how cortical lesions in the primary sensorimotor hand area (SM1-HAND) relate to corticomotor physiology and sensorimotor function of the contralateral hand. 50 relapse-free patients with relapsing-remitting or secondary-progressive multiple sclerosis and 28 healthy age- and sex-matched participants underwent whole-brain 7 T MRI to map cortical lesions. Brain scans were also used to estimate normalized brain volume, pericentral cortical thickness, white matter lesion fraction of the corticospinal tract, infratentorial lesion volume and the cross-sectional area of the upper cervical spinal cord. We tested sensorimotor hand function and calculated a motor and sensory composite score for each hand. In 37 patients and 20 healthy controls, we measured maximal motor evoked potential (MEP) amplitude, resting motor threshold and corticomotor conduction time with transcranial magnetic stimulation (TMS) and the N20 latency from somatosensory evoked potentials (SSEPs).
Patients showed at least one cortical lesion in the SM1-HAND in 47 of 100 hemispheres. The presence of a lesion was associated with worse contralateral sensory (P = 0.014) and motor (P = 0.009) composite scores. TMS of a lesion-positive SM1-HAND revealed a decreased maximal MEP amplitude (P < 0.001) and delayed corticomotor conduction (P = 0.002) relative to a lesion-negative SM1-HAND. Stepwise mixed linear regressions showed that the presence of an SM1-HAND lesion, higher white-matter lesion fraction of the corticospinal tract, reduced spinal cord cross-sectional area and higher infratentorial lesion volume were associated with reduced contralateral motor hand function. Cortical lesions in SM1-HAND, spinal cord cross-sectional area and normalized brain volume were also associated with smaller maximal MEP amplitude and longer corticomotor conduction times. The effect of cortical lesions on sensory function was no longer significant when controlling for MRI-based covariates. Lastly, we found that intracortical and subpial lesions had the largest effect on reduced motor hand function, intracortical lesions on reduced MEP amplitude and leukocortical lesions on delayed corticomotor conduction.
Together, this comprehensive multi-level assessment of sensorimotor brain damage shows that the presence of a cortical lesion in SM1-HAND is associated with impaired corticomotor function of the hand, after accounting for damage at the subcortical level. The results also provide preliminary evidence that cortical lesion types may affect the various facets of corticomotor function differentially.
Collapse
Affiliation(s)
- Mads A. J. Madsen
- Copenhagen University Hospital - Amager & Hvidovre Danish Research Centre for Magnetic Resonance, , 2650 Hvidovre, Denmark
| | - Vanessa Wiggermann
- Copenhagen University Hospital - Amager & Hvidovre Danish Research Centre for Magnetic Resonance, , 2650 Hvidovre, Denmark
| | - Marta F. M. Marques
- Copenhagen University Hospital - Amager & Hvidovre Danish Research Centre for Magnetic Resonance, , 2650 Hvidovre, Denmark
| | - Henrik Lundell
- Copenhagen University Hospital - Amager & Hvidovre Danish Research Centre for Magnetic Resonance, , 2650 Hvidovre, Denmark
| | - Stefano Cerri
- Copenhagen University Hospital - Amager & Hvidovre Danish Research Centre for Magnetic Resonance, , 2650 Hvidovre, Denmark
- Technical University of Denmark Department of Health Technology, , 2800 Kgs. Lyngby, Denmark
| | - Oula Puonti
- Copenhagen University Hospital - Amager & Hvidovre Danish Research Centre for Magnetic Resonance, , 2650 Hvidovre, Denmark
| | - Morten Blinkenberg
- Copenhagen University Hospital – Rigshospitalet Danish Multiple Sclerosis Center, Department of Neurology, , 2600 Glostrup, Denmark
| | - Jeppe Romme Christensen
- Copenhagen University Hospital – Rigshospitalet Danish Multiple Sclerosis Center, Department of Neurology, , 2600 Glostrup, Denmark
| | - Finn Sellebjerg
- Copenhagen University Hospital – Rigshospitalet Danish Multiple Sclerosis Center, Department of Neurology, , 2600 Glostrup, Denmark
- University of Copenhagen Department of Clinical Medicine, , 2200 Copenhagen, Denmark
| | - Hartwig R. Siebner
- Copenhagen University Hospital - Amager & Hvidovre Danish Research Centre for Magnetic Resonance, , 2650 Hvidovre, Denmark
- Copenhagen University Hospital - Bispebjerg & Frederiksberg Department of Neurology, , 2400 Copenhagen, Denmark
- University of Copenhagen Department of Clinical Medicine, , 2200 Copenhagen, Denmark
| |
Collapse
|
11
|
Sandström KO, Baltzersen OB, Marsman A, Lemvigh CK, Boer VO, Bojesen KB, Nielsen MØ, Lundell H, Sulaiman DK, Sørensen ME, Fagerlund B, Lahti AC, Syeda WT, Pantelis C, Petersen ET, Glenthøj BY, Siebner HR, Ebdrup BH. Add-On MEmaNtine to Dopamine Antagonism to Improve Negative Symptoms at First Psychosis- the AMEND Trial Protocol. Front Psychiatry 2022; 13:889572. [PMID: 35669271 PMCID: PMC9163784 DOI: 10.3389/fpsyt.2022.889572] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 04/13/2022] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Antipsychotic drugs are primarily efficacious in treating positive symptoms by blocking the dopamine D2 receptor, but they fail to substantially improve negative symptoms and cognitive deficits. The limited efficacy may be attributed to the fact that the pathophysiology of psychosis involves multiple neurotransmitter systems. In patients with chronic schizophrenia, memantine, a non-competitive glutamatergic NMDA receptor antagonist, shows promise for ameliorating negative symptoms and improving cognition. Yet, it is unknown how memantine modulates glutamate levels, and memantine has not been investigated in patients with first-episode psychosis. AIMS This investigator-initiated double-blinded randomized controlled trial is designed to (1) test the clinical effects on negative symptoms of add-on memantine to antipsychotic medication, and (2) neurobiologically characterize the responders to add-on memantine. MATERIALS AND EQUIPMENT Antipsychotic-naïve patients with first-episode psychosis will be randomized to 12 weeks treatment with [amisulpride + memantine] or [amisulpride + placebo]. We aim for a minimum of 18 patients in each treatment arm to complete the trial. Brain mapping will be performed before and after 12 weeks focusing on glutamate and neuromelanin in predefined regions. Regional glutamate levels will be probed with proton magnetic resonance spectroscopy (MRS), while neuromelanin signal will be mapped with neuromelanin-sensitive magnetic resonance imaging (MRI). We will also perform structural and diffusion weighted, whole-brain MRI. MRS and MRI will be performed at an ultra-high field strength (7 Tesla). Alongside, participants undergo clinical and neuropsychological assessments. Twenty matched healthy controls will undergo similar baseline- and 12-week examinations, but without receiving treatment. OUTCOME MEASURES The primary endpoint is negative symptom severity. Secondary outcomes comprise: (i) clinical endpoints related to cognition, psychotic symptoms, side effects, and (ii) neurobiological endpoints related to regional glutamate- and neuromelanin levels, and structural brain changes. ANTICIPATED RESULTS We hypothesize that add-on memantine to amisulpride will be superior to amisulpride monotherapy in reducing negative symptoms, and that this effect will correlate with thalamic glutamate levels. Moreover, we anticipate that add-on memantine will restore regional white matter integrity and improve cognitive functioning. PERSPECTIVES By combining two licensed, off-patent drugs, AMEND aims to optimize treatment of psychosis while investigating the memantine response. Alongside, AMEND will provide neurobiological insights to effects of dual receptor modulation, which may enable future stratification of patients with first-episode psychosis before initial antipsychotic treatment. CLINICAL TRIAL REGISTRATION [ClinicalTrials.gov], identifier [NCT04789915].
Collapse
Affiliation(s)
- Katharina O Sandström
- Center for Neuropsychiatric Schizophrenia Research (CNSR), Centre for Clinical Intervention and Neuropsychiatric Schizophrenia Research (CINS), Mental Health Centre Glostrup, Glostrup, Denmark
| | - Olga B Baltzersen
- Center for Neuropsychiatric Schizophrenia Research (CNSR), Centre for Clinical Intervention and Neuropsychiatric Schizophrenia Research (CINS), Mental Health Centre Glostrup, Glostrup, Denmark
| | - Anouk Marsman
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Copenhagen, Denmark
| | - Cecilie K Lemvigh
- Center for Neuropsychiatric Schizophrenia Research (CNSR), Centre for Clinical Intervention and Neuropsychiatric Schizophrenia Research (CINS), Mental Health Centre Glostrup, Glostrup, Denmark
| | - Vincent O Boer
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Copenhagen, Denmark
| | - Kirsten B Bojesen
- Center for Neuropsychiatric Schizophrenia Research (CNSR), Centre for Clinical Intervention and Neuropsychiatric Schizophrenia Research (CINS), Mental Health Centre Glostrup, Glostrup, Denmark
| | - Mette Ø Nielsen
- Center for Neuropsychiatric Schizophrenia Research (CNSR), Centre for Clinical Intervention and Neuropsychiatric Schizophrenia Research (CINS), Mental Health Centre Glostrup, Glostrup, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Henrik Lundell
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Copenhagen, Denmark
| | - Daban K Sulaiman
- Center for Neuropsychiatric Schizophrenia Research (CNSR), Centre for Clinical Intervention and Neuropsychiatric Schizophrenia Research (CINS), Mental Health Centre Glostrup, Glostrup, Denmark
| | - Mikkel E Sørensen
- Center for Neuropsychiatric Schizophrenia Research (CNSR), Centre for Clinical Intervention and Neuropsychiatric Schizophrenia Research (CINS), Mental Health Centre Glostrup, Glostrup, Denmark
| | - Birgitte Fagerlund
- Center for Neuropsychiatric Schizophrenia Research (CNSR), Centre for Clinical Intervention and Neuropsychiatric Schizophrenia Research (CINS), Mental Health Centre Glostrup, Glostrup, Denmark.,Department of Psychology, University of Copenhagen, Copenhagen, Denmark
| | - Adrienne C Lahti
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Warda T Syeda
- Department of Psychiatry, Melbourne Neuropsychiatry Centre, The University of Melbourne and Melbourne Health, Carlton South, VIC, Australia
| | - Christos Pantelis
- Department of Psychiatry, Melbourne Neuropsychiatry Centre, The University of Melbourne and Melbourne Health, Carlton South, VIC, Australia
| | - Esben T Petersen
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Copenhagen, Denmark.,Section for Magnetic Resonance, DTU Health Tech, Technical University of Denmark, Lyngby, Denmark
| | - Birte Y Glenthøj
- Center for Neuropsychiatric Schizophrenia Research (CNSR), Centre for Clinical Intervention and Neuropsychiatric Schizophrenia Research (CINS), Mental Health Centre Glostrup, Glostrup, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Hartwig R Siebner
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Copenhagen, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Neurology, Copenhagen University Hospital Bispebjerg and Frederiksberg, Copenhagen, Denmark
| | - Bjørn H Ebdrup
- Center for Neuropsychiatric Schizophrenia Research (CNSR), Centre for Clinical Intervention and Neuropsychiatric Schizophrenia Research (CINS), Mental Health Centre Glostrup, Glostrup, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
12
|
Wiingaard Uldall S, Lundell H, Baaré WFC, Roman Siebner H, Rostrup E, Carlsson J. White matter diffusivity and its correlations to state measures of psychopathology in male refugees with posttraumatic stress disorder. Neuroimage Clin 2021; 33:102929. [PMID: 34998125 PMCID: PMC8741622 DOI: 10.1016/j.nicl.2021.102929] [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] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 09/29/2021] [Accepted: 10/20/2021] [Indexed: 12/03/2022]
Abstract
Post-traumatic stress disorder (PTSD) is a heterogenous condition and the underlying neurobiology is still poorly understood. In this study, we tested the hypothesis that PTSD is associated with microstructural changes in white matter (WM) fibre tracts that connect regions involved in emotional processing, memory, attention, and language. Furthermore, we examined how different response patterns to individualized trauma-provoking stimuli related to underlying WM microstructure. Sixty-nine trauma-affected male refugees with PTSD (N = 38) or without PTSD (N = 31) underwent clinical assessments and diffusion-weighted magnetic resonance imaging (DWI) of the whole brain at 3 Tesla. Diffusion tensor metrics were computed from DWI data and used to characterize regional white-matter microstructure. An automated tract segmentation method was used to extract diffusion tensor metrics from subject-based reconstructions of tract segments (ROI), including uncinate fasciculus (UF), cingulum bundle (CB), superior longitudinal fasciculus (SLF) in three subdivisions (SLF I - III), and fibre bundles connecting orbito-frontal cortex to striatum (OF-ST). Outside the scanner we obtained measures of immediate (state) arousal, avoidance and dissociation symptoms assessed in response to auditory exposure to a personal traumatic memory. Using mean FA of the middle part of each ROI, mixed ANOVA revealed a significant interaction between group, ROI and hemisphere. Post-hoc comparisons showed that, relative to refugees without PTSD, refugees with PTSD had lower FA in right CB, left SLF-I, bilateral OF-ST and bilateral SLF-II. Mean FA scaled negatively with avoidance in right CB while mean FA in bilateral UF scaled positively with individual scores reflecting dissociation symptoms. The results support a pathophysiological model of PTSD that implicates limbic structures, prefrontal cortex and striatum. The results also emphasize the need to consider PTSD's multifaceted manifestations when searching for functional-structural relationships.
Collapse
Affiliation(s)
- Sigurd Wiingaard Uldall
- Competence Centre for Transcultural Psychiatry (CTP), Mental Health Centre, Ballerup, Denmark; Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital - Amager and Hvidovre, Copenhagen, Denmark.
| | - Henrik Lundell
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital - Amager and Hvidovre, Copenhagen, Denmark
| | - William F C Baaré
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital - Amager and Hvidovre, Copenhagen, Denmark
| | - Hartwig Roman Siebner
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital - Amager and Hvidovre, Copenhagen, Denmark; Department for Neurology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark; Institute of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Egill Rostrup
- Center for Neuropsychiatric Schizophrenia Research and Center for Clinical Intervention and Neuropsychiatric Schizophrenia Research, Mental Health Centre, Glostrup, Copenhagen University Hospital, Denmark
| | - Jessica Carlsson
- Competence Centre for Transcultural Psychiatry (CTP), Mental Health Centre, Ballerup, Denmark; Center for Neuropsychiatric Schizophrenia Research and Center for Clinical Intervention and Neuropsychiatric Schizophrenia Research, Mental Health Centre, Glostrup, Copenhagen University Hospital, Denmark
| |
Collapse
|
13
|
Rahbek S, Madsen KH, Lundell H, Mahmood F, Hanson LG. Data-driven separation of MRI signal components for tissue characterization. J Magn Reson 2021; 333:107103. [PMID: 34801822 DOI: 10.1016/j.jmr.2021.107103] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 10/14/2021] [Accepted: 11/02/2021] [Indexed: 06/13/2023]
Abstract
PURPOSE MRI can be utilized for quantitative characterization of tissue. To assess e.g. water fractions or diffusion coefficients for compartments in the brain, a decomposition of the signal is necessary. Imposing standard models carries the risk of estimating biased parameters if model assumptions are violated. This work introduces a data-driven multicomponent analysis, the monotonous slope non-negative matrix factorization (msNMF), tailored to extract data features expected in MR signals. METHODS The msNMF was implemented by extending the standard NMF with monotonicity constraints on the signal profiles and their first derivatives. The method was validated using simulated data, and subsequently applied to both ex vivo DWI data and in vivo relaxometry data. Reproducibility of the method was tested using the latter. RESULTS The msNMF recovered the multi-exponential signals in the simulated data and showed superiority to standard NMF (based on the explained variance, area under the ROC curve, and coefficient of variation). Diffusion components extracted from the DWI data reflected the cell density of the underlying tissue. The relaxometry analysis resulted in estimates of edema water fractions (EWF) highly correlated with published results, and demonstrated acceptable reproducibility. CONCLUSION The msNMF can robustly separate MR signals into components with relation to the underlying tissue composition, and may potentially be useful for e.g. tumor tissue characterization.
Collapse
Affiliation(s)
- Sofie Rahbek
- Department of Health Technology, Technical University of Denmark, Kgs. Lyngby 2800, Denmark
| | - Kristoffer H Madsen
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, 2650, Denmark; Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kgs. Lyngby 2800, Denmark
| | - Henrik Lundell
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, 2650, Denmark
| | - Faisal Mahmood
- Laboratory of Radiation Physics, Department of Oncology, Odense University Hospital, Odense C 5000, Denmark; Department of Clinical Research, University of Southern Denmark, Odense 5000, Denmark
| | - Lars G Hanson
- Department of Health Technology, Technical University of Denmark, Kgs. Lyngby 2800, Denmark; Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, 2650, Denmark.
| |
Collapse
|
14
|
Andersson M, Pizzolato M, Kjer HM, Skodborg KF, Lundell H, Dyrby TB. Does powder averaging remove dispersion bias in diffusion MRI diameter estimates within real 3D axonal architectures? Neuroimage 2021; 248:118718. [PMID: 34767939 DOI: 10.1016/j.neuroimage.2021.118718] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [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: 05/07/2021] [Revised: 10/26/2021] [Accepted: 11/08/2021] [Indexed: 11/26/2022] Open
Abstract
Noninvasive estimation of axon diameter with diffusion MRI holds the potential to investigate the dynamic properties of the brain network and pathology of neurodegenerative diseases. Recent studies use powder averaging to account for complex white matter architectures, but these have not been validated for real axonal geometries from regions that contain fibre crossings. Here, we present 120-304μm long segmented axons from X-ray nano-holotomography volumes of a splenium and crossing fibre region of a vervet monkey brain. We show that the axons in the complex crossing fibre region, which contains callosal, association, and corticospinal connections, are larger and exhibit a wider distribution than those of the splenium region. To accurately estimate the axon diameter in these regions, therefore, sensitivity to a wide range of diameters is required. We demonstrate how the q-value, b-value, signal-to-noise ratio and the assumed intra-axonal parallel diffusivity influence the range of measurable diameters with powder average approaches. Furthermore, we show how Gaussian distributed noise results in a wider range of measurable diameter at high b-values than Rician distributed noise, even at high signal-to-noise ratios of 100. The number of gradient directions is also shown to impose a lower bound on measurable diameter. Our results indicate that axon diameter estimation can be performed with only few b-shells, and that additional shells do not improve the accuracy of the estimate. For strong gradients available on human Connectom and preclinical scanners, Monte Carlo simulations of diffusion confirm that powder averaging techniques succeed in providing accurate estimates of axon diameter across a range of sequence parameters and diffusion times, even in complex white matter architectures. At relatively low b-values, the diameter estimate becomes sensitive to axonal microdispersion and the intra-axonal parallel diffusivity shows time dependency at both in vivo and ex vivo intrinsic diffusivities.
Collapse
Affiliation(s)
- Mariam Andersson
- Danish Research Centre for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Hvidovre 2650, Denmark; Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kongens Lyngby 2800, Denmark
| | - Marco Pizzolato
- Danish Research Centre for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Hvidovre 2650, Denmark; Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kongens Lyngby 2800, Denmark; Signal Processing Laboratory (LTS5), École Polytechnique Fédérale de Lausanne, Lausanne 1015, Switzerland
| | - Hans Martin Kjer
- Danish Research Centre for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Hvidovre 2650, Denmark; Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kongens Lyngby 2800, Denmark
| | - Katrine Forum Skodborg
- Danish Research Centre for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Hvidovre 2650, Denmark; Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kongens Lyngby 2800, Denmark
| | - Henrik Lundell
- Danish Research Centre for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Hvidovre 2650, Denmark; Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kongens Lyngby 2800, Denmark
| | - Tim B Dyrby
- Danish Research Centre for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Hvidovre 2650, Denmark; Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kongens Lyngby 2800, Denmark
| |
Collapse
|
15
|
Just Madsen MA, Wiggermann V, Lundell H, Puonti O, Blinkenberg M, Christensen JR, Sellebjerg F, Siebner HR. Neurophysiological changes associated with cortical lesions in multiple sclerosis. Brain Stimul 2021. [DOI: 10.1016/j.brs.2021.10.129] [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] Open
|
16
|
Chow HH, Talbot J, Marstrand L, Lundell H, Roman Siebner H, Bach Søndergaard H, Sellebjerg F. Smoking, cardiovascular risk factors and LRP2 gene variation: Associations with disease severity, cognitive function and brain structure in primary progressive multiple sclerosis. Mult Scler Relat Disord 2021; 56:103296. [PMID: 34678704 DOI: 10.1016/j.msard.2021.103296] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 09/28/2021] [Accepted: 09/30/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND Smoking, cardiovascular risk factors, and genetic factors can have adverse effects in MS. OBJECTIVE To determine if smoking after disease onset, cardiovascular risk factors, and genetic variants influence primary progressive MS (PPMS). METHOD In this cross-sectional study, smoking habits, Framingham Risk Score (FRS), genetic variants, including the low-density lipoprotein receptor-related protein 2 (LRP2) SNP rs12988804 and MRI were collected in 60 PPMS trial participants. Disability and cognition were assessed with the Age-Related Multiple Sclerosis Severity (ARMSS) score, the Progressive-Onset MS Multiple Sclerosis Severity Score, and the Brief International Cognitive Assessment for MS. RESULTS Smoking after PPMS onset was significantly associated with higher ARMSS (95% CI 0.8-2.4, p = 0.00016) statistically significant after Bonferroni correction. Lower magnetization transfer ratio in lesions was also significantly associated with smoking after onset of PPMS after correction (95% CI -0.9--4.4, p = 0.0035). Pack-years in people who smoked after onset was likewise significantly associated with higher ARMSS score (b = 0.06 95% CI 0.02-0.09, p = 0.0021) as well as lower Symbol Digit Modalities Test scores (b = -0.40; 95% CI -0.66--0.13, p = 0.0037), both statistically significant after Bonferroni correction. The LRP2 risk allele was associated with decreased performance on the California Verbal Learning Test 2 after correction (CC vs. CT+TT 95% CI -14.2--3.4, p = 0.0018). CONCLUSION If validated, these findings suggest that intervention regarding smoking may be beneficial in PPMS. If confirmed, assessment of the LRP2 gene variant may aid in the understanding of underlying pathological mechanisms in PPMS.
Collapse
Affiliation(s)
- Helene Højsgaard Chow
- Danish Multiple Sclerosis Center, Copenhagen University Hospital-Rigshospitalet, Nordre Ringevej, 57 2600 Glostrup, Denmark.
| | - Jacob Talbot
- Danish Multiple Sclerosis Center, Copenhagen University Hospital-Rigshospitalet, Nordre Ringevej, 57 2600 Glostrup, Denmark
| | - Lisbet Marstrand
- Danish Multiple Sclerosis Center, Copenhagen University Hospital-Rigshospitalet, Nordre Ringevej, 57 2600 Glostrup, Denmark
| | - Henrik Lundell
- Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital-Hvidovre, Kettegård Alle 30 2650 Hvidovre, Denmark
| | - Hartwig Roman Siebner
- Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital-Hvidovre, Kettegård Alle 30 2650 Hvidovre, Denmark; Department of Neurology, Copenhagen University Hospital Bispebjerg, Bispebjerg Bakke 23 2400 Copenhagen, Denmark; Institute for Clinical Medicine, University of Copenhagen, Blegdamsvej 3B 2200 Copenhagen N Copenhagen, Denmark
| | - Helle Bach Søndergaard
- Danish Multiple Sclerosis Center, Copenhagen University Hospital-Rigshospitalet, Nordre Ringevej, 57 2600 Glostrup, Denmark
| | - Finn Sellebjerg
- Danish Multiple Sclerosis Center, Copenhagen University Hospital-Rigshospitalet, Nordre Ringevej, 57 2600 Glostrup, Denmark; Department of Neurology, Copenhagen University Hospital Bispebjerg, Bispebjerg Bakke 23 2400 Copenhagen, Denmark
| |
Collapse
|
17
|
Højsgaard Chow H, Talbot J, Lundell H, Gøbel Madsen C, Marstrand L, Lange T, Mahler MR, Buhelt S, Holm Hansen R, Blinkenberg M, Romme Christensen J, Soelberg Sørensen P, Rode von Essen M, Siebner HR, Sellebjerg F. Dimethyl Fumarate Treatment in Patients With Primary Progressive Multiple Sclerosis: A Randomized, Controlled Trial. Neurol Neuroimmunol Neuroinflamm 2021; 8:8/5/e1037. [PMID: 34429340 PMCID: PMC8407149 DOI: 10.1212/nxi.0000000000001037] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 05/17/2021] [Indexed: 11/15/2022]
Abstract
Background and Objective To study whether dimethyl fumarate is superior to placebo in decreasing CSF concentrations of neurofilament light chain (NFL) in patients with primary progressive MS (PPMS). Methods In the double-blind, placebo-controlled phase 2 study dimethyl FUMArate treatment in Progressive Multiple Sclerosis (FUMAPMS), patients with PPMS were randomly assigned to treatment with 240 mg dimethyl fumarate or placebo in a 1:1 ratio for 48 weeks. The primary endpoint was change in concentration of NFL in the CSF. Secondary endpoints included other CSF biomarkers and clinical and MRI measures. Efficacy was evaluated for the full data set by multiple imputations to account for missing data. Safety was assessed for the full data set. Results Fifty-four patients (mean age 54.9 years [SD 6.1], median Expanded Disability Status Scale 4.0 [nterquartile range 4.0–6.0], disease duration 14.1 [SD 9.4], and 21 [39%] female) were randomized to either placebo (n = 27) or dimethyl fumarate (n = 27) therapy. At screening CSF concentrations, adjusted for age and sex, of NFL, myelin basic protein (MBP), soluble CD27, chitinase 3-like 1, and B-cell maturation antigen were higher than in a group of symptomatic controls. Twenty-six patients (96%) in the dimethyl fumarate group and 24 patients (89%) in the placebo group completed the randomized phase. Mean change in CSF concentrations of NFL did not differ between groups (mean difference 99 ng/L; 95% CI −292 to 491 ng/L). MBP in CSF decreased in the treatment group (−182 ng/L, 95% CI −323 to −41 ng/L compared with placebo). The difference observed in the multiple imputation data set was not significant in a per protocol analysis. This was nominally significant in the multiple imputation data set but not in the per protocol analysis This was not found in the per protocol analysis Other secondary and tertiary outcomes were not affected. Various infections, lymphopenia, flushing, and gastrointestinal side effects were more frequent in the dimethyl fumarate group. Serious adverse events were similar between groups. Discussion Dimethyl fumarate treatment for 48 weeks had no effect on any of the investigated efficacy measures in patients with PPMS. We did not observe adverse events not anticipated for dimethyl fumarate treatment. Trial Registration Information Clinicaltrials.gov identifier NCT02959658. Classification of Evidence This study provides Class I evidence that for patients with PPMS, dimethyl fumarate treatment has no effect on CSF NFL levels compared with placebo treatment.
Collapse
Affiliation(s)
- Helene Højsgaard Chow
- From the Danish Multiple Sclerosis Center (H.H.C., J.T., L.M., M.M., S.B., R.H.H., M.B., J.R.C., P.S.S., M.E., F.S.), Copenhagen University Hospital, Rigshospitalet Glostrup, Glostrup; Danish Research Centre for Magnetic Resonance (H.L., C.G.M., H.R.S.), Copenhagen University Hospital Hvidovre, Hvidovre; Section of Biostatistics (T.L.), Department of Public Health, University of Copenhagen, Copenhagen K; Department of Neurology (H.R.S.), Copenhagen University Hospital Bispebjerg, Copenhagen; and Institute for Clinical Medicine (H.R.S.), University of Copenhagen, Copenhagen N, Denmark
| | - Jacob Talbot
- From the Danish Multiple Sclerosis Center (H.H.C., J.T., L.M., M.M., S.B., R.H.H., M.B., J.R.C., P.S.S., M.E., F.S.), Copenhagen University Hospital, Rigshospitalet Glostrup, Glostrup; Danish Research Centre for Magnetic Resonance (H.L., C.G.M., H.R.S.), Copenhagen University Hospital Hvidovre, Hvidovre; Section of Biostatistics (T.L.), Department of Public Health, University of Copenhagen, Copenhagen K; Department of Neurology (H.R.S.), Copenhagen University Hospital Bispebjerg, Copenhagen; and Institute for Clinical Medicine (H.R.S.), University of Copenhagen, Copenhagen N, Denmark
| | - Henrik Lundell
- From the Danish Multiple Sclerosis Center (H.H.C., J.T., L.M., M.M., S.B., R.H.H., M.B., J.R.C., P.S.S., M.E., F.S.), Copenhagen University Hospital, Rigshospitalet Glostrup, Glostrup; Danish Research Centre for Magnetic Resonance (H.L., C.G.M., H.R.S.), Copenhagen University Hospital Hvidovre, Hvidovre; Section of Biostatistics (T.L.), Department of Public Health, University of Copenhagen, Copenhagen K; Department of Neurology (H.R.S.), Copenhagen University Hospital Bispebjerg, Copenhagen; and Institute for Clinical Medicine (H.R.S.), University of Copenhagen, Copenhagen N, Denmark
| | - Camilla Gøbel Madsen
- From the Danish Multiple Sclerosis Center (H.H.C., J.T., L.M., M.M., S.B., R.H.H., M.B., J.R.C., P.S.S., M.E., F.S.), Copenhagen University Hospital, Rigshospitalet Glostrup, Glostrup; Danish Research Centre for Magnetic Resonance (H.L., C.G.M., H.R.S.), Copenhagen University Hospital Hvidovre, Hvidovre; Section of Biostatistics (T.L.), Department of Public Health, University of Copenhagen, Copenhagen K; Department of Neurology (H.R.S.), Copenhagen University Hospital Bispebjerg, Copenhagen; and Institute for Clinical Medicine (H.R.S.), University of Copenhagen, Copenhagen N, Denmark
| | - Lisbet Marstrand
- From the Danish Multiple Sclerosis Center (H.H.C., J.T., L.M., M.M., S.B., R.H.H., M.B., J.R.C., P.S.S., M.E., F.S.), Copenhagen University Hospital, Rigshospitalet Glostrup, Glostrup; Danish Research Centre for Magnetic Resonance (H.L., C.G.M., H.R.S.), Copenhagen University Hospital Hvidovre, Hvidovre; Section of Biostatistics (T.L.), Department of Public Health, University of Copenhagen, Copenhagen K; Department of Neurology (H.R.S.), Copenhagen University Hospital Bispebjerg, Copenhagen; and Institute for Clinical Medicine (H.R.S.), University of Copenhagen, Copenhagen N, Denmark
| | - Theis Lange
- From the Danish Multiple Sclerosis Center (H.H.C., J.T., L.M., M.M., S.B., R.H.H., M.B., J.R.C., P.S.S., M.E., F.S.), Copenhagen University Hospital, Rigshospitalet Glostrup, Glostrup; Danish Research Centre for Magnetic Resonance (H.L., C.G.M., H.R.S.), Copenhagen University Hospital Hvidovre, Hvidovre; Section of Biostatistics (T.L.), Department of Public Health, University of Copenhagen, Copenhagen K; Department of Neurology (H.R.S.), Copenhagen University Hospital Bispebjerg, Copenhagen; and Institute for Clinical Medicine (H.R.S.), University of Copenhagen, Copenhagen N, Denmark
| | - Mie Reith Mahler
- From the Danish Multiple Sclerosis Center (H.H.C., J.T., L.M., M.M., S.B., R.H.H., M.B., J.R.C., P.S.S., M.E., F.S.), Copenhagen University Hospital, Rigshospitalet Glostrup, Glostrup; Danish Research Centre for Magnetic Resonance (H.L., C.G.M., H.R.S.), Copenhagen University Hospital Hvidovre, Hvidovre; Section of Biostatistics (T.L.), Department of Public Health, University of Copenhagen, Copenhagen K; Department of Neurology (H.R.S.), Copenhagen University Hospital Bispebjerg, Copenhagen; and Institute for Clinical Medicine (H.R.S.), University of Copenhagen, Copenhagen N, Denmark
| | - Sophie Buhelt
- From the Danish Multiple Sclerosis Center (H.H.C., J.T., L.M., M.M., S.B., R.H.H., M.B., J.R.C., P.S.S., M.E., F.S.), Copenhagen University Hospital, Rigshospitalet Glostrup, Glostrup; Danish Research Centre for Magnetic Resonance (H.L., C.G.M., H.R.S.), Copenhagen University Hospital Hvidovre, Hvidovre; Section of Biostatistics (T.L.), Department of Public Health, University of Copenhagen, Copenhagen K; Department of Neurology (H.R.S.), Copenhagen University Hospital Bispebjerg, Copenhagen; and Institute for Clinical Medicine (H.R.S.), University of Copenhagen, Copenhagen N, Denmark
| | - Rikke Holm Hansen
- From the Danish Multiple Sclerosis Center (H.H.C., J.T., L.M., M.M., S.B., R.H.H., M.B., J.R.C., P.S.S., M.E., F.S.), Copenhagen University Hospital, Rigshospitalet Glostrup, Glostrup; Danish Research Centre for Magnetic Resonance (H.L., C.G.M., H.R.S.), Copenhagen University Hospital Hvidovre, Hvidovre; Section of Biostatistics (T.L.), Department of Public Health, University of Copenhagen, Copenhagen K; Department of Neurology (H.R.S.), Copenhagen University Hospital Bispebjerg, Copenhagen; and Institute for Clinical Medicine (H.R.S.), University of Copenhagen, Copenhagen N, Denmark
| | - Morten Blinkenberg
- From the Danish Multiple Sclerosis Center (H.H.C., J.T., L.M., M.M., S.B., R.H.H., M.B., J.R.C., P.S.S., M.E., F.S.), Copenhagen University Hospital, Rigshospitalet Glostrup, Glostrup; Danish Research Centre for Magnetic Resonance (H.L., C.G.M., H.R.S.), Copenhagen University Hospital Hvidovre, Hvidovre; Section of Biostatistics (T.L.), Department of Public Health, University of Copenhagen, Copenhagen K; Department of Neurology (H.R.S.), Copenhagen University Hospital Bispebjerg, Copenhagen; and Institute for Clinical Medicine (H.R.S.), University of Copenhagen, Copenhagen N, Denmark
| | - Jeppe Romme Christensen
- From the Danish Multiple Sclerosis Center (H.H.C., J.T., L.M., M.M., S.B., R.H.H., M.B., J.R.C., P.S.S., M.E., F.S.), Copenhagen University Hospital, Rigshospitalet Glostrup, Glostrup; Danish Research Centre for Magnetic Resonance (H.L., C.G.M., H.R.S.), Copenhagen University Hospital Hvidovre, Hvidovre; Section of Biostatistics (T.L.), Department of Public Health, University of Copenhagen, Copenhagen K; Department of Neurology (H.R.S.), Copenhagen University Hospital Bispebjerg, Copenhagen; and Institute for Clinical Medicine (H.R.S.), University of Copenhagen, Copenhagen N, Denmark
| | - Per Soelberg Sørensen
- From the Danish Multiple Sclerosis Center (H.H.C., J.T., L.M., M.M., S.B., R.H.H., M.B., J.R.C., P.S.S., M.E., F.S.), Copenhagen University Hospital, Rigshospitalet Glostrup, Glostrup; Danish Research Centre for Magnetic Resonance (H.L., C.G.M., H.R.S.), Copenhagen University Hospital Hvidovre, Hvidovre; Section of Biostatistics (T.L.), Department of Public Health, University of Copenhagen, Copenhagen K; Department of Neurology (H.R.S.), Copenhagen University Hospital Bispebjerg, Copenhagen; and Institute for Clinical Medicine (H.R.S.), University of Copenhagen, Copenhagen N, Denmark
| | - Marina Rode von Essen
- From the Danish Multiple Sclerosis Center (H.H.C., J.T., L.M., M.M., S.B., R.H.H., M.B., J.R.C., P.S.S., M.E., F.S.), Copenhagen University Hospital, Rigshospitalet Glostrup, Glostrup; Danish Research Centre for Magnetic Resonance (H.L., C.G.M., H.R.S.), Copenhagen University Hospital Hvidovre, Hvidovre; Section of Biostatistics (T.L.), Department of Public Health, University of Copenhagen, Copenhagen K; Department of Neurology (H.R.S.), Copenhagen University Hospital Bispebjerg, Copenhagen; and Institute for Clinical Medicine (H.R.S.), University of Copenhagen, Copenhagen N, Denmark
| | - Hartwig Roman Siebner
- From the Danish Multiple Sclerosis Center (H.H.C., J.T., L.M., M.M., S.B., R.H.H., M.B., J.R.C., P.S.S., M.E., F.S.), Copenhagen University Hospital, Rigshospitalet Glostrup, Glostrup; Danish Research Centre for Magnetic Resonance (H.L., C.G.M., H.R.S.), Copenhagen University Hospital Hvidovre, Hvidovre; Section of Biostatistics (T.L.), Department of Public Health, University of Copenhagen, Copenhagen K; Department of Neurology (H.R.S.), Copenhagen University Hospital Bispebjerg, Copenhagen; and Institute for Clinical Medicine (H.R.S.), University of Copenhagen, Copenhagen N, Denmark
| | - Finn Sellebjerg
- From the Danish Multiple Sclerosis Center (H.H.C., J.T., L.M., M.M., S.B., R.H.H., M.B., J.R.C., P.S.S., M.E., F.S.), Copenhagen University Hospital, Rigshospitalet Glostrup, Glostrup; Danish Research Centre for Magnetic Resonance (H.L., C.G.M., H.R.S.), Copenhagen University Hospital Hvidovre, Hvidovre; Section of Biostatistics (T.L.), Department of Public Health, University of Copenhagen, Copenhagen K; Department of Neurology (H.R.S.), Copenhagen University Hospital Bispebjerg, Copenhagen; and Institute for Clinical Medicine (H.R.S.), University of Copenhagen, Copenhagen N, Denmark.
| |
Collapse
|
18
|
Postans M, Parker GD, Lundell H, Ptito M, Hamandi K, Gray WP, Aggleton JP, Dyrby TB, Jones DK, Winter M. Uncovering a Role for the Dorsal Hippocampal Commissure in Recognition Memory. Cereb Cortex 2021; 30:1001-1015. [PMID: 31364703 PMCID: PMC7132945 DOI: 10.1093/cercor/bhz143] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 05/31/2019] [Accepted: 05/31/2019] [Indexed: 01/24/2023] Open
Abstract
The dorsal hippocampal commissure (DHC) is a white matter tract that provides interhemispheric connections between temporal lobe brain regions. Despite the importance of these regions for learning and memory, there is scant evidence of a role for the DHC in successful memory performance. We used diffusion-weighted magnetic resonance imaging (DW-MRI) and white matter tractography to reconstruct the DHC in both humans (in vivo) and nonhuman primates (ex vivo). Across species, our findings demonstrate a close consistency between the known anatomy and tract reconstructions of the DHC. Anterograde tract-tracer techniques also highlighted the parahippocampal origins of DHC fibers in nonhuman primates. Finally, we derived diffusion tensor MRI metrics from the DHC in a large sample of human subjects to investigate whether interindividual variation in DHC microstructure is predictive of memory performance. The mean diffusivity of the DHC correlated with performance in a standardized recognition memory task, an effect that was not reproduced in a comparison commissure tract—the anterior commissure. These findings highlight a potential role for the DHC in recognition memory, and our tract reconstruction approach has the potential to generate further novel insights into the role of this previously understudied white matter tract in both health and disease.
Collapse
Affiliation(s)
- M Postans
- Cardiff University Brain Research Imaging Centre, CF24 4HQ.,School of Psychology, CF10 3AS
| | - G D Parker
- Cardiff University Brain Research Imaging Centre, CF24 4HQ.,Experimental MRI Centre, School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - H Lundell
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, DK-2650, Denmark
| | - M Ptito
- School of Optometry, University of Montreal, H3T 1J4 Montreal, Canada.,Department of Neurology and Neurosurgery, Montreal Neurological Institute, H3A 2B4 Montreal, Canada
| | - K Hamandi
- Cardiff University Brain Research Imaging Centre, CF24 4HQ.,The Alan Richens Welsh Epilepsy Centre, Department of Neurology, University Hospital of Wales, Cardiff CF14 4XW, UK.,Institute of Psychological Medicine and Clinical Neurosciences.,Brain Repair And Intracranial Neurotherapeutics Unit, School of Medicine, Cardiff University, Cardiff CF24 4HQ, UK
| | - W P Gray
- Cardiff University Brain Research Imaging Centre, CF24 4HQ.,The Alan Richens Welsh Epilepsy Centre, Department of Neurology, University Hospital of Wales, Cardiff CF14 4XW, UK.,Institute of Psychological Medicine and Clinical Neurosciences.,Brain Repair And Intracranial Neurotherapeutics Unit, School of Medicine, Cardiff University, Cardiff CF24 4HQ, UK.,Department of Neurosurgery, Neurosciences Division, University Hospital Wales, Cardiff, CF14 4XW, UK
| | - J P Aggleton
- Cardiff University Brain Research Imaging Centre, CF24 4HQ.,School of Psychology, CF10 3AS
| | - T B Dyrby
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, DK-2650, Denmark.,Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kongens Lyngby, Denmark, DK-2800
| | - D K Jones
- Cardiff University Brain Research Imaging Centre, CF24 4HQ.,School of Psychology, CF10 3AS.,Brain Repair And Intracranial Neurotherapeutics Unit, School of Medicine, Cardiff University, Cardiff CF24 4HQ, UK.,Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne 3000, Australia
| | - M Winter
- Cardiff University Brain Research Imaging Centre, CF24 4HQ.,School of Psychology, CF10 3AS.,Brain Repair And Intracranial Neurotherapeutics Unit, School of Medicine, Cardiff University, Cardiff CF24 4HQ, UK.,Department of Clinical Neuropsychology, University Hospital of Wales, Cardiff, CF14 4XW, UK
| |
Collapse
|
19
|
Lundell H, Ingo C, Dyrby TB, Ronen I. Cytosolic diffusivity and microscopic anisotropy of N-acetyl aspartate in human white matter with diffusion-weighted MRS at 7 T. NMR Biomed 2021; 34:e4304. [PMID: 32232909 PMCID: PMC8244075 DOI: 10.1002/nbm.4304] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 03/11/2020] [Accepted: 03/12/2020] [Indexed: 06/10/2023]
Abstract
Metabolite diffusion measurable in humans in vivo with diffusion-weighted spectroscopy (DW-MRS) provides a window into the intracellular morphology and state of specific cell types. Anisotropic diffusion in white matter is governed by the microscopic properties of the individual cell types and their structural units (axons, soma, dendrites). However, anisotropy is also markedly affected by the macroscopic orientational distribution over the imaging voxel, particularly in DW-MRS, where the dimensions of the volume of interest (VOI) are much larger than those typically used in diffusion-weighted imaging. One way to address the confound of macroscopic structural features is to average the measurements acquired with uniformly distributed gradient directions to mimic a situation where fibers present in the VOI are orientationally uniformly distributed. This situation allows the extraction of relevant microstructural features such as transverse and longitudinal diffusivities within axons and the related microscopic fractional anisotropy. We present human DW-MRS data acquired at 7 T in two different white matter regions, processed and analyzed as described above, and find that intra-axonal diffusion of the neuronal metabolite N-acetyl aspartate is in good correspondence to simple model interpretations, such as multi-Gaussian diffusion from disperse fibers where the transverse diffusivity can be neglected. We also discuss the implications of our approach for current and future applications of DW-MRS for cell-specific measurements.
Collapse
Affiliation(s)
- Henrik Lundell
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and ResearchCopenhagen University Hospital HvidovreDenmark
| | - Carson Ingo
- Department of Physical Therapy and Human Movement SciencesNorthwestern UniversityChicagoIllinois
- Department of NeurologyNorthwestern UniversityChicagoIllinois
| | - Tim B. Dyrby
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and ResearchCopenhagen University Hospital HvidovreDenmark
- Department of Applied Mathematics and Computer ScienceTechnical University of DenmarkKongens LyngbyDenmark
| | - Itamar Ronen
- C. J. Gorter Center for High Field MRI, Department of RadiologyLeiden University Medical CenterLeidenThe Netherlands
| |
Collapse
|
20
|
Lundell H, Najac C, Bulk M, Kan HE, Webb AG, Ronen I. Compartmental diffusion and microstructural properties of human brain gray and white matter studied with double diffusion encoding magnetic resonance spectroscopy of metabolites and water. Neuroimage 2021; 234:117981. [PMID: 33757904 PMCID: PMC8204266 DOI: 10.1016/j.neuroimage.2021.117981] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 02/05/2021] [Accepted: 03/13/2021] [Indexed: 02/02/2023] Open
Abstract
Double diffusion encoding (DDE) of the water signal offers a unique ability to separate the effect of microscopic anisotropic diffusion in structural units of tissue from the overall macroscopic orientational distribution of cells. However, the specificity in detected microscopic anisotropy is limited as the signal is averaged over different cell types and across tissue compartments. Performing side-by-side water and metabolite DDE spectroscopic (DDES) experiments provides complementary measures from which intracellular and extracellular microscopic fractional anisotropies (μFA) and diffusivities can be estimated. Metabolites are largely confined to the intracellular space and therefore provide a benchmark for intracellular μFA and diffusivities of specific cell types. By contrast, water DDES measurements allow examination of the separate contributions to water μFA and diffusivity from the intra- and extracellular spaces, by using a wide range of b values to gradually eliminate the extracellular contribution. Here, we aimed to estimate tissue and compartment specific human brain microstructure by combining water and metabolites DDES experiments. We performed our DDES measurements in two brain regions that contain widely different amounts of white matter (WM) and gray matter (GM): parietal white matter (PWM) and occipital gray matter (OGM) in a total of 20 healthy volunteers at 7 Tesla. Metabolite DDES measurements were performed at b = 7199 s/mm2, while water DDES measurements were performed with a range of b values from 918 to 7199 s/mm2. The experimental framework we employed here resulted in a set of insights pertaining to the morphology of the intracellular and extracellular spaces in both gray and white matter. Results of the metabolite DDES experiments in both PWM and OGM suggest a highly anisotropic intracellular space within neurons and glia, with the possible exception of gray matter glia. The water μFA obtained from the DDES results at high b values in both regions converged with that of the metabolite DDES, suggesting that the signal from the extracellular space is indeed effectively suppressed at the highest b value. The μFA measured in the OGM significantly decreased at lower b values, suggesting a considerably lower anisotropy of the extracellular space in GM compared to WM. In PWM, the water μFA remained high even at the lowest b value, indicating a high degree of organization in the interstitial space in WM. Tortuosity values in the cytoplasm for water and tNAA, obtained with correlation analysis of microscopic parallel diffusivity with respect to GM/WM tissue fraction in the volume of interest, are remarkably similar for both molecules, while exhibiting a clear difference between gray and white matter, suggesting a more crowded cytoplasm and more complex cytomorphology of neuronal cell bodies and dendrites in GM than those found in long-range axons in WM.
Collapse
Affiliation(s)
- Henrik Lundell
- Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Centre for Functional and Diagnostic Imaging and Research, Kettegaards Allé 30, 2650 Hvidovre, Denmark.
| | - Chloé Najac
- C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Marjolein Bulk
- C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Hermien E Kan
- C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Andrew G Webb
- C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Itamar Ronen
- C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| |
Collapse
|
21
|
Henriques RN, Palombo M, Jespersen SN, Shemesh N, Lundell H, Ianuş A. Double diffusion encoding and applications for biomedical imaging. J Neurosci Methods 2020; 348:108989. [PMID: 33144100 DOI: 10.1016/j.jneumeth.2020.108989] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 09/25/2020] [Accepted: 10/20/2020] [Indexed: 12/11/2022]
Abstract
Diffusion Magnetic Resonance Imaging (dMRI) is one of the most important contemporary non-invasive modalities for probing tissue structure at the microscopic scale. The majority of dMRI techniques employ standard single diffusion encoding (SDE) measurements, covering different sequence parameter ranges depending on the complexity of the method. Although many signal representations and biophysical models have been proposed for SDE data, they are intrinsically limited by a lack of specificity. Advanced dMRI methods have been proposed to provide additional microstructural information beyond what can be inferred from SDE. These enhanced contrasts can play important roles in characterizing biological tissues, for instance upon diseases (e.g. neurodegenerative, cancer, stroke), aging, learning, and development. In this review we focus on double diffusion encoding (DDE), which stands out among other advanced acquisitions for its versatility, ability to probe more specific diffusion correlations, and feasibility for preclinical and clinical applications. Various DDE methodologies have been employed to probe compartment sizes (Section 3), decouple the effects of microscopic diffusion anisotropy from orientation dispersion (Section 4), probe displacement correlations, study exchange, or suppress fast diffusing compartments (Section 6). DDE measurements can also be used to improve the robustness of biophysical models (Section 5) and study intra-cellular diffusion via magnetic resonance spectroscopy of metabolites (Section 7). This review discusses all these topics as well as important practical aspects related to the implementation and contrast in preclinical and clinical settings (Section 9) and aims to provide the readers a guide for deciding on the right DDE acquisition for their specific application.
Collapse
Affiliation(s)
- Rafael N Henriques
- Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Marco Palombo
- Centre for Medical Image Computing and Dept. of Computer Science, University College London, London, UK
| | - Sune N Jespersen
- Center of Functionally Integrative Neuroscience (CFIN) and MINDLab, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - Noam Shemesh
- Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Henrik Lundell
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Denmark
| | - Andrada Ianuş
- Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal.
| |
Collapse
|
22
|
Andersen KW, Lasič S, Lundell H, Nilsson M, Topgaard D, Sellebjerg F, Szczepankiewicz F, Siebner HR, Blinkenberg M, Dyrby TB. Disentangling white-matter damage from physiological fibre orientation dispersion in multiple sclerosis. Brain Commun 2020; 2:fcaa077. [PMID: 32954329 PMCID: PMC7472898 DOI: 10.1093/braincomms/fcaa077] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 04/20/2020] [Accepted: 05/07/2020] [Indexed: 01/23/2023] Open
Abstract
Multiple sclerosis leads to diffuse damage of the central nervous system, affecting also the normal-appearing white matter. Demyelination and axonal degeneration reduce regional fractional anisotropy in normal-appearing white matter, which can be routinely mapped with diffusion tensor imaging. However, the standard fractional anisotropy metric is also sensitive to physiological variations in orientation dispersion of white matter fibres. This complicates the detection of disease-related damage in large parts of cerebral white matter where microstructure physiologically displays a high degree of fibre dispersion. To resolve this ambiguity, we employed a novel tensor-valued encoding method for diffusion MRI, which yields a microscopic fractional anisotropy metric that is unaffected by regional variations in orientation dispersion. In 26 patients with relapsing-remitting multiple sclerosis, 14 patients with primary-progressive multiple sclerosis and 27 age-matched healthy controls, we compared standard fractional anisotropy mapping with the novel microscopic fractional anisotropy mapping method, focusing on normal-appearing white matter. Mean microscopic fractional anisotropy and standard fractional anisotropy of normal-appearing white matter were significantly reduced in both patient groups relative to healthy controls, but microscopic fractional anisotropy yielded a better reflection of disease-related white-matter alterations. The reduction in mean microscopic fractional anisotropy showed a significant positive linear relationship with physical disability, as reflected by the expanded disability status scale. Mean reduction of microscopic fractional anisotropy in normal-appearing white matter also scaled positively with individual cognitive dysfunction, as measured with the symbol digit modality test. Mean microscopic fractional anisotropy reduction in normal-appearing white matter also showed a positive relationship with total white-matter lesion load as well as lesion load in specific tract systems. None of these relationships between normal-appearing white-matter microstructure and clinical, cognitive or structural measures emerged when using mean fractional anisotropy. Together, the results provide converging evidence that microscopic fractional anisotropy mapping substantially advances the assessment of cerebral white matter in multiple sclerosis by disentangling microstructure damage from variations in physiological fibre orientation dispersion at the stage of data acquisition. Since tensor-valued encoding can be implemented in routine diffusion MRI, microscopic fractional anisotropy mapping bears considerable potential for the future assessment of disease progression in normal-appearing white matter in both relapsing-remitting and progressive forms of multiple sclerosis as well as other white-matter-related brain diseases.
Collapse
Affiliation(s)
- Kasper Winther Andersen
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, 2650 Hvidovre, Denmark
| | - Samo Lasič
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, 2650 Hvidovre, Denmark
- Random Walk Imaging, AB, 222 24 Lund, Sweden
| | - Henrik Lundell
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, 2650 Hvidovre, Denmark
| | - Markus Nilsson
- Department of Radiology, Clinical Sciences, Lund, Lund University, 221 00 Lund, Sweden
| | - Daniel Topgaard
- Division of Physical Chemistry, Department of Chemistry, Lund University, 221 00 Lund, Sweden
| | - Finn Sellebjerg
- Danish Multiple Sclerosis Center, Copenhagen University Hospital, Rigshospitalet, 2100 Copenhagen, Denmark
| | - Filip Szczepankiewicz
- Department of Medical Radiation Physics, Clinical Sciences, Lund, Lund University, 221 00 Lund, Sweden
| | - Hartwig Roman Siebner
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, 2650 Hvidovre, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark
- Department of Neurology, Copenhagen University Hospital Bispebjerg, 2400 Copenhagen NV, Denmark
| | - Morten Blinkenberg
- Danish Multiple Sclerosis Center, Copenhagen University Hospital, Rigshospitalet, 2100 Copenhagen, Denmark
| | - Tim B Dyrby
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, 2650 Hvidovre, Denmark
- Department of Applied Mathematics and Computer Science, Technical University of Denmark, 2700 Kongens Lyngby, Denmark
| |
Collapse
|
23
|
Ambrosen KS, Eskildsen SF, Hinne M, Krug K, Lundell H, Schmidt MN, van Gerven MAJ, Mørup M, Dyrby TB. Validation of structural brain connectivity networks: The impact of scanning parameters. Neuroimage 2019; 204:116207. [PMID: 31539592 DOI: 10.1016/j.neuroimage.2019.116207] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 08/20/2019] [Accepted: 09/17/2019] [Indexed: 12/20/2022] Open
Abstract
Evaluation of the structural connectivity (SC) of the brain based on tractography has mainly focused on the choice of diffusion model, tractography algorithm, and their respective parameter settings. Here, we systematically validate SC derived from a post mortem monkey brain, while varying key acquisition parameters such as the b-value, gradient angular resolution and image resolution. As gold standard we use the connectivity matrix obtained invasively with histological tracers by Markov et al. (2014). As performance metric, we use cross entropy as a measure that enables comparison of the relative tracer labeled neuron counts to the streamline counts from tractography. We find that high angular resolution and high signal-to-noise ratio are important to estimate SC, and that SC derived from low image resolution (1.03 mm3) are in better agreement with the tracer network, than those derived from high image resolution (0.53 mm3) or at an even lower image resolution (2.03 mm3). In contradiction, sensitivity and specificity analyses suggest that if the angular resolution is sufficient, the balanced compromise in which sensitivity and specificity are identical remains 60-64% regardless of the other scanning parameters. Interestingly, the tracer graph is assumed to be the gold standard but by thresholding, the balanced compromise increases to 70-75%. Hence, by using performance metrics based on binarized tracer graphs, one risks losing important information, changing the performance of SC graphs derived by tractography and their dependence of different scanning parameters.
Collapse
Affiliation(s)
- Karen S Ambrosen
- Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kgs. Lyngby, Denmark; Danish Research Centre for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Simon F Eskildsen
- Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Max Hinne
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands
| | - Kristine Krug
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK; Institute of Biology, Otto-von-Guericke-Universität Magdeburg, Magdeburg, Germany; Leibniz-Insitute for Neurobiology, Magdeburg, Germany
| | - Henrik Lundell
- Danish Research Centre for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Mikkel N Schmidt
- Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Marcel A J van Gerven
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands
| | - Morten Mørup
- Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Tim B Dyrby
- Danish Research Centre for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kgs. Lyngby, Denmark.
| |
Collapse
|
24
|
Lundell H, Nilsson M, Dyrby TB, Parker GJM, Cristinacce PLH, Zhou FL, Topgaard D, Lasič S. Multidimensional diffusion MRI with spectrally modulated gradients reveals unprecedented microstructural detail. Sci Rep 2019; 9:9026. [PMID: 31227745 PMCID: PMC6588609 DOI: 10.1038/s41598-019-45235-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Accepted: 06/04/2019] [Indexed: 12/11/2022] Open
Abstract
Characterization of porous media is essential in a wide range of biomedical and industrial applications. Microstructural features can be probed non-invasively by diffusion magnetic resonance imaging (dMRI). However, diffusion encoding in conventional dMRI may yield similar signatures for very different microstructures, which represents a significant limitation for disentangling individual microstructural features in heterogeneous materials. To solve this problem, we propose an augmented multidimensional diffusion encoding (MDE) framework, which unlocks a novel encoding dimension to assess time-dependent diffusion specific to structures with different microscopic anisotropies. Our approach relies on spectral analysis of complex but experimentally efficient MDE waveforms. Two independent contrasts to differentiate features such as cell shape and size can be generated directly by signal subtraction from only three types of measurements. Analytical calculations and simulations support our experimental observations. Proof-of-concept experiments were applied on samples with known and distinctly different microstructures. We further demonstrate substantially different contrasts in different tissue types of a post mortem brain. Our simultaneous assessment of restriction size and shape may be instrumental in studies of a wide range of porous materials, enable new insights into the microstructure of biological tissues or be of great value in diagnostics.
Collapse
Affiliation(s)
- H Lundell
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark.
| | - M Nilsson
- Clinical Sciences Lund, Radiology, Lund University, Lund, Sweden
| | - T B Dyrby
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
- Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kongens Lyngby, Denmark
| | - G J M Parker
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, The University of Manchester, Manchester, M13 9PT, United Kingdom
- Bioxydyn Limited, Manchester, United Kingdom
| | - P L Hubbard Cristinacce
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, The University of Manchester, Manchester, M13 9PT, United Kingdom
| | - F-L Zhou
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, The University of Manchester, Manchester, M13 9PT, United Kingdom
| | - D Topgaard
- Division of Physical Chemistry, Department of Chemistry, Lund University, Lund, Sweden
| | - S Lasič
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
- Random Walk Imaging AB, Lund, Sweden
| |
Collapse
|
25
|
Sangari S, Lundell H, Kirshblum S, Perez MA. Residual descending motor pathways influence spasticity after spinal cord injury. Ann Neurol 2019; 86:28-41. [PMID: 31102289 DOI: 10.1002/ana.25505] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 05/14/2019] [Accepted: 05/15/2019] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Spasticity is one of the most common symptoms manifested in humans with spinal cord injury (SCI). The neural mechanisms contributing to its development are not yet understood. Using neurophysiological and imaging techniques, we examined the influence of residual descending motor pathways on spasticity in humans with SCI. METHODS We measured spasticity in 33 individuals with motor complete SCI (determined by clinical examination) without preservation of voluntary motor output in the quadriceps femoris muscle. To examine residual descending motor pathways, we used magnetic and electrical stimulation over the leg motor cortex to elicit motor evoked potentials (MEPs) in the quadriceps femoris muscle and structural magnetic resonance imaging to measure spinal cord atrophy. RESULTS We found that 60% of participants showed symptoms of spasticity, whereas the other 40% showed no spasticity, demonstrating the presence of 2 clear subgroups of humans with motor complete SCI. MEPs were only present in individuals who had spasticity, and MEP size correlated with the severity of spasticity. Spinal cord atrophy was greater in nonspastic compared with spastic subjects. Notably, the degree of spared tissue in the lateral regions of the spinal cord was positively correlated with the severity of spasticity, indicating preservation of white matter related to motor tracts when spasticity was present. INTERPRETATION These results support the hypothesis that preservation of descending motor pathways influences spasticity in humans with motor complete SCI; this knowledge might help the rehabilitation and assessment of people with SCI. ANN NEUROL 2019.
Collapse
Affiliation(s)
- Sina Sangari
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami and Bruce W. Carter Department of Veterans Affairs Medical Center, Miami, FL
| | - Henrik Lundell
- Danish Research Center for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Steven Kirshblum
- Kessler Institute for Rehabilitation, Department of Physical Medicine and Rehabilitation, Rutgers New Jersey Medical School, Newark, NJ
| | - Monica A Perez
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami and Bruce W. Carter Department of Veterans Affairs Medical Center, Miami, FL
| |
Collapse
|
26
|
Karabanov A, Grønlund, Mogensen J, Lundell H, Siebner H. The dynamic modulation of inter-hemispheric inhibition during bimanual grip force control. Brain Stimul 2019. [DOI: 10.1016/j.brs.2018.12.857] [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: 10/27/2022] Open
|
27
|
Dyrby TB, Innocenti GM, Bech M, Lundell H. Validation strategies for the interpretation of microstructure imaging using diffusion MRI. Neuroimage 2018; 182:62-79. [PMID: 29920374 DOI: 10.1016/j.neuroimage.2018.06.049] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [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: 10/18/2017] [Revised: 06/08/2018] [Accepted: 06/15/2018] [Indexed: 12/19/2022] Open
Abstract
Extracting microanatomical information beyond the image resolution of MRI would provide valuable tools for diagnostics and neuroscientific research. A number of mathematical models already suggest microstructural interpretations of diffusion MRI (dMRI) data. Examples of such microstructural features could be cell bodies and neurites, e.g. the axon's diameter or their orientational distribution for global connectivity analysis using tractography, and have previously only been possible to access through conventional histology of post mortem tissue or invasive biopsies. The prospect of gaining the same knowledge non-invasively from the whole living human brain could push the frontiers for the diagnosis of neurological and psychiatric diseases. It could also provide a general understanding of the development and natural variability in the healthy brain across a population. However, due to a limited image resolution, most of the dMRI measures are indirect estimations and may depend on the whole chain from experimental parameter settings to model assumptions and implementation. Here, we review current literature in this field and highlight the integrative work across anatomical length scales that is needed to validate and trust a new dMRI method. We encourage interdisciplinary collaborations and data sharing in regards to applying and developing new validation techniques to improve the specificity of future dMRI methods.
Collapse
Affiliation(s)
- Tim B Dyrby
- Danish Research Centre for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kongens Lyngby, Denmark.
| | - Giorgio M Innocenti
- Karolinska Institutet, Department of Neuroscience, Stockholm, Sweden; Brain and Mind Institute, Swiss Federal Institute of Technology in Lausanne, Lausanne, Switzerland
| | - Martin Bech
- Medical Radiation Physics, Lund University, Lund, Sweden
| | - Henrik Lundell
- Danish Research Centre for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| |
Collapse
|
28
|
Nielsen JS, Dyrby TB, Lundell H. Magnetic resonance temporal diffusion tensor spectroscopy of disordered anisotropic tissue. Sci Rep 2018; 8:2930. [PMID: 29440724 PMCID: PMC5811563 DOI: 10.1038/s41598-018-19475-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [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: 07/12/2017] [Accepted: 12/17/2017] [Indexed: 01/09/2023] Open
Abstract
Molecular diffusion measured with diffusion weighted MRI (DWI) offers a probe for tissue microstructure. However, inferring microstructural properties from conventional DWI data is a complex inverse problem and has to account for heterogeneity in sizes, shapes and orientations of the tissue compartments contained within an imaging voxel. Alternative experimental means for disentangling the signal signatures of such features could provide a stronger link between the data and its interpretation. Double diffusion encoding (DDE) offers the possibility to factor out variation in compartment shapes from orientational dispersion of anisotropic domains by measuring the correlation between diffusivity in multiple directions. Time dependence of the diffusion is another effect reflecting the dimensions and distributions of barriers. In this paper we extend on DDE with a modified version of the oscillating gradient spin echo (OGSE) experiment, giving a basic contrast mechanism closely linked to both the temporal diffusion spectrum and the compartment anisotropy. We demonstrate our new method on post mortem brain tissue and show that we retrieve the correct temporal diffusion tensor spectrum in synthetic data from Monte Carlo simulations of random walks in a range of disordered geometries of different sizes and shapes.
Collapse
Affiliation(s)
- Jonathan Scharff Nielsen
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark
- Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Tim B Dyrby
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark
- Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Henrik Lundell
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark.
| |
Collapse
|
29
|
Lundell H, Svolgaard O, Dogonowski AM, Romme Christensen J, Selleberg F, Soelberg Sørensen P, Blinkenberg M, Siebner HR, Garde E. Spinal cord atrophy in anterior-posterior direction reflects impairment in multiple sclerosis. Acta Neurol Scand 2017; 136:330-337. [PMID: 28070886 DOI: 10.1111/ane.12729] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/22/2016] [Indexed: 01/28/2023]
Abstract
OBJECTIVE To investigate how atrophy is distributed over the cross section of the upper cervical spinal cord and how this relates to functional impairment in multiple sclerosis (MS). METHODS We analysed the structural brain MRI scans of 54 patients with relapsing-remitting MS (n=22), primary progressive MS (n=9), secondary progressive MS (n=23) and 23 age- and sex-matched healthy controls. We measured the cross-sectional area (CSA), left-right width (LRW) and anterior-posterior width (APW) of the spinal cord at the segmental level C2. We tested for a nonparametric linear relationship between these atrophy measures and clinical impairments as reflected by the Expanded Disability Status Scale (EDSS) and Multiple Sclerosis Impairment Scale (MSIS). RESULTS In patients with MS, CSA and APW but not LRW were reduced compared to healthy controls (P<.02) and showed significant correlations with EDSS, MSIS and specific MSIS subscores. CONCLUSION In patients with MS, atrophy of the upper cervical cord is most evident in the antero-posterior direction. As APW of the cervical cord can be readily derived from standard structural MRI of the brain, APW constitutes a clinically useful neuroimaging marker of disease-related neurodegeneration in MS.
Collapse
Affiliation(s)
- H. Lundell
- Danish Research Centre for Magnetic Resonance; Copenhagen University Hospital Hvidovre; Hvidovre Denmark
| | - O. Svolgaard
- Danish Research Centre for Magnetic Resonance; Copenhagen University Hospital Hvidovre; Hvidovre Denmark
| | - A.-M. Dogonowski
- Danish Research Centre for Magnetic Resonance; Copenhagen University Hospital Hvidovre; Hvidovre Denmark
| | - J. Romme Christensen
- Danish Multiple Sclerosis Center; Rigshospitalet; University of Copenhagen; Copenhagen Denmark
| | - F. Selleberg
- Danish Multiple Sclerosis Center; Rigshospitalet; University of Copenhagen; Copenhagen Denmark
| | - P. Soelberg Sørensen
- Danish Multiple Sclerosis Center; Rigshospitalet; University of Copenhagen; Copenhagen Denmark
| | - M. Blinkenberg
- Danish Multiple Sclerosis Center; Rigshospitalet; University of Copenhagen; Copenhagen Denmark
| | - H. R. Siebner
- Danish Research Centre for Magnetic Resonance; Copenhagen University Hospital Hvidovre; Hvidovre Denmark
- Department of Neurology; Copenhagen University Hospital Bispebjerg; Copenhagen Denmark
| | - E. Garde
- Danish Research Centre for Magnetic Resonance; Copenhagen University Hospital Hvidovre; Hvidovre Denmark
| |
Collapse
|
30
|
Lasič S, Lundell H, Topgaard D, Dyrby TB. Effects of imaging gradients in sequences with varying longitudinal storage time—Case of diffusion exchange imaging. Magn Reson Med 2017; 79:2228-2235. [DOI: 10.1002/mrm.26856] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 06/28/2017] [Accepted: 07/07/2017] [Indexed: 12/20/2022]
Affiliation(s)
- Samo Lasič
- Danish Research Centre for Magnetic ResonanceCentre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital HvidovreHvidovre Copenhagen Denmark
- CR Development ABLundSweden
| | - Henrik Lundell
- Danish Research Centre for Magnetic ResonanceCentre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital HvidovreHvidovre Copenhagen Denmark
| | | | - Tim B. Dyrby
- Danish Research Centre for Magnetic ResonanceCentre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital HvidovreHvidovre Copenhagen Denmark
- Department of Applied Mathematics and Computer ScienceTechnical University of DenmarkKongens Lyngby Denmark
| |
Collapse
|
31
|
Shemesh N, Jespersen SN, Alexander DC, Cohen Y, Drobnjak I, Dyrby TB, Finsterbusch J, Koch MA, Kuder T, Laun F, Lawrenz M, Lundell H, Mitra PP, Nilsson M, Özarslan E, Topgaard D, Westin CF. Conventions and nomenclature for double diffusion encoding NMR and MRI. Magn Reson Med 2015; 75:82-7. [DOI: 10.1002/mrm.25901] [Citation(s) in RCA: 140] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 07/13/2015] [Accepted: 07/29/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Noam Shemesh
- Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown; Lisbon Portugal
| | - Sune N. Jespersen
- CFIN/MindLab, Aarhus University; Aarhus Denmark
- Department of Physics and Astronomy; Aarhus University; Aarhus Denmark
| | - Daniel C. Alexander
- Centre for Medical Image Computing, Department of Computer Science, University College London; London United Kingdom
| | - Yoram Cohen
- School of Chemistry, the Raymond and Beverly Sackler Faculty of Exact Sciences; Tel Aviv University; Tel Aviv Israel
- Sagol School of Neurosciences; Tel Aviv University; Tel Aviv Israel
| | - Ivana Drobnjak
- Centre for Medical Image Computing, Department of Computer Science, University College London; London United Kingdom
| | - Tim B. Dyrby
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre; Hvidovre Denmark
| | - Jurgen Finsterbusch
- Department of Systems Neuroscience; University Medical Center Hamburg-Eppendorf; Hamburg Germany
- Neuroimage Nord, University Medical Centers Hamburg-Kiel-Lübeck; Germany
| | - Martin A. Koch
- Institute of Medical Engineering; University of Lübeck; Lübeck Germany
| | - Tristan Kuder
- Medical Physics in Radiology, German Cancer Research Center; Im Neuenheimer Feld 280 Heidelberg Germany
| | - Fredrik Laun
- Medical Physics in Radiology, German Cancer Research Center; Im Neuenheimer Feld 280 Heidelberg Germany
| | - Marco Lawrenz
- Department of Systems Neuroscience; University Medical Center Hamburg-Eppendorf; Hamburg Germany
| | - Henrik Lundell
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre; Hvidovre Denmark
| | - Partha P. Mitra
- Cold Spring Harbor Laboratory; Cold Spring Harbor New York USA
| | - Markus Nilsson
- Lund University Bioimaging Center, Lund University; Lund Sweden
| | - Evren Özarslan
- Department of Physics; Boğaziçi University; Bebek Istanbul Turkey
| | - Daniel Topgaard
- Division of Physical Chemistry, Department of Chemistry; Lund University; Lund Sweden
| | - Carl-Fredrik Westin
- Department of Radiology, Brigham and Women's Hospital; Harvard Medical School; Boston Massachusetts USA
| |
Collapse
|
32
|
Barthélemy D, Willerslev-Olsen M, Lundell H, Biering-Sørensen F, Nielsen JB. Assessment of transmission in specific descending pathways in relation to gait and balance following spinal cord injury. Sensorimotor Rehabilitation - At the Crossroads of Basic and Clinical Sciences 2015; 218:79-101. [DOI: 10.1016/bs.pbr.2014.12.012] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
|
33
|
Dyrby TB, Lundell H, Burke MW, Reislev NL, Paulson OB, Ptito M, Siebner HR. Interpolation of diffusion weighted imaging datasets. Neuroimage 2014; 103:202-213. [PMID: 25219332 DOI: 10.1016/j.neuroimage.2014.09.005] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [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: 02/07/2014] [Revised: 09/02/2014] [Accepted: 09/03/2014] [Indexed: 10/24/2022] Open
Abstract
Diffusion weighted imaging (DWI) is used to study white-matter fibre organisation, orientation and structural connectivity by means of fibre reconstruction algorithms and tractography. For clinical settings, limited scan time compromises the possibilities to achieve high image resolution for finer anatomical details and signal-to-noise-ratio for reliable fibre reconstruction. We assessed the potential benefits of interpolating DWI datasets to a higher image resolution before fibre reconstruction using a diffusion tensor model. Simulations of straight and curved crossing tracts smaller than or equal to the voxel size showed that conventional higher-order interpolation methods improved the geometrical representation of white-matter tracts with reduced partial-volume-effect (PVE), except at tract boundaries. Simulations and interpolation of ex-vivo monkey brain DWI datasets revealed that conventional interpolation methods fail to disentangle fine anatomical details if PVE is too pronounced in the original data. As for validation we used ex-vivo DWI datasets acquired at various image resolutions as well as Nissl-stained sections. Increasing the image resolution by a factor of eight yielded finer geometrical resolution and more anatomical details in complex regions such as tract boundaries and cortical layers, which are normally only visualized at higher image resolutions. Similar results were found with typical clinical human DWI dataset. However, a possible bias in quantitative values imposed by the interpolation method used should be considered. The results indicate that conventional interpolation methods can be successfully applied to DWI datasets for mining anatomical details that are normally seen only at higher resolutions, which will aid in tractography and microstructural mapping of tissue compartments.
Collapse
Affiliation(s)
- Tim B Dyrby
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark.
| | - Henrik Lundell
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Mark W Burke
- Department of Physiology and Biophysics, Howard University, Washington, DC, USA
| | - Nina L Reislev
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Olaf B Paulson
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Maurice Ptito
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; School of Optometry, University of Montreal, Montreal, Canada; Department of Neuroscience and Pharmacology, Copenhagen University, Copenhagen, Denmark
| | - Hartwig R Siebner
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| |
Collapse
|
34
|
Lundell H, Alexander DC, Dyrby TB. High angular resolution diffusion imaging with stimulated echoes: compensation and correction in experiment design and analysis. NMR Biomed 2014; 27:918-25. [PMID: 24890716 PMCID: PMC4312915 DOI: 10.1002/nbm.3137] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 04/01/2014] [Accepted: 04/18/2014] [Indexed: 05/18/2023]
Abstract
Stimulated echo acquisition mode (STEAM) diffusion MRI can be advantageous over pulsed-gradient spin-echo (PGSE) for diffusion times that are long compared with T2 . It therefore has potential for biomedical diffusion imaging applications at 7T and above where T2 is short. However, gradient pulses other than the diffusion gradients in the STEAM sequence contribute much greater diffusion weighting than in PGSE and lead to a disrupted experimental design. Here, we introduce a simple compensation to the STEAM acquisition that avoids the orientational bias and disrupted experiment design that these gradient pulses can otherwise produce. The compensation is simple to implement by adjusting the gradient vectors in the diffusion pulses of the STEAM sequence, so that the net effective gradient vector including contributions from diffusion and other gradient pulses is as the experiment intends. High angular resolution diffusion imaging (HARDI) data were acquired with and without the proposed compensation. The data were processed to derive standard diffusion tensor imaging (DTI) maps, which highlight the need for the compensation. Ignoring the other gradient pulses, a bias in DTI parameters from STEAM acquisition is found, due both to confounds in the analysis and the experiment design. Retrospectively correcting the analysis with a calculation of the full B matrix can partly correct for these confounds, but an acquisition that is compensated as proposed is needed to remove the effect entirely.
Collapse
Affiliation(s)
- Henrik Lundell
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital HvidovreDenmark
- *Correspondence to: H. Lundell, DRCMR, Kettegaards Allé 30, DK-2650 Hvidovre, Denmark., E-mail:
| | - Daniel C Alexander
- Centre for Medical Image Computing, Department of Computer Science, University College LondonGower Street, London, WC1E 6BT, UK
| | - Tim B Dyrby
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital HvidovreDenmark
| |
Collapse
|
35
|
Lundell H, Sønderby CK, Dyrby TB. Diffusion weighted imaging with circularly polarized oscillating gradients. Magn Reson Med 2014; 73:1171-6. [DOI: 10.1002/mrm.25211] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 01/30/2014] [Accepted: 02/17/2014] [Indexed: 11/09/2022]
Affiliation(s)
- Henrik Lundell
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre; Denmark
| | - Casper Kaae Sønderby
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre; Denmark
| | - Tim B. Dyrby
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre; Denmark
| |
Collapse
|
36
|
Jespersen SN, Lundell H, Sønderby CK, Dyrby TB. Orientationally invariant metrics of apparent compartment eccentricity from double pulsed field gradient diffusion experiments. NMR Biomed 2013; 26:1647-1662. [PMID: 24038641 DOI: 10.1002/nbm.2999] [Citation(s) in RCA: 139] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 06/11/2013] [Accepted: 06/13/2013] [Indexed: 06/02/2023]
Abstract
Pulsed field gradient diffusion sequences (PFG) with multiple diffusion encoding blocks have been indicated to offer new microstructural tissue information, such as the ability to detect nonspherical compartment shapes in macroscopically isotropic samples, i.e. samples with negligible directional signal dependence on diffusion gradients in standard diffusion experiments. However, current acquisition schemes are not rotationally invariant in the sense that the derived metrics depend on the orientation of the sample, and are affected by the interplay of sampling directions and compartment orientation dispersion when applied to macroscopically anisotropic systems. Here we propose a new framework, the d-PFG 5-design, to enable rotationally invariant estimation of double wave vector diffusion metrics (d-PFG). The method is based on the idea that an appropriate orientational average of the signal emulates the signal from a powder preparation of the same sample, where macroscopic anisotropy is absent by construction. Our approach exploits the theory of exact numerical integration (quadrature) of polynomials on the rotation group, and we exemplify the general procedure with a set consisting of 60 pairs of diffusion wave vectors (the d-PFG 5-design) facilitating a theoretically exact determination of the fourth order Taylor or cumulant expansion of the orientationally averaged signal. The d-PFG 5-design is evaluated with numerical simulations and ex vivo high field diffusion MRI experiments in a nonhuman primate brain. Specifically, we demonstrate rotational invariance when estimating compartment eccentricity, which we show offers new microstructural information, complementary to that of fractional anisotropy (FA) from diffusion tensor imaging (DTI). The imaging observations are supported by a new theoretical result, directly relating compartment eccentricity to FA of individual pores.
Collapse
Affiliation(s)
- Sune Nørhøj Jespersen
- Center of Functionally Integrative Neuroscience (CFIN) and MINDLab, Clinical Institute, Aarhus University, Aarhus, Denmark; Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | | | | | | |
Collapse
|
37
|
Barthélemy D, Knudsen H, Willerslev-Olsen M, Lundell H, Nielsen JB, Biering-Sørensen F. Functional implications of corticospinal tract impairment on gait after spinal cord injury. Spinal Cord 2013; 51:852-6. [DOI: 10.1038/sc.2013.84] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 06/19/2013] [Accepted: 06/27/2013] [Indexed: 11/09/2022]
|
38
|
Assaf Y, Alexander DC, Jones DK, Bizzi A, Behrens TEJ, Clark CA, Cohen Y, Dyrby TB, Huppi PS, Knoesche TR, Lebihan D, Parker GJM, Poupon C, Anaby D, Anwander A, Bar L, Barazany D, Blumenfeld-Katzir T, De-Santis S, Duclap D, Figini M, Fischi E, Guevara P, Hubbard P, Hofstetter S, Jbabdi S, Kunz N, Lazeyras F, Lebois A, Liptrot MG, Lundell H, Mangin JF, Dominguez DM, Morozov D, Schreiber J, Seunarine K, Nava S, Poupon C, Riffert T, Sasson E, Schmitt B, Shemesh N, Sotiropoulos SN, Tavor I, Zhang HG, Zhou FL. The CONNECT project: Combining macro- and micro-structure. Neuroimage 2013; 80:273-82. [PMID: 23727318 DOI: 10.1016/j.neuroimage.2013.05.055] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Revised: 05/06/2013] [Accepted: 05/08/2013] [Indexed: 11/28/2022] Open
Abstract
In recent years, diffusion MRI has become an extremely important tool for studying the morphology of living brain tissue, as it provides unique insights into both its macrostructure and microstructure. Recent applications of diffusion MRI aimed to characterize the structural connectome using tractography to infer connectivity between brain regions. In parallel to the development of tractography, additional diffusion MRI based frameworks (CHARMED, AxCaliber, ActiveAx) were developed enabling the extraction of a multitude of micro-structural parameters (axon diameter distribution, mean axonal diameter and axonal density). This unique insight into both tissue microstructure and connectivity has enormous potential value in understanding the structure and organization of the brain as well as providing unique insights to abnormalities that underpin disease states. The CONNECT (Consortium Of Neuroimagers for the Non-invasive Exploration of brain Connectivity and Tracts) project aimed to combine tractography and micro-structural measures of the living human brain in order to obtain a better estimate of the connectome, while also striving to extend validation of these measurements. This paper summarizes the project and describes the perspective of using micro-structural measures to study the connectome.
Collapse
Affiliation(s)
- Yaniv Assaf
- Department of Neurobiology, George S. Wise Faculty of Life Science, Tel Aviv University, Tel Aviv, Israel.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Lundell H, Barthelemy D, Biering-Sørensen F, Cohen-Adad J, Nielsen JB, Dyrby TB. Fast diffusion tensor imaging and tractography of the whole cervical spinal cord using point spread function corrected echo planar imaging. Magn Reson Med 2012; 69:144-9. [PMID: 22396180 DOI: 10.1002/mrm.24235] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Revised: 01/09/2012] [Accepted: 02/03/2012] [Indexed: 11/10/2022]
Abstract
Diffusion tensor imaging has been used in a number of spinal cord studies, but severe distortions caused by susceptibility induced field inhomogeneities limit its applicability to investigate small volumes within acceptable acquisition times. A way to evaluate image distortions is to map the point spread function of the voxel intensity in a reference scan. In this study, the point spread function was mapped for an echo-planar imaging sequence in the human cervical spinal cord with isotropic resolution and large field of view. Correction with the point spread function map improved anatomical consistency, and full cervical tractography was thereby possible from a C1 seed region in healthy controls and one individual with spinal cord injury. It is suggested that point spread function mapping of the spinal cord can be used in combination with sequence-based methods for reduction of susceptibility artifacts or in high-field imaging settings where off-resonance effects are pronounced.
Collapse
Affiliation(s)
- Henrik Lundell
- Department of Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark.
| | | | | | | | | | | |
Collapse
|
40
|
Lundell H, Nielsen JB, Ptito M, Dyrby TB. Distribution of collateral fibers in the monkey cervical spinal cord detected with diffusion-weighted magnetic resonance imaging. Neuroimage 2011; 56:923-9. [PMID: 21352926 DOI: 10.1016/j.neuroimage.2011.02.043] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 02/13/2011] [Accepted: 02/15/2011] [Indexed: 11/28/2022] Open
Abstract
Diffusion anisotropy monitored with diffusion-weighted magnetic resonance imaging (DWMRI) is a sensitive marker to monitor developmental or pathological microstructural changes in spinal cord. The white matter is often treated as a unidirectional axonal bundle but collateral fibers branching off the main spinal pathways contradicts this assumption and affects the diffusion anisotropy. It is the aim of this study to investigate to what extent collateral fibers are apparent in diffusion tensor data and if collaterals can be detected as individual fiber directions using crossing fiber detection techniques. We calculate the diffusion tensor and the persistent angular structure (PAS), a multi-fiber reconstruction technique, from high quality post mortem data of a perfusion-fixed vervet monkey cervical spinal cord sample and simulated crossing fiber data. Our results show that (i) cylindrical geometry in the white matter of the spinal cord is an invalid assumption due to collateral fibers. We also demonstrate that (ii) collateral fibers can be resolved as distinct peaks in the water diffusion propagator in white matter using multi-fiber models. Finally, we show that (iii) crossing fibers are mainly located laterally and increase towards the cervical enlargement.
Collapse
Affiliation(s)
- Henrik Lundell
- Department of Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark.
| | | | | | | |
Collapse
|
41
|
Barthelemy D, Willerslev-Olsen M, Lundell H, Conway B, Knudsen H, Biering-Seren F, Neilsen JB. *Poster 43: Gait Deficits Due to Impairment of the Corticospinal Tract in Persons With Incomplete Spinal Cord Injury. Arch Phys Med Rehabil 2010. [DOI: 10.1016/j.apmr.2010.07.070] [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]
|
42
|
Lundell H, Christensen MS, Barthélemy D, Willerslev-Olsen M, Biering-Sørensen F, Nielsen JB. Cerebral activation is correlated to regional atrophy of the spinal cord and functional motor disability in spinal cord injured individuals. Neuroimage 2010; 54:1254-61. [PMID: 20851198 DOI: 10.1016/j.neuroimage.2010.09.009] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2010] [Revised: 09/02/2010] [Accepted: 09/03/2010] [Indexed: 11/17/2022] Open
Abstract
Recovery of function following lesions in the nervous system requires adaptive changes in surviving circuitries. Here we investigate whether changes in cerebral activation are correlated to spinal cord atrophy and recovery of functionality in individuals with incomplete spinal cord injury (SCI). 19 chronic SCI individuals and 7 age-comparable controls underwent functional magnetic resonance imaging (fMRI) while performing rhythmic dorsiflexion of the ankle. A significant negative correlation was found between the activation in the ipsilateral motor (M1) and bilateral premotor cortex (PMC) on one hand and the functional ability of the SCI participants measured by the clinical motor score on the other. There was no significant correlation between activation in any other cerebral area and the motor score. Activation in ipsilateral somatosensory cortex (S1), M1 and PMC was negatively correlated to the width of the spinal cord in the left-right direction, where the corticospinal tract is located, but not in the antero-posterior direction. There was a tendency for a negative correlation between cerebral activation in ipsilateral S1, M1 and PMC and the amplitude of motor evoked potentials in the tibialis anterior muscle elicited by transcranial magnetic stimulation, but this did not reach statistical significance. There was no correlation between motor score or spinal cord dimensions and the volume of the cortical motor areas. The observations show that lesion of descending tracts in the lateral part of the spinal cord results in increased activation in ipsilateral motor and sensory areas, which may help to compensate for the functional deficit following SCI.
Collapse
Affiliation(s)
- H Lundell
- Department of Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | | | | | | | | |
Collapse
|
43
|
Lundell H, Barthelemy D, Skimminge A, Dyrby TB, Biering-Sørensen F, Nielsen JB. Independent spinal cord atrophy measures correlate to motor and sensory deficits in individuals with spinal cord injury. Spinal Cord 2010; 49:70-5. [PMID: 20697420 DOI: 10.1038/sc.2010.87] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
STUDY DESIGN Cross-sectional descriptive analysis of magnetic resonance imaging (MRI) and clinical outcome. OBJECTIVES The aim of this study was to present anatomically consistent and independent spinal cord atrophy measures based on standard MRI material and analyze their specific relations to sensory and motor outcome in individuals with chronic incomplete spinal cord injury (SCI). SETTING Danish study on human SCI. METHODS We included 19 individuals with chronic incomplete SCI and 16 healthy controls. Participants underwent MRI and a neurological examination including sensory testing for light touch and pinprick, and muscle strength. Antero-posterior width (APW), left-right width (LRW) and cross-sectional spinal cord area (SCA) were extracted from MRI at the spinal level of C2. The angular variation of the spinal cord radius over the full circle was also extracted and compared with the clinical scores. RESULTS The motor score was correlated to LRW and the sensory scores were correlated to APW. The scores correlated also well with decreases in spinal cord radius in oblique angles in coherent and non-overlapping sectors for the sensory and motor qualities respectively. CONCLUSION APW and LRW can be used to assess sensory and motor function independently. The finding is corresponding well with the respective locations of the main sensory and motor pathways.
Collapse
Affiliation(s)
- H Lundell
- Department of Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark.
| | | | | | | | | | | |
Collapse
|
44
|
Barthélemy D, Willerslev-Olsen M, Lundell H, Conway BA, Knudsen H, Biering-Sørensen F, Nielsen JB. Impaired transmission in the corticospinal tract and gait disability in spinal cord injured persons. J Neurophysiol 2010; 104:1167-76. [PMID: 20554839 DOI: 10.1152/jn.00382.2010] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Rehabilitation following spinal cord injury is likely to depend on recovery of corticospinal systems. Here we investigate whether transmission in the corticospinal tract may explain foot drop (inability to dorsiflex ankle) in persons with spinal cord lesion. The study was performed in 24 persons with incomplete spinal cord lesion (C1 to L1) and 15 healthy controls. Coherence in the 10- to 20-Hz frequency band between paired tibialis anterior muscle (TA) electromyographic recordings obtained in the swing phase of walking, which was taken as a measure of motor unit synchronization. It was significantly correlated with the degree of foot drop, as measured by toe elevation and ankle angle excursion in the first part of swing. Transcranial magnetic stimulation was used to elicit motor-evoked potentials (MEPs) in the TA. The amplitude of the MEPs at rest and their latency during contraction were correlated to the degree of foot drop. Spinal cord injured participants who exhibited a large foot drop had little or no MEP at rest in the TA muscle and had little or no coherence in the same muscle during walking. Gait speed was correlated to foot drop, and was the lowest in participants with no MEP at rest. The data confirm that transmission in the corticospinal tract is of importance for lifting the foot during the swing phase of human gait.
Collapse
Affiliation(s)
- Dorothy Barthélemy
- Department of Physical Exercise and Sport Sciences, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | | | | | | | | | | | | |
Collapse
|
45
|
Lundell H. [Community services and service affairs]. Sairaanhoitaja 1971; 47:551-2. [PMID: 5208992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|