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Wade RG, Teh I, Andersson G, Yeh FC, Wiberg M, Bourke G. Fractional anisotropy thresholding for deterministic tractography of the roots of the brachial plexus. Sci Rep 2021; 11:80. [PMID: 33420207 PMCID: PMC7794285 DOI: 10.1038/s41598-020-79840-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 12/07/2020] [Indexed: 02/03/2023] Open
Abstract
Diffusion tensor imaging (DTI) metrics, such as the fractional anisotropy (FA) and estimates of diffusivity are sensitive to the microstructure of peripheral nerves and may be displayed as tractograms. However, the ideal conditions for tractography of the roots of the brachial plexus are unclear, which represents the rationale for this study. Ten healthy adults were scanned using a Siemens Prisma (3T) and single-shot echo-planar imaging (b-value 0/1000 s/mm2, 64 directions, 2.5 mm3 with 4 averages; repeated in opposing phase encoding directions). Susceptibility correction and tractography were performed in DSI Studio by two independent raters. The effect of FA thresholding at increments of 0.01 (from 0.04 to 0.10) were tested. The mean FA varied between subjects by 2% (95% CI 1%, 3%). FA thresholds of 0.04, 0.05 and 0.06 all propagated 96% of tracts representing the roots; thresholding at 0.07 yielded 4% fewer tracts (p = 0.2), 0.08 yielded 11% fewer tracts (p = 0.008), 0.09 yielded 15% fewer tracts (p = 0.001) and 0.1 yielded 20% fewer tracts (p < 0.001). There was < 0.1% inter-rater variability in the measured FA and 99% agreement for tractography (κ = 0.92, p < 0.001). The fractional anisotropy thresholds required to generate tractograms of the roots of the brachial plexus appears to be lower than those used in the brain. We provide estimates of the probability of generating true tracts for each spinal nerve root of the brachial plexus, at different fractional anisotropy thresholds.
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Affiliation(s)
- Ryckie G Wade
- Academic Plastic Surgery Office, Department of Plastic and Reconstructive Surgery, Leeds General Infirmary, Leeds Teaching Hospitals Trust, Leeds, LS1 3EX, UK. .,Faculty of Medicine and Health Sciences, University of Leeds, Leeds, UK.
| | - Irvin Teh
- Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Gustav Andersson
- Department of Integrative Medical Biology, Faculty of Medicine, Umeå University, Umeå, Sweden.,Department of Surgical and Perioperative Science, Faculty of Medicine, Umeå University, Umeå, Sweden.,Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Fang-Cheng Yeh
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, USA
| | - Mikael Wiberg
- Department of Integrative Medical Biology, Faculty of Medicine, Umeå University, Umeå, Sweden.,Department of Surgical and Perioperative Science, Faculty of Medicine, Umeå University, Umeå, Sweden.,Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Grainne Bourke
- Academic Plastic Surgery Office, Department of Plastic and Reconstructive Surgery, Leeds General Infirmary, Leeds Teaching Hospitals Trust, Leeds, LS1 3EX, UK.,Faculty of Medicine and Health Sciences, University of Leeds, Leeds, UK.,Department of Integrative Medical Biology, Faculty of Medicine, Umeå University, Umeå, Sweden.,Department of Surgical and Perioperative Science, Faculty of Medicine, Umeå University, Umeå, Sweden
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Takemura H, Pestilli F, Weiner KS. Comparative neuroanatomy: Integrating classic and modern methods to understand association fibers connecting dorsal and ventral visual cortex. Neurosci Res 2019; 146:1-12. [PMID: 30389574 PMCID: PMC6491271 DOI: 10.1016/j.neures.2018.10.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 10/19/2018] [Accepted: 10/25/2018] [Indexed: 12/13/2022]
Abstract
Comparative neuroanatomy studies improve understanding of brain structure and function and provide insight regarding brain development, evolution, and also what features of the brain are uniquely human. With modern methods such as diffusion MRI (dMRI) and quantitative MRI (qMRI), we are able to measure structural features of the brain with the same methods across human and non-human primates. In this review article, we discuss how recent dMRI measurements of vertical occipital connections in humans and macaques can be compared with previous findings from invasive anatomical studies that examined connectivity, including relatively forgotten classic strychnine neuronography studies. We then review recent progress in understanding the neuroanatomy of vertical connections within the occipitotemporal cortex by combining modern quantitative MRI and classical histological measurements in human and macaque. Finally, we a) discuss current limitations of dMRI and tractography and b) consider potential paths for future investigations using dMRI and tractography for comparative neuroanatomical studies of white matter tracts between species. While we focus on vertical association connections in visual cortex in the present paper, this same approach can be applied to other white matter tracts. Similar efforts are likely to continue to advance our understanding of the neuroanatomical features of the brain that are shared across species, as well as to distinguish the features that are uniquely human.
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Affiliation(s)
- Hiromasa Takemura
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, and Osaka University, Suita, Japan; Graduate School of Frontier Biosciences, Osaka University, Suita, Japan.
| | - Franco Pestilli
- Departments of Psychological and Brain Sciences, Computer Science and Intelligent Systems Engineering, Programs in Neuroscience and Cognitive Science, School of Optometry, Indiana University, Bloomington, IN, USA
| | - Kevin S Weiner
- Department of Psychology, University of California, Berkeley, CA, USA; Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
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3
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Maffei C, Sarubbo S, Jovicich J. Diffusion-based tractography atlas of the human acoustic radiation. Sci Rep 2019; 9:4046. [PMID: 30858451 PMCID: PMC6411970 DOI: 10.1038/s41598-019-40666-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 02/08/2019] [Indexed: 02/06/2023] Open
Abstract
Diffusion MRI tractography allows in-vivo characterization of white matter architecture, including the localization and description of brain fibre bundles. However, some primary bundles are still only partially reconstructed, or not reconstructed at all. The acoustic radiation (AR) represents a primary sensory pathway that has been largely omitted in many tractography studies because its location and anatomical features make it challenging to reconstruct. In this study, we investigated the effects of acquisition and tractography parameters on the AR reconstruction using publicly available Human Connectome Project data. The aims of this study are: (i) using a subgroup of subjects and a reference AR for each subject, define an optimum set of parameters for AR reconstruction, and (ii) use the optimum parameters set on the full group to build a tractography-based atlas of the AR. Starting from the same data, the use of different acquisition and tractography parameters lead to very different AR reconstructions. Optimal results in terms of topographical accuracy and correspondence to the reference were obtained for probabilistic tractography, high b-values and default tractography parameters: these parameters were used to build an AR probabilistic tractography atlas. A significant left-hemispheric lateralization was found in the AR reconstruction of the 34 subjects.
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Affiliation(s)
- Chiara Maffei
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, USA.
- Center for Mind/Brain Sciences - CIMeC, University of Trento, Rovereto (TN), Italy.
| | - Silvio Sarubbo
- Division of Neurosurgery, Structural and Functional Connectivity Lab (SFC-LSB) Project, "S.Chiara" Hospital, Trento APSS, Italy
| | - Jorge Jovicich
- Center for Mind/Brain Sciences - CIMeC, University of Trento, Rovereto (TN), Italy
- Department of Psychology and Cognitive Sciences, University of Trento, Trento, Italy
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Sani I, McPherson BC, Stemmann H, Pestilli F, Freiwald WA. Functionally defined white matter of the macaque monkey brain reveals a dorso-ventral attention network. eLife 2019; 8:e40520. [PMID: 30601116 PMCID: PMC6345568 DOI: 10.7554/elife.40520] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Accepted: 12/20/2018] [Indexed: 12/18/2022] Open
Abstract
Classical studies of attention have identified areas of parietal and frontal cortex as sources of attentional control. Recently, a ventral region in the macaque temporal cortex, the posterior infero-temporal dorsal area PITd, has been suggested as a third attentional control area. This raises the question of whether and how spatially distant areas coordinate a joint focus of attention. Here we tested the hypothesis that parieto-frontal attention areas and PITd are directly interconnected. By combining functional MRI with ex-vivo high-resolution diffusion MRI, we found that PITd and dorsal attention areas are all directly connected through three specific fascicles. These results ascribe a new function, the communication of attention signals, to two known fiber-bundles, highlight the importance of vertical interactions across the two visual streams, and imply that the control of endogenous attention, hitherto thought to reside in macaque dorsal cortical areas, is exerted by a dorso-ventral network.
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Affiliation(s)
- Ilaria Sani
- Laboratory of Neural SystemsThe Rockefeller UniversityNew YorkUnited States
| | - Brent C McPherson
- Department of Psychological and Brain SciencesIndiana UniversityBloomingtonUnited States
| | - Heiko Stemmann
- Institute for Brain Research and Center for Advanced ImagingUniversity of BremenBremenGermany
| | - Franco Pestilli
- Department of Psychological and Brain SciencesIndiana UniversityBloomingtonUnited States
| | - Winrich A Freiwald
- Laboratory of Neural SystemsThe Rockefeller UniversityNew YorkUnited States
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Jin C, Chao YP, Lin L, Fu Z, Zhang B, Wu S. The Study of Graph Measurements for Hub Identification in Multiple Parcellated Brain Networks of Healthy Older Adult. J Med Biol Eng 2017. [DOI: 10.1007/s40846-017-0259-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
BACKGROUND Deterministic diffusion tractography obtained from high angular resolution diffusion imaging (HARDI) requires user-defined quantitative anisotropy (QA) thresholds. Most studies employ a common threshold across all subjects even though there is a strong degree of individual variation within groups. We sought to explore whether it would be beneficial to use individual thresholds in order to accommodate individual variance. To do this, we conducted two independent experiments. METHOD First, tractography of the arcuate fasciculus and network connectivity measures were examined in a sample of 14 healthy participants. Second, we assessed the effects of QA threshold on group differences in network connectivity measures between healthy young (n=19) and old (n=14) individuals. RESULTS The results of both experiments were significantly influenced by QA threshold. Common thresholds set too high failed to produce sufficient reconstructions in most subjects, thus decreasing the likelihood of detecting meaningful group differences. On the other hand, common thresholds set too low resulted in spurious reconstructions, providing deleterious results. COMPARISON WITH EXISTING METHODS Subject specific thresholds acquired using our QA threshold selection method (QATS) appeared to provide the most meaningful networks while ensuring that data from all subjects contributed to the analyses. CONCLUSIONS Together, these results support the use of a subject-specific threshold to ensure that data from all subjects are included in the analyses being conducted.
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Lischke A, Domin M, Freyberger HJ, Grabe HJ, Mentel R, Bernheim D, Lotze M. Structural Alterations in the Corpus Callosum Are Associated with Suicidal Behavior in Women with Borderline Personality Disorder. Front Hum Neurosci 2017; 11:196. [PMID: 28484382 PMCID: PMC5401902 DOI: 10.3389/fnhum.2017.00196] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 04/04/2017] [Indexed: 12/14/2022] Open
Abstract
Structural alterations in the corpus callosum (CC), the major white matter tract connecting functionally related brain regions in the two hemispheres, have been shown to be associated with emotional instability, impulsivity and suicidality in various mental disorders. To explore whether structural alterations of the CC would be similarly associated with emotional instability, impulsivity and suicidality in borderline personality disorder (BPD), we used diffusion tensor imaging (DTI) to assess the structural integrity of the CC in 21 BPD and 20 healthy control (HC) participants. Our hypothesis-driven analyses revealed a positive correlation between BPD participants’ suicidal behavior and fractional anisotropy (FA) in the splenium and genu of the CC and a negative correlation between BPD participants’ suicidal behavior and mean diffusivity (MD) in the splenium of CC. Our exploratory analyses suggested that suicidal BPD participants showed less FA and more MD in these regions than HC participants but that non-suicidal BPD participants showed similar FA and MD in these regions as HC participants. Taken together, our findings suggest an association between BPD participants’ suicidal behavior and structural alterations in regions of the CC that are connected with brain regions implicated in emotion regulation and impulse control. Structural alterations of the CC may, thus, account for deficits in emotion regulation and impulse control that lead to suicidal behavior in BPD. However, these findings should be considered as preliminary until replicated and extended in future studies that comprise larger samples of suicidal and non-suicidal BPD participants.
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Affiliation(s)
- Alexander Lischke
- Department of Psychiatry and Psychotherapy, University of GreifswaldGreifswald, Germany.,Department of Psychology, University of GreifswaldGreifswald, Germany.,Functional Imaging Unit, Center for Diagnostic Radiology and Neuroradiology, University of GreifswaldGreifswald, Germany
| | - Martin Domin
- Functional Imaging Unit, Center for Diagnostic Radiology and Neuroradiology, University of GreifswaldGreifswald, Germany
| | - Harald J Freyberger
- Department of Psychiatry and Psychotherapy, University of GreifswaldGreifswald, Germany.,Helios HospitalStralsund, Germany
| | - Hans J Grabe
- Department of Psychiatry and Psychotherapy, University of GreifswaldGreifswald, Germany
| | - Renate Mentel
- Department of Psychiatry and Psychotherapy, University of GreifswaldGreifswald, Germany
| | - Dorothee Bernheim
- Department of Child and Adolescent Psychiatry and Psychotherapy, University of UlmUlm, Germany
| | - Martin Lotze
- Functional Imaging Unit, Center for Diagnostic Radiology and Neuroradiology, University of GreifswaldGreifswald, Germany
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Baur ADJ, Daqqaq T, Collettini F, Denecke T, Hamm B, Durmus T, Scheel M. Influence of fractional anisotropy thresholds on diffusion tensor imaging tractography of the periprostatic neurovascular bundle and selected pelvic tissues: do visualized tracts really represent nerves? Acta Radiol 2017; 58:472-480. [PMID: 27235453 DOI: 10.1177/0284185116651004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Background Diffusion tensor imaging (DTI) tractography has recently been shown to successfully visualize periprostatic tracts allegedly representing the neurovascular bundle. Purpose To examine the impact of different fractional anisotropy (FA) thresholds on the results of DTI tractography in the male pelvis as well as to evaluate the resulting specificity for nerve tracts. Material and Methods Ten healthy male volunteers were examined at 3 Tesla. DTI tractography was performed based on seed points placed circularly around the prostate, in the rectoprostatic angle, the peripheral zone of the prostate, the sciatic nerve, and in addition the urinary bladder using FA thresholds of 0.20, 0.05, and 0.01. DTI tract number and DTI tract length measured with different FA thresholds were compared. ANOVA with repeated measures was used for statistics. Results DTI tract number and tract length were significantly dependent on FA thresholds. While a FA threshold of 0.20 visualized the typical distribution of DTI tracts in the sciatic nerve, a FA threshold of ≤0.05 was necessary to yield results visually mimicking the distribution of nerve tracts in the NVB. However, with such low FA thresholds even in the filled urinary bladder DTI tracts could be visualized. With FA thresholds of 0.20, the number and length of periprostatic DTI tracts did not differ from those measured within the prostate. Conclusion DTI tractography can be used to visualize DTI tracts periprostatically. However, one may doubt that these DTI tracts represent nerve tracts and that the periprostatic neurovascular bundle can be evaluated in a meaningful way with the current methods available.
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Affiliation(s)
- Alexander DJ Baur
- Department of Radiology, Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Tareef Daqqaq
- Department of Radiology, Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Federico Collettini
- Department of Radiology, Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Timm Denecke
- Department of Radiology, Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Bernd Hamm
- Department of Radiology, Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Tahir Durmus
- Department of Radiology, Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Michael Scheel
- Department of Radiology, Charité – Universitätsmedizin Berlin, Berlin, Germany
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Reply to “The usefulness of diffusion tensor tractography for estimating the state of corticobulbar tract in stroke patients”. Clin Neurophysiol 2016; 127:2710. [DOI: 10.1016/j.clinph.2016.04.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 04/25/2016] [Indexed: 11/23/2022]
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Takemura H, Caiafa CF, Wandell BA, Pestilli F. Ensemble Tractography. PLoS Comput Biol 2016; 12:e1004692. [PMID: 26845558 PMCID: PMC4742469 DOI: 10.1371/journal.pcbi.1004692] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 12/03/2015] [Indexed: 01/02/2023] Open
Abstract
Tractography uses diffusion MRI to estimate the trajectory and cortical projection zones of white matter fascicles in the living human brain. There are many different tractography algorithms and each requires the user to set several parameters, such as curvature threshold. Choosing a single algorithm with specific parameters poses two challenges. First, different algorithms and parameter values produce different results. Second, the optimal choice of algorithm and parameter value may differ between different white matter regions or different fascicles, subjects, and acquisition parameters. We propose using ensemble methods to reduce algorithm and parameter dependencies. To do so we separate the processes of fascicle generation and evaluation. Specifically, we analyze the value of creating optimized connectomes by systematically combining candidate streamlines from an ensemble of algorithms (deterministic and probabilistic) and systematically varying parameters (curvature and stopping criterion). The ensemble approach leads to optimized connectomes that provide better cross-validated prediction error of the diffusion MRI data than optimized connectomes generated using a single-algorithm or parameter set. Furthermore, the ensemble approach produces connectomes that contain both short- and long-range fascicles, whereas single-parameter connectomes are biased towards one or the other. In summary, a systematic ensemble tractography approach can produce connectomes that are superior to standard single parameter estimates both for predicting the diffusion measurements and estimating white matter fascicles. Diffusion MRI and tractography opened a new avenue for studying white matter fascicles and their tissue properties in the living human brain. There are many different tractography methods, and each requires the user to set several parameters. A limitation of tractography is that the results depend on the selection of algorithms and parameters. Here, we analyze an ensemble method, Ensemble Tractography (ET), that reduces the effect of algorithm and parameter selection. ET creates a large set of candidate streamlines using an ensemble of algorithms and parameter values and then selects the streamlines with strong support from the data using a global fascicle evaluation method. Compared to single parameter connectomes, ET connectomes predict diffusion MRI signals better and cover a wider range of white matter volume. Importantly, ET connectomes include both short- and long-association fascicles, which are not typically found together in single-parameter connectomes.
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Affiliation(s)
- Hiromasa Takemura
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, and Osaka University, Suita, Japan
- The Japan Society for the Promotion of Science, Tokyo, Japan
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
- Department of Psychology, Stanford University, Stanford, California, United States of America
- * E-mail: (HT); (FP)
| | - Cesar F. Caiafa
- Instituto Argentino de Radioastronomía (IAR)—CCT La Plata—CONICET, Villa Elisa, Buenos Aires, Argentina
| | - Brian A. Wandell
- Department of Psychology, Stanford University, Stanford, California, United States of America
| | - Franco Pestilli
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, United States of America
- Programs in Neuroscience and Cognitive Science, Indiana University Network Science Institute, Indiana University, Bloomington, Indiana, United States of America
- * E-mail: (HT); (FP)
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Lischke A, Domin M, Freyberger HJ, Grabe HJ, Mentel R, Bernheim D, Lotze M. Structural alterations in white-matter tracts connecting (para-)limbic and prefrontal brain regions in borderline personality disorder. Psychol Med 2015; 45:3171-3180. [PMID: 26087850 DOI: 10.1017/s0033291715001142] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND A dysfunctional network of prefrontal and (para-)limbic brain region has been suggested to underlie emotional dysregulation in borderline personality disorder (BPD). Abnormal activity in this network may be due to structural alterations in white-matter tracts connecting prefrontal and (para-)limbic brain regions. To test this hypothesis, we investigated the structural integrity of major white-matter tracts connecting these regions in BPD. METHOD Using diffusion tensor imaging, we investigated fractional anisotropy (FA), axonal anisotropy (AD) and radial diffusivity (RD) in the uncinate fasciculus, the major white-matter tract connecting (para-)limbic and prefrontal brain regions, in 26 healthy controls (HC) and 26 BPD participants. To clarify the specificity of possible white-matter alterations among HC and BPD participants, FA, AD and RD were also investigated in the cingulum. RESULTS We found distinct structural alterations in the uncinate fasciculus but not in the cingulum of BPD participants. Compared to HC participants, BPD participants showed lower FA and higher RD in the uncinate fasciculus. By contrast, AD did not differ in the uncinate fasciculus of HC and BPD participants. CONCLUSIONS Our finding of abnormal FA and RD in the uncinate fasciculus indicates distinct white-matter alterations in BPD, presumably due to stress-induced myelin degeneration in the aftermath of stressful life events. Although these alterations may account for abnormal activity in brain regions implicated in emotion dysregulation, such as the amygdala, anterior cingulate cortex and prefrontal cortex, it remains to be determined whether these alterations are specific for BPD.
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Affiliation(s)
- A Lischke
- Department of Psychiatry and Psychotherapy,University of Greifswald,Germany
| | - M Domin
- Functional Imaging,Center for Diagnostic Radiology and Neuroradiology,University of Greifswald,Germany
| | - H J Freyberger
- Department of Psychiatry and Psychotherapy,University of Greifswald,Germany
| | - H J Grabe
- Department of Psychiatry and Psychotherapy,University of Greifswald,Germany
| | - R Mentel
- Department of Psychiatry and Psychotherapy,University of Greifswald,Germany
| | - D Bernheim
- Department of Child and Adolescent Psychiatry and Psychotherapy,University of Ulm,Germany
| | - M Lotze
- Functional Imaging,Center for Diagnostic Radiology and Neuroradiology,University of Greifswald,Germany
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