1
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Albishi AM. Why do different motor cortical areas activate the same muscles? Brain Struct Funct 2023; 228:2017-2024. [PMID: 37709903 DOI: 10.1007/s00429-023-02703-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 08/27/2023] [Indexed: 09/16/2023]
Abstract
The cortex contains multiple motor areas, including the primary motor cortex (M1) and supplementary motor area (SMA). Many muscles are represented in both the M1 and SMA, but the reason for this dual representation remains unclear. Previous work has shown that the M1 and SMA representations of a specific human muscle can be differentiated according to their functional connectivity with different brain areas located outside of the motor cortex. It is our perspective that this differential functional connectivity may be the neural substrate that allows an individual muscle to be accessed by distinct neural processes, such as those implementing volitional vs. postural task control. Here, we review existing human and animal literature suggesting how muscles are represented in the M1 and SMA and how these brain regions have distinct functions. We also discuss potential studies to further elucidate the distinct roles of the SMA and M1 in normal and dysfunctional motor control.
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Affiliation(s)
- Alaa M Albishi
- Department of Rehabilitation Sciences-Physical Therapy Division, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
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2
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Nguyen H, Zhu W, Baltan S. Casein Kinase 2 Signaling in White Matter Stroke. Front Mol Biosci 2022; 9:908521. [PMID: 35911974 PMCID: PMC9325966 DOI: 10.3389/fmolb.2022.908521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 06/21/2022] [Indexed: 11/27/2022] Open
Abstract
The growth of the aging population, together with improved stroke care, has resulted in an increase in stroke survivors and a rise in recurrent events. Axonal injury and white matter (WM) dysfunction are responsible for much of the disability observed after stroke. The mechanisms of WM injury are distinct compared to gray matter and change with age. Therefore, an ideal stroke therapeutic must restore neuronal and axonal function when applied before or after a stroke, and it must also protect across age groups. Casein kinase 2 (CK2), is expressed in the brain, including WM, and is regulated during the development and numerous disease conditions such as cancer and ischemia. CK2 activation in WM mediates ischemic injury by activating the Cdk5 and AKT/GSK3β signaling pathways. Consequently, CK2 inhibition using the small molecule inhibitor CX-4945 (Silmitasertib) correlates with preservation of oligodendrocytes, conservation of axon structure, and axonal mitochondria, leading to improved functional recovery. Remarkably, CK2 inhibition promotes WM function when applied after ischemic injury by specifically regulating the AKT/GSK3β pathways. The blockade of the active conformation of AKT confers post-ischemic protection to young and old WM by preserving mitochondria, implying AKT as a common therapeutic target across age groups. Using a NanoString nCounter miRNA expression profiling, comparative analyses of ischemic WM with or without CX-4945 treatment reveal that miRNAs are expressed at high levels in WM after ischemia, and CX-4945 differentially regulates some of these miRNAs. Therefore, we propose that miRNA regulation may be one of the protective actions of CX-4945 against WM ischemic injury. Silmitasertib is FDA approved and currently in use for cancer and Covid patients; therefore, it is plausible to repurpose CK2 inhibitors for stroke patients.
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Affiliation(s)
| | | | - Selva Baltan
- Anesthesiology and Peri-Operative Medicine (APOM), Oregon Health and Science University, Portland, OR, United States
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3
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Baltan S, Sandau US, Brunet S, Bastian C, Tripathi A, Nguyen H, Liu H, Saugstad JA, Zarnegarnia Y, Dutta R. Identification of miRNAs That Mediate Protective Functions of Anti-Cancer Drugs During White Matter Ischemic Injury. ASN Neuro 2021; 13:17590914211042220. [PMID: 34619990 PMCID: PMC8642107 DOI: 10.1177/17590914211042220] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
We have previously shown that two anti-cancer drugs, CX-4945 and MS-275, protect and preserve white matter (WM) architecture and improve functional recovery in a model of WM ischemic injury. While both compounds promote recovery, CX-4945 is a selective Casein kinase 2 (CK2) inhibitor and MS-275 is a selective Class I histone deacetylase (HDAC) inhibitor. Alterations in microRNAs (miRNAs) mediate some of the protective actions of these drugs. In this study, we aimed to (1) identify miRNAs expressed in mouse optic nerves (MONs); (2) determine which miRNAs are regulated by oxygen glucose deprivation (OGD); and (3) determine the effects of CX-4945 and MS-275 treatment on miRNA expression. RNA isolated from MONs from control and OGD-treated animals with and without CX-4945 or MS-275 treatment were quantified using NanoString nCounter® miRNA expression profiling. Comparative analysis of experimental groups revealed that 12 miRNAs were expressed at high levels in MONs. OGD upregulated five miRNAs (miR-1959, miR-501-3p, miR-146b, miR-201, and miR-335-3p) and downregulated two miRNAs (miR-1937a and miR-1937b) compared to controls. OGD with CX-4945 upregulated miR-1937a and miR-1937b, and downregulated miR-501-3p, miR-200a, miR-1959, and miR-654-3p compared to OGD alone. OGD with MS-275 upregulated miR-2134, miR-2141, miR-2133, miR-34b-5p, miR-153, miR-487b, miR-376b, and downregulated miR-717, miR-190, miR-27a, miR-1959, miR-200a, miR-501-3p, and miR-200c compared to OGD alone. Interestingly, miR-501-3p and miR-1959 were the only miRNAs upregulated by OGD, and downregulated by OGD plus CX-4945 and MS-275. Therefore, we suggest that protective functions of CX-4945 or MS-275 against WM injury maybe mediated, in part, through miRNA expression.
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Affiliation(s)
- Selva Baltan
- Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR 97239, USA
- Department of Neurosciences, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
- Selva Baltan, Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Mackenzie Hall 2140A, L459, 3181 S.W. Sam Jackson Park Rd., Portland, OR 97239, USA.
| | - Ursula S. Sandau
- Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR 97239, USA
| | - Sylvain Brunet
- Department of Neurosciences, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
| | - Chinthasagar Bastian
- Department of Neurosciences, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
| | - Ajai Tripathi
- Department of Neurosciences, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
| | - Hung Nguyen
- Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR 97239, USA
| | - Helen Liu
- Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR 97239, USA
| | - Julie A. Saugstad
- Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR 97239, USA
| | - Yalda Zarnegarnia
- Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR 97239, USA
| | - Ranjan Dutta
- Department of Neurosciences, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
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4
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Zhou C, Su M, Sun P, Tang X, Yin KJ. Nitro-oleic acid-mediated blood-brain barrier protection reduces ischemic brain injury. Exp Neurol 2021; 346:113861. [PMID: 34499902 DOI: 10.1016/j.expneurol.2021.113861] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 08/28/2021] [Accepted: 09/05/2021] [Indexed: 10/20/2022]
Abstract
Nitro-oleic acid (OA-NO2), a nitroalkene formed in nitric oxide-dependent oxidative reactions, has been found in human plasma and is thought to regulate pathophysiological functions. Recently, accumulating evidence suggests that OA-NO2 may function as an anti-inflammatory mediator, and ameliorate the progression of diabetes and cardiovascular diseases. However, the role of OA-NO2 in ischemic brain injury remains unexplored. In this study, C57BL/6 mice were subjected to 1 h transient middle cerebral artery occlusion (MCAO) and followed by 1- 7 days of reperfusion. These mice were treated with vehicle, OA, or OA-NO2 (10 mg/kg) via tail vein injection at 2 h after the onset of MCAO. Our results show that intravenous administration of OA-NO2 led to reduced BBB leakage in ischemic brains, reduced brain infarct, and improved sensorimotor functions in response to ischemic insults when compared to OA and vehicle controls. Also, OA-NO2 significantly reduced BBB leakage-triggered infiltration of neutrophils and macrophages in the ischemic brains. Moreover, OA-NO2 treatment reduced the M1-type microglia and increased M2-type microglia. Mechanistically, OA-NO2 alleviated the decline of mRNA and protein level of major endothelial TJs including ZO-1 in stroke mice. Treatment of OA-NO2 also significantly inhibited stroke-induced inflammatory mediators, iNOS, E-selectin, P-selectin, and ICAM1, in mouse brains. In conclusion, OA-NO2 preserves BBB integrity and confers neurovascular protection in ischemic brain damage. OA-NO2-mediated brain protection may help us to develop a novel therapeutic strategy for the treatment of ischemic stroke.
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Affiliation(s)
- Chao Zhou
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, PA 15261, USA; Pittsburgh Institute of Brain Disorders & Recovery, Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Moxi Su
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, PA 15261, USA; Pittsburgh Institute of Brain Disorders & Recovery, Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Ping Sun
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, PA 15261, USA; Pittsburgh Institute of Brain Disorders & Recovery, Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Xuelian Tang
- Pittsburgh Institute of Brain Disorders & Recovery, Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Ke-Jie Yin
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, PA 15261, USA; Pittsburgh Institute of Brain Disorders & Recovery, Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
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5
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Pillette L, Lotte F, N'Kaoua B, Joseph PA, Jeunet C, Glize B. Why we should systematically assess, control and report somatosensory impairments in BCI-based motor rehabilitation after stroke studies. NEUROIMAGE-CLINICAL 2020; 28:102417. [PMID: 33039972 PMCID: PMC7551360 DOI: 10.1016/j.nicl.2020.102417] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 08/22/2020] [Accepted: 09/03/2020] [Indexed: 11/25/2022]
Abstract
Brain-Computer Interfaces (BCI)-based therapy relies on timely sensory feedback. Somatosensory loss is usually not reported for these therapies. Yet, it influences motor imagery, neuroplasticity and motor rehabilitation. And stroke-induced somatosensory impairments are frequent and diverse. Thus, BCI-based motor therapy efficiency likely depends on somatosensory abilities.
The neuronal loss resulting from stroke forces 80% of the patients to undergo motor rehabilitation, for which Brain-Computer Interfaces (BCIs) and NeuroFeedback (NF) can be used. During the rehabilitation, when patients attempt or imagine performing a movement, BCIs/NF provide them with a synchronized sensory (e.g., tactile) feedback based on their sensorimotor-related brain activity that aims at fostering brain plasticity and motor recovery. The co-activation of ascending (i.e., somatosensory) and descending (i.e., motor) networks indeed enables significant functional motor improvement, together with significant sensorimotor-related neurophysiological changes. Somatosensory abilities are essential for patients to perceive the feedback provided by the BCI system. Thus, somatosensory impairments may significantly alter the efficiency of BCI-based motor rehabilitation. In order to precisely understand and assess the impact of somatosensory impairments, we first review the literature on post-stroke BCI-based motor rehabilitation (14 randomized clinical trials). We show that despite the central role that somatosensory abilities play on BCI-based motor rehabilitation post-stroke, the latter are rarely reported and used as inclusion/exclusion criteria in the literature on the matter. We then argue that somatosensory abilities have repeatedly been shown to influence the motor rehabilitation outcome, in general. This stresses the importance of also considering them and reporting them in the literature in BCI-based rehabilitation after stroke, especially since half of post-stroke patients suffer from somatosensory impairments. We argue that somatosensory abilities should systematically be assessed, controlled and reported if we want to precisely assess the influence they have on BCI efficiency. Not doing so could result in the misinterpretation of reported results, while doing so could improve (1) our understanding of the mechanisms underlying motor recovery (2) our ability to adapt the therapy to the patients’ impairments and (3) our comprehension of the between-subject and between-study variability of therapeutic outcomes mentioned in the literature.
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Affiliation(s)
- Léa Pillette
- Inria, 200 av.de la Vieille Tour, 33400 Talence, France; LaBRI (Univ.Bordeaux, CNRS, Bordeaux-INP), 351, cours de la Libération, 33405 Talence, France.
| | - Fabien Lotte
- Inria, 200 av.de la Vieille Tour, 33400 Talence, France; LaBRI (Univ.Bordeaux, CNRS, Bordeaux-INP), 351, cours de la Libération, 33405 Talence, France.
| | - Bernard N'Kaoua
- Handicap, Activity, Cognition, Health, Inserm/University of Bordeaux, 146 rue Léo Saignat, 33076 Bordeaux cedex, France.
| | - Pierre-Alain Joseph
- Handicap, Activity, Cognition, Health, Inserm/University of Bordeaux, 146 rue Léo Saignat, 33076 Bordeaux cedex, France; Service MPR Pôle de Neurosciences Cliniques CHU, University of Bordeaux, Place Amélie Raba-Léon, 33000 Bordeaux cedex, France.
| | - Camille Jeunet
- CLLE (CNRS, Univ.Toulouse Jean Jaurès), 5 Allées Antonio Machado, 31058 Toulouse cedex 9, France.
| | - Bertrand Glize
- Handicap, Activity, Cognition, Health, Inserm/University of Bordeaux, 146 rue Léo Saignat, 33076 Bordeaux cedex, France; Service MPR Pôle de Neurosciences Cliniques CHU, University of Bordeaux, Place Amélie Raba-Léon, 33000 Bordeaux cedex, France.
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6
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Arnold SA, Platt SR, Gendron KP, West FD. Imaging Ischemic and Hemorrhagic Disease of the Brain in Dogs. Front Vet Sci 2020; 7:279. [PMID: 32528985 PMCID: PMC7266937 DOI: 10.3389/fvets.2020.00279] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 04/27/2020] [Indexed: 01/12/2023] Open
Abstract
Strokes, both ischemic and hemorrhagic, are the most common underlying cause of acute, non-progressive encephalopathy in dogs. In effect, substantial information detailing the underlying causes and predisposing factors, affected vessels, imaging features, and outcomes based on location and extent of injury is available. The features of canine strokes on both computed tomography (CT) and magnetic resonance imaging (MRI) have been described in numerous studies. This summary article serves as a compilation of these various descriptions. Drawing from the established and emerging stroke evaluation sequences used in the investigation of strokes in humans, this summary describes all theoretically available sequences. Particular detail is given to logistics of image acquisition, description of imaging findings, and each sequence's advantages and disadvantages. As the imaging features of both forms of strokes are highly representative of the underlying pathophysiologic stages in the hours to months following stroke onset, the descriptions of strokes at various stages are also discussed. It is unlikely that canine strokes can be diagnosed within the same rapid time frame as human strokes, and therefore the opportunity for thrombolytic intervention in ischemic strokes is unattainable. However, a thorough understanding of the appearance of strokes at various stages can aid the clinician when presented with a patient that has developed a stroke in the days or weeks prior to evaluation. Additionally, investigation into new imaging techniques may increase the sensitivity and specificity of stroke diagnosis, as well as provide new ways to monitor strokes over time.
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Affiliation(s)
- Susan A Arnold
- Department of Veterinary Clinical Sciences, University of Minnesota Twin Cities, St. Paul, MN, United States
| | - Simon R Platt
- Department of Small Animal Medicine and Surgery, University of Georgia, Athens, GA, United States
| | - Karine P Gendron
- Department of Small Animal Medicine and Surgery, University of Georgia, Athens, GA, United States
| | - Franklin D West
- Department of Small Animal Medicine and Surgery, University of Georgia, Athens, GA, United States
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7
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Jang SH, Seo YS. Effect of Neuromuscular Electrical Stimulation Training on the Finger Extensor Muscles for the Contralateral Corticospinal Tract in Normal Subjects: A Diffusion Tensor Tractography Study. Front Hum Neurosci 2018; 12:432. [PMID: 30524256 PMCID: PMC6256237 DOI: 10.3389/fnhum.2018.00432] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Accepted: 10/02/2018] [Indexed: 11/16/2022] Open
Abstract
Objectives: Neuromuscular electrical stimulation (NMES) is a popular rehabilitative modality to improve motor function of the extremities and trunk. In this study, we investigated changes of hand function and the contralateral corticospinal tract (CST) with treatment by NMES on the finger extensor muscles for 2 weeks, using serial diffusion tensor tractography (DTT). Methods: Thirteen right handed normal subjects were recruited. Treatment was applied to the left hand (the NMES side), and the right hand was the control side. NMES was applied for 30 min/day, 7 days per week, for 2 weeks. Hand motor function was evaluated twice at pre-NMES and post-NMES training using grip strength (GS), Purdue pegboard test (PPT) and tip pinch. The fractional anisotropy (FA), mean diffusivity (MD) and tract volume (TV) of the CST in both hemispheres were measured using DTT. Results: On the control side, the clinical scores did not differ significantly between pre- and post-NMES training (p > 0.05). However, on the NMES side, PPT and tip pinch improved significantly (p < 0.05), although GS did not. TV of the right CST increased significantly at post-NMES training (p < 0.05) whereas FA and MD did not differ significantly (p > 0.05). By contrast, FA, MD and TV on the left CST did not change significantly (p > 0.05). Conclusion: We demonstrated facilitation of the contralateral CST with improvement of fine motor activity by 2 weeks of NMES training of peripheral muscles in normal subjects. We think our results can be applied to the normal subjects and patients with brain injury to improve the fine motor function of the hand and facilitate the normal CST or healing of the injured CST.
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Affiliation(s)
- Sung Ho Jang
- Department of Physical Medicine and Rehabilitation, College of Medicine, Yeungnam University, Daegu, South Korea
| | - You Sung Seo
- Department of Physical Medicine and Rehabilitation, College of Medicine, Yeungnam University, Daegu, South Korea
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Boyd LA, Hayward KS, Ward NS, Stinear CM, Rosso C, Fisher RJ, Carter AR, Leff AP, Copland DA, Carey LM, Cohen LG, Basso DM, Maguire JM, Cramer SC. Biomarkers of Stroke Recovery: Consensus-Based Core Recommendations from the Stroke Recovery and Rehabilitation Roundtable. Neurorehabil Neural Repair 2018; 31:864-876. [PMID: 29233071 DOI: 10.1177/1545968317732680] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The most difficult clinical questions in stroke rehabilitation are "What is this patient's potential for recovery?" and "What is the best rehabilitation strategy for this person, given her/his clinical profile?" Without answers to these questions, clinicians struggle to make decisions regarding the content and focus of therapy, and researchers design studies that inadvertently mix participants who have a high likelihood of responding with those who do not. Developing and implementing biomarkers that distinguish patient subgroups will help address these issues and unravel the factors important to the recovery process. The goal of the present paper is to provide a consensus statement regarding the current state of the evidence for stroke recovery biomarkers. Biomarkers of motor, somatosensory, cognitive and language domains across the recovery timeline post-stroke are considered; with focus on brain structure and function, and exclusion of blood markers and genetics. We provide evidence for biomarkers that are considered ready to be included in clinical trials, as well as others that are promising but not ready and so represent a developmental priority. We conclude with an example that illustrates the utility of biomarkers in recovery and rehabilitation research, demonstrating how the inclusion of a biomarker may enhance future clinical trials. In this way, we propose a way forward for when and where we can include biomarkers to advance the efficacy of the practice of, and research into, rehabilitation and recovery after stroke.
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Affiliation(s)
- Lara A Boyd
- 1 Department of Physical Therapy & the Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Kathryn S Hayward
- 2 Department of Physical Therapy, University of British Columbia, Vancouver, Canada; Stroke Division, The Florey Institute of Neuroscience and Mental Health, Heidelberg, Australia
| | - Nick S Ward
- 3 Sobell Department of Motor Neuroscience, UCL Institute of Neurology, Queen Square, London, UK
| | - Cathy M Stinear
- 4 Department of Medicine and Centre for Brain Research, University of Auckland, Auckland, New Zealand
| | - Charlotte Rosso
- 5 Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, France; AP-HP, Stroke Unit, Pitié-Salpêtrière Hospital, France
| | - Rebecca J Fisher
- 6 Division of Rehabilitation & Ageing, University of Nottingham, Nottingham, UK
| | - Alexandre R Carter
- 7 Department of Neurology, Washington University in Saint Louis, St Louis, MO, USA
| | - Alex P Leff
- 8 Department of Brain Repair and Rehabilitation, Institute of Neurology & Institute of Cognitive Neuroscience, University College London, Queens Square, London, UK
| | - David A Copland
- 9 School of Health & Rehabilitation Sciences, University of Queensland, Brisbane, Australia; and University of Queensland Centre for Clinical Research, Brisbane, Australia
| | - Leeanne M Carey
- 10 School of Allied Health, College of Science, Health and Engineering, La Trobe, University, Bundoora, Australia; and Neurorehabilitation and Recovery, Stroke Division, The Florey Institute of Neuroscience and Mental Health, Heidelberg, Australia
| | - Leonardo G Cohen
- 11 Human Cortical Physiology and Neurorehabilitation Section, NINDS, NIH, Bethesda, MD, USA
| | - D Michele Basso
- 12 School of Health and Rehabilitation Sciences, The Ohio State University, Columbus, OH, USA
| | - Jane M Maguire
- 13 Faculty of Health, University of Technology Sydney, Ultimo, Sydney, Australia
| | - Steven C Cramer
- 14 University of California, Irvine, CA, USA; Depts. Neurology, Anatomy & Neurobiology, and Physical Medicine & Rehabilitation, Irvine, CA, USA
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9
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Manivannan S, Makwana M, Ahmed AI, Zaben M. Profiling biomarkers of traumatic axonal injury: From mouse to man. Clin Neurol Neurosurg 2018; 171:6-20. [PMID: 29803093 DOI: 10.1016/j.clineuro.2018.05.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Revised: 05/05/2018] [Accepted: 05/14/2018] [Indexed: 12/20/2022]
Abstract
Traumatic brain injury (TBI) poses a major public health problem on a global scale. Its burden results from high mortality and significant morbidity in survivors. This stems, in part, from an ongoing inadequacy in diagnostic and prognostic indicators despite significant technological advances. Traumatic axonal injury (TAI) is a key driver of the ongoing pathological process following TBI, causing chronic neurological deficits and disability. The science underpinning biomarkers of TAI has been a subject of many reviews in recent literature. However, in this review we provide a comprehensive account of biomarkers from animal models to clinical studies, bridging the gap between experimental science and clinical medicine. We have discussed pathogenesis, temporal kinetics, relationships to neuro-imaging, and, most importantly, clinical applicability in order to provide a holistic perspective of how this could improve TBI diagnosis and predict clinical outcome in a real-life setting. We conclude that early and reliable identification of axonal injury post-TBI with the help of body fluid biomarkers could enhance current care of TBI patients by (i) increasing speed and accuracy of diagnosis, (ii) providing invaluable prognostic information, (iii) allow efficient allocation of rehabilitation services, and (iv) provide potential therapeutic targets. The optimal model for assessing TAI is likely to involve multiple components, including several blood biomarkers and neuro-imaging modalities, at different time points.
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Affiliation(s)
- Susruta Manivannan
- Department of Neurosurgery, University Hospital of Wales, Heath Park, Cardiff, CF14 4XN, United Kingdom
| | - Milan Makwana
- Department of Neurosurgery, University Hospital of Wales, Heath Park, Cardiff, CF14 4XN, United Kingdom
| | - Aminul Islam Ahmed
- Clinical Neurosciences, University of Southampton, Southampton, SO16 6YD, United Kingdom; Wessex Neurological Centre, University Hospitals Southampton, Southampton, SO16 6YD, United Kingdom
| | - Malik Zaben
- Department of Neurosurgery, University Hospital of Wales, Heath Park, Cardiff, CF14 4XN, United Kingdom; Brain Repair & Intracranial Neurotherapeutics (BRAIN) Unit, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ, United Kingdom.
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10
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Boyd LA, Hayward KS, Ward NS, Stinear CM, Rosso C, Fisher RJ, Carter AR, Leff AP, Copland DA, Carey LM, Cohen LG, Basso DM, Maguire JM, Cramer SC. Biomarkers of stroke recovery: Consensus-based core recommendations from the Stroke Recovery and Rehabilitation Roundtable. Int J Stroke 2018; 12:480-493. [PMID: 28697711 DOI: 10.1177/1747493017714176] [Citation(s) in RCA: 225] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The most difficult clinical questions in stroke rehabilitation are "What is this patient's potential for recovery?" and "What is the best rehabilitation strategy for this person, given her/his clinical profile?" Without answers to these questions, clinicians struggle to make decisions regarding the content and focus of therapy, and researchers design studies that inadvertently mix participants who have a high likelihood of responding with those who do not. Developing and implementing biomarkers that distinguish patient subgroups will help address these issues and unravel the factors important to the recovery process. The goal of the present paper is to provide a consensus statement regarding the current state of the evidence for stroke recovery biomarkers. Biomarkers of motor, somatosensory, cognitive and language domains across the recovery timeline post-stroke are considered; with focus on brain structure and function, and exclusion of blood markers and genetics. We provide evidence for biomarkers that are considered ready to be included in clinical trials, as well as others that are promising but not ready and so represent a developmental priority. We conclude with an example that illustrates the utility of biomarkers in recovery and rehabilitation research, demonstrating how the inclusion of a biomarker may enhance future clinical trials. In this way, we propose a way forward for when and where we can include biomarkers to advance the efficacy of the practice of, and research into, rehabilitation and recovery after stroke.
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Affiliation(s)
- Lara A Boyd
- 1 Department of Physical Therapy & the Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada
| | - Kathryn S Hayward
- 2 Department of Physical Therapy, University of British Columbia, Vancouver, Canada; Stroke Division, The Florey Institute of Neuroscience and Mental Health, Heidelberg, Australia
| | - Nick S Ward
- 3 Sobell Department of Motor Neuroscience, UCL Institute of Neurology, Queen Square, London, UK
| | - Cathy M Stinear
- 4 Department of Medicine and Centre for Brain Research, University of Auckland, Auckland, New Zealand
| | - Charlotte Rosso
- 5 Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, Paris, France.,6 AP-HP, Urgences Cérébro-Vasculaires, Hôpital Pitié-Salpêtrière, Paris, France
| | - Rebecca J Fisher
- 7 Division of Rehabilitation & Ageing, University of Nottingham, Nottingham, UK
| | - Alexandre R Carter
- 8 Department of Neurology, Washington University in Saint Louis, St Louis, MO, USA
| | - Alex P Leff
- 9 Department of Brain Repair and Rehabilitation, Institute of Neurology & Institute of Cognitive Neuroscience, University College London, Queens Square, London, UK
| | - David A Copland
- 10 School of Health & Rehabilitation Sciences, University of Queensland, Brisbane, Australia; and University of Queensland Centre for Clinical Research, Brisbane, Australia
| | - Leeanne M Carey
- 11 School of Allied Health, College of Science, Health and Engineering, La Trobe, University, Bundoora, Australia; and Neurorehabilitation and Recovery, Stroke Division, The Florey Institute of Neuroscience and Mental Health, Heidelberg, Australia
| | - Leonardo G Cohen
- 12 Human Cortical Physiology and Neurorehabilitation Section, NINDS, NIH, Bethesda, MD, USA
| | - D Michele Basso
- 13 School of Health and Rehabilitation Sciences, The Ohio State University, Columbus, OH, USA
| | - Jane M Maguire
- 14 Faculty of Health, University of Technology, Ultimo, Sydney, Australia
| | - Steven C Cramer
- 15 University of California, Irvine, CA, USA; Depts. Neurology, Anatomy & Neurobiology, and Physical Medicine & Rehabilitation, Irvine, CA, USA
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Diffusion Tensor Imaging Evaluation of Neural Network Development in Patients Undergoing Therapeutic Repetitive Transcranial Magnetic Stimulation following Stroke. Neural Plast 2018; 2018:3901016. [PMID: 29725347 PMCID: PMC5872629 DOI: 10.1155/2018/3901016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 12/04/2017] [Indexed: 11/29/2022] Open
Abstract
We aimed to investigate plastic changes in cerebral white matter structures using diffusion tensor imaging following a 15-day stroke rehabilitation program. We compared the detection of cerebral plasticity between generalized fractional anisotropy (GFA), a novel tool for investigating white matter structures, and fractional anisotropy (FA). Low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) of 2400 pulses applied to the nonlesional hemisphere and 240 min intensive occupation therapy (OT) daily over 15 days. Motor function was evaluated using the Fugl-Meyer assessment (FMA) and Wolf Motor Function Test (WMFT). Patients underwent diffusion tensor magnetic resonance imaging (MRI) on admission and discharge, from which bilateral FA and GFA values in Brodmann area (BA) 4 and BA6 were calculated. Motor function improved following treatment (p < 0.001). Treatment increased GFA values for both the lesioned and nonlesioned BA4 (p < 0.05, p < 0.001, resp.). Changes in GFA value for BA4 of the lesioned hemisphere were significantly inversely correlated with changes in WMFT scores (R2 = 0.363, p < 0.05). Our findings indicate that the GFA may have a potentially more useful ability than FA to detect changes in white matter structures in areas of fiber intersection for any such future investigations.
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Jang SH, Kim DH, Kim SH, Seo JP. The relation between the motor evoked potential and diffusion tensor tractography for the corticospinal tract in chronic hemiparetic patients with cerebral infarct. Somatosens Mot Res 2017; 34:134-138. [DOI: 10.1080/08990220.2017.1343188] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Sung Ho Jang
- Department of Physical Medicine and Rehabilitation, College of Medicine, Yeungnam University, Taegu, Republic of Korea
| | - Dea Hee Kim
- Paramedical Robot Research & Support Center, Korea Institute of Robot and Convergence, Gumi, Republic of Korea
| | - Seong Ho Kim
- Department of Neurosurgery, College of Medicine Yeungnam University, Taegu, Republic of Korea
| | - Jeong Pyo Seo
- Department of Physical Medicine and Rehabilitation, College of Medicine, Yeungnam University, Taegu, Republic of Korea
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Main KL, Soman S, Pestilli F, Furst A, Noda A, Hernandez B, Kong J, Cheng J, Fairchild JK, Taylor J, Yesavage J, Wesson Ashford J, Kraemer H, Adamson MM. DTI measures identify mild and moderate TBI cases among patients with complex health problems: A receiver operating characteristic analysis of U.S. veterans. Neuroimage Clin 2017; 16:1-16. [PMID: 28725550 PMCID: PMC5503837 DOI: 10.1016/j.nicl.2017.06.031] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 06/10/2017] [Accepted: 06/23/2017] [Indexed: 01/10/2023]
Abstract
Standard MRI methods are often inadequate for identifying mild traumatic brain injury (TBI). Advances in diffusion tensor imaging now provide potential biomarkers of TBI among white matter fascicles (tracts). However, it is still unclear which tracts are most pertinent to TBI diagnosis. This study ranked fiber tracts on their ability to discriminate patients with and without TBI. We acquired diffusion tensor imaging data from military veterans admitted to a polytrauma clinic (Overall n = 109; Age: M = 47.2, SD = 11.3; Male: 88%; TBI: 67%). TBI diagnosis was based on self-report and neurological examination. Fiber tractography analysis produced 20 fiber tracts per patient. Each tract yielded four clinically relevant measures (fractional anisotropy, mean diffusivity, radial diffusivity, and axial diffusivity). We applied receiver operating characteristic (ROC) analyses to identify the most diagnostic tract for each measure. The analyses produced an optimal cutpoint for each tract. We then used kappa coefficients to rate the agreement of each cutpoint with the neurologist's diagnosis. The tract with the highest kappa was most diagnostic. As a check on the ROC results, we performed a stepwise logistic regression on each measure using all 20 tracts as predictors. We also bootstrapped the ROC analyses to compute the 95% confidence intervals for sensitivity, specificity, and the highest kappa coefficients. The ROC analyses identified two fiber tracts as most diagnostic of TBI: the left cingulum (LCG) and the left inferior fronto-occipital fasciculus (LIF). Like ROC, logistic regression identified LCG as most predictive for the FA measure but identified the right anterior thalamic tract (RAT) for the MD, RD, and AD measures. These findings are potentially relevant to the development of TBI biomarkers. Our methods also demonstrate how ROC analysis may be used to identify clinically relevant variables in the TBI population.
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Key Words
- AD, axial diffusivity
- Axon degeneration
- CC, corpus callosum
- Concussion
- DAI, diffuse axonal injury
- DTI, diffusion tensor imaging
- FA, fractional anisotropy
- GN, genu
- Imaging
- LAT, left anterior thalamic tract
- LCG, left cingulum
- LCH, left cingulum – hippocampus
- LCS, left cortico-spinal tract
- LIF, left inferior fronto-occipital fasciculus
- LIL, left inferior longitudinal fasciculus
- LSL, left superior longitudinal fasciculus
- LST, left superior longitudinal fasciculus – temporal
- LUN, left uncinate
- MD, mean diffusivity
- Neurodegeneration
- PTSD, post-traumatic stress disorder
- RAT, right anterior thalamic tract
- RCG, right cingulum
- RCH, right cingulum – Hippocampus
- RCS, right cortico-spinal tract
- RD, radial diffusivity
- RIF, right inferior fronto-occipital fasciculus
- RIL, right inferior longitudinal fasciculus
- ROC, receiver operating characteristic
- RSL, right superior longitudinal fasciculus
- RST, right superior longitudinal fasciculus – temporal
- RUN, right uncinate
- SP, splenium
- TBI, traumatic brain injury
- Traumatic brain injury
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Affiliation(s)
- Keith L. Main
- War Related Illness and Injury Study Center, Veterans Affairs, Palo Alto Health Care System (VAPAHCS), Palo Alto, CA, United States
- Defense and Veterans Brain Injury Center (DVBIC), Silver Spring, MD, United States
- General Dynamics Health Solutions (GDHS), Fairfax, VA, United States
| | - Salil Soman
- War Related Illness and Injury Study Center, Veterans Affairs, Palo Alto Health Care System (VAPAHCS), Palo Alto, CA, United States
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, United States
- Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
| | - Franco Pestilli
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, United States
| | - Ansgar Furst
- War Related Illness and Injury Study Center, Veterans Affairs, Palo Alto Health Care System (VAPAHCS), Palo Alto, CA, United States
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, United States
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, United States
| | - Art Noda
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, United States
| | - Beatriz Hernandez
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, United States
| | - Jennifer Kong
- War Related Illness and Injury Study Center, Veterans Affairs, Palo Alto Health Care System (VAPAHCS), Palo Alto, CA, United States
| | - Jauhtai Cheng
- War Related Illness and Injury Study Center, Veterans Affairs, Palo Alto Health Care System (VAPAHCS), Palo Alto, CA, United States
| | - Jennifer K. Fairchild
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, United States
| | - Joy Taylor
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, United States
| | - Jerome Yesavage
- War Related Illness and Injury Study Center, Veterans Affairs, Palo Alto Health Care System (VAPAHCS), Palo Alto, CA, United States
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, United States
| | - J. Wesson Ashford
- War Related Illness and Injury Study Center, Veterans Affairs, Palo Alto Health Care System (VAPAHCS), Palo Alto, CA, United States
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, United States
| | - Helena Kraemer
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, United States
| | - Maheen M. Adamson
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, United States
- Department of Neurosurgery, Stanford School of Medicine, Stanford, CA, United States
- Defense and Veterans Brain Injury Center (DVBIC), Veterans Affairs, Palo Alto Health Care System (VAPAHCS), Palo Alto, CA, United States
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Yu X, Song R, Jiaerken Y, Yuan L, Huang P, Lou M, Jiang Q, Zhang M. White matter injury induced by diabetes in acute stroke is clinically relevant: A preliminary study. Diab Vasc Dis Res 2017; 14:40-46. [PMID: 27941055 DOI: 10.1177/1479164116675491] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The importance of white matter injury induced by diabetes in stroke severity and prognosis is largely unknown. We aimed to investigate the relationship between diabetes-related white matter injury beyond stroke lesions with acute neurological deficits and clinical outcome after stroke. In total, 36 stroke patients within 3-7 days after onset were enrolled. Neurological deficits on admission were assessed by National Institute of Health Stroke Score, and poor outcome at 3 months was defined as modified Rankin score >2. White matter tracts were compared between patients with diabetic and non-diabetic stroke using fractional anisotropy from diffusion tensor imaging. Regional white matter abnormality with decreased fractional anisotropy was observed in diabetic patients (n = 18) when compared to non-diabetic patients (n = 18). Decreased fractional anisotropy in ipsilesional distal corticospinal tract was independently associated with higher National Institute of Health Stroke Score motor component score (β = -0.444, p = 0.005), and decreased fractional anisotropy in contralesional superior longitudinal fasciculus I was independently related to poor outcome (odds ratio, 0.900; p = 0.033). Our findings suggested that only white matter injury induced by diabetes in specific tracts like corticospinal tract and superior longitudinal fasciculus beyond stroke lesions has clinically relevant, providing insight into the mechanism of stroke recovery under the diabetic condition.
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Affiliation(s)
- Xinfeng Yu
- Department of Radiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Ruirui Song
- Department of Radiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yerfan Jiaerken
- Department of Radiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Lixia Yuan
- Key Laboratory for Biomedical Engineering of Education Ministry of China, Departments of Biomedical Engineering & Instrument Science Engineering, Zhejiang University, Hangzhou, China
| | - Peiyu Huang
- Department of Radiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Min Lou
- Department of Neurology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Quan Jiang
- Department of Neurology, Henry Ford Health System, Detroit, MI, USA
| | - Minming Zhang
- Department of Radiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
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15
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Jang SH, Kwon HG. Traumatic axonal injury of the medial lemniscus pathway in a patient with traumatic brain injury: validation by diffusion tensor tractography. Neural Regen Res 2016; 11:130-1. [PMID: 26981101 PMCID: PMC4774205 DOI: 10.4103/1673-5374.175058] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- Sung Ho Jang
- Department of Physical Medicine and Rehabilitation, College of Medicine, Yeungnam University, Namku, Daegu, Republic of Korea
| | - Hyeok Gyu Kwon
- Department of Physical Medicine and Rehabilitation, College of Medicine, Yeungnam University, Namku, Daegu, Republic of Korea
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Ueda R, Yamada N, Kakuda W, Abo M, Senoo A. White matter structure and clinical characteristics of stroke patients: A diffusion tensor MRI study. Brain Res 2016; 1635:61-70. [PMID: 26783693 DOI: 10.1016/j.brainres.2015.12.059] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 12/17/2015] [Accepted: 12/29/2015] [Indexed: 11/18/2022]
Abstract
Fractional anisotropy has been used in many studies that examined post-stroke changes in white matter. This study was performed to clarify cerebral white matter changes after stroke using generalized fractional anisotropy (GFA). White matter structure was visualized using diffusion tensor imaging in 72 patients with post-stroke arm paralysis. Exercise-related brain regions were examined in cerebral white matter using GFA. The relationship between GFA and clinical characteristics was examined. Overall, the mean GFA of the lesioned hemisphere was significantly lower than that of the non-lesioned hemisphere (P<0.05), the white matter of the lesioned side was severely affected by stroke. A weak negative correlation between GFA and time since stroke onset was found in Brodmann area 5 of the non-lesioned hemisphere. Age correlated negatively with GFA in Brodmann areas 5 and 7 of the lesioned hemisphere. Though these results may be due to a decrease in the frequency of use of the paralyzed limb over time, GFA overall was significantly and negatively affected by the subject's age. The GFA values of patients with paralysis of the dominant hand were significantly different from those of patients with paralysis of the nondominant hand in Brodmann areas 4 and 6 of the non-lesioned hemisphere and Brodmann area 4 of the lesioned hemisphere (P<0.05). The stroke size and location were not associated with GFA differences. Differences between the GFA of the lesioned and non-lesioned hemispheres varied depending on the affected brain region, age at onset of paralysis, and paralysis of the dominant or non-dominant hand.
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Affiliation(s)
- Ryo Ueda
- Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, 7-2-10 Higashi-Ogu, Arakawa-ku, Tokyo 116-8551, Japan.
| | - Naoki Yamada
- Department of Rehabilitation Medicine, Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo 105-8461, Japan.
| | - Wataru Kakuda
- Department of Rehabilitation Medicine, Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo 105-8461, Japan.
| | - Masahiro Abo
- Department of Rehabilitation Medicine, Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo 105-8461, Japan.
| | - Atsushi Senoo
- Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, 7-2-10 Higashi-Ogu, Arakawa-ku, Tokyo 116-8551, Japan.
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17
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Niu C, Liu X, Yang Y, Zhang K, Min Z, Wang M, Li W, Guo L, Lin P, Zhang M. Assessing Region of Interest Schemes for the Corticospinal Tract in Patients With Brain Tumors. Medicine (Baltimore) 2016; 95:e3189. [PMID: 27015212 PMCID: PMC4998407 DOI: 10.1097/md.0000000000003189] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) techniques are widely used for identifying the corticospinal tract (CST) white matter pathways as part of presurgical planning. However, mass effects in patients with brain tumors tend to cause anatomical distortions and compensatory functional reorganization of the cortex, which may lead to inaccurate mapping of white matter tracts. To overcome these problems, we compared different region-of-interest (ROI) selection schemes to track CST fibers in patients with brain tumors. Our study investigated the CSTs of 16 patients with intracranial tumors. The patients were classified into 3 subgroups according to the spatial relationships of the lesion and the primary motor cortex (PMC)/internal capsule. Specifically, we investigated the key factors that cause distorted tractography in patients with tumors. We compared 3 CST tractography methods that used different ROI selection schemes. The results indicate that CST fiber tracking methods based only on anatomical ROIs could possibly lead to distortions near the PMC region and may be unable to effectively localize the PMC. In contrast, the dual ROI method, which uses ROIs that have been selected from both blood oxygen level-dependent functional MRI (BOLD-fMRI) activation and anatomical landmarks, enabled the tracking of fibers to the motor cortex. The results demonstrate that the dual ROI method can localize the entire CST fiber pathway and can accurately describe the spatial relationships of CST fibers relative to the tumor. These results illustrate the reliability of using fMRI-guided DTT in patients with tumors. The combination of fMRI and anatomical information enhances the identification of tracts of interest in brains with anatomical deformations, which provides neurosurgeons with a more accurate approach for visualizing and localizing white matter fiber tracts in patients with brain tumors. This approach enhances surgical performance and perserves brain function.
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Affiliation(s)
- Chen Niu
- From the Department of Medical Imaging, The First Affiliated Hospital of Xi'An Jiaotong University, Xi'an, Shaanxi (CN, MG, WL, LG, MZ); Key Laboratory of Biomedical Information Engineering of Education Ministry, Institute of Biomedical Engineering, Xi'an Jiaotong University, Xi'an (XL); School of Information Technology, Jiangxi University of Finance and Economics, Nanchang, People's Republic of China (YY); Department of Electronics Engineering, Northwestern Polytechnical University, Xi'an (KZ); Department of Neurosurgey, First Affiliated Hospital of Xi'An Jiaotong University, Xi'an, Shaanxi (MW); Key Laboratory of Biomedical Information Engineering of Education Ministry, Institute of Biomedical Engineering, Xi'an Jiaotong University, Xi'an (PL); and Department of Medical Imaging, The First Affiliated Hospital of Xi'An Jiaotong University, Xi'an (MZ), Shaanxi, China
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18
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Understanding the role of the primary somatosensory cortex: Opportunities for rehabilitation. Neuropsychologia 2015; 79:246-55. [PMID: 26164474 DOI: 10.1016/j.neuropsychologia.2015.07.007] [Citation(s) in RCA: 164] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 06/19/2015] [Accepted: 07/07/2015] [Indexed: 12/14/2022]
Abstract
Emerging evidence indicates impairments in somatosensory function may be a major contributor to motor dysfunction associated with neurologic injury or disorders. However, the neuroanatomical substrates underlying the connection between aberrant sensory input and ineffective motor output are still under investigation. The primary somatosensory cortex (S1) plays a critical role in processing afferent somatosensory input and contributes to the integration of sensory and motor signals necessary for skilled movement. Neuroimaging and neurostimulation approaches provide unique opportunities to non-invasively study S1 structure and function including connectivity with other cortical regions. These research techniques have begun to illuminate casual contributions of abnormal S1 activity and connectivity to motor dysfunction and poorer recovery of motor function in neurologic patient populations. This review synthesizes recent evidence illustrating the role of S1 in motor control, motor learning and functional recovery with an emphasis on how information from these investigations may be exploited to inform stroke rehabilitation to reduce motor dysfunction and improve therapeutic outcomes.
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Diffusion tensor imaging in Alzheimer's disease and affective disorders. Eur Arch Psychiatry Clin Neurosci 2014; 264:467-83. [PMID: 24595744 DOI: 10.1007/s00406-014-0496-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 02/20/2014] [Indexed: 12/18/2022]
Abstract
The functional organization of the brain in segregated neuronal networks has become a leading paradigm in the study of brain diseases. Diffusion tensor imaging (DTI) allows testing the validity and clinical utility of this paradigm on the structural connectivity level. DTI in Alzheimer's disease (AD) suggests a selective impairment of intracortical projecting fiber tracts underlying the functional disorganization of neuronal networks supporting memory and other cognitive functions. These findings have already been tested for their utility as clinical markers of AD in large multicenter studies. Affective disorders, including major depressive disorder (MDD) and bipolar disorder (BP), show a high comorbidity with AD in geriatric populations and may even have a pathogenetic overlap with AD. DTI studies in MDD and BP are still limited to small-scale monocenter studies, revealing subtle abnormalities in cortico-subcortial networks associated with affect regulation and reward/aversion control. The clinical utility of these findings remains to be further explored. The present paper presents the methodological background of diffusion imaging, including DTI and diffusion spectrum imaging, and discusses key findings in AD and affective disorders. The results of our review strongly point toward the necessity of large-scale multicenter multimodal transnosological networks to study the structural and functional basis of neuronal disconnection underlying different neuropsychiatric diseases.
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Abstract
BACKGROUND AND PURPOSE Impaired hand function decreases quality of life after stroke. The purpose of this study was to pilot a novel 2-week upper extremity sensorimotor training program. This case series describes the training program and highlights outcome measures used for documenting behavioral change and neural reorganization. CASE DESCRIPTION Behavioral/performance changes were identified via sensorimotor evaluation. Activity-induced neural reorganization was examined using sensory functional magnetic resonance imaging, diffusion tensor tractography, and brain volume measurement. Participant 1 was a 75-year-old right-handed man 1 year post-right hemisphere stroke, with severe sensory impairment across domains in his left hand; he reported limited left-hand/arm use. Participant 2 was a 63-year-old right-handed woman who had experienced a left hemisphere stroke 9 months earlier, resulting in mild sensory impairment across domains in her right hand, as well as mild motor deficit. INTERVENTION Participants were trained 4 hours per day, 5 days per week for 2 weeks. Training tasks required sensory discrimination of temperature, weights, textures, shapes, and objects in the context of active exploration with the involved hand. Random multimodal feedback was used. OUTCOMES Both participants had improved scores on the Wolf Motor Function Test after training. Participant 1 had no measurable change in sensory function, while participant 2 improved in touch perception, proprioception, and haptic performance. Sensory functional magnetic resonance imaging suggested neural reorganization in both participants; participant 1 had a small increase in brain volume, while superior thalamic radiation white matter connectivity was unchanged in either participant. DISCUSSION Participating in sensorimotor training focused on sensory discrimination during manual manipulation was feasible for both participants. Future research to determine efficacy and identify optimal measures of sensory function and neural reorganization is recommended. VIDEO ABSTRACT AVAILABLE (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A38) for more insights from the authors.
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21
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Zhang Y, Wan S, Zhang X. Geniculocalcarine tract disintegration after ischemic stroke: a diffusion tensor imaging study. AJNR Am J Neuroradiol 2013; 34:1890-4. [PMID: 23639556 DOI: 10.3174/ajnr.a3535] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND AND PURPOSE Our aim was to investigate the disintegration of the geniculocalcarine tract by using DTI-derived parameters in cases of unilateral occipital or temporal-occipital ischemic stroke with geniculocalcarine tract involvement and to determine whether geniculocalcarine tract fibers affected by infarction and unaffected ipsilateral geniculocalcarine tract fibers have different disintegration processes. MATERIALS AND METHODS Seventy-one patients underwent routine MR imaging and DTI of the brain. Fractional anisotropy and mean diffusivity of the geniculocalcarine tract fibers affected by infarction, ipsilateral unaffected GCT fibers, and the contralateral geniculocalcarine tract were measured and compared at 5 different time points (from <1 week to >1 year) poststroke. RESULTS The fractional anisotropy of geniculocalcarine tract fibers affected by infarction (0.27 ± 0.06) was lower than that of contralateral GCT fibers (0.49 ± 0.03). The fractional anisotropy of geniculocalcarine tract fibers affected by infarction was not different in the first 3 weeks (P = .306). The mean diffusivity of geniculocalcarine tract fibers affected by infarction (0.53 ± 0.14) was lower than that of the contralateral GCT fibers (0.79 ± 0.07) in the first week but higher after the second week (0.95 ± 0.20 to 0.79 ± 0.06). The mean diffusivity gradually increased until it was equal to the mean diffusivity of CSF after the eighth week (2.43 ± 0.26), at which time both the fractional anisotropy and mean diffusivity values stabilized. The fractional anisotropy (0.50 ± 0.04) and mean diffusivity (0.77 ± 0.06) of the ipsilateral unaffected GCT fibers were similar to those of the contralateral GCT fibers (0.50 ± 0.03 and 0.79 ± 0.07) during the first 3 weeks. The fractional anisotropy then gradually decreased (from 0.42 ± 0.03 to 0.27 ± 0.05), while the mean diffusivity increased (from 0.95 ± 0.09 to 1.35 ± 0.11), though to a lesser degree than in the corresponding geniculocalcarine tract fibers affected by infarction. CONCLUSIONS The geniculocalcarine tract fibers affected by infarction and the ipsilateral unaffected GCT fibers showed different disintegration processes. The progressive disintegration of geniculocalcarine tract fibers affected by infarction was stable until the eighth week poststroke. The ipsilateral unaffected GCT fibers began to disintegrate at the fourth week, but to a lesser degree than the geniculocalcarine tract fibers affected by infarction.
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Affiliation(s)
- Y Zhang
- Zhongshan Ophthalmic Center, State Key Laboratory of Ophthalmology, Sun Yat-sen University, Guangzhou, GuangDong, China
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22
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Maeshima S, Osawa A, Nishio D, Hirano Y, Kigawa H, Takeda H. Diffusion tensor MR imaging of the pyramidal tract can predict the need for orthosis in hemiplegic patients with hemorrhagic stroke. Neurol Sci 2013; 34:1765-70. [PMID: 23430171 DOI: 10.1007/s10072-013-1330-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 02/05/2013] [Indexed: 10/27/2022]
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Seo JP, Jang SH. Different characteristics of the corticospinal tract according to the cerebral origin: DTI study. AJNR Am J Neuroradiol 2013; 34:1359-63. [PMID: 23370470 DOI: 10.3174/ajnr.a3389] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Little is known about differences in corticospinal tract fibers according to cerebral origin. Using diffusion tensor tractography, we attempted to investigate the characteristics of the CST according to the cerebral origin in the human brain. MATERIALS AND METHODS Thirty-six healthy subjects were recruited for this study. A 1.5T Gyroscan Intera system was used for acquisition of DTI. CSTs were reconstructed by selection of fibers passing through seed and target ROIs: seed ROIs, the area of the CST at the pontomedullary junction; target ROIs, the primary motor cortex, the primary somatosensory cortex, the dorsal premotor cortex, and the supplementary motor area. RESULTS A significant difference in tract volume was observed in each ROI (P < .05): M1 (2373.6, 36.9%), S1 (2037.7, 31.7%), SMA (1588.0, 24.7%), and dPMC (429.8, 6.7%). Regarding fractional anisotropy values, the dPMC or SMA showed higher values than the M1 or S1; however, the opposite occurred in terms of the mean diffusivity value (P < .05). In addition, fractional anisotropy and mean diffusivity values of the dPMC differed from those of the SMA (P < .05); in contrast, no significant difference was observed between the M1 and S1 (P > .05). CONCLUSIONS Tract volume was found to differ according to cerebral origin and was, in descending order, M1, S1, SMA, and dPMC. In addition, the directionality and diffusivity of CST fibers in the SMA and the dPMC differed from those of the M1 and S1, which showed similar characteristics.
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Affiliation(s)
- J P Seo
- Department of Physical Medicine and Rehabilitation, College of Medicine, Yeungnam University, Taegu, Republic of Korea
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Borstad A, Schmalbrock P, Choi S, Nichols-Larsen DS. Neural correlates supporting sensory discrimination after left hemisphere stroke. Brain Res 2012; 1460:78-87. [PMID: 22592076 PMCID: PMC3774522 DOI: 10.1016/j.brainres.2012.03.060] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Revised: 03/26/2012] [Accepted: 03/27/2012] [Indexed: 11/18/2022]
Abstract
BACKGROUND Nearly half of stroke patients have impaired sensory discrimination, however, the neural structures that support post-stroke sensory function have not been described. OBJECTIVES 1) To evaluate the role of the primary somatosensory (S1) cortex in post-stroke sensory discrimination and 2) To determine the relationship between post-stroke sensory discrimination and structural integrity of the sensory component of the superior thalamic radiation (sSTR). METHODS 10 healthy adults and 10 individuals with left hemisphere stroke participated. Stroke participants completed sensory discrimination testing. An fMRI was conducted during right, impaired hand sensory discrimination. Fractional anisotropy and volume of the sSTR were quantified using diffusion tensor tractography. RESULTS Sensory discrimination was impaired in 60% of participants with left stroke. Peak activation in the left (S1) did not correlate with sensory discrimination ability, rather a more distributed pattern of activation was evident in post-stroke subjects with a positive correlation between peak activation in the parietal cortex and discrimination ability (r=.70, p=.023). The only brain region in which stroke participants had significantly different cortical activation than control participants was the precuneus. Region of interest analysis of the precuneus across stroke participants revealed a positive correlation between peak activation and sensory discrimination ability (r=.77, p=.008). The L/R ratio of sSTR fractional anisotropy also correlated with right hand sensory discrimination (r=.69, p=.027). CONCLUSIONS Precuneus cortex, distributed parietal lobe activity, and microstructure of the sSTR support sensory discrimination after left hemisphere stroke.
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Affiliation(s)
- Alexandra Borstad
- School of Health and Rehabilitation Sciences, The Ohio State University, USA
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Tong T, Zhenwei Y, Xiaoyuan F. Transient ischemic attack and stroke can be differentiated by analyzing the diffusion tensor imaging. Korean J Radiol 2011; 12:280-8. [PMID: 21603287 PMCID: PMC3088845 DOI: 10.3348/kjr.2011.12.3.280] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Accepted: 12/29/2010] [Indexed: 11/15/2022] Open
Abstract
Objective We wanted to differentiate between transient ischemic attack (TIA) and minor stroke using fractional anisotropy and three-dimensional (3D) fiber tractography. Materials and Methods The clinical data, conventional magnetic resonance imaging (MRI), diffusion weighted imaging (DWI) and diffusion tensor imaging (DTI) were obtained for 45 TIA patients and 33 minor stroke patients. The fractional anisotrophy ratio (rFA) between the lesion and the mirrored corresponding contralateral normal tissue was calculated and analyzed. The spatial relationship between the lesion and the corticospinal tract (CST) was analyzed and the lesion sizes in the minor stroke patients and TIA patients were compared. Results Twenty-two of the 45 TIA patients (49%) revealed focal abnormalities following DWI. The rFA was significantly lower (p < 0.05) in the stroke patients (0.71 ± 0.29) compared to that of the TIA patients (1.05 ± 0.37). The CST was involved in almost all stroke lesions, but it was not involved in 68% of the TIA lesions. The TIA patients had significantly lower CST injury scores (3.25 ± 1.75) than did the stroke patients (8.80 ± 2.39) (p = 0.004). Conclusion Our data indicate that TIA and minor stroke can be identified by analyzing the rFA and the degree of CST involvement, and this may also allow more accurate prediction of a patient's long-term recovery or disability.
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Affiliation(s)
- Tong Tong
- Department of Radiology, Fudan University Shanghai Cancer Center, The Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China.
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Bihel E, Roussel S, Toutain J, Bernaudin M, Touzani O. Diffusion tensor MRI reveals chronic alterations in white matter despite the absence of a visible ischemic lesion on conventional MRI: a nonhuman primate study. Stroke 2011; 42:1412-9. [PMID: 21441158 DOI: 10.1161/strokeaha.110.596650] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE The impact of stroke on white matter is poorly described in preclinical investigations mainly based on rodents with a low white (WM)/gray matter ratio. Using diffusion tensor imaging, we evaluated WM alterations and correlated them with sensorimotor deficits after stroke in the marmoset, a nonhuman primate that displays a WM/gray matter ratio close to that of humans. METHODS Marmosets underwent a transient brain ischemia (3-hour). Eight serial MRI examinations were made during ischemia and up to 45 days after reperfusion. The sensorimotor deficits were evaluated weekly over 45 days. To assess WM alterations, the SD of the angle of the first eigenvector projection was calculated in the cortex and in the internal and external capsules. The fiber-tracking approach was used to measure the number and the length of bundles. RESULTS Changes in the apparent diffusion coefficient and the fractional anisotropy values were similar during the temporal evolution of the lesion in the marmoset model of ischemia to that reported in patients with stroke. Despite an absence of visible lesions on T2-MRI and diffusion tensor imaging at the chronic stage, diffusion tensor MRI evidenced alterations in WM by the increase in the standard deviation of the angle of the first eigenvector projection in the cortex, internal and external capsules, and the decrease in the number of bundles of fibers tracked. The disruption of WM was strongly correlated with the chronic sensorimotor deficits. CONCLUSIONS Despite an absence of a visible ischemic lesion at the chronic stage, diffusion tensor MRI revealed disorganization of WM, which probably underlies the persistence of functional deficits.
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Affiliation(s)
- Ebeline Bihel
- CERVOxy, Hypoxia and Cerebrovascular Pathophysiology, CI-NAPS UMR-6232, University of Caen, 59, Boulevard Henri Becquerel BP5229, Caen, France 14074
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Polonara G, Salvolini S, Fabri M, Mascioli G, Cavola GL, Neri P, Mariotti C, Giovannini A, Salvolini U. Unilateral visual loss due to ischaemic injury in the right calcarine region: a functional magnetic resonance imaging and diffusion tension imaging follow-up study. Int Ophthalmol 2011; 31:129-34. [PMID: 21293901 DOI: 10.1007/s10792-011-9420-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2009] [Accepted: 01/01/2011] [Indexed: 10/18/2022]
Abstract
To study the functional recovery of a patient with cerebrovascular injury using combined functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI). A 24-year-old woman with left hemianopsia underwent fMRI and DTI in a 1.5-tesla machine both in the acute phase and 1 month after an ischaemic stroke involving the right calcarine cortex. Acute-phase fMRI demonstrated that peripheral left visual field stimulation did not activate the right primary visual cortex, whereas stimulation 1 month later activated the visual cortex bilaterally. Analysis of acute-phase DTI data disclosed that a reduction of fractional anisotropy in the right optic radiation had almost resolved after 1 month. Fibre direction was normal at either time point. fMRI and DTI can demonstrate functional damage and recovery in patients with neuro-ophthalmological lesions.
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Affiliation(s)
- Gabriele Polonara
- Sezione Scienze Radiologiche, Dipartimento di Scienze Cliniche Specialistiche ed Odontostomatologiche, Università Politecnica delle Marche, Ancona, Italy,
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MORITA N, WANG S, KADAKIA P, CHAWLA S, POPTANI H, MELHEM ER. Diffusion Tensor Imaging of the Corticospinal Tract in Patients with Brain Neoplasms. Magn Reson Med Sci 2011; 10:239-43. [DOI: 10.2463/mrms.10.239] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Abstracts. Neuroradiol J 2010. [DOI: 10.1177/19714009100230s111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Yamada K, Sakai K, Akazawa K, Yuen S, Nishimura T. MR tractography: a review of its clinical applications. Magn Reson Med Sci 2010; 8:165-74. [PMID: 20035125 DOI: 10.2463/mrms.8.165] [Citation(s) in RCA: 213] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Magnetic resonance tractography based on diffusion-tensor imaging was first introduced to the medical imaging community a decade ago. It has been successfully applied to a number of neurological conditions and most commonly used for preoperative planning for brain tumors and vascular malformations. Areas of active research include stroke, and dementia, where it provides valuable information not available through other imaging techniques. This technique was first introduced using the deterministic streamline algorithm and has evolved to use more sophisticated probabilistic approaches. We will review the past, present, and future of tractography, focusing primarily on its clinical applications.
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Affiliation(s)
- Kei Yamada
- Department of Radiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
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Hamaguchi A, Kodera S. [Influence exerted by MPG-directions on diffusion tensor imaging (DTI)]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2009; 65:913-920. [PMID: 19661725 DOI: 10.6009/jjrt.65.913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
When diffusion tensor was analyzed, increasing motion probing gradient (MPG) directions and increasing signal-to-noise ratio (SNR) as result might influence diffusion tensor calculation. This study determined that mean diffusivity (MD) and fractional anisotropy (FA) are calculated by changing MPG-directions or SNR in the volunteer. There were no statistically significant differences in MD, which is calculated from all scanning parameters (p>0.05). FA of the caudate nucleus was similar as well. However, there were statistically significant differences between FA calculated from 31 MPG-directions and from 13 MPG-directions or less for the frontal lobe and caudate nucleus (p<0.05). If SNR of a trace image is 30 or more, FA wasn't affected by SNR (p>0.05). To calculate FA, minimum MPG-directions that were not statistically different compared with 31 MPG-directions were 15 MPG-directions (p<0.05).
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Son SM, Park SH, Moon HK, Lee E, Ahn SH, Cho YW, Byun WM, Jang SH. Diffusion tensor tractography can predict hemiparesis in infants with high risk factors. Neurosci Lett 2009; 451:94-7. [DOI: 10.1016/j.neulet.2008.12.033] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2008] [Revised: 12/12/2008] [Accepted: 12/16/2008] [Indexed: 11/17/2022]
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Corticospinal tract restoration: combined study of diffusion tensor tractography, functional MRI, and transcranial magnetic stimulation. J Comput Assist Tomogr 2008; 31:901-4. [PMID: 18043354 DOI: 10.1097/rct.0b013e31804089a6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We tried to demonstrate the restoration of corticospinal tract in a patient with intracerebral hemorrhage, using diffusion tensor tractography and functional magnetic resonance imaging, and transcranial magnetic stimulation. Transcranial magnetic stimulation demonstrated the corticospinal tract had been spared since subacute stage. Diffusion tensor tractography and functional magnetic resonance imaging showed that the corticospinal tract that was displaced by a hematoma had been restored. These combined modalities would be helpful in elucidating the state and change of corticospinal tract.
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Nucifora PGP, Verma R, Lee SK, Melhem ER. Diffusion-tensor MR imaging and tractography: exploring brain microstructure and connectivity. Radiology 2007; 245:367-84. [PMID: 17940300 DOI: 10.1148/radiol.2452060445] [Citation(s) in RCA: 214] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Diffusion magnetic resonance (MR) imaging is evolving into a potent tool in the examination of the central nervous system. Although it is often used for the detection of acute ischemia, evaluation of directionality in a diffusion measurement can be useful in white matter, which demonstrates strong diffusion anisotropy. Techniques such as diffusion-tensor imaging offer a glimpse into brain microstructure at a scale that is not easily accessible with other modalities, in some cases improving the detection and characterization of white matter abnormalities. Diffusion MR tractography offers an overall view of brain anatomy, including the degree of connectivity between different regions of the brain. However, optimal utilization of the wide range of data provided with directional diffusion MR measurements requires careful attention to acquisition and postprocessing. This article will review the principles of diffusion contrast and anisotropy, as well as clinical applications in psychiatric, developmental, neurodegenerative, neoplastic, demyelinating, and other types of disease.
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Affiliation(s)
- Paolo G P Nucifora
- Department of Radiology, Sections of Neuroradiology and Biomedical Image Analysis, Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA
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Bérubé J, McLaughlin N, Bourgouin P, Beaudoin G, Bojanowski MW. Diffusion tensor imaging analysis of long association bundles in the presence of an arteriovenous malformation. J Neurosurg 2007; 107:509-14. [PMID: 17886548 DOI: 10.3171/jns-07/09/0509] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Conventional imaging demonstrates intertwined fibers of the cerebral white matter as a homogeneous substrate. Recently, diffusion tensor imaging has allowed 3D reconstruction of these fiber bundles. The goal of this study was to analyze the modifications of the association fibers induced by an arteriovenous malformation (AVM) in the parietotemporooccipital (PTO) associative area and their clinical significance. METHODS The authors analyzed the long association fibers in seven patients harboring an AVM in or near the PTO region in relation with the fibers' clinical manifestation. The fibers include the arcuate fasciculus (AF), the occipitofrontal fasciculus (OFF), and the inferior longitudinal fasciculus (ILF). These structures were compared with the contralateral bundles. RESULTS The modification of the tracts could establish a pattern signature depending on the specific location of the vascular malformation. There was a positive correlation between the degree of modifications of OFF and ILF fiber tracts and visual deficits. Alteration of the AF correlated with a speech disorder and the risk of postoperative deficits. CONCLUSIONS Diffusion tensor imaging enables in vivo dissection of fiber tracts coursing through the PTO area. Depending on the location of the AVMs, long association fibers are variously modified. These findings correlate with clinical manifestations and may predict outcome after surgery.
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Affiliation(s)
- Josée Bérubé
- Department of Physiology, University of Montréal, Quebec, Canada
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Lai C, Zhang SZ, Liu HM, Zhou YB, Zhang YY, Zhang QW, Han GC. White matter tractography by diffusion tensor imaging plays an important role in prognosis estimation of acute lacunar infarctions. Br J Radiol 2007; 80:782-9. [PMID: 17875590 DOI: 10.1259/bjr/99366083] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The aim of this study was to evaluate the anatomical and clinical relationship between lacunar infarction and the corticospinal tract (CST) in patients with acute lacunar infarction and predict clinical outcome. We examined 28 pyramidal tract stroke patients in the acute phase or early subacute phase (<3 days) with a marked motor deficit. The anatomical location and the extent of CST involvement within the infarcts were visualized on three-dimensional colour-coded diffusion tensor tractography (DTT). With regard to the CST, all patients were divided into three clinical subgroups: Group 1 (intact type), Group 2 (partial involvement type) and Group 3 (whole involvement type). Subsequently, the severity of the motor deficit of each patient was determined according to the National Institutes of Health Stroke Scale (NIHSS) scores at the acute/early subacute phase (<3 days after onset of symptoms), early chronic phase (8-14 days) and outcome (30-60 days). NIHSS scores of Group 1 (12/28) were significantly lower than those of Group 2 (9/28) at the acute phase or early subacute phase (U = -2.816, p<0.01), and those of Group 2 were significantly lower than those of Group 3 (7/28) (U = -3.136, p<0.01). At outcome,NIHSS scores of Group 1 were significantly lower than those of Group 2 (U = -2.846, p<0.01), and scores of Group 2 were significantly lower than those of Group 3 (U = -3.130, p<0.01). At the same time, the NIHSS scores of each group gradually decreased from acute phase to outcome, Neurological improvement was statistically different among the three topographical types of infarction (H = 26.15, p<0.01; H = 11.03, p<0.01; H = 10.05, p<0.01). In conclusion, the three-dimensional colour-coded DTT allows in vivo differentiation of distinct CST stroke subtypes and may help in better establishing the prognosis for patients after CST stroke.
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Affiliation(s)
- C Lai
- Department of Radiology, The Children's Hospital, The Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
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Cho SH, Kim DG, Kim DS, Kim YH, Lee CH, Jang SH. Motor outcome according to the integrity of the corticospinal tract determined by diffusion tensor tractography in the early stage of corona radiata infarct. Neurosci Lett 2007; 426:123-7. [PMID: 17897782 DOI: 10.1016/j.neulet.2007.08.049] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2007] [Revised: 08/21/2007] [Accepted: 08/22/2007] [Indexed: 11/21/2022]
Abstract
Diffusion tensor tractography (DTT) is useful for exploring the state of the corticospinal tract (CST). An accurate estimation of the integrity of the CST in the early stage of a cerebral infarct would enable a determination of motor recovery. DTT was performed to classify CST integrity following a corona radiata infarct to evaluate if the procedure could characterize the motor outcome of the affected hand. Fifty-five patients with completely paralyzed hands due to a corona radiata infarct were recruited for the study, and DTT images were obtained within 7-30 days after a stroke. The DTI findings for the patients were classified into four groups. In type A, the CST was preserved around the infarct; in type B, the CST originated from a cortex other than the primary motor cortex; in type C, the CST was interrupted at the infarct; in type D, the CST failed to reach the infarct due to degeneration. Six months after a stroke, the motor function of the affected hand was evaluated with the motricity index (MI) for the hand, the Medical Research Council score (MRC) for finger extensors and the modified Brunnstrom classification (MBC). These indices were significantly influenced by the DTT type (p<0.05). The highest MI, MRC and MBC were seen in the DTT type A patients; the lowest MI, MRC and MBC were seen in the DTT type D patients (p<0.05). The integrity of the corticospinal tract determined by DTT obtained during the early stage of a corona radiata infarct seems to be helpful in predicting the motor outcome of the affected hand.
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Affiliation(s)
- Sang-Hyun Cho
- Department of Physical Therapy, Institute of Health Science, Yonsei University College of Health Science, Republic of Korea
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Møller M, Frandsen J, Andersen G, Gjedde A, Vestergaard-Poulsen P, Østergaard L. Dynamic changes in corticospinal tracts after stroke detected by fibretracking. J Neurol Neurosurg Psychiatry 2007; 78:587-92. [PMID: 17210628 PMCID: PMC2077935 DOI: 10.1136/jnnp.2006.100248] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND AND AIMS The integrity of motor pathways and functional connectivity patterns are important in assessing plastic changes related to successful recovery, to obtain prognostic information and to monitor future therapeutic strategies of stroke patients. We tested the following hypotheses: (1) that changes in axonal integrity along the corticospinal tract after stroke can be detected as a reduction in fractional anisotropy; and (2) that sustained low fractional anisotropy is indicative of axonal loss and therefore is correlated with poor motor outcome, as measured by specific neurological motor scores. METHODS We developed a segmentation tool based on magnetic resonance diffusion tensor imaging in conjunction with three dimensional fibretracking for longitudinal studies of the corticospinal tract, and used specific neurological motor scores to test the hypotheses in five stroke patients within the first week and 30 and 90 days after the stroke. RESULTS Reduction in fractional anisotropy within the first weeks after stroke reflected a decline in axonal integrity, leading to Wallerian degeneration, and demonstrated a correlation between the temporal evolution of fractional anisotropy and motor function in patients with poor motor outcome. CONCLUSION The study demonstrated the feasibility of fibretracking as a segmentation tool for mapping distal parts of the corticospinal motor pathways and showed that fractional anisotropy in the segmented corticospinal tract is a sensitive measure of structural changes after stroke.
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Affiliation(s)
- M Møller
- Centre of Functionally Integrative Neuroscience, Aarhus University, Denmark.
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Yamada K, Nagakane Y, Yoshikawa K, Kizu O, Ito H, Kubota T, Akazawa K, Oouchi H, Matsushima S, Nakagawa M, Nishimura T. Somatotopic Organization of Thalamocortical Projection Fibers as Assessed with MR Tractography. Radiology 2007; 242:840-5. [PMID: 17325069 DOI: 10.1148/radiol.2423060297] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To prospectively evaluate the course of sensory fibers through the supratentorial brain with diffusion-tensor-based tractography. MATERIALS AND METHODS This study was approved by the institutional review board. Informed consent was obtained. Seven healthy volunteers (five men, two women; age range, 20-55 years) underwent 1.5-T magnetic resonance imaging. Diffusion-tensor images with isotropic voxels (2 x 2 x 2 mm) were obtained by using a single-shot echo-planar imaging technique, with a motion-probing gradient in 15 orientations, a b value of 1000 sec/mm(2), and nine signals acquired. The total imaging time was approximately 30 minutes. Fiber tracking of the sensorimotor pathways was performed with the fiber assignment by continuous tracking method. RESULTS All the pyramidal tracts rotated anteriorly as they traveled through the centrum semiovale. On the other hand, the sensory tracts rotated posteriorly as they coursed through the centrum semiovale toward the cortex. When the sensorimotor tracts were viewed as a unit, the tracts of the lower extremity formed the axis of rotation around which the other parts of the pyramidal and sensory homunculus rotated. CONCLUSION Sensorimotor fibers of the lower extremity form an axis of rotation, around which the pyramidal fibers rotate anteriorly and the sensory fibers rotate posteriorly.
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Affiliation(s)
- Kei Yamada
- Department of Radiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kajii-cyo, Kawaramachi Hirokoji Sagaru, Kamigyo-ku, Kyoto City, Kyoto 602-8566, Japan.
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Ahn YH, Ahn SH, Kim H, Hong JH, Jang SH. Can stroke patients walk after complete lateral corticospinal tract injury of the affected hemisphere? Neuroreport 2006; 17:987-90. [PMID: 16791089 DOI: 10.1097/01.wnr.0000220128.01597.e0] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The lateral corticospinal tract is the major motor pathway in humans. The role of this tract on walking, however, is uncertain. The development of diffusion tensor tractography enables corticospinal tract status to be visualized at the subcortical level. In the present study, we undertook to demonstrate that some stroke patients can walk despite complete lateral corticospinal tract injury. Ten stroke patients who were able to walk with evidence of complete unilateral lateral corticospinal tract injury, as determined by clinical course, brain magnetic resonance imaging, and diffusion tensor tractography, were recruited. We conclude that some stroke patients can walk despite complete lateral corticospinal tract injury of the affected hemisphere.
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Affiliation(s)
- Young Hwan Ahn
- Department of Neurosurgery, Ajou University School of Medicine, Suwon, South Korea
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Jang SH, Kwon YH, Lee MY, Ahn SH, Kim JH, Jeong DH, Choi BY, Lee DG. Corticospinal tract compression by hematoma in a patient with intracerebral hemorrhage: a diffusion tensor tractography and functional MRI study. Yonsei Med J 2006; 47:135-9. [PMID: 16502496 PMCID: PMC2687571 DOI: 10.3349/ymj.2006.47.1.135] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
The purpose of this study was to demonstrate corticospinal tract compression that was due to a hematoma by using diffusion tensor tractography (DTT) and functional MRI (fMRI) in a patient with an intracerebral hemorrhage (ICH). A 23-year-old right-handed woman presented with severe paralysis of her right extremities at the onset of a spontaneous ICH. Over the first three days from onset, the motor function of the affected upper and lower extremities rapidly recovered to the extent that she was able to overcome applied resistance to the affected limbs, and her limbs regained normal function 3 weeks after onset. The tract of the right hemisphere originated from the primary sensori-motor cortex (SM1) and it passed through the known corticospinal tract pathway. However, the tract of the left hemisphere was similar to that of the right hemisphere except that it was displaced to the antero-medial side by the hematoma at the cerebral peduncle. Only the contralateral SM1 area centered on the precentral knob was activated during affected (right) or unaffected (left) hand movements, respectively. In conclusion, fMRI and DTT demonstrated a corticospinal tract compression due to hematoma in this patient. We conclude that the combined use of these two modalities appears to improve the accuracy of investigating the state of the corticospinal tract.
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Affiliation(s)
- Sung-Ho Jang
- Department of Physical Medicine and Rehabilitation, School of Medicine, Yeungnam University, Daegu, Korea
| | - Yong-Hyun Kwon
- Department of Rehabilitation Science, Graduate School, Daegu University, Daegu, Korea
| | - Mi Young Lee
- Department of Rehabilitation Science, Graduate School, Daegu University, Daegu, Korea
| | - Sang Ho Ahn
- Department of Physical Medicine and Rehabilitation, School of Medicine, Yeungnam University, Daegu, Korea
| | - Joong Hwi Kim
- Department of Rehabilitation Science, Graduate School, Daegu University, Daegu, Korea
| | - Dong-Hoon Jeong
- Department of Rehabilitation Technology, Korea Nasarene University, Chonan, Korea
| | - Byung Yeun Choi
- Department of Neurosurgery, School of Medicine, Yeungnam University, Daegu, Korea
| | - Dong Gyu Lee
- Department of Physical Medicine and Rehabilitation, School of Medicine, Yeungnam University, Daegu, Korea
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Yamamoto T, Yamada K, Nishimura T, Kinoshita S. Tractography to depict three layers of visual field trajectories to the calcarine gyri. Am J Ophthalmol 2005; 140:781-785. [PMID: 16310456 DOI: 10.1016/j.ajo.2005.05.018] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2004] [Revised: 05/05/2005] [Accepted: 05/05/2005] [Indexed: 11/18/2022]
Abstract
PURPOSE Fiber-tracking by diffusion tensor magnetic resonance imaging (DT-MRI) is currently the only noninvasive in vivo method for white matter fiber-tracking in the human brain. We used this method in attempts to visualize the optic radiation and to examine the clinical applicability of this technique. DESIGN Observational case series. METHODS DT-MRI scans for fiber-tracking were obtained in five healthy volunteers by use of a whole-body, 1.5 Tesla imager. DT-MRI data were transferred to an off-line workstation; PRIDE software was used for image analysis. We constructed 3 diopters fiber trajectories by tracking the direction of the fastest diffusion from the lateral geniculate nucleus, and then selected tracts on the basis of anatomical knowledge of the optic radiation. RESULTS Our method successfully reconstructed the macroscopic 3 diopters architecture of the three major groups of optic radiation in all subjects. Meyer's loop depicted by tractography was located more posterior than the known anatomical locations, although our results on the central and posterior bundles were in good agreement with them. DT-MRI scanning required 7 minutes; preliminary images of the optic radiation could be obtained in approximately 20 minutes. CONCLUSIONS Fiber-tracking enabled us to obtain information quickly on the 3 diopters course of the optic radiation in vivo. The finding that the fiber-tracking method underestimates the anterior extent of the optic radiations could prove to be an important limitation in the utility of this technique for preoperative planning. The time required for data acquisition and processing makes this method acceptable for routine clinical use.
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Affiliation(s)
- Takami Yamamoto
- Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan
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Lee JS, Han MK, Kim SH, Kwon OK, Kim JH. Fiber tracking by diffusion tensor imaging in corticospinal tract stroke: Topographical correlation with clinical symptoms. Neuroimage 2005; 26:771-6. [PMID: 15955486 DOI: 10.1016/j.neuroimage.2005.02.036] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2004] [Revised: 02/05/2005] [Accepted: 02/17/2005] [Indexed: 11/19/2022] Open
Abstract
Fiber tracking of the white matter using diffusion tensor imaging is a new imaging technique to visualize the integrity of the white matter. This study investigated the capability of this technique to localize the lacunar infarctions, particularly with respect to the body parts affected, by correlating the location of the lesion with the clinical symptoms topographically. Twenty-seven patients with capsular and pericapsular small acute infarctions underwent diffusion tensor imaging and subsequent fiber tracking of the corticospinal tract (CST). According to the lesion topography with regard to the CST, the infarctions were classified into four types: (1) the anterior type (n = 9) involving the anterior part of the CST, (2) the central type (n = 9) involving the middle or whole part of the CST, (3) the posterior type (n = 5) involving the posterior part of the CST and (4) the intact type (n = 4) not involving the CST. Motor weakness of the face, upper extremities and lower extremities was found at 100%, 67% and 44%, respectively in the anterior type, at 89%, 100% and 89%, respectively in the central type and at 20%, 80% and 100%, respectively in the posterior type. The intact type was not associated with motor weakness. In conclusion, the fiber tracking technique of the CST enables the specific localization of capsular and pericapsular infarctions with regard to the body parts affected. These results also confirm the topographical accuracy of the fiber tracking of the CST.
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Affiliation(s)
- Jong Sea Lee
- Department of Radiology, Seoul National University, College of Medicine, Bundang Hospital, 300 Gumi-Dong, Bundang-Gu, Seongnam-Si, 463-707 Seoul, Korea
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Kinoshita M, Yamada K, Hashimoto N, Kato A, Izumoto S, Baba T, Maruno M, Nishimura T, Yoshimine T. Fiber-tracking does not accurately estimate size of fiber bundle in pathological condition: initial neurosurgical experience using neuronavigation and subcortical white matter stimulation. Neuroimage 2005; 25:424-9. [PMID: 15784421 DOI: 10.1016/j.neuroimage.2004.07.076] [Citation(s) in RCA: 194] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2004] [Revised: 06/21/2004] [Accepted: 07/29/2004] [Indexed: 10/25/2022] Open
Abstract
The fiber-tracking method enables in vivo visualization of the white matter tracts of the brain using a diffusion tensor MR imaging technique. While this method represents a promising tool in the field of neurosurgery, especially when confronted with brain tumors in eloquent areas, its reliability remains unknown. We present here our preliminary validation of tractography in human subjects harboring brain tumors by comparing the results produced by neuronavigation and electrical white matter stimulation in two patients with gliomas in the eloquent area. Although we were able to visualize the pyramidal tract with the fiber-tracking technique, the images failed to present the actual size of the fiber bundles. Here we discuss the advantages and limitations of fiber-tracking in the field of neurosurgery.
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Affiliation(s)
- Manabu Kinoshita
- Department of Neurosurgery, Osaka University Medical School, Yamadaoka, 2-2, Suita, Osaka 565-0871, Japan
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Kim YH, Jang SH, Han BS, Kwon YH, You SH, Byun WM, Park JW, Yoo WK. Ipsilateral motor pathway confirmed by diffusion tensor tractography in a patient with schizencephaly. Neuroreport 2004; 15:1899-902. [PMID: 15305133 DOI: 10.1097/00001756-200408260-00013] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We evaluated the hand motor function of a right hemiparetic patient with schizencephaly using a combination of fMRI, transcranial magnetic stimulation, and diffusion tensor tractography (DTT). Only the unaffected (right) primary sensori-motor cortex was found to be activated during either affected (right) or unaffected hand movements. Evoked motor potentials with similar characteristics were obtained from both abductor pollicis brevis muscles simultaneously when stimulating the unaffected motor cortex. Moreover, a tract presumed to be a corticospinal tract was observed in the unaffected hemisphere by DTT, however, no tract was observed in the affected hemisphere. Our results indicate that the ipsilateral corticospinal tract extended from the unaffected (right) motor cortex to both hands. This finding may reflect functional reorganization of motor function in a patient with congenital brain disorder.
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Affiliation(s)
- Yun-Hee Kim
- Department of Physical Medicine and Rehabilitation, Sungkyunkwan University School of Medicine, Samsung Medical Center, 50 Ilwon-dong, Kangnam-ku, Seoul, 135-710, Republic of Korea
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Kunimatsu A, Aoki S, Masutani Y, Abe O, Hayashi N, Mori H, Masumoto T, Ohtomo K. The Optimal Trackability Threshold of Fractional Anisotropy for Diffusion Tensor Tractography of the Corticospinal Tract. Magn Reson Med Sci 2004; 3:11-7. [PMID: 16093615 DOI: 10.2463/mrms.3.11] [Citation(s) in RCA: 197] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE In order to ensure that three-dimensional diffusion tensor tractography (3D-DTT) of the corticospinal tract (CST), is performed accurately and efficiently, we set out to find the optimal lower threshold of fractional anisotropy (FA) below which tract elongation is terminated (trackability threshold). METHODS Thirteen patients with acute or early subacute ischemic stroke causing motor deficits were enrolled in this study. We performed 3D-DTT of the CST with diffusion tensor MR (magnetic resonance) imaging. We segmented the CST and established a cross-section of the CST in a transaxial plane as a region of interest. Thus, we selectively measured the FA values of the right and left corticospinal tracts at the level of the cerebral peduncle, the posterior limb of the internal capsule, and the centrum semiovale. The FA values of the CST were also measured on the affected side at the level where the clinically relevant infarction was present in isotropic diffusion-weighted imaging. RESULTS 3D-DTT allowed us to selectively measure the FA values of the CST. Among the 267 regions of interest we measured, the minimum FA value was 0.22. The FA values of the CST were smaller and more variable in the centrum semiovale than in the other regions. The mean minus twice the standard deviation of the FA values of the CST in the centrum semiovale was calculated at 0.22 on the normal unaffected side and 0.16 on the affected side. CONCLUSION An FA value of about 0.20 was found to be the optimal trackability threshold.
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Affiliation(s)
- Akira Kunimatsu
- Department of Radiology, Graduate School of Medicine, Tokyo University, Hongo, Tokyo.
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