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Phua CS, Moffat B, Paul E, Ang M, Law M, Bertram K, Hutton E. Quantitative analysis of MR T2 relaxation times in neck muscles. Magn Reson Imaging 2023; 103:156-161. [PMID: 37517766 DOI: 10.1016/j.mri.2023.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 07/26/2023] [Accepted: 07/27/2023] [Indexed: 08/01/2023]
Abstract
T2 relaxation times (T2 times) are different between resting and exercised muscles and between muscles of healthy subjects and subjects with muscle pathology. However, studies specifically focusing on neck muscles are lacking. Furthermore, normative neck muscle T2 times are not well defined and methodology used to analyse T2 times in neck muscles is not robust. We analysed T2 times in key neck muscles and explored factors affecting variability between muscles. 20 healthy subjects were recruited. Two circular regions of interest (ROIs) were drawn in two mutually exclusive regions within neck muscles on T2 weighted images and values averaged. ROI measurements were performed by a co-investigator, supervised by a neuro-radiologist. For the first ten subjects, measurements were done from C1-T1. For the remaining subjects, ROIs were drawn at two pre-determined levels. Two MRIs were repeated at 31 degrees acquisition to evaluate the effect of muscle fibre orientation. ROI values were translated into T2 times. Results showed semispinalis capitis had the longest T2 times (range 46.88-51.42 ms), followed by splenius capitis (range 47.37-48.33 ms), trapezius (range 45.27-47.46 ms), levator scapulae (range 43.17-45.63 ms) and sternocleidomastoid (range 38.45-42.91 ms). T2 times did not vary along length of muscles and were unaffected by muscle fibre orientation (P > 0.05). T2 times of splenius capitis correlated significantly with age at C2/C3 and C5/C6 levels and trapezius at C7/T1 level. Gender did not influence relaxation times (P > 0.05). In conclusion, results of normative neck muscle T2 time values and factors influencing the T2 times could serve as a reference for future MR analysis of neck muscles. The methodology used may also be useful for related studies of neck muscles.
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Affiliation(s)
- Chun Seng Phua
- Alfred Health, Department of Neurology, Melbourne, Australia; Monash University, Department of Neurosciences, Melbourne, Australia; Universiti Teknologi Mara, Selangor, Malaysia.
| | - Bradford Moffat
- Melbourne Brain Centre Imaging Unit, University of Melbourne, Melbourne, Australia
| | - Eldho Paul
- Alfred Health, Department of Neurology, Melbourne, Australia; Monash University, School of Public Health and Preventive Medicine, Melbourne, Australia
| | - Megan Ang
- Alfred Health, Department of Radiology, Melbourne, Australia
| | - Meng Law
- Monash University, Department of Neurosciences, Melbourne, Australia; Alfred Health, Department of Radiology, Melbourne, Australia
| | - Kelly Bertram
- Alfred Health, Department of Neurology, Melbourne, Australia; Monash University, Department of Neurosciences, Melbourne, Australia
| | - Elspeth Hutton
- Alfred Health, Department of Neurology, Melbourne, Australia; Monash University, Department of Neurosciences, Melbourne, Australia
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Lott DJ, Taivassalo T, Cooke KD, Park H, Moslemi Z, Batra A, Forbes SC, Byrne BJ, Walter GA, Vandenborne K. Safety, feasibility, and efficacy of strengthening exercise in Duchenne muscular dystrophy. Muscle Nerve 2020; 63:320-326. [PMID: 33295018 DOI: 10.1002/mus.27137] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 12/02/2020] [Accepted: 12/06/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND This two-part study explored the safety, feasibility, and efficacy of a mild-moderate resistance isometric leg exercise program in ambulatory boys with Duchenne muscular dystrophy (DMD). METHODS First, we used a dose escalation paradigm with varying intensity and frequency of leg isometric exercise to determine the dose response and safety in 10 boys. Second, we examined safety and feasibility of a 12-wk in-home, remotely supervised, mild-moderate intensity strengthening program in eight boys. Safety measures included T2 MRI, creatine kinase levels, and pain. Peak strength and function (time to ascend/descend four stairs) were also measured. RESULTS Dose-escalation revealed no signs of muscle damage. Seven of the eight boys completed the 12-wk in-home program with a compliance of 84.9%, no signs of muscle damage, and improvements in strength (knee extensors P < .01; knee flexors P < .05) and function (descending steps P < .05). CONCLUSIONS An in-home, mild-moderate intensity leg exercise program is safe with potential to positively impact both strength and function in ambulatory boys with DMD.
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Affiliation(s)
- Donovan J Lott
- Department of Physical Therapy, University of Florida, Gainesville, Florida, USA
| | - Tanja Taivassalo
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida, USA
| | - Korey D Cooke
- Department of Physical Therapy, University of Florida, Gainesville, Florida, USA
| | - Hyunjun Park
- Department of Physical Therapy, University of Florida, Gainesville, Florida, USA
| | - Zahra Moslemi
- Department of Applied Physiology & Kinesiology, University of Florida, Gainesville, Florida, USA
| | - Abhinandan Batra
- Department of Physical Therapy, University of Florida, Gainesville, Florida, USA
| | - Sean C Forbes
- Department of Physical Therapy, University of Florida, Gainesville, Florida, USA
| | - Barry J Byrne
- Department of Pediatrics, University of Florida, Gainesville, Florida, USA
| | - Glenn A Walter
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida, USA
| | - Krista Vandenborne
- Department of Physical Therapy, University of Florida, Gainesville, Florida, USA
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Locomotor Training Promotes Time-dependent Functional Recovery after Experimental Spinal Cord Contusion. Neuroscience 2018; 392:258-269. [DOI: 10.1016/j.neuroscience.2018.08.033] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 08/28/2018] [Accepted: 08/29/2018] [Indexed: 12/13/2022]
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Sharafi A, Chang G, Regatte RR. Bi-component T1ρ and T2 Relaxation Mapping of Skeletal Muscle In-Vivo. Sci Rep 2017; 7:14115. [PMID: 29074883 PMCID: PMC5658335 DOI: 10.1038/s41598-017-14581-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 10/12/2017] [Indexed: 12/26/2022] Open
Abstract
The goal of this paper was to evaluate the possibility of bi-component T1ρ and T2 relaxation mapping of human skeletal muscle at 3 T in clinically feasible scan times. T1ρ- and T2-weighted images of calf muscle were acquired using a modified 3D-SPGR sequence on a standard 3 T clinical MRI scanner. The mono- and biexponential models were fitted pixel-wise to the series of T1ρ and T2 weighted images. The biexponential decay of T1ρ and T2 relaxations was detected in ~30% and ~40% of the pixels across all volunteers, respectively. Monoexponential and bi-exponential short and long T1ρ relaxation times were estimated to be 26.9 ms, 4.6 ms (fraction 22%) and 33.2 ms (fraction: 78%), respectively. Similarly, the mono- and bi-exponential short and long T2 relaxation times were 24.7 ms, 4.2 ms (fraction 15%) and 30.4 ms (fraction 85%) respectively. The experiments had good repeatability with RMSCV < 15% and ICC > 60%. This approach could potentially be used in exercise intervention studies or in studies of inflammatory myopathies or muscle fibrosis, permitting greater sensitivity and specificity via measurement of different water compartments and their fractions.
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Affiliation(s)
- Azadeh Sharafi
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA.
| | - Gregory Chang
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA
| | - Ravinder R Regatte
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA
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Sun MY, Lü JQ, Ma ZC, Lü JJ, Huang Q, Sun YN, Liu Y. Effects of the Inertia Barbell Training on Lumbar Muscle T2 Relaxation Time. J Strength Cond Res 2017; 34:3454-3462. [PMID: 28475549 DOI: 10.1519/jsc.0000000000001974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Sun, M-Y, Lu, J-Q, Ma, Z-C, Lü, J-J, Huang, Q, Sun, Y-N, and Liü, Y. Effects of the inertia barbell training on lumbar muscle T2 relaxation time. J Strength Cond Res 34(12): 3454-3462, 2020-The purpose of this study was to investigate variations in T2 relaxation time in normal human lumbar muscles caused by inertia barbell training. Thirty undergraduate healthy men (mean age = 19 ± 1.2 years, body mass = 72 ± 10.0 kg, and height = 1.78 ± 0.1 m) were recruited to participate in this study. Subjects were randomly assigned into 2 groups: an inertia barbell training group (IBTG) (n = 15) and a normal barbell-training group (NBTG) (n = 15). All subjects participated in lumbar flexion and extension muscle strength training for 1 hour per time, 3 times per week for a total of 8 weeks. The lumbar area of each subject was scanned before and after the experiment using a 3.0T superconductive magnetic resonance imaging system. The T2 values measured after intervention were significantly different compared with the T2 values measured before the experiment in both the IBTG and NBTG groups (p < 0.001). After intervention, there was no significant difference in T2 values between the IBTG and NBTG groups (p = 0.17). The ([INCREMENT]T2)/T2 percentage was significantly different in the IBTG group (p < 0.01). This study demonstrated that 8 weeks of strength training led to significant improvements in the values for T2 relaxation time of the lumbar muscles. Furthermore, the ([INCREMENT]T2)/T2 percentage for IBTG was higher than that for NBTG, which suggested that lumbar muscle activity increased more with inertial barbell training.
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Affiliation(s)
- Ming-Yun Sun
- Institute of Physical Education, Anqing Normal University, Anqing, China.,Institute and Intelligent of Machines, Chinese Academy of Sciences, Hefei, China; and
| | - Jian-Qiang Lü
- Key Laboratory of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, Shanghai, China
| | - Zu-Chang Ma
- Institute and Intelligent of Machines, Chinese Academy of Sciences, Hefei, China; and
| | - Jiao-Jiao Lü
- Key Laboratory of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, Shanghai, China
| | - Qing Huang
- Institute of Physical Education, Anqing Normal University, Anqing, China
| | - Yi-Ning Sun
- Institute and Intelligent of Machines, Chinese Academy of Sciences, Hefei, China; and
| | - Yu Liu
- Key Laboratory of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, Shanghai, China
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Robles PG, Sussman MS, Naraghi A, Brooks D, Goldstein RS, White LM, Mathur S. Intramuscular Fat Infiltration Contributes to Impaired Muscle Function in COPD. Med Sci Sports Exerc 2016; 47:1334-41. [PMID: 25373483 DOI: 10.1249/mss.0000000000000556] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
UNLABELLED Muscle weakness is a prevalent complication in chronic obstructive pulmonary disease (COPD). Atrophy does not fully explain muscle weakness in this population. The recent focus on fat infiltration and its clinical implications in age and diseased muscles are important because it may further explain the extent of declining muscle strength and mobility seen in COPD. PURPOSE The objectives of this study are to quantify fat infiltration (muscle quality) of lower-limb muscles in people with COPD and healthy older adults using magnetic resonance imaging and proton magnetic resonance spectroscopy, and to explore its relationship with muscle strength and walking capacity in COPD. METHODS T1-weighted magnetic resonance imaging and proton magnetic resonance spectroscopy were performed in people with COPD (n = 10) and control subjects (n = 10) matched for age, gender, and body mass index. Maximal cross-sectional area (muscle size), isokinetic and isometric muscle peak torques, and 6-min walk distance were also assessed. RESULTS In addition to muscle atrophy (mean between-group differences of 20% to 25%, P < 0.05), COPD group presented with fatty infiltration in thigh and calf muscles that were significantly greater than what was observed in their healthy counterparts (mean between-group differences of 74% to 89%, P = 0.001). There was a strong inverse correlation between intramuscular fat infiltration, muscle peak torque, and walking distance (r = -0.6 to -0.8, P < 0.001) in this group as opposed to fair-to-moderate correlations between muscle size and the same outcomes (r = 0.4-0.6, P < 0.01). CONCLUSION Poor muscle quality accompanies atrophy in people with COPD. Intramuscular fat infiltration not only appears to have a strong correlation with impaired function but also is more profound than muscle atrophy in this group. Monitoring both muscle size and quality may enable a more comprehensive assessment of exercise programs in COPD.
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Affiliation(s)
- Priscila Games Robles
- 1Graduate Department of Rehabilitation Sciences, University of Toronto, Toronto, Ontario, CANADA; 2Joint Department of Medical Imaging, University Health Network and Mount Sinai Hospital, University of Toronto, Toronto, Ontario, CANADA; 3Department of Physical Therapy, University of Toronto, Toronto, Ontario, CANADA; and 4Respiratory Medicine, West Park Healthcare Centre, Toronto, Ontario, CANADA
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Transcriptional Pathways Associated with Skeletal Muscle Changes after Spinal Cord Injury and Treadmill Locomotor Training. BIOMED RESEARCH INTERNATIONAL 2015; 2015:387090. [PMID: 26380273 PMCID: PMC4561307 DOI: 10.1155/2015/387090] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 05/19/2015] [Indexed: 01/06/2023]
Abstract
The genetic and molecular events associated with changes in muscle mass and
function after SCI and after the implementation of candidate therapeutic
approaches are still not completely known. The overall objective of this study was
to identify key molecular pathways activated with muscle remodeling after SCI
and locomotor training. We implemented treadmill training in a well-characterized
rat model of moderate SCI and performed genome wide expression profiling on
soleus muscles at multiple time points: 3, 8, and 14 days after SCI. We found that the
activity of the protein ubiquitination and mitochondrial function related pathways
was altered with SCI and corrected with treadmill training. The BMP pathway was
differentially activated with early treadmill training as shown by Ingenuity
Pathway Analysis. The expression of several muscle mass regulators was
modulated by treadmill training, including Fst, Jun, Bmpr2, Actr2b, and Smad3. In
addition, key players in fatty acids metabolism (Lpl and Fabp3) responded to
both SCI induced inactivity and reloading with training. The decrease in Smad3 and Fst early after the initiation of treadmill training was confirmed by RT-PCR. Our data suggest that TGFβ/Smad3 signaling may be mainly involved in the decrease in muscle mass observed with SCI, while the BMP pathway was activated with treadmill training.
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Vohra RS, Mathur S, Bryant ND, Forbes SC, Vandenborne K, Walter GA. Age-related T2 changes in hindlimb muscles of mdx mice. Muscle Nerve 2015; 53:84-90. [PMID: 25846867 DOI: 10.1002/mus.24675] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2015] [Indexed: 11/11/2022]
Abstract
INTRODUCTION Magnetic resonance imaging (MRI) was used to monitor changes in the transverse relaxation time constant (T2) in lower hindlimb muscles of mdx mice at different ages. METHODS Young (5 weeks), adult (44 weeks), and old mdx (96 weeks), and age-matched control mice were studied. Young mdx mice were imaged longitudinally, whereas adult and old mdx mice were imaged at a single time-point. RESULTS Mean muscle T2 and percent of pixels with elevated T2 were significantly different between mdx and control mice at all ages. In young mdx mice, mean muscle T2 peaked at 7-8 weeks and declined at 9-11 weeks. In old mdx mice, mean muscle T2 was decreased compared with young and adult mice, which could be attributed to fibrosis. CONCLUSIONS MRI captured longitudinal changes in skeletal muscle integrity of mdx mice. This information will be valuable for pre-clinical testing of potential therapeutic interventions for muscular dystrophy.
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Affiliation(s)
- Ravneet S Vohra
- Department of Physical Therapy, University of Florida, Gainesville, Florida, USA
| | - Sunita Mathur
- Department of Physical Therapy, University of Toronto, Toronto, Ontario, Canada
| | - Nathan D Bryant
- Department of Physiology and Functional Genomics, University of Florida, Box 100274, Gainesville, Florida, 32610-0274, USA
| | - Sean C Forbes
- Department of Physical Therapy, University of Florida, Gainesville, Florida, USA
| | - Krista Vandenborne
- Department of Physical Therapy, University of Florida, Gainesville, Florida, USA
| | - Glenn A Walter
- Department of Physiology and Functional Genomics, University of Florida, Box 100274, Gainesville, Florida, 32610-0274, USA
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Azzabou N, Loureiro de Sousa P, Caldas E, Carlier PG. Validation of a generic approach to muscle water T2 determination at 3T in fat-infiltrated skeletal muscle. J Magn Reson Imaging 2014; 41:645-53. [PMID: 24590466 DOI: 10.1002/jmri.24613] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 02/12/2014] [Indexed: 11/06/2022] Open
Abstract
PURPOSE To introduce a novel method for skeletal muscle water T2 determination in fat-infiltrated tissues, using a tri-exponential fit of the global muscle signal decay. MATERIALS AND METHODS In all, 48 patients with various neuromuscular diseases were retrospectively selected and their thigh muscles analyzed. Each patient was imaged using a multispin-echo (MSME) sequence with a 17-echo train. The transmit field (B1+) inhomogeneities were evaluated using the actual flip angle imaging method toward voxel sorting. Muscle water T2 was quantified using a tri-exponential signal decay model. The difference between water T2 of voxels within the same muscle but having different fat ratio was analyzed using nonparametric statistical tests. In addition, we evaluated the correlation between fat ratio and T2 values obtained using both a mono- and tri-exponential approach. RESULTS The results showed that muscle water T2 values obtained using a tri-exponential approach combined with B1+ map-based voxel sorting were independent of the fat infiltration degree inside the muscle (R(2) < 0.03). This was not the case using the mono-exponential model, which measured different T2s between voxels of the same muscle but with various fat ratio (R(2) > 0.67; P < 10e(-4) ). CONCLUSION The tri-exponential model is an accurate tool to monitor muscle tissue disease activity devoid of bias introduced by fat infiltration.
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Affiliation(s)
- Noura Azzabou
- Institute of Myology, NMR Laboratory, Paris, France; CEA, I2BM MIRCen IdM NMR Laboratory, Paris, France
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Ormond DR, Shannon C, Oppenheim J, Zeman R, Das K, Murali R, Jhanwar-Uniyal M. Stem cell therapy and curcumin synergistically enhance recovery from spinal cord injury. PLoS One 2014; 9:e88916. [PMID: 24558450 PMCID: PMC3928327 DOI: 10.1371/journal.pone.0088916] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Accepted: 01/13/2014] [Indexed: 01/11/2023] Open
Abstract
Acute traumatic spinal cord injury (SCI) is marked by the enhanced production of local cytokines and pro-inflammatory substances that induce gliosis and prevent reinnervation. The transplantation of stem cells is a promising treatment strategy for SCI. In order to facilitate functional recovery, we employed stem cell therapy alone or in combination with curcumin, a naturally-occurring anti-inflammatory component of turmeric (Curcuma longa), which potently inhibits NF-κB. Spinal cord contusion following laminectomy (T9–10) was performed using a weight drop apparatus (10 g over a 12.5 or 25 mm distance, representing moderate or severe SCI, respectively) in Sprague-Dawley rats. Neural stem cells (NSC) were isolated from subventricular zone (SVZ) and transplanted at the site of injury with or without curcumin treatment. Functional recovery was assessed by BBB score and body weight gain measured up to 6 weeks following SCI. At the conclusion of the study, the mass of soleus muscle was correlated with BBB score and body weight. Stem cell therapy improved recovery from moderate SCI, however, it had a limited effect on recovery after severe SCI. Curcumin stimulated NSC proliferation in vitro, and in combination with stem cell therapy, induced profound recovery from severe SCI as evidenced by improved functional locomotor recovery, increased body weight, and soleus muscle mass. These findings demonstrate that curcumin in conjunction with stem cell therapy synergistically improves recovery from severe SCI. Furthermore, our results indicate that the effect of curcumin extends beyond its known anti-inflammatory properties to the regulation of stem cell proliferation.
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Affiliation(s)
- D. Ryan Ormond
- Department of Neurosurgery, New York Medical College, Valhalla, New York, United States of America
| | - Craig Shannon
- Department of Neurosurgery, New York Medical College, Valhalla, New York, United States of America
| | - Julius Oppenheim
- Department of Neurosurgery, New York Medical College, Valhalla, New York, United States of America
| | - Richard Zeman
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York, United States of America
| | - Kaushik Das
- Department of Neurosurgery, New York Medical College, Valhalla, New York, United States of America
| | - Raj Murali
- Department of Neurosurgery, New York Medical College, Valhalla, New York, United States of America
| | - Meena Jhanwar-Uniyal
- Department of Neurosurgery, New York Medical College, Valhalla, New York, United States of America
- * E-mail:
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Jayaraman A, Liu M, Ye F, Walter GA, Vandenborne K. Regenerative responses in slow- and fast-twitch muscles following moderate contusion spinal cord injury and locomotor training. Eur J Appl Physiol 2012; 113:191-200. [DOI: 10.1007/s00421-012-2429-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Accepted: 05/15/2012] [Indexed: 11/30/2022]
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Tawara N, Nitta O, Kuruma H, Niitsu M, Itoh A. T2 mapping of muscle activity using ultrafast imaging. Magn Reson Med Sci 2011; 10:85-91. [PMID: 21720110 DOI: 10.2463/mrms.10.85] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Measuring exercise-induced muscle activity is essential in sports medicine. Previous studies proposed measuring transverse relaxation time (T(2)) using muscle functional magnetic resonance imaging (mfMRI) to map muscle activity. However, mfMRI uses a spin-echo (SE) sequence that requires several minutes for acquisition. We evaluated the feasibility of T(2) mapping of muscle activity using ultrafast imaging, called fast-acquired mfMRI (fast-mfMRI), to reduce image acquisition time. The current method uses 2 pulse sequences, spin-echo echo-planar imaging (SE-EPI) and true fast imaging with steady precession (TrueFISP). SE-EPI images are used to calculate T(2), and TrueFISP images are used to obtain morphological information. The functional image is produced by subtracting the image of muscle activity obtained using T(2) at rest from that produced after exercise. Final fast-mfMRI images are produced by fusing the functional images with the morphologic images. Ten subjects repeated ankle plantar flexion 200 times. In the fused images, the areas of activated muscle in the fast-mfMRI and SE-EPI images were identical. The geometric location of the fast-mfMRI did not differ between the morphologic and functional images. Morphological and functional information from fast-mfMRI can be applied to the human trunk, which requires limited scan duration. The difference obtained by subtracting T(2) at rest from T(2) after exercise can be used as a functional image of muscle activity.
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Affiliation(s)
- Noriyuki Tawara
- Department of Sports Medicine, Japan Institute of Sports Sciences, Tokyo, Japan.
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13
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Magnitude of spinal muscle damage is not statistically associated with exercise-induced low back pain intensity. Spine J 2011; 11:1135-42. [PMID: 22208857 PMCID: PMC3437659 DOI: 10.1016/j.spinee.2011.11.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 09/26/2011] [Accepted: 11/15/2011] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Findings on imaging of noncontractile anatomic abnormalities and the intensity of low back pain have weak associations because of false-positive rates among asymptomatic individuals. This association might be stronger for contractile tissues. PURPOSE The purpose of this study was to examine the relationship between location and reports of pain intensity in the low back and exercise-induced muscle damage to the lumbar paraspinal muscles. STUDY DESIGN Nondiagnostic observational study in a laboratory setting. METHODS Delayed onset muscle soreness was induced in the low back of healthy pain-free volunteers. Measures of pain intensity (100-mm visual analog scale [VAS]) and location (area on the pain diagram) were taken before and 48 hours after exercise. Muscle damage was quantified using mechanical pain thresholds, motor performance deficits, and transverse relaxation time (T2)-weighted magnetic resonance imaging (MRI). Changes pre- to postexercise in signal intensity on T2-weighted imaging within the erector spinae, pain intensity, pain area, mechanical pain threshold, and isometric torque were assessed using paired t tests. Bivariate correlations were conducted to assess associations among muscle damage, pain intensity, and pain drawing area. RESULTS Twenty participants volunteered (11 women; average age, 22.3 years; average body mass index, 23.5) for study participation. Reports of pain intensity at 48 hours ranged from 0 to 59 mm on the VAS. Muscle damage was confirmed by reductions in mechanical threshold (p=.011) and motor performance (p<.001) and by changes in T2-weighted MRI (p=.007). This study was powered to find an association of at least r=0.5 to be statistically significant. Correlations of continuous variables revealed no significant correlations between pain intensity and measures of muscle damage (ranging between -0.075 and 0.151). There was a significant association between the remaining torque deficit at 48 hours and pain area. CONCLUSIONS The results of this study indicate that there was no association between the magnitude of muscle damage in the lumbar erector spinae and reported pain intensity in the low back. In future studies, larger cohorts may report statistically significant associations, but our data suggest that there will be low magnitude potentially indicating limited clinical relevance.
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Mathur S, Vohra RS, Germain SA, Forbes S, Bryant ND, Vandenborne K, Walter GA. Changes in muscle T2 and tissue damage after downhill running in mdx mice. Muscle Nerve 2011; 43:878-86. [PMID: 21488051 DOI: 10.1002/mus.21986] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/07/2010] [Indexed: 11/07/2022]
Abstract
INTRODUCTION In this study we compared the effects of downhill or horizontal treadmill running on the magnetic resonance imaging (MRI) transverse relaxation time constant (T(2)) in mdx mice. METHODS Mice underwent either downhill (n = 11 mdx, n = 6 controls) or horizontal running (n = 9, mdx only) on a treadmill. MRI was conducted prior to exercise, immediately afterward (∽20 minutes), and then 24 and 48 hours after exercise. RESULTS A higher percentage of pixels with elevated T(2) in the lower hindlimb muscles was observed in the mdx mice compared with controls both pre-exercise (P < 0.001) and at each time-point after downhill running (P < 0.05), but not with horizontal running. The medial compartment muscles appeared to be the most susceptible to increased T(2). CONCLUSIONS Downhill running provides a stimulus for inducing acute changes in muscle T(2) in mdx mice. MRI is a non-invasive approach for examining acute muscle damage and recovery in multiple muscle groups simultaneously.
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Affiliation(s)
- Sunita Mathur
- Department of Physical Therapy, University of Florida, Gainesville, Florida, USA
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Ilha J, da Cunha NB, Jaeger M, de Souza DF, Nascimento PSD, Marcuzzo S, Figueiró M, Gottfried C, Achaval M. Treadmill step training-induced adaptive muscular plasticity in a chronic paraplegia model. Neurosci Lett 2011; 492:170-4. [PMID: 21310212 DOI: 10.1016/j.neulet.2011.02.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 02/01/2011] [Accepted: 02/01/2011] [Indexed: 02/01/2023]
Abstract
The purpose of this study was to provide evidence that treadmill step training is capable of attenuating muscle atrophy and may regulate brain derived neurotrophic factor (BDNF) in soleus muscle after complete spinal cord transection (SCT) at T8-T9 in rats. Five days after SCT, spinal animals started a 9-week step-training program on a treadmill with partial body weight support and manual step help. The muscular trophism was studied by analyzing muscle weight and myofiber cross-sectional area of the soleus, while Western blot analysis was used to detect BDNF expression in the same muscle. Step training, initiated immediately after SCT in rats, may partially impede/revert muscular atrophy in chronic paralyzed soleus muscle. Moreover, treadmill step training promoted upregulation of the BDNF in soleus muscle, which was positively correlated with muscle weight and myofiber cross-sectional size. These findings have important implications for the comprehension of the neurobiological substrate that promotes exercise-induced effects on paralyzed skeletal muscle and suggests treadmill training is a viable therapeutic approach in spinal cord injuries.
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Affiliation(s)
- Jocemar Ilha
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, UFRGS, Porto Alegre, RS, Brazil
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Impact of treadmill locomotor training on skeletal muscle IGF1 and myogenic regulatory factors in spinal cord injured rats. Eur J Appl Physiol 2010; 109:709-20. [PMID: 20213470 DOI: 10.1007/s00421-010-1392-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/03/2010] [Indexed: 12/29/2022]
Abstract
The objective of this study was to determine the impact of treadmill locomotor training on the expression of insulin-like growth factor I (IGF1) and changes in myogenic regulatory factors (MRFs) in rat soleus muscle following spinal cord injury (SCI). Moderate, midthoracic (T(8)) contusion SCIs were produced using a NYU (New York University) impactor. Animals were randomly assigned to treadmill training or untrained groups. Rats in the training group were trained starting at 1 week after SCI, for either 3 bouts of 20 min over 1.5 days or 10 bouts over 5 days. Five days of treadmill training completely prevented the decrease in soleus fiber size resulting from SCI. In addition, treadmill training triggered increases in IGF1, MGF and IGFBP4 mRNA expression, and a concurrent reduction of IGFBP5 mRNA in skeletal muscle. Locomotor training also caused an increase in markers of muscle regeneration, including small muscle fibers expressing embryonic myosin and Pax7 positive nuclei and increased expression of the MRFs, myogenin and MyoD. We concluded that treadmill locomotor training ameliorated muscle atrophy in moderate contusion SCI rats. Training-induced muscle regeneration and fiber hypertrophy following SCI was associated with an increase in IGF1, an increase in Pax7 positive nuclei, and upregulation of MRFs.
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Karampinos DC, King KF, Sutton BP, Georgiadis JG. In vivo study of cross-sectional skeletal muscle fiber asymmetry with diffusion-weighted MRI. ACTA ACUST UNITED AC 2008; 2007:327-30. [PMID: 18001956 DOI: 10.1109/iembs.2007.4352290] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Skeletal muscles are highly organized hierarchical structures characterized by an anisotropic arrangement of muscle fibers (myocytes) in fascicles. Due to its unique non-invasive microstructure probing capabilities, diffusion-weighted Magnetic Resonance Imaging (DW-MRI) constitutes a valuable non-invasive tool in the study of such fibrous biological tissues. We have implemented a DW-MRI sequence with highly sensitive directional encoding to quantify the microarchitectural properties of human calf muscles at rest. We have specifically focused on a composite model-based analysis of diffusion tensor MRI measurements to quantify in vivo the cross-sectional asymmetry of muscle fiber geometry, which is a microstructural feature well documented in prior histological studies.
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Affiliation(s)
- Dimitrios C Karampinos
- Department of Mechanical Science and Engineering and the Beckman Institute, University of Illinois at Urbana-Champaign, IL, USA
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Non-invasive assessment of lower extremity muscle composition after incomplete spinal cord injury. Spinal Cord 2008; 46:565-70. [PMID: 18347608 DOI: 10.1038/sc.2008.10] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
STUDY DESIGN Cross-sectional study. OBJECTIVE (1) To quantify intramyocellular lipid (IMCL) content of the soleus muscle. (2) To assess the T(2) relaxation rates in the lower extremity skeletal muscles in persons with incomplete spinal cord injury (SCI). SETTING Academic Institution, Florida. METHODS Eight subjects (42+/-10 years old; 70+/-12 kg; 176+/-10 cm) with chronic (17+/-9 months post injury) motor SCI (C4-T12; ASIA C or D) and eight matched healthy controls were tested. Localized unsuppressed proton spectroscopy (H-MRS) was performed to estimate total lipid content and individual lipid components; IMCL and extramyocellular lipid (EMCL) from the soleus muscle. T(2)-weighted imaging of lower extremity muscles yielded muscle T(2) rates. RESULTS The IMCL content of the soleus muscle was 3.3 times higher in the patient group as compared to controls (P=0.002; 0.0401 (0.0234-0.0849) versus 0.0123 (0.0090-0.0175)). Similarly, EMCL measures were 4.5 times higher as compared to the controls (P=0.002). Significant differences were observed in the T(2) relaxation times of the soleus and gastrocnemius muscles (P<0.05). CONCLUSION The increased levels of IMCL might interfere with the glucose uptake in skeletal muscle; potentially predisposing persons with incomplete SCI to the development of peripheral insulin resistance. Marked elevations in the T(2) relaxation times of the locomotor muscles are reflective of an altered muscle composition.
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Jayaraman A, Shah P, Gregory C, Bowden M, Stevens J, Bishop M, Walter G, Behrman A, Vandenborne K. Locomotor training and muscle function after incomplete spinal cord injury: case series. J Spinal Cord Med 2008; 31:185-93. [PMID: 18581666 PMCID: PMC2578797 DOI: 10.1080/10790268.2008.11760710] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
BACKGROUND/OBJECTIVE To determine whether 9 weeks of locomotor training (LT) results in changes in muscle strength and alterations in muscle size and activation after chronic incomplete spinal cord injury (SCI). STUDY DESIGN Longitudinal prospective case series. METHODS Five individuals with chronic incomplete SCI completed 9 weeks of LT. Peak isometric torque, torque developed within the initial 200 milliseconds of contraction (Torque 200), average rate of torque development (ARTD), and voluntary activation deficits were determined using isokinetic dynamometry for the knee-extensor (KE) and plantar-flexor (PF) muscle groups before and after LT. Maximum muscle cross-sectional area (CSA) was measured prior to and after LT. RESULTS Locomotor training resulted in improved peak torque production in all participants, with the largest increases in the more-involved PF (43.9% +/- 20.0%), followed by the more-involved KE (21.1% +/- 12.3%). Even larger improvements were realized in Torque 200 and ARTD (indices of explosive torque), after LT. In particular, the largest improvements were realized in the Torque 200 measures of the PF muscle group. Improvements in torque production were associated with enhanced voluntary activation in both the KE and ankle PF muscles and an increase in the maximal CSA of the ankle PF muscles. CONCLUSION Nine weeks of LT resulted in positive alterations in the KE and PF muscle groups that included an increase in muscle size, improved voluntary activation, and an improved ability to generate both peak and explosive torque about the knee and ankle joints.
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