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Sahama I, Sinclair K, Fiori S, Doecke J, Pannek K, Reid L, Lavin M, Rose S. Motor pathway degeneration in young ataxia telangiectasia patients: A diffusion tractography study. Neuroimage Clin 2015; 9:206-15. [PMID: 26413479 PMCID: PMC4561673 DOI: 10.1016/j.nicl.2015.08.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 07/17/2015] [Accepted: 08/13/2015] [Indexed: 12/13/2022]
Abstract
BACKGROUND Our understanding of the effect of ataxia-telangiectasia mutated gene mutations on brain structure and function is limited. In this study, white matter motor pathway integrity was investigated in ataxia telangiectasia patients using diffusion MRI and probabilistic tractography. METHODS Diffusion MRI were obtained from 12 patients (age range: 7-22 years, mean: 12 years) and 12 typically developing age matched participants (age range 8-23 years, mean: 13 years). White matter fiber tracking and whole tract statistical analyses were used to assess quantitative fractional anisotropy and mean diffusivity differences along the cortico-ponto-cerebellar, cerebellar-thalamo-cortical, somatosensory and lateral corticospinal tract length in patients using a linear mixed effects model. White matter tract streamline number and apparent fiber density in patient and control tracts were also assessed. RESULTS Reduced fractional anisotropy along all analyzed patient tracts were observed (p < 0.001). Mean diffusivity was significantly elevated in anterior tract locations but was reduced within cerebellar peduncle regions of all patient tracts (p < 0.001). Reduced tract streamline number and tract volume in the left and right corticospinal and somatosensory tracts were observed in patients (p < 0.006). In addition, reduced apparent fiber density in the left and right corticospinal and right somatosensory tracts (p < 0.006) occurred in patients. CONCLUSIONS Whole tract analysis of the corticomotor, corticospinal and somatosensory pathways in ataxia telangiectasia showed significant white matter degeneration along the entire length of motor circuits, highlighting that ataxia-telangiectasia gene mutation impacts the cerebellum and multiple other motor circuits in young patients.
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Affiliation(s)
- Ishani Sahama
- University of Queensland, School of Medicine, Brisbane, Australia
| | - Kate Sinclair
- Neurology, The Royal Children's Hospital, Brisbane, Australia
| | | | - James Doecke
- Digital Productivity Flagship/The Australian E-Health Research Centre, Commonwealth Scientific and Industrial Research Organization, Brisbane, Australia
| | | | - Lee Reid
- Digital Productivity Flagship/The Australian E-Health Research Centre, Commonwealth Scientific and Industrial Research Organization, Brisbane, Australia
| | - Martin Lavin
- University of Queensland Centre for Clinical Research, Brisbane, Australia
| | - Stephen Rose
- Digital Productivity Flagship/The Australian E-Health Research Centre, Commonwealth Scientific and Industrial Research Organization, Brisbane, Australia
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Jeong JW, Lee J, Kamson DO, Chugani HT, Juhász C. Detection of hand and leg motor tract injury using novel diffusion tensor MRI tractography in children with central motor dysfunction. Magn Reson Imaging 2015; 33:895-902. [PMID: 25959649 DOI: 10.1016/j.mri.2015.05.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Revised: 04/09/2015] [Accepted: 05/01/2015] [Indexed: 10/23/2022]
Abstract
PURPOSE To examine whether an objective segmenation of corticospinal tract (CST) associated with hand and leg movements can be used to detect central motor weakness in the corresponding extremities in a pediatric population. MATERIAL AND METHODS This retrospective study included diffusion tensor imaging (DTI) of 25 children with central paresis affecting at least one limb (age: 9.0±4.2years, 15 boys, 5/13/7 children with left/right/both hemispheric lesions including ischemia, cyst, and gliosis), as well as 42 pediatric control subjects with no motor dysfunction (age: 9.0±5.5years, 21 boys, 31 healthy/11 non-lesional epilepsy children). Leg- and hand-related CST pathways were segmented using DTI-maximum a posteriori (DTI-MAP) classification. The resulting CST volumes were then divided by total supratentorial white matter volume, resulting in a marker called "normalized streamline volume ratio (NSVR)" to quantify the degree of axonal loss in separate CST pathways associated with leg and hand motor functions. A receiver operating characteristic curve was applied to measure the accuracy of this marker to identify extremities with motor weakness. RESULTS NSVR values of hand/leg CST selectively achieved the following values of accuracy/sensitivity/specificity: 0.84/0.84/0.57, 0.82/0.81/0.55, 0.78/0.75/0.55, 0.79/0.81/0.54 at a cut-off of 0.03/0.03/0.03/0.02 for right hand CST, left hand CST, right leg CST, and left leg CST, respectively. Motor weakness of hand and leg was most likely present at the cut-off values of hand and leg NSVR (i.e., 0.029/0.028/0.025/0.020 for left-hand/right-hand/left-leg/right-leg). The control group showed a moderate age-related increase in absolute CST volumes and a biphasic age-related variation of the normalized CST volumes, which were lacking in the paretic children. CONCLUSIONS This study demonstrates that DTI-MAP classification may provide a new imaging tool to quantify axonal loss in children with central motor dysfunction. Using this technique, we found that early-life brain lesions affect the maturational trajectory of the primary motor pathway which may be used as an effective marker to facilitate evidence-based treatment of paretic children.
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Affiliation(s)
- Jeong-Won Jeong
- Translational Imaging Laboratory, Children's Hospital of Michigan, Detroit, MI, USA; Carman and Ann Adams Department of Pediatrics, School of Medicine, Wayne State University, Detroit, MI, USA; Department of Neurology, School of Medicine, Wayne State University, Detroit, MI, USA.
| | - Jessica Lee
- School of Medicine, Wayne State University, Detroit, MI, USA
| | - David O Kamson
- Translational Imaging Laboratory, Children's Hospital of Michigan, Detroit, MI, USA
| | - Harry T Chugani
- Translational Imaging Laboratory, Children's Hospital of Michigan, Detroit, MI, USA; Carman and Ann Adams Department of Pediatrics, School of Medicine, Wayne State University, Detroit, MI, USA; Department of Neurology, School of Medicine, Wayne State University, Detroit, MI, USA
| | - Csaba Juhász
- Translational Imaging Laboratory, Children's Hospital of Michigan, Detroit, MI, USA; Carman and Ann Adams Department of Pediatrics, School of Medicine, Wayne State University, Detroit, MI, USA; Department of Neurology, School of Medicine, Wayne State University, Detroit, MI, USA
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