Christopher Nishioka1,2, Hsiao-Fang Liang1,3, Chen-Fang Chung1, Shu-Wei Sun4,5,6. 1. Basic Science, School of Medicine, Loma Linda University, 11175 Campus St., Loma Linda, CA, 92350, USA. 2. Neuroscience Graduate Program, University of California, Riverside, CA, USA. 3. Pharmaceutical Science, School of Pharmacy, Loma Linda University, Loma Linda, CA, USA. 4. Basic Science, School of Medicine, Loma Linda University, 11175 Campus St., Loma Linda, CA, 92350, USA. rsun@llu.edu. 5. Neuroscience Graduate Program, University of California, Riverside, CA, USA. rsun@llu.edu. 6. Pharmaceutical Science, School of Pharmacy, Loma Linda University, Loma Linda, CA, USA. rsun@llu.edu.
Abstract
PURPOSE: Diffusion tensor imaging (DTI) is commonly used to evaluate white matter integrity in multiple sclerosis (MS), but the relationship between DTI measures and functional changes during disease remains ambiguous. Using a mouse model of MS, we tested the hypothesis that DTI measures would correlate to the visual evoked potential (VEPs) dynamically at different disease stages. METHODS: In vivo DTI, gadolinium-enhanced T1WI (Gd-T1WI) and VEPs were performed in 5 control and 25 mice after 2-12 weeks of experimental autoimmune encephalomyelitis (EAE). DTI indices, including fractional anisotropy (FA), axial and radial diffusivities (AD and RD), and Gd-T1WI enhancement, were measured in the optic nerve and tract (ON and OT), which were compared with measured VEPs. RESULTS: Gd-T1WI showed a 3- to 4-fold enhancement over controls beginning after 2 weeks of EAE. Across the time course, we found progressive reductions in FA and increases in RD with increases in VEP latency and reductions in amplitude. Significant correlations between DTI (FA and RD) and VEP evolved; in control/early asymptomatic EAE mice, both FA and RD were highly correlated with VEP latency (but not amplitude), while in late EAE, both DTI indices were highly correlated with VEP amplitude (but not latency). CONCLUSION: DTI measures FA and RD are associated to VEP latency in early stages of EAE but associated to VEP amplitude in later stages, suggesting that the patterns of DTI related to the functional decline may depend on the stage of disease progression.
PURPOSE: Diffusion tensor imaging (DTI) is commonly used to evaluate white matter integrity in multiple sclerosis (MS), but the relationship between DTI measures and functional changes during disease remains ambiguous. Using a mouse model of MS, we tested the hypothesis that DTI measures would correlate to the visual evoked potential (VEPs) dynamically at different disease stages. METHODS: In vivo DTI, gadolinium-enhanced T1WI (Gd-T1WI) and VEPs were performed in 5 control and 25 mice after 2-12 weeks of experimental autoimmune encephalomyelitis (EAE). DTI indices, including fractional anisotropy (FA), axial and radial diffusivities (AD and RD), and Gd-T1WI enhancement, were measured in the optic nerve and tract (ON and OT), which were compared with measured VEPs. RESULTS:Gd-T1WI showed a 3- to 4-fold enhancement over controls beginning after 2 weeks of EAE. Across the time course, we found progressive reductions in FA and increases in RD with increases in VEP latency and reductions in amplitude. Significant correlations between DTI (FA and RD) and VEP evolved; in control/early asymptomatic EAE mice, both FA and RD were highly correlated with VEP latency (but not amplitude), while in late EAE, both DTI indices were highly correlated with VEP amplitude (but not latency). CONCLUSION: DTI measures FA and RD are associated to VEP latency in early stages of EAE but associated to VEP amplitude in later stages, suggesting that the patterns of DTI related to the functional decline may depend on the stage of disease progression.
Authors: Scott Kolbe; Caron Chapman; Thanh Nguyen; Clare Bajraszewski; Leigh Johnston; Michael Kean; Peter Mitchell; Mark Paine; Helmut Butzkueven; Trevor Kilpatrick; Gary Egan Journal: Neuroimage Date: 2009-01-07 Impact factor: 6.556
Authors: Maria Camilla Rossi-Espagnet; Martina Lucignani; Luca Pasquini; Antonio Napolitano; Stefano Pro; Andrea Romano; Daria Diodato; Diego Martinelli; Daniela Longo Journal: Neuroradiology Date: 2019-11-04 Impact factor: 2.804