Xiaojie Wang1, Joong Hee Kim2, Jenet O'Neal3, Shawn O'Neal4, Joan Brieland3, Sheng-Kwei Song2
1Chemistry, Washington University, Saint Louis, MO, United States; 2Radiology, Washington University, Saint Louis, MO; 3Exploratory Immunobiology, Pfizer Inc.; 4Investigative Pathology, Pfizer Inc.
In Vivo DTI was performed on experimental autoimmune encephalomyelitis (EAE) mice undergoing daily prophylactic (immediately after immunization) and therapeutic (immediately after disease onset) treatments of FTY720 at 3 and 10 mg/Kg. Axon and myelin integrity of lumbar segments was assessed using axial and radial diffusivity. Prophylactic treatment significantly reduced clinical scores of EAE mice while therapeutic treatment was only marginally effective. However, both treatments significantly preserved axon and myelin integrity based on in vivo axial and radial diffusivity measurements. The finding suggests that in vivo DTI may detect treatment effect before neurological evaluation responding to the disease modifying intervention.