Manus Donahue1, 2, Charlotte Stagg2, Jacinta O'Shea2, Peter Jezzard2, Leif Ostergaard3, Bradley MacIntosh, 24, Heidi Johansen-Berg2, Jakob Blicher3
1Vanderbilt University, Nashville, TN, United States; 2FMRIB Centre, Oxford University, Oxford, Oxfordshire, United Kingdom; 3Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark; 4Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
The aim of this work is to apply a multi-modal, noninvasive fMRI approach to better quantify hemodynamic compensation mechanisms during stroke recovery (n=22). Despite robust BOLD, CBF-weighted and CBV-weighted reactivity changes in healthy subjects, in stroke patients with motor impairment, BOLD-fMRI yielded no significant (P>0.05) average changes, despite significant (P<0.01) changes in CBF and CBV. Therefore in chronic stroke, neuronal activity can lead to measurable changes in CBF and CBV in expected cortical areas despite an absent BOLD-fMRI response. Thus, multi-modal fMRI may be better suited than BOLD-fMRI for interrogating cortical reorganization under circumstance of impaired neurovascular coupling.
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