Resting-State FMRI After Experimental Hemispherectomy in Rats: Changes in Functional Connectivity and Network Synchronization

Willem M. Otte^1,2, Rick M. Dijkhuizen², Peter C. van Rijen¹, Peter H. Gosselaar¹, Maurits P.A. van Meer^1,2, Onno van Nieuwenhuizen¹, Kees P.J. Braun¹

Hemispherectomy is a last resort treatment for catastrophic hemispheric epilepsy. The remarkable motor recovery after hemispherectomy reflects the plastic capacities of the brain. We studied the remaining brain in hemispherectomized rats, 7 and 49 days post surgery using resting-state fMRI, graph analysis and interregional connectivity. The sensorimotor cortex and striatum in the healthy contralesional hemisphere exhibited significantly increased functional connectivity after surgery. The graph analysis results assume a shift toward a more regular network organization. We have shown that rs-fMRI, connectivity analyses and specific network measures can provide unique insights into functional reorganization in the remaining brain after experimental hemispherectomy.