Understand: the potential for lesion-induced neurovascular uncoupling at fMRI; the limitations of fMRI in establishing the presence of cortical reorganization; the need for corroborating fMRI results with intraoperative mapping or WADA testing; the brain regions that are prone to show a pattern of lesion-induced homotopic cortical reorganization.

FMRI is a clinical tool for preoperative mapping of eloquent cortex in patients with brain tumors and other resectable lesions, and has generated excitement in the study of lesion-induced cortical reorganization. However, lesion-induced neurovascular uncoupling is a recognized phenomena that may impact the accuracy of BOLD fMRI data. This exhibit reviews fMRI data in 50 patients with brain tumors and other resectable lesions, to characterize fMRI patterns of lesion-induced homotopic reorganization. The functional brain regions that are prone to such an fMRI pattern are illustrated. Case scenarios illustrate how lesion-induced neurovascular uncoupling can mimic homotopic cortical reorganization. The exhibit emphasizes the limitations of fMRI in establishing that homotopic cortical reorganization has occurs and that alternative localization methods are required to corroborate fMRI in surgical patients.