Functional MRI of the brain: localisation of eloquent cortex in focal brain lesion therapy

The aim of this study was to assess the feasibility of functional MRI (fMRI ) in a clinical environment on a large patient group, and to evaluate the p retherapeutic value of localisation of eloquent cortex. Forty patients with focal brain lesions of different origin were studied using fMRI. Functiona l information was obtained using motor, somatosensory, auditory and phonolo gical stimuli depending on the localisation of the lesions. To obtain infor mation about the spatial accuracy of fMRI, the results were compared with p ostoperative electrocortical stimulation. Two patients with secondary trige minal neuralgia were scanned using a motor protocol and were implanted with an extradural plate electrode. Imaging was successful in 40 of 42 patients (including the 2 with trigeminal neuralgia). These patients were analysed for strength of activation, the relation of the lesion to activation sites and the presence of mass effect. The correlation between these data and sur gical findings provided significant additional clinical information. Functi onal MRI can be accurately performed in patients with focal brain lesions u sing a dedicated approach. Functional MRI offers important clinical informa tion as a contribution to a decrease in post-therapeutic morbidity. The acc uracy of the technique can be confirmed by other modalities, including inva sive cortical electrostimulation.