MRI and brain stimulation in common practice: Toward precision medicine

Abstract

Background Repetitive transcranial magnetic stimulation (rTMS) is a validated treatment for patients with depression resistant to antidepressant medication. To a lesser extent, rTMS is considered as a second-line treatment for auditory hallucinations in patients with schizophrenia resistant to antipsychotic medication. However, roughly 50% of patients with resistant depression are not responding to TMS. Thus, finding predictive factors for rTMS response is key to offer personalized treatment to patients. Drysdale et al. [1] have proposed that combining clinical characteristics and functional MRI could lead to the prediction of TMS outcome in patients with depression. However, there is still a limited access to functional MRI in common practice. Structural MRI is an accessible and short duration exam used in common practice for neuronavigation purposes. Methods We conducted a neuroimaging retrospective study in our center and analyzed structural MRI of patients treated both in open label and randomized trials for resistant depression and hallucinations. We processed structural MRI with FreeSurfer software, which provide an automated segmentation of the brain. All MRI were acquired with the same neuroimaging protocol. We compared both skull and brain anatomical features in patients responding and not responding to rTMS. Results We here present preliminary results of our study and demonstrate the feasibility of analyzing structural MRI in the context of brain stimulation in common practice. We discuss MRI-based potential factors that could be taken into account to understand rTMS response.