Cortical Excitability, Plasticity and Oscillations in Major Psychiatric Disorders: A Neuronavigated TMS-EEG Based Approach

Developing biomarkers for psychiatric disorders represents a major challenge. Indeed, the identification of dependable brain-based measures, such as those derived from electrophysiological techniques, would represent a key step toward better profiling of patients with major psychiatric disorders. A principled neurophysiological approach would also deepen our understanding of the physiopathology and inform therapeutic decisions. The present chapter focuses on a neurophysiological technique, based on the combination of neuronavigated Transcranial Magnetic Stimulation and Electroencephalography (TMS-EEG), which allows probing directly and non-invasively cortical excitability, plasticity as well as the fundamental oscillatory properties of thalamocortical circuits. Since these parameters are often altered in psychiatric disorders, neuronavigated TMS-EEG may be in a suitable position to provide neurophysiological objective measures to support the diagnosis of psychiatric disorders, to highlight their physiopathological underpinnings, and to objectively assess the efficacy of treatment options.