Patients with schizophrenia may have difficulty extracting nonverbal emotional content from language and have difficulty inferring the thoughts and intentions of others. Recently, we suggested a link between such (social cognition) deficits and a hypofunction of a particular brain region located in the interhemispheric fissure at the front of the brain: the medial prefrontal cortex.

rTMS is a non-invasive cerebral neuromodulation technique that increases or decreases cortical excitability focally depending on the stimulation parameters.  Up to now, rTMS is used in the treatment of verbal auditory hallucinations and negative symptoms by stimulating the left temporal and left dorsolateral prefrontal regions depending on the predominance of the symptoms. Our hypothesis is that the increase in the excitability of the medial prefrontal cortex induced by magnetic stimulation improves the social cognition abilities in patients with schizophrenia.

In this study, involving 61 patients, we plan to assess the social cognition deficit before and after 10 sessions of magnetic stimulation (intermittent theta burst type) with 2 sessions per day for 5 days, using a neuronavigation system targeting precise brain sites. The effects of this treatment will be compared to the effects of the same treatment directed this time on the dorsolateral prefrontal cortex, also involved in the negative symptoms of schizophrenia, and to the placebo effects induced by a placebo stimulation (sham coil). An anatomical MRI will be performed before stimulation to guide the location of the stimulation target. For patients recruited in Caen, a functional and spectroscopic MRI will be performed before treatment and 1 month later.

Determination of the CDLP target (left side) and CPM target (right side). Red arrow: superior frontal sulcus; yellow arrow: inferior frontal sulcus; green arrow: cingulate sulcus; blue cross: rTMS stimulation target.

TBS-COG is financed by the French Health Ministry (PHRCi) and the Perceneige Fondamental Foundation