Cortico-cortical connectivity between the superior and inferior parietal lobules and the motor cortex assessed by intraoperative dual cortical stimulation

•The parietal cortex controls goal-directed movement by unclear neural pathways.•We performed intraoperative monitoring of the corticospinal tract for brain tumours.•Motor cortex stimulation was conditioned by preceding electrical stimuli of the parietal cortex.•We show that the parietal cortex is functionally connected with the motor cortex.•Dual cortical stimulation is a tool for assessing connectivity intraoperatively.