Each patient will receive an intravenous infusion of lidocaine. Drug will be infused using a computer-controlled paradigm. This paradigm allows increasing plasma concentrations in a step-wise manner, keeping the concentration during each infusion step constant. Plasma concentrations will be increased gradually from 0 to 5 ug/ml in a method at the discretion of the medical team. This will be conducted according to standard medical practice for the infusion and the study procedures will not affect the infusion paradigm. Total infusion time is approximately 1-2 hours. During the course of the study, the primary outcome measure was changed from blood oxygenation level dependent (BOLD) signal to pain intensity.