**4. Imaging during intervention**

Plain control radiographs are more commonly used by most of the neurosurgery teams during placement of implants to ensure that the electrodes are accurately following the predetermined pathway [36]. In addition, intraoperative use of MR imaging or CT scan has been recently developed for this purpose [37, 38].

Although it has remained a controversy, electrophysiological study of brain has been used intraoperatively for checking electrode placement in DBS surgery. Some neurosurgeons consider electrophysiologic mapping of the anatomic target during STN electrode implantation while others prefer not to apply it, as it prolongs the surgery and may be associated with risks and complications [39–41].
