Improved surgical procedure using intraoperative navigation for the implantation of the SPG microstimulator in patients with chronic cluster headache. - Carsten Kohlmeier; Peter Behrens; Andreas Böger; Brinda Ramachandran; Anthony Caparso; Dirk Schulze; Philipp Stude; Max Heiland; Alexandre T. Assaf (Int. J. Comput. Assist. Radiol. Surg., 2017)