In vivo measurement of the frame-based application accuracy of the Neuromate neurosurgical robot.

OBJECT: The application accuracy of the Neuromate neurosurgical robot has been validated in vitro but has not been evaluated in vivo for deep brain stimulation (DBS) electrode implantations. The authors conducted a study to evaluate this application accuracy in routine frame-based DBS procedures, with an independent system of measurement. METHODS: The Euclidian distance was measured between the point theoretically targeted by the robot and the point actually reached, based on their respective stereotactic coordinates. The coordinates of the theoretical target were given by the robot's dedicated targeting software. The coordinates of the point actually reached were recalculated using the Stereoplan localizer system. This experiment was performed in vitro, with the frame fixed in the robot space without a patient, for 21 points spatially distributed. The in vivo accuracy was then measured in 30 basal ganglia targets in 17 consecutive patients undergoing DBS for movement disorders. RESULTS: The mean in vitro application accuracy was 0.44 ± 0.23 mm. The maximal localization error was 1.0 mm. The mean (± SD) in vivo application accuracy was 0.86 ± 0.32 mm (Δx = 0.37 ± 0.34 mm, Δy = 0.32 ± 0.24 mm, Δz = 0.58 ± 0.31 mm). The maximal error was 1.55 mm. CONCLUSIONS: The in vivo application accuracy of the Neuromate neurosurgical robot, measured with a system independent from the robot, in frame-based DBS procedures was better than 1 mm. This accuracy is at least similar to the accuracy of stereotactic frame arms and is compatible with the accuracy required in DBS procedures.

Two-step tunneling technique of deep brain stimulation extension wires-a description.

INTRODUCTION: While a significant body of literature exists on the intracranial part of deep brain stimulation surgery, the equally important second part of the intervention related to the subcutaneous tunneling of deep brain stimulation extension wires is rarely described. The tunneling strategy can consist of a single passage of the extension wires from the frontal incision site to the subclavicular area, or of a two-step approach that adds a retro-auricular counter-incision. Each technique harbors the risk of intraoperative and postoperative complications. METHOD: At our center, we perform a two-step tunneling procedure that we developed based on a cadaveric study. RESULTS: In 125 consecutive patients operated since 2002, we did not encounter any complication related to our tunneling method. CONCLUSION: Insufficient data exist to fully evaluate the advantages and disadvantages of each tunneling technique. It is of critical importance that authors detail their tunneling modus operandi and report the presence or absence of complications. This gathered data pool may help to formulate a definitive conclusions on the safest method for subcutaneous tunneling of extension wires in deep brain stimulation.

Effect of subthalamic nucleus stimulation on obsessive-compulsive disorder in a patient with Parkinson disease. Case report.

The authors report on a patient with Parkinson disease (PD) and severe obsessive-compulsive disorder (OCD), in whom bilateral stimulation of the subthalamic nucleus (STN) was used to treat both PD and OCD symptoms. This 49-year-old man had displayed symptoms of PD for 13 years. Progressively, his motor disability became severe despite optimal medical treatment. In parallel, he suffered severe OCD for 16 years, with obsessions of accumulation and compulsions of gathering and rubbing that lasted more than 8 hours per day. Bilateral high-frequency STN stimulation was performed to treat motor disability. After surgery (at 1-year follow up), motor and OCD symptoms were dramatically improved. The pre- and postoperative Yale-Brown Obsessive-Compulsive Scale scores were 32 and 1, respectively. No additional antiparkinsonian drugs were administered. This case and other recent reports indicate that OCD symptoms can be improved by deep brain stimulation, a finding that opens new perspectives in the surgical treatment of severe and medically intractable OCD.