Comparison of Accuracy and Precision between Frame-Based and Frameless Stereotactic Navigation for Deep Brain Stimulation Electrode Implantation

Abstract

The accuracy and precision of frameless neuronavigation as compared to conventional frame-based stereotaxy for implantation of deep brain stimulation (DBS) electrodes were studied in 14 patients with essential tremor. DBS electrodes were implanted bilaterally in the ventrolateral thalamus [ventrointermediate nucleus (VIM)] in one procedure. Frameless neuronavigation was used on one side and the conventional frame-based technique on the other. Targeting was guided by MRI and CT imaging. Intraoperative stereotactic plain X-ray verified final electrode positions and electrode deviations from the planned target were measured. Clinical outcome was evaluated with the Essential Tremor Rating Scale. Thirteen of the patients were eligible for measuring electrode deviations and 10 of them were available for a clinical follow-up. Electrode deviations from target were larger using the frameless technique in the medial-lateral (x: 1.9 ± 1.3 mm) and anterior-posterior (y:0.9 ± 0.8 mm) directions as compared to the frame-based technique (x: 0.5 ± 0.5 and y: 0.4 ± 0.4 mm) but similar in the superior-inferior direction (z). The vector of deviation was 2.5 ± 1.4 mm with the frameless technique and 1.2 ± 0.6 with the frame-based technique. The differences were statistically significant (p < 0.05–0.001). The dispersion was larger with the frameless technique as represented by the larger standard deviations in all three planes. At clinical follow-ups, tremor reduction was similar irrespective of the implantation technique. It is concluded that conventional frame-based stereotaxy has higher accuracy/precision for hitting a small brain target than the frameless technique. However, the difference is relatively small and does not influence the clinical result of DBS electrode implantations in the VIM when treating tremor.

Neuroimaging and Deep Brain Stimulation

“…C, Zoom on the electrodes showing that their contacts are located inside the STN tion and conventional frame-based stereotaxy. 51 In this study, frameless neuronavigation was used on 1 side, and the framebased technique, on the other side in the same patient. The authors compared the final electrode position with the planned position on the basis of intraoperative stereotactic plain x-ray.…”

Electrophysiologic Validation of Diffusion Tensor Imaging Tractography during Deep Brain Stimulation Surgery

“…The localization accuracy of stereotactic frames ranges between 1.5 and 2 mm. 29,30 However the vector error can be as high as 3.15 mm. Thus, a new imaging technique should probably not be far outside this accuracy range.…”

Stereotactic implantation of deep brain stimulation electrodes: a review of technical systems, methods and emerging tools

“…In general fiducials are affixed to the skull of the patient via a stereotactic system in order to introduce a reference system to the images. Different frameless fiducial systems for DBS implantation have been described and compared with frame based systems [9,13,24,30,56,75,102] but stereotactic frame based systems remain the gold standard. In consequence, this article will concentrate on the procedures using the stereotactic frame.…”

“…In general, these measurements are performed in millimetre steps before reaching the target and often measurements even go beyond the target structure. Most centres using microelectrode recording perform, as well, intraoperative stimulation along the trajectory using the microelectrodes stimulating in the microampere range [24,32,110] or macroelectrodes stimulating in the milliampere range for example using RF-or DBS stimulation electrodes [13,88,106]. In general this is done at the same measurement points as for MER, to evaluate the clinical effects with increasing stimulation voltage and to determine symptom reduction, the clinical therapeutic and side effect thresholds at each measurement point.…”