Bjartmarz Hjálmar, Rehncrona Stig
Unit of Functional and Stereotactic Neurosurgery, Department of Clinical Sciences, Division of Neurosurgery, University Hospital, Lund, Sweden.
Stereotact Funct Neurosurg. 2007;85(5):235-42. doi: 10.1159/000103262. Epub 2007 May 25.
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.
在14例特发性震颤患者中，研究了与传统框架立体定向术相比，无框架神经导航用于植入脑深部刺激（DBS）电极的准确性和精确性。在一次手术中双侧腹外侧丘脑[腹中间核（VIM）]植入DBS电极。一侧使用无框架神经导航，另一侧使用传统框架技术。靶向由MRI和CT成像引导。术中立体定向平片验证最终电极位置，并测量电极与计划靶点的偏差。用特发性震颤评定量表评估临床结果。13例患者符合测量电极偏差的条件，其中10例可进行临床随访。与基于框架的技术相比，使用无框架技术时，电极在内外侧（x：1.9±1.3mm）和前后方向（y：0.9±0.8mm）偏离靶点更大，但在上下方向（z）相似。无框架技术的偏差向量为2.5±1.4mm，基于框架的技术为1.2±0.6mm。差异具有统计学意义（p<0.05 - 0.001）。无框架技术的离散度更大，这在所有三个平面上的标准差更大中得到体现。在临床随访中无论植入技术如何，震颤减轻情况相似。结论是，对于击中脑内小靶点，传统框架立体定向术比无框架技术具有更高的准确性/精确性。然而，差异相对较小，并且在治疗震颤时不影响VIM中DBS电极植入的临床结果。
