Stereotactic implantation of deep brain stimulation electrodes: a review of technical systems, methods and emerging tools <s> Surgical implantation and current supporting techniques <s> Deep brain stimulation (DBS) is a widely accepted therapy for medically refractory Parkinson's disease (PD). Both globus pallidus internus (GPi) and subthalamic nucleus (STN) stimulation are safe and effective in improving the symptoms of PD and reducing dyskinesias. STN DBS is the most commonly performed surgery for PD as compared to GPi DBS. Ventral intermediate nucleus (Vim) DBS is infrequently used as an alternative for tremor predominant PD patients. Patient selection is critical in achieving good outcomes. Differential diagnosis should be emphasized as well as neurological and nonneurological comorbidities. Good response to a levodopa challenge is an important predictor of favorable long-term outcomes. The DBS surgery is typically performed in an awake patient and involves stereotactic frame application, CT/MRI imaging, anatomical targeting, physiological confirmation, and implantation of the DBS lead and pulse generator. Anatomical targeting consists of direct visualization of the target in MR images, formula-derived coordinates based on the anterior and posterior commissures, and reformatted anatomical stereotactic atlases. Physiological verification is achieved most commonly via microelectrode recording followed by implantation of the DBS lead and intraoperative test stimulation to assess benefits and side effects. The various aspects of DBS surgery will be presented. <s> BIB001 </s> Stereotactic implantation of deep brain stimulation electrodes: a review of technical systems, methods and emerging tools <s> Surgical implantation and current supporting techniques <s> Numerous factors need to be taken into account when implanting deep brain stimulation (DBS) systems into patients with Parkinson's disease. The surgical procedure itself can be divided into immediate preoperative, intraoperative, and immediate postoperative phases. Preoperative considerations include medication withdrawal issues, stereotactic equipment choices, imaging modalities, and targeting strategy. Intraoperative considerations focus on methods for physiological confirmation of a given target for DBS electrode deployment. Terms such as microelectrode recording, microstimulation, and macrostimulation will be defined to clarify inconsistencies in the literature. Advantages and disadvantages of each technique will be addressed. Furthermore, operative decisions such as staging, choice of electrode and implantable pulse generator, and methods of device fixation will be outlined. Postoperative issues include imaging considerations, including magnetic resonance safety, device–device interactions, and immediate surgical complications pertaining to the DBS procedure. This report outlines answers to a series of questions developed to address all aspects of the DBS surgical procedure and decision-making with a systematic overview of the literature (until mid-2004) and by the expert opinion of the authors. This is a report from the Consensus on Deep Brain Stimulation for Parkinson's Disease, a project commissioned by the Congress of Neurological Surgeons and the Movement Disorder Society. It outlines answers to a series of questions developed to address all surgical aspects of deep brain stimulation. © 2006 Movement Disorder Society <s> BIB002 </s> Stereotactic implantation of deep brain stimulation electrodes: a review of technical systems, methods and emerging tools <s> Surgical implantation and current supporting techniques <s> Surgery combining stereotactically guided implantation of brain electrodes in subcortical key structures of the brain with the connection of these brain electrodes to subcutaneously implanted impulse generators is one precondition for the therapeutic application of deep brain stimulation (DBS). During the last 10-15 years minimal requirements concerning this surgery have been formulated, addressing in particular technical equipment and operational procedures and being also in parts supported quantitatively by systematic investigations. Only appropriate patient management, high technical standards and an adequate surgical technique can minimize the frequency of those complications, which are supposed to be directly caused by surgery. High-resolution imaging is the basis for target definition, determination of the surgical approach, documentation of final electrode position and postoperative exclusion of iatrogenic intracerebral haemorrhage. In addition, the quality of treatment planning depends largely on the image processing and viewing possibilities provided by specific planning software. Further issues, for which standards are defined, address electrophysiological and clinical examinations to be performed intraoperatively and general surgical measures, which should be considered during implantation of DBS systems. This review summarizes and evaluates requirements imposed on the aforementioned system components and working steps, taking into consideration data from the literature. <s> BIB003 </s> Stereotactic implantation of deep brain stimulation electrodes: a review of technical systems, methods and emerging tools <s> Surgical implantation and current supporting techniques <s> Functional neurosurgery involves precise surgical targeting of anatomic structures to modulate neurologic function. The ultimate aim is to improve the symptoms and quality of life of patients suffering from chronic neurologic disorders; this demands minimal risk of inflicting morbidity and mortality. Well-established indications for functional neurosurgery include movement disorders such as Parkinson disease (PD), several forms of dystonia, essential tremor, and chronic pain. Other indications proposed in recent literature, either novel or revisited, are less well established but hold promise for patients with chronic debilitating conditions including cluster headache, Tourette syndrome, obsessive compulsive disorder, severe refractory depression, and epilepsy. This article focuses on the role of imaging in the surgical treatment of movement disorders. Imaging has played a central role in the practice of functional neurosurgery since its inception. The current situation and likely future directions are best appreciated by reviewing their parallel development. <s> BIB004
Until now Medtronic Corporation (Minneapolis, MN, USA) provides the only DBS system approved by the FDA for clinical use of Parkinson's disease and related movement disorders. This is expected to change in the future as several companies are known to do research and development in the area. The most commonly used DBS electrodes have four contacts (Medtronic's leads and electrode models 3389 and 3387). The voltage is often set at a value between 1 and 4 V; the frequency is set between 130 and 185 Hz; the pulse width is between 60 and 450 ls; and the stimulation mode can be mono-or bipolar. Uni-or bilateral implantation is used depending on symptoms and target areas. The surgical procedure is divided in two steps: the implantation of the DBS electrode and the pulse generator. This paper focuses on the DBS implantation. However, the way in which different clinical centres perform DBS electrode implantations often differs. In general, the procedure can be distinguished according to preoperative planning, surgical procedure and postoperative follow-up BIB001 BIB002 BIB003 BIB004 . Figure 1 summarises the current supporting techniques in form of a diagram. Figure 2 shows typical stereotactic planning and postoperative control images.