Stereotactic implantation of deep brain stimulation electrodes: a review of technical systems, methods and emerging tools <s>  <s> Both posteroventral pallidotomy and pallidal deep brain stimulation (DBS) have a documented effect on Parkinsonian symptoms. DBS is more costly and more laborious than pallidotomy. The aim of this ... <s> BIB001 </s> Stereotactic implantation of deep brain stimulation electrodes: a review of technical systems, methods and emerging tools <s>  <s> Parkinson's disease is most commonly treated with a range of pharmacotherapeutics, with the more recent introduction of surgical techniques including deep-brain stimulation. These have limited capabilities to improve symptoms of the disease in more advanced stages, thus new therapeutic strategies including the use of viral vectors and stem cells are in development. Providing a continuous supply of dopamine to the striatum in an attempt to improve the treatment of motor symptoms using enzymes in the dopamine synthesis and machinery is one approach. Alternatively, there are tools which may serve to both protect and encourage outgrowth of surviving neurons using growth factors or to directly replace lost innervation by transplantation of primary tissue or stem cell-derived dopaminergic neurons. We summarize some of the potential therapeutic approaches and also consider the recent EU directives on practical aspects of handling viral vectors, cells and tissues, and in the running of clinical trials in Europe which impact on their development. <s> BIB002 </s> Stereotactic implantation of deep brain stimulation electrodes: a review of technical systems, methods and emerging tools <s>  <s> Psychiatric neurosurgery, specifically stereotactic ablation, has continued since the 1940s, mainly at a few centers in Europe and the US. Since the late 1990s, the resurgence of interest in this field has been remarkable; reports of both lesion procedures and the newer technique of deep brain stimulation (DBS) have increased rapidly. In early 2009, the US FDA granted limited humanitarian approval for DBS for otherwise intractable obsessive-compulsive disorder (OCD), the first such approval for a psychiatric illness. Several factors explain the emergence of DBS and continued small-scale use of refined lesion procedures. DBS and stereotactic ablation have been successful and widely used for movement disorders. There remains an unmet clinical need: current drug and behavioral treatments offer limited benefit to some seriously ill people. Understandings of the neurocircuitry underlying psychopathology and the response to treatment, while still works in progress, are much enhanced. Here, we review modern lesion procedures and DBS for OCD in the context of neurocircuitry. A key issue is that clinical benefit can be obtained after surgeries targeting different brain structures. This fits well with anatomical models, in which circuits connecting orbitofrontal cortex (OFC), medial prefrontal cortex (mPFC), basal ganglia, and thalamus are central to OCD pathophysiology and treatment response. As in movement disorders, dedicated interdisciplinary teams, here led by psychiatrists, are required to implement these procedures and maintain care for patients so treated. Available data, although limited, support the promise of stereotactic ablation or DBS in carefully selected patients. Benefit in such cases appears not to be confined to obsessions and compulsions, but includes changes in affective state. Caution is imperative, and key issues in long-term management of psychiatric neurosurgery patients deserve focused attention. DBS and contemporary ablation also present different patterns of potential benefits and burdens. Translational research to elucidate how targeting specific nodes in putative OCD circuitry might lead to therapeutic gains is accelerating in tandem with clinical use. <s> BIB003
been published, but only very few of them are technical ones. Other interventional methods used for similar therapeutic purposes are radiofrequency (RF)-lesioning   , targeted drug therapy and neural cell grafting BIB002 . RF-lesioning is sometimes suggested as an option together with DBS in order to tailor the patient treatment BIB001 BIB003 . Targeted drug therapy and neural cell grafting are procedures assumed to have major potential applications for the future though it has not yet become established clinically. Thus, DBS implantation is expected to remain the main surgical mode of treatment for Parkinson's disease and related movement disorders for at least the next decade. As DBS implantations and any other stereotactic and functional intervention procedure require accurate, precise and safe targeting of the brain structure for optimal clinical outcome, the technical aids have become increasingly important. The concept of stereotactic and functional neurosurgery has a history back to the 1940  when the first lesioning procedures were commenced due to the development of stereotactic frames and later on the introduction of brain atlases with well-defined landmarks. Recent improvements of biomedical imaging and intraoperative measurement techniques have contributed to a fast increase in the number of stereotactic procedures and thus DBS implantations. The aim of this paper was to give an overview, from a biomedical engineering perspective, of the current technical aids and future trends in stereotactic DBS implantation procedures.