No abstract

Objective: To determine the surgery-related and hardware-related complications of deep-brain stimulation (DBS) at a single centre. Methods: 262 consecutive patients (472 electrodes) operated for DBS in our department from February 1996 to March 2003 were retrospectively analysed to document acute adverse events (30 days postoperatively). The data of 180 of these patients were additionally revised to assess long-term complications (352 electrodes, months).Results: The frequency of minor intraoperative complications was 4.2% (11/262 patients). Transient (0.2%) or permanent (0.4%) neurological deficits, and in one case asymptomatic intracranial haemorrhage (0.2%), were registered as acute severe adverse events caused by surgery. Among minor acute complications were subcutaneous bleeding along the extension wire (1.2%) and haematoma at the pulse generator implantation site (1.2%). Skin infection caused by the implanted material was registered in 15 of 262 patients (5.7%). The infection rate during the first observation period was 1.5% (4/262 patients) and the late infection rate was 6.1% (11/180 patients). Partial or complete removal of the stimulation system was necessitated in 12 of 262 (4.6%) patients because of skin infection. During the long-term observation period, hardware-related problems were registered in 25 of 180 (13.9%) patients. Conclusions: Stereotactic implantation of electrodes for DBS, if performed with multiplanar threedimensional imaging and advanced treatment planning software, is a safe procedure with no mortality and low morbidity. The main causes for the patients' prolonged hospital stay and repeated surgery were wound infections and hardware-related complications. D uring the past 10 years, worldwide, a growing number of patients with movement disorders have been treated with deep-brain stimulation (DBS). The most frequent indications were Parkinson's disease, tremor and dystonia. At present, new indications such as obsessive-compulsive disorders (OCD), Gilles-de-la-Tourette syndrome, severe depression or epilepsy are under investigation. [1][2][3][4][5] DBS is now considered to modulate the functional units of the CNS, serving as a permanent and lifelong treatment. Therefore, a realistic analysis of complications should not be restricted to acute hardware-related and surgery-related adverse events, but should also document problems occurring in the long term. In the literature, a reasonably high number of publications have already dealt with the adverse events associated with DBS. Only a few studies, however, analysed a larger number of patients (n.50), 6-11 and some of this work considered only one possible source for complications, either surgery 6 10 or the implanted hardware. 8 9 In this article, we present a comprehensive analysis of 262 patients of a single centre (Department of Stereotaxy and Functional Neurosurgery, University of Cologne, Cologne, Germany). CLINICAL MATERIAL AND METHODS Data assessmentBetween February 1996 and March 2003, 262 consecutive patients underwent DBS surg...

Summary: Deep brain stimulation of the subthalamic nucleus (STN-DBS) is a highly effective surgical treatment in patients with advanced Parkinson's disease (PD). Because the STN has been shown to represent an important relay station not only in motor basal ganglia circuits, the modification of brain areas also involved in nonmotor functioning can be expected by this intervention. To determine the impact of STN-DBS upon the regional cerebral metabolic rate of glucose (rCMRGlc), we performed positron emission tomography (PET) with 18-fluorodeoxyglucose (FDG) in eight patients with advanced PD before surgery as well as in the DBS on-and off-conditions 4 months after electrode implantation and in ten age-matched healthy controls. Before surgery, PD patients showed widespread bilateral reductions of cortical rCMRGlc versus controls but a hypermetabolic state in the left rostral cerebellum. In the STN-DBS on-condition, clusters of significantly increased rCMRGlc were found in both lower thalami reaching down to the midbrain area and remote from the stimulation site in the right frontal cortex, temporal cortex, and parietal cortex, whereas rCMRGlc significantly decreased in the left rostral cerebellum. Therefore, STN-DBS was found to suppress cerebellar hypermetabolism and to partly restore physiologic glucose consumption in limbic and associative projection territories of the basal ganglia. These data suggest an activating effect of DBS upon its target structures and confirm a central role of the STN in motor as well as associative, limbic, and cerebellar basal ganglia circuits.

In a prospective phase I/II clinical study, we treated eight patients suffering from recurrent glioblastoma multiform with stereotactically guided intratumoral convection-enhanced delivery of an HSV-1-tk gene-bearing liposomal vector and systemic ganciclovir. Noninvasive identification of target tissue together with assessment of vector-distribution volume and the effects of gene therapy were achieved using magnetic resonance imaging and positron emission tomography. The treatment was tolerated well without major side effects. In two of eight patients, we observed a greater than 50% reduction of tumor volume and in six of eight patients focal treatment effects. Intracerebral infusion of contrast medium before vector application displayed substantial inhomogeneity of tissue staining indicating the need of test infusions to monitor the mechanical distribution of vectors. Visualization of therapeutic effects on tumor metabolism and documentation of gene expression using positron emission tomography indicated that molecular imaging technology appears to be essential for the further development of biological treatment strategies.

BackgroundFor patients with psychiatric illnesses remaining refractory to ‘standard’ therapies, neurosurgical procedures may be considered. Guidelines for safe and ethical conduct of such procedures have previously and independently been proposed by various local and regional expert groups.MethodsTo expand on these earlier documents, representative members of continental and international psychiatric and neurosurgical societies, joined efforts to further elaborate and adopt a pragmatic worldwide set of guidelines. These are intended to address a broad range of neuropsychiatric disorders, brain targets and neurosurgical techniques, taking into account cultural and social heterogeneities of healthcare environments.FindingsThe proposed consensus document highlights that, while stereotactic ablative procedures such as cingulotomy and capsulotomy for depression and obsessive-compulsive disorder are considered ‘established’ in some countries, they still lack level I evidence. Further, it is noted that deep brain stimulation in any brain target hitherto tried, and for any psychiatric or behavioural disorder, still remains at an investigational stage. Researchers are encouraged to design randomised controlled trials, based on scientific and data-driven rationales for disease and brain target selection. Experienced multidisciplinary teams are a mandatory requirement for the safe and ethical conduct of any psychiatric neurosurgery, ensuring documented refractoriness of patients, proper consent procedures that respect patient's capacity and autonomy, multifaceted preoperative as well as postoperative long-term follow-up evaluation, and reporting of effects and side effects for all patients.InterpretationThis consensus document on ethical and scientific conduct of psychiatric surgery worldwide is designed to enhance patient safety.