Bilateral hypothalamic deep brain stimulation was performed to treat a patient with morbid obesity. We observed, quite unexpectedly, that stimulation evoked detailed autobiographical memories. Associative memory tasks conducted in a double-blinded "on" versus "off" manner demonstrated that stimulation increased recollection but not familiarity-based recognition, indicating a functional engagement of the hippocampus. Electroencephalographic source localization showed that hypothalamic deep brain stimulation drove activity in mesial temporal lobe structures. This shows that hypothalamic stimulation in this patient modulates limbic activity and improves certain memory functions.

Long-term follow-up reveals that hardware-related complications occur in a significant number of patients. Factors that lead to such complications must be identified and addressed to maximize the important benefits of DBS therapy.

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The accuracy of freehand ventriculostomy catheterization at the authors' institution typically required 2 passes per successful placement, and, when successful, was 1.6 cm from the Monro foramen. More importantly, 22.4% of these catheter tips were in nonventricular spaces. Although many neurosurgeons believe that the current practice of ventriculostomy is good enough, the results of this study show that there is certainly much room for improvement.

Object Deep brain stimulation (DBS) of the lateral hypothalamic area (LHA) has been suggested as a potential treatment for intractable obesity. The authors present the 2-year safety results as well as early efficacy and metabolic effects in 3 patients undergoing bilateral LHA DBS in the first study of this approach in humans. Methods Three patients meeting strict criteria for intractable obesity, including failed bariatric surgery, under-went bilateral implantation of LHA DBS electrodes as part of an institutional review board– and FDA-approved pilot study. The primary focus of the study was safety; however, the authors also received approval to collect data on early efficacy including weight change and energy metabolism. Results No serious adverse effects, including detrimental psychological consequences, were observed with continuous LHA DBS after a mean follow-up of 35 months (range 30–39 months). Three-dimensional nonlinear transformation of postoperative imaging superimposed onto brain atlas anatomy was used to confirm and study DBS contact proximity to the LHA. No significant weight loss trends were seen when DBS was programmed using standard settings derived from movement disorder DBS surgery. However, promising weight loss trends have been observed when monopolar DBS stimulation has been applied via specific contacts found to increase the resting metabolic rate measured in a respiratory chamber. Conclusions Deep brain stimulation of the LHA may be applied safely to humans with intractable obesity. Early evidence for some weight loss under metabolically optimized settings provides the first “proof of principle” for this novel antiobesity strategy. A larger follow-up study focused on efficacy along with a more rigorous metabolic analysis is planned to further explore the benefits and therapeutic mechanism behind this investigational therapy.

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Deep brain stimulation of the VIM is an efficient and safe treatment for ET. Tremor and handwriting improvements in long-term follow-up are stable. The patients' perception of their outcome is quite good. However, tolerance may develop in some patients requiring changes in stimulation parameters.

Aims: Infection of hardware is a serious complication after deep brain stimulation (DBS), as this may result in additional surgery, cost and loss of treatment benefit for the patient. We report the incidence and management of infections after DBS in a single institution over the past 11 years. Methods: A database of 270 patients with 484 implants was used in the study. Incidence, clinical characteristics and management of infections were analyzed. Results: The overall infection rate was 9.3% (25/270) by patients and 6.8% (33/484) by episode/implants. The median time of infection after implantation was 64 days. Only 7/33 episodes (21.2%) occurred within 30 days after surgery, 22/33 episodes (66.7%) within 6 months and 28/33 episodes (84.8%) within 12 months. There was no age difference between infected and noninfected patients, while comorbidities were more frequent in the former. Infection rates before and after January 2003 were 14.3 and 4.9%, respectively. The rate of complete and partial hardware salvage was 30.3 and 21.2% while that of complete hardware removal was 48.5%. Patients with deep purulent infections and patients with Staphylococcus aureus as the causative organism were more likely to have their hardware removed. Conclusions: The incidence of hardware infections declined significantly over time. Improvements in hardware and implantation techniques may be responsible. Hardware can often be completely or partly saved in infected patients.