Recommendations for the Prevention and Management of Deep Brain Stimulation Infections Based on 26-Year Single-Center Experience.

INTRODUCTION: Infections related to deep brain stimulation (DBS) can lead to discontinuation of the treatment and increased morbidity. Various measures of reducing infection rates have been proposed in the literature, but scientific consensus is lacking. The aim of this study was to report a 26-year single center experience of DBS infections and provide recommendations for the prevention and management of them. METHODS: The retrospective analysis consisted of 978 DBS surgeries performed at Oulu University Hospital (OUH) from 1997 to 2022. This included 342 primary or reimplantations of DBS electrodes and 559 primary or reimplantations of implantable pulse generator (IPG). Infections within approximately 1 year after the surgery without secondary cause were considered surgical-site infections (SSIs). χ2 test was used to compare infection rates before and after 2013, when the systematic implementation of infection prevention measures was started. RESULTS: A total of 35 DBS implants were found to be infected. The number of SSIs was 30, of which 29 were originally operated in OUH leading to a center-specific infection rate of 3.1%. Of the SSIs, 17.2% occurred after IPG replacement. Staphylococcus aureus was found in 75.0% of cultures and 32.1% were mixed infections. The treatment of SSIs included aggressive surgical revision combined with cefuroxime and vancomycin antibiotics, as most patients in the initial conservative treatment group eventually required surgical revision. A statistically significant difference in infection rates before and after the implementation of preventative measures was not observed (risk ratio 2.20, 95% confidence interval 0.94-5.75, p = 0.051), despite over two-fold difference in the incidence of SSIs. CONCLUSION: Our findings show that the rates of surgical infections are low in modern DBS, but due to their serious consequences, preventative measures should be implemented. We highlight that mixed infections should be accounted for in the antibiotic selection. Furthermore, our treatment recommendation includes aggressive surgical revision combined with antibiotic treatment.

Deep Brain Stimulation of Subthalamic Nucleus Improves Quality of Life in General and Mental Health Domains in Parkinson's Disease to the Level of the General Population.

OBJECTIVES: Parkinson's disease (PD) leads to significant impairment in quality of life (QoL) across various domains. Deep brain stimulation of the subthalamic nucleus (STN-DBS) is known to improve motor and nonmotor symptoms in PD. The aim was to study whether STN-DBS could improve the QoL of patients with PD to the level of the general population, and to determine factors predicting better motor outcomes. MATERIALS AND METHODS: The retrospective analysis included 43 patients who underwent either primary or revision STN-DBS. Patients filled out a general QoL questionnaire (RAND 36-item health survey) before and 12 months after surgery, and scores were compared with age- and sex-adjusted national population values. In addition, motor scores were calculated using Unified Parkinson Disease Rating Scale part 3 (UPDRS 3) with the best PD medication. Levodopa equivalent daily dose (LEDD) was also collected. Changes in the QoL were compared with operation age, disease duration, and preoperative QoL. RESULTS: Preoperatively, patients had significantly impaired QoL in all subsections compared with that of the general population. The mean postoperative UPDRS 3 improvement was 50.0%, and reduction in LEDD was 69.0%. Statistically significant QoL improvements were found in Physical Function, Mental Health, Social Function, Vitality, and Role Physical 12 months postoperatively compared with baseline. The mean differences compared with a healthy population were not statistically significant in General Health, Mental Health, Vitality, and Role Emotional. Furthermore, disease duration was found to be negatively correlated with improvements in UPDRS 3 score, and worse preoperative QoL positively correlated with changes in Physical Function. CONCLUSIONS: Patients experienced significant QoL improvements after STN-DBS. The General Health and Mental Health of patients were postoperatively most comparable with age- and sex-adjusted population values. Moreover, earlier stimulation predicted better motor improvements, which emphasizes the importance of earlier timing of STN-DBS surgery and minimizing loss of function at a critical disease stage.

Stimulation of the Presupplementary Motor Area Cluster of the Subthalamic Nucleus Predicts More Consistent Clinical Outcomes.

BACKGROUND: The development of diffusion tensor imaging and tractography has raised increasing interest in the functional targeting of deep brain stimulation of the subthalamic nucleus (STN) in Parkinson disease. OBJECTIVE: To study, using deterministic tractography, the functional subdivisions of the STN and hyperdirect white matter connections located between the STN and the medial frontal cortex, especially the presupplementary motor area (preSMA), SMA, primary motor area (M1), and dorsolateral premotor cortex, and to study retrospectively whether this information correlates with clinical outcome. METHODS: Twenty-two patients with Parkinson disease who underwent STN deep brain stimulation were analyzed. Using 3 T MR images, the medial frontal cortex was manually segmented into preSMA, SMA, M1, and dorsolateral premotor cortex, which were then used to determine the functional subdivisions of the lateral border of the STN. The intersectional quantities of the volume of activated tissue (VAT) and the hyperdirect white matter connections were calculated. The results were combined with clinical data including unilateral 12-month postoperative motor outcome and levodopa equivalent daily dose. RESULTS: Stimulated clusters of the STN were connected mostly to the cortical SMA and preSMA regions. Patients with primarily preSMA cluster stimulation (presmaVAT% ≥ 50%) had good responses to the treatment with unilateral motor improvement over 40% and levodopa equivalent daily dose reduction over 60%. Larger VAT was not found to correlate with better patient outcomes. CONCLUSION: Our study is the first to suggest that stimulating, predominantly, the STN cluster where preSMA hyperdirect pathways are located, could be predictive of more consistent treatment results.