Takuto Emura

BACKGROUND AND OBJECTIVES: Placement of stereotactic electroencephalography (SEEG) electrodes involves insertion of an obturator toward the target under image guidance without direct vision. Thus, tactile feedback during obturator manipulation is key to avoiding complications. Resistance encountered during advancement of the obturator that hinders planned electrode placement has prompted us to investigate the factors contributing to this resistance. METHODS: We analyzed 168 trajectories in 24 consecutive patients who underwent SEEG electrode placement between May 2019 and March 2023: 135 were placed using a 1.5-mm obturator and 33 were placed using a 0.86-mm obturator. The depth at which resistance was encountered was documented intraoperatively and compared with the preplanned trajectory to determine the structure where resistance occurred. Factors that may contribute to resistance were analyzed. RESULTS: Resistance was encountered in a total of 22 trajectories: 19 from the 1.5-mm obturator group and 3 from the 0.86-mm obturator group. Sulcal bank penetration was observed in 15 trajectories (68%) with resistance and in 42/146 trajectories (29%) without resistance. Sulcal bank penetration contributed most to resistance, more than lesion presence or trajectory length. In the 1.5-mm obturator group, insertion angles differed between trajectories with and without resistance (37.1° ± 19.0 vs 58.8° ± 15.5, 95% CI = 11.8-31.6, P = .000055). The difference remained significant when considering all pia penetrations, including at the cortical surface (37.6° ± 18.5 vs 66.1° ± 13.3, 95% CI = 21.3-35.5, P = 2.19 × 10 ⁻¹³ ). CONCLUSION: Sulcal bank penetration is the main factor contributing to resistance; resistance risk increases as the insertion angle decreases. Our findings guide forecasting resistance during sulci-traversing in SEEG electrode implantation, which may be unavoidable for optimal gray matter coverage, although forceful advancement against resistance should be avoided to minimize hemorrhagic risks.

Background: Parkinson's disease (PD) often involves motor fluctuations and dyskinesia, which are difficult to manage with medication alone. Conventional deep brain stimulation (cDBS) effectively alleviates symptoms but has limitations, including the challenge of balancing therapeutic effects against potential side effects, as well as limited battery life. To address these issues, adaptive DBS (aDBS) systems, which dynamically adjust stimulation parameters based on real‐time physiological feedback, have attracted growing interest. Objectives: The aim of this study was to assess the efficacy, tolerability, and safety of aDBS in patients with advanced PD over a 1‐year period, using the Movement Disorder Society‐Sponsored Revision of the Unified Parkinson's Disease Rating Scale (MDS‐UPDRS) and Parkinson's Disease Questionnaire‐39 (PDQ‐39). Methods: This prospective, single‐arm study involved 19 patients who transitioned from cDBS to aDBS. Baseline assessments were conducted under cDBS, and patients were re‐evaluated 1 year after switching to aDBS. Results: Sixteen patients completed 1 year of aDBS. Significant improvements in motor function, as measured by MDS‐UPDRS Part III scores in the medication‐off/stimulation‐on condition, were observed. Patients with severe baseline wearing‐off showed greater reductions in motor fluctuation (MDS‐UPDRS Part IV) scores. Younger patients showed better quality of life (PDQ‐39) and activity of daily living (MDS‐UPDRS Part II) scores, though overall changes were not statistically significant. Conclusions: aDBS shows promise in managing motor symptoms in PD, particularly in patients with pronounced wearing‐off and younger patients, by dynamically adjusting stimulation parameters. Although further optimization and long‐term studies are necessary, these findings underscore the potential of aDBS to offer personalized treatment options for advanced PD.