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Microlesion effect as a predictor of the effectiveness of subthalamic deep brain stimulation for Parkinson's disease
Tomasz Tykocki1, Paweł Nauman, Henryk Koziara
1Departments of Neurosurgery, Institute of Psychiatry and Neurology, Warsaw, Poland. ttomasz@mp.pl
Background:
Microlesion effect (MLE) is a commonly observed phenomenon after electrode insertion into the subthalamic nucleus (STN) for deep brain stimulation (DBS).
Objectives:
The aim of this study was to determine the presence of the MLE in the early postoperative period and the relationship between MLE and STN DBS.
Methods:
74 patients with Parkinson's disease were included in this study. Motor symptoms were evaluated preoperatively, within 48 h after electrode implantation and at 6 months with United Parkinson's Disease Rating Scale part III (UPDRS-III). According to the improvement level with MLE, all participants were stratified into three groups: (1) less than 20%; (2) 20-40%, and (3) more than 40% in OFF medication states. The degree of improvement in UPDRS-III with DBS ON for each MLE group was assessed at the 6-month follow-up. Regression analysis was applied for the evaluation of the relationship between MLE and improvement with DBS ON.
Results:
Mean results in UPDRS-III with the MLE in ON and OFF medication states were 22.1 ± 10.5 and 42.1 ± 14 points, respectively. At the 6-month follow-up, with active stimulation, results tended to further ameliorate to 14.6 (59.4%) points in ON and 20.8 (55.3%) in OFF. Mean improvement in MLE groups were: 33.6% group 1, 47.5% group 2 and 61.4% group 3. Regression analysis revealed a positive correlation between the MLE and results at 6 months with DBS ON.
Conclusion:
Results proved the presence of MLE in the early postoperative period. Furthermore, a positive correlation between MLE and improvement degree with active stimulation was observed.
Insights
The microlesion effect (MLE) is present early after subthalamic nucleus deep brain stimulation (STN DBS) in Parkinson's patients. Greater MLE correlates with better motor improvement from STN DBS.
Area of Science:
- Neurosurgery
- Neurology
- Biomedical Engineering
Background:
- The microlesion effect (MLE) is a recognized phenomenon following electrode insertion into the subthalamic nucleus (STN) for deep brain stimulation (DBS).
- Understanding the early presence and impact of MLE is crucial for optimizing DBS therapy.
Purpose of the Study:
- To confirm the existence of the MLE in the early postoperative phase.
- To investigate the association between the MLE and the efficacy of STN DBS.
Main Methods:
- Seventy-four Parkinson's disease patients underwent motor symptom evaluation using the UPDRS-III scale preoperatively, within 48 hours post-implantation, and at 6 months.
- Patients were stratified into three groups based on MLE improvement levels ( <20%, 20-40%, >40%) in OFF-medication states.
- Regression analysis assessed the relationship between MLE and UPDRS-III improvement with DBS ON at 6 months.
Main Results:
- Mean UPDRS-III scores were 22.1 (ON medication) and 42.1 (OFF medication) with MLE.
- At 6 months, active stimulation improved scores to 14.6 (ON) and 20.8 (OFF).
- Mean improvements in MLE groups were 33.6% (Group 1), 47.5% (Group 2), and 61.4% (Group 3), showing a positive correlation with DBS efficacy.
Conclusions:
- The study confirms the presence of the microlesion effect in the early postoperative period after STN DBS.
- A significant positive correlation exists between the degree of MLE and the level of motor improvement achieved with active deep brain stimulation.
