Factors related to outcomes of subthalamic deep brain stimulation in Parkinson's disease

Parkinson Disease-Related Pattern of Glucose Metabolism Associated With the Potential for Motor Improvement After Deep Brain Stimulation

BACKGROUND

Motor dysfunctions in Parkinson disease (PD) patients are not completely normalized by deep brain stimulation (DBS), and there is an obvious difference in the degree of symptom improvement after DBS for each patient.

OBJECTIVE

To test our hypothesis that each patient has their own restoration capacity for motor improvement after DBS, and to investigate whether regional cerebral glucose metabolism in 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) scans is associated with the capacity for off-medication motor improvement (MIoff) after DBS.

METHODS

The MIoff (%) was calculated using the Unified Parkinson's Disease Rating Scale part III in 27 PD patients undergoing DBS in the globus pallidus interna. The standardized uptake value ratios (SUVRs) on FDG-PET were quantitatively measured, and the areas where the SUVR correlated with the MIoff (%) were identified. Also, the areas where the SUVR was significantly different between the 2 MIoff groups (≥60% vs <60%) were determined.

RESULTS

Ten patients achieved MIoff > 60% at 12 mo after DBS. In general, the MIoff (%) was positively correlated with preoperative SUVR in the temporo-parieto-occipital lobes, while it was inversely correlated with the metabolism in the primary motor cortex. The patients in the MIoff < 60% group showed a significant decrease in SUVR in the parieto-occipital lobes, while parieto-occipital metabolism in those with MIoff ≥ 60% was relatively preserved (Mann-Whitney U test, P = .03).

CONCLUSION

Our findings suggest that the parieto-occipital lobes may be implicated more generally in the prognosis of motor improvement after DBS in advanced PD than other regions.

Comparison of elderly and young patient populations treated with deep brain stimulation for Parkinson's disease: long-term outcomes with up to 7 years of follow-up

OBJECTIVE

Deep brain stimulation (DBS) is the procedure of choice for Parkinson's disease (PD). It has been used in PD patients younger than 70 years because of better perceived intra- and postoperative outcomes than in patients 70 years or older. However, previous studies with limited follow-up have demonstrated benefits associated with the treatment of elderly patients. This study aims to evaluate the long-term outcomes in elderly PD patients treated with DBS in comparison with a younger population.

METHODS

PD patients treated with DBS at the authors' institution from 2008 to 2014 were divided into 2 groups: 1) elderly patients, defined as having an age at surgery ≥ 70 years, and 2) young patients, defined as those < 70 years at surgery. Functional and medical treatment outcomes were evaluated using the Unified Parkinson's Disease Rating Scale part III (UPDRS III), levodopa-equivalent daily dose (LEDD), number of daily doses, and number of anti-PD medications. Study outcomes were compared using univariate analyses, 1-sample paired t-tests, and 2-sample t-tests.

RESULTS

A total of 151 patients were studied, of whom 24.5% were ≥ 70 years. The most common preoperative Hoehn and Yahr stages for both groups were 2 and 3. On average, elderly patients had more comorbidities at the time of surgery than their younger counterparts (1 vs 0, p = 0.0001) as well as a higher average LEDD (891 mg vs 665 mg, p = 0.008). Both groups experienced significant decreases in LEDD following surgery (elderly 331.38 mg, p = 0.0001; and young 108.6 mg, p = 0.0439), with a more significant decrease seen in elderly patients (young 108.6 mg vs elderly 331.38 mg, p = 0.0153). Elderly patients also experienced more significant reductions in daily doses (young 0.65 vs elderly 3.567, p = 0.0344). Both groups experienced significant improvements in motor function determined by reductions in UPDRS III scores (elderly 16.29 vs young 12.85, p < 0.0001); however, reductions in motor score between groups were not significant. Improvement in motor function was present for a mean follow-up of 3.383 years postsurgery for the young group and 3.51 years for the elderly group. The average follow-up was 40.6 months in the young group and 42.2 months in the elderly group.

CONCLUSIONS

This study found long-term improvements in motor function and medication requirements in both elderly and young PD patients treated with DBS. These outcomes suggest that DBS can be successfully used in PD patients ≥ 70 years. Further studies will expand on these findings.

Factors predicting the instant effect of motor function after subthalamic nucleus deep brain stimulation in Parkinson's disease

Background

Subthalamic nucleus deep brain stimulation (STN-DBS) is an effective treatment for Parkinson’s disease (PD), the predictive effect of levodopa responsiveness on surgical outcomes was confirmed by some studies, however there were different conclusions about that through long- and short-term follow-ups. We aimed to investigate the factors which influence the predictive value of levodopa responsiveness, and discover more predictive factors of surgical outcomes.

Methods

Twenty-three PD patients underwent bilateral STN-DBS and completed our follow-up. Clinical evaluations were performed 1 week before and 3 months after surgery.

Results

STN-DBS significantly improved motor function of PD patients after 3 months; preoperative levodopa responsiveness and disease subtype predicted the effect of DBS on motor function; gender, disease duration and duration of motor fluctuations modified the predictive effect of levodopa responsiveness on motor improvement; the duration of motor fluctuations and severity of preoperative motor symptoms modified the predictive effect of disease subtype on motor improvement.

Conclusions

The intensity of levodopa responsiveness served as a predictor of motor improvement more accurately in female patients, patients with shorter disease duration or shorter motor fluctuations; PD patients with dominant axial symptoms benefit less from STN-DBS compared to those with limb-predominant symptoms, especially in their later disease stage.

The treatment of Parkinson's disease with deep brain stimulation: current issues

Deep brain stimulation has become a well-established symptomatic treatment for Parkinson's disease during the last 25 years. Besides improving motor symptoms and long-term motor complications, positive effects on patients' mobility, activities of daily living, emotional well-being and health-related quality of life have been recognized. Apart from that, numerous clinical trials analyzed effects on non-motor symptoms and side effects of deep brain stimulation. Several technical issues and stimulation paradigms have been and are still being developed to optimize the therapeutic effects, minimize the side effects and facilitate handling. This review summarizes current therapeutic issues, i.e., patient and target selection, surgical procedure and programming paradigms. In addition it focuses on neuropsychological effects and side effects of deep brain stimulation.