Subthalamic nucleus deep brain stimulation programming settings do not correlate with Parkinson's disease severity.

BACKGROUND: Deep brain stimulation (DBS) is a well-established treatment for Parkinson's disease (PD). While the success of DBS is dependent on careful patient selection and accurate lead placement, programming parameters play a pivotal role in tailoring therapy on the individual level. Various algorithms have been developed to streamline the initial programming process, but the relationship between pre-operative patient characteristics and post-operative device settings is unclear. In this study, we investigated how PD severity correlates with DBS settings. METHODS: We conducted a retrospective review of PD patients who underwent DBS of the subthalamic nucleus at one US tertiary care center between 2014 and 2018. Pre-operative patient characteristics and post-operative programming data at various intervals were collected. Disease severity was measured using the Unified Parkinson's Disease Rating Scale score (UPDRS) as well as levodopa equivalent dose (LED). Correlation analyses were conducted looking for associations between pre-operative disease severity and post-operative programming parameters. RESULTS: Fifty-six patients were analyzed. There was no correlation between disease severity and any of the corresponding programming parameters. Pre-operative UPDRS scores on medication were similar to post-operative scores with DBS. Settings of amplitude, frequency, and pulse width increased significantly from 1 to 6 months post-operatively. Stimulation volume, inferred by the distance between contacts used, also increased significantly over time. CONCLUSIONS: Interestingly, we found that patients with more advanced disease responded to electrical stimulation similarly to patients with less advanced disease. These data provide foundational knowledge of DBS programming parameters used in a single cohort of PD patients over time.

Atypical antipsychotic therapy in Parkinson's disease psychosis: A retrospective study.

OBJECTIVE: Parkinson's disease psychosis (PDP) is a frequent complication of idiopathic Parkinson's disease (iPD) with significant impact on quality of life and association with poorer outcomes. Atypical antipsychotic drugs (APDs) are often used for the treatment of PDP; however, their use is often complicated by adverse drug reactions (ADRs). In this study, we present patients with PDP who were treated with the most commonly used atypical antipsychotic agents and review their respective ADRs. METHODS: A retrospective study was carried out to include a total of 45 patients with iPD who visited a movement disorders clinic between 2006 and 2015. All PDP patients treated with atypical APDs were included in the analysis for their specific ADRs. RESULTS: Forty-five iPD patients (mean age of onset: 62.67 ± 9.86 years) were included, of those 10 patients had psychosis (mean age of onset: 76.80 ± 4.61 years). Of the 45 patients, 22.2% were found to have psychotic symptoms, of whom 70% had hallucinations, 20% had delusions, and 10% illusions. Seventy percent of psychotic symptoms occurred after ten or more years from diagnosis of iPD. PDP patients were treated with quetiapine, olanzapine, and risperidone separately or in combination, all of which were found to have certain ADRs. LIMITATIONS: This study was limited by its retrospective study design and small sample size and with likely selection bias. CONCLUSIONS: The prevalence of PDP is relatively high in older patients with iPD. The uses of the currently available atypical APDs in this patient population are often complicated by ADRs. The selective 5-HT 2A inverse agonist, pimavanserin, could be a better alternative in the treatment of PDP.

Target Selection Recommendations Based on Impact of Deep Brain Stimulation Surgeries on Nonmotor Symptoms of Parkinson's Disease.

OBJECTIVE: This review examines the evidence that deep brain stimulation (DBS) has extensive impact on nonmotor symptoms (NMSs) of patients with Parkinson's disease (PD). DATA SOURCES: We retrieved information from the PubMed database up to September, 2015, using various search terms and their combinations including PD, NMSs, DBS, globus pallidus internus (GPi), subthalamic nucleus (STN), and ventral intermediate thalamic nucleus. STUDY SELECTION: We included data from peer-reviewed journals on impacts of DBS on neuropsychological profiles, sensory function, autonomic symptoms, weight changes, and sleep disturbances. For psychological symptoms and cognitive impairment, we tried to use more reliable proofs: Random, control, multicenter, large sample sizes, and long period follow-up clinical studies. We categorized the NMSs into four groups: those that would improve definitively following DBS; those that are not significantly affected by DBS; those that remain controversial on their surgical benefit; and those that can be worsened by DBS. RESULTS: In general, it seems to be an overall beneficial effect of DBS on NMSs, such as sensory, sleep, gastrointestinal, sweating, cardiovascular, odor, urological symptoms, and sexual dysfunction, GPi-DBS may produce similar results; Both STN and Gpi-DBS are safe with regard to cognition and psychology over long-term follow-up, though verbal fluency decline is related to DBS; The impact of DBS on behavioral addictions and dysphagia is still uncertain. CONCLUSIONS: As the motor effects of STN-DBS and GPi-DBS are similar, NMSs may determine the target choice in surgery of future patients.