RESUMO
Introduction: Essential tremor (ET) is a common neurological disease. Deep brain stimulation (DBS) to the thalamic ventral intermediate nucleus (VIM) or the adjacent structures, such as caudal zona incerta/ posterior subthalamic area (cZi/PSA), can be effective in treating medication refractory tremor. However, it is not clear whether DBS can cause cognitive changes, in which domain, and to what extent if so. Methods: We systematically searched PubMed and the Web of Science for available publications reporting on cognitive outcomes in patients with ET who underwent DBS following the PICO (population, intervention, comparators, and outcomes) concept. The PRISMA guideline for systematic reviews was applied. Results: Twenty relevant articles were finally identified and included for review, thirteen of which were prospective (one also randomized) studies and seven were retrospective. Cognitive outcomes included attention, memory, executive function, language, visuospatial function, and mood-related variables. VIM and cZi/PSA DBS were generally well tolerated, although verbal fluency and language production were affected in some patients. Additionally, left-sided VIM DBS was associated with negative effects on verbal abstraction, word recall, and verbal memory performance in some patients. Conclusion: Significant cognitive decline after VIM or cZi/PSA DBS in ET patients appears to be rare. Future prospective randomized controlled trials are needed to meticulously study the effect of the location, laterality, and stimulation parameters of the active contacts on cognitive outcomes while considering possible medication change post-DBS, timing, standard neuropsychological battery, practice effects, the timing of assessment, and effect size as potential confounders.
RESUMO
INTRODUCTION: Racial disparities in diagnosis, treatment and survival in Black patients with Parkinson's disease (PD) compared to White patients have not been well studied, largely due to limited number of studies and information on Black patients in healthcare systems. Studying racial disparities and identifying underlying factors in large populations are important to understand PD and improve care. METHODS: We retrospectively identified PD patients on both races from 1/1/2006 to 10/31/2017 and compared demographics, socioeconomic status (educations, incomes and insurances), comorbidities (all categories, including mood, cognition and psychosis), treatment (medications for parkinsonism and major non-motor symptoms, and frequency and locations of healthcare) and survival, and identified factors associated with medication usage and survival. RESULTS: We retrospectively studied 2033 PD patients, of whom 725 were Black. Black patients lacked male predominance, were 4 years older at first diagnosis here, more likely to smoke and live in a low education and income community, and possessed limited insurances compared to White patients. Black patients also had more comorbidities and were more likely to receive care through emergency or inpatient service, but less likely to be on medications for parkinsonism and mood disorders. Race, age, smoking status, insurance type, frequency and locations of healthcare and comorbidities were associated with medication usage. Black race, older age, inpatient admission and malignancy were associated with increased risk of death. CONCLUSION: We revealed racial disparities in diagnosis, treatment and survival, and factors associated with medication usage and survival in the largest reported Black PD cohort from a single center.