Cognitive outcomes in patients with essential tremor treated with deep brain stimulation: a systematic review.

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.

Identification of genetic risk loci and causal insights associated with Parkinson's disease in African and African admixed populations: a genome-wide association study.

Background: An understanding of the genetic mechanisms underlying diseases in ancestrally diverse populations is an important step towards development of targeted treatments. Research in African and African admixed populations can enable mapping of complex traits, because of their genetic diversity, extensive population substructure, and distinct linkage disequilibrium patterns. We aimed to do a comprehensive genome-wide assessment in African and African admixed individuals to better understand the genetic architecture of Parkinson's disease in these underserved populations.

Using Downgaze Palsy Progression Rate to Model Survival in Progressive Supranuclear Palsy-Richardson Syndrome.

Background: Rapid development of downgaze palsy, the most specific symptom of progressive supranuclear palsy (PSP), has been associated with shorter survival in small studies.

Objective: We hypothesized that the progression rate of downgaze palsy and other disease features could predict survival if assessed soon after the onset of downgaze palsy in a large data set.

Methods: We used a longitudinal database of 414 patients with probable PSP-Richardson syndrome from 1994 to 2020.

Effect of Deep Brain Stimulation on Cerebellar Tremor Compared to Non-Cerebellar Tremor Using a Wearable Device in a Patient With Multiple Sclerosis: Case Report.

Tremor of the upper extremity is a significant cause of disability in some patients with multiple sclerosis (MS). The MS tremor is complex because it contains an ataxic intentional tremor component due to the involvement of the cerebellum and cerebellar outflow pathways by MS plaques, which makes the MS tremor, in general, less responsive to medications or deep brain stimulation (DBS) than those associated with essential tremor or Parkinson's disease. The cerebellar component has been thought to be the main reason for making DBS less effective, although it is not clear whether it is due to the lack of suppression of the ataxic tremor by DBS or else.

Severity of Downgaze Palsy in the Context of Disease Duration Could Estimate Survival Duration in Patients With Progressive Supranuclear Palsy.

It is an unmet need to estimate survival duration for patients with progressive supranuclear palsy (PSP). The objective of this study was to identify factors associated with the survival duration in patients with PSP. We followed up 23 patients with probable PSP-RS (Richardson syndrome) or PSP-P (parkinsonism) in our PSP center until death from 2011 to 2019.

Disparities in diagnosis, treatment and survival between Black and White Parkinson patients.

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.

Deep Brain Stimulation Impedance Decreases Over Time Even When Stimulation Settings Are Held Constant.

: To study whether and to what extent the therapeutic impedance and current change under long-term deep brain stimulation (DBS) with constant stimulation settings, which could inform the role of constant current stimulation. : Therapy impedance and current measurements were retrospectively collected from patients with Parkinson's disease (PD) undergoing DBS of the subthalamic nucleus (STN) or essential tremor (ET) undergoing ventral intermediate nucleus (VIM). Baseline and follow-up measurements were obtained for intervals of at least 6 months without changes in stimulation settings.

Long-term effect of low frequency stimulation of STN on dysphagia, freezing of gait and other motor symptoms in PD.

Objective: To evaluate the long-term effect of 60 Hz stimulation of the subthalamic nucleus (STN) on dysphagia, freezing of gait (FOG) and other motor symptoms in patients with Parkinson's disease (PD) who have FOG at the usual 130 Hz stimulation.

Methods: This is a prospective, sequence randomised, crossover, double-blind study. PD patients with medication refractory FOG at 130 Hz stimulation of the STN were randomised to the sequences of 130 Hz, 60 Hz or deep brain stimulation off to assess swallowing function (videofluoroscopic evaluation and swallowing questionnaire), FOG severity (stand-walk-sit test and FOG questionnaire) and motor function (Unified PD Rating Scale, Part III motor examination (UPDRS-III)) at initial visit (V1) and follow-up visit (V2, after being on 60 Hz stimulation for an average of 14.

Effect of low versus high frequency stimulation on freezing of gait and other axial symptoms in Parkinson patients with bilateral STN DBS: a mini-review.

Some studies have shown that low frequency stimulation (LFS, most commonly 60 Hz), compared to high frequency stimulation (HFS, most commonly 130 Hz), has beneficial effects, short-term or even long-term, on improving freezing of gait (FOG) and other axial symptoms, including speech and swallowing function, in Parkinson disease (PD) patients with bilateral subthalamic nucleus deep brain stimulation (STN DBS). However, other studies failed to confirm this. It seems not clear what determines the difference in response to LFS.

Evaluation of parkinsonism and striatal dopamine transporter loss in patients with spinocerebellar ataxia type 6.

It is unclear whether patients with spinocerebellar ataxia type 6 (SCA6) have parkinsonism and striatal dopamine transporter (DAT) loss, based on previously small size studies without well-matched controls. A study with a larger number of patients and both age- and gender-matched healthy controls (HCs) is needed for a better answer to this question. Twelve genetically confirmed ataxic SCA6 patients (six male six female, age 65.