Effect of Anisotropic Brain Conductivity on Patient-Specific Volume of Tissue Activation in Deep Brain Stimulation for Parkinson Disease.

Objective: Deep brain stimulation (DBS) modeling can improve surgical targeting by quantifying the spatial extent of stimulation relative to subcortical structures of interest. A certain degree of model complexity is required to obtain accurate predictions, particularly complexity regarding electrical properties of the tissue around DBS electrodes. In this study, the effect of anisotropy on the volume of tissue activation (VTA) was evaluated in an individualized manner.

Intrinsic auricular muscle zone stimulation for Parkinson disease: The EARSTIM-PD Phase II multi-center pilot study results.

Background: Studies have suggested that intrinsic auricular muscle zones (IAMZ) stimulation alleviates motor features of Parkinson disease (PD).

Methods: A randomized, blinded, active sham-controlled pilot trial was conducted to evaluate the safety and dose-response-time curve of Earstim using a 3-treatment, 3-period crossover design in PD patients experiencing OFF time on levodopa. Treatments were: short (20-min) IAMZ stimulation; long (60-min) IAMZ stimulation; and 20-min active sham stimulation of non-muscular areas.

Impact of subthalamic nucleus stimulation on urinary dysfunction and constipation in Parkinson's disease.

Objective: The effect of subthalamic nucleus (STN) deep brain stimulation (DBS) on urinary dysfunction and constipation in Parkinson's disease (PD) is variable. This study aimed to identify potential surgical and nonsurgical variables predictive of these outcomes.

Methods: The authors used the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part I to assess urinary dysfunction (item 10) and constipation (item 11) preoperatively and at 6-12 months postoperatively.

Dorsal subthalamic deep brain stimulation improves pain in Parkinson's disease.

Introduction: Inconsistent effects of subthalamic deep brain stimulation (STN DBS) on pain, a common non-motor symptom of Parkinson's disease (PD), may be due to variations in active contact location relative to some pain-reducing locus of stimulation. This study models and compares the loci of maximal effect for pain reduction and motor improvement in STN DBS.

Methods: We measured Movement Disorder Society Unified PD Rating Scale (MDS-UPDRS) Part I pain score (item-9), and MDS-UPDRS Part III motor score, preoperatively and 6-12 months after STN DBS.

Predictors of Cognitive Change in Parkinson Disease: A 2-year Follow-up Study.

Background: Mild cognitive impairment is common in Parkinson disease (PD-MCI). However, instability in this clinical diagnosis and variability in rates of progression to dementia raises questions regarding its utility for longitudinal tracking and prediction of cognitive change in PD. We examined baseline neuropsychological test and cognitive diagnosis predictors of cognitive change in PD.

Localization of deep brain stimulation trajectories via automatic mapping of microelectrode recordings to MRI.

. Suboptimal electrode placement during subthalamic nucleus deep brain stimulation (STN DBS) surgery may arise from several sources, including frame-based targeting errors and intraoperative brain shift. We present a computer algorithm that can accurately localize intraoperative microelectrode recording (MER) tracks on preoperative magnetic resonance imaging (MRI) in real-time, thereby predicting deviation between the surgical plan and the MER trajectories.

Thalamic Segmentation and Neural Activation Modeling Based on Individual Tissue Microstructure in Deep Brain Stimulation for Essential Tremor.

Objective: Thalamic deep brain stimulation (DBS) is the primary surgical therapy for essential tremor (ET). Thalamic DBS traditionally uses an atlas-based targeting approach, which, although nominally accurate, may obscure individual anatomic differences from population norms. The objective of this study was to compare this traditional atlas-based approach with a novel quantitative modeling methodology grounded in individual tissue microstructure (N-of-1 approach).

Perceived social support declines after deep brain stimulation surgery in patients with Parkinson's disease.

Introduction: The Social Provisions Scale (SPS) measures a person's perceived social support. We evaluated the perceived social support in Parkinson's disease (PD) patients before and after subthalamic nucleus (STN) deep brain stimulation (DBS) and its impact on clinical outcomes following DBS.

Methods: We analyzed 55 PD patients who underwent STN DBS surgery and completed the SPS, PDQ-39, and MDS-UPDRS Parts I-IV before and 6-12 months after surgery.

Serotonin Transporter Imaging in Multiple System Atrophy and Parkinson's Disease.

Background: Both Parkinson's disease (PD) and multiple system atrophy (MSA) exhibit degeneration of brainstem serotoninergic nuclei, affecting multiple subcortical and cortical serotoninergic projections. In MSA, medullary serotoninergic neuron pathology is well documented, but serotonin system changes throughout the rest of the brain are less well characterized.

Objectives: To use serotonin transporter [ C]3-amino-4-(2-dimethylaminomethyl-phenylsulfaryl)-benzonitrile positron emission tomography (PET) to compare serotoninergic innervation in patients with MSA and PD.

Neural correlates of risky decision making in Parkinson's disease patients with impulse control disorders.

Some patients with Parkinson's disease (PD) experience impulse control disorders (ICDs), characterized by deficient voluntary control over impulses, drives, or temptations regarding excessive hedonic behavior. The present study aimed to better understand the neural basis of impulsive, risky decision making in PD patients with ICDs by disentangling potential dysfunctions in decision and outcome mechanisms. We collected fMRI data from 20 patients with ICDs and 28 without ICDs performing an information gathering task.

Clinically-derived oscillatory biomarker predicts optimal subthalamic stimulation for Parkinson's disease.

. Choosing the optimal electrode trajectory, stimulation location, and stimulation amplitude in subthalamic nucleus deep brain stimulation (STN DBS) for Parkinson's disease remains a time-consuming empirical effort. In this retrospective study, we derive a data-driven electrophysiological biomarker that predicts clinical DBS location and parameters, and we consolidate this information into a quantitative score that may facilitate an objective approach to STN DBS surgery and programming.

Motor speech effects in subthalamic deep brain stimulation for Parkinson's disease.

Objective: A motor speech disorder or dysarthria commonly arises in patients with Parkinson's disease (PD). The impact of subthalamic nucleus (STN) deep brain stimulation (DBS) on motor speech and the potential of intraoperative motor speech testing to predict outcomes are unknown. This study examined 1) the types and prevalence of motor speech changes observed with STN DBS and their relation to the preoperative condition, 2) the ability of intraoperative testing to predict postoperative changes in motor speech, and 3) the spatial relationship between stimulation sites producing maximal motor improvement, as measured by the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS), and maximal motor speech deterioration.

Characterization and localization of upper and lower extremity motor improvements in STN DBS for Parkinson's disease.

Introduction: Subthalamic deep brain stimulation (STN DBS) may have differential effects on cardinal motor signs of Parkinson's disease (PD) in the upper and lower extremities. In addition, sites of maximally effective DBS for each sign and extremity may be distinct. Our study seeks to elucidate these structure-function relationships.

Longitudinal Change in Quality of Life in Neurological Disorders Measures Over 3 Years in Patients with Early Parkinson's Disease.

Background: The Quality of Life in Neurological Disorders (Neuro-QoL) is a publicly available health-related quality-of-life measurement system.

Objective: The aim of this study was to evaluate the utility of Neuro-QoL item banks as outcome measures for clinical trials in Parkinson's disease.

Methods: An analysis of Neuro-QoL responsiveness to change and construct validity was performed in a multicenter clinical trial cohort.

Non-Motor Fluctuations in Parkinson's Disease: Validation of the Non-Motor Fluctuation Assessment Questionnaire.

Background: In patients with Parkinson's disease (PD), sleep, mood, cognitive, autonomic, and other non-motor symptoms may fluctuate in a manner similar to motor symptoms.

Objectives: To validate a final version of a patient-rated questionnaire that captures the presence and severity of non-motor fluctuations in levodopa-treated PD patients (NoMoFA).

Methods: We recruited PD subjects from five movement disorders centers across the US and Canada.

Atlas-independent, N-of-1 tissue activation modeling to map optimal regions of subthalamic deep brain stimulation for Parkinson disease.

Background: Motor outcomes after subthalamic deep brain stimulation (STN DBS) for Parkinson disease (PD) vary considerably among patients and strongly depend on stimulation location. The objective of this retrospective study was to map the regions of optimal STN DBS for PD using an atlas-independent, fully individualized (N-of-1) tissue activation modeling approach and to assess the relationship between patient-level therapeutic volumes of tissue activation (VTAs) and motor improvement.

Methods: The stimulation-induced electric field for 40 PD patients treated with bilateral STN DBS was modeled using finite element analysis.

Psychedelic-assisted therapy for functional neurological disorders: A theoretical framework and review of prior reports.

Functional neurological disorders (FNDs), which are sometimes also referred to as psychogenic neurological disorders or conversion disorder, are common disabling neuropsychiatric disorders with limited treatment options. FNDs can present with sensory and/or motor symptoms, and, though they may mimic other neurological conditions, they are thought to occur via mechanisms other than those related to identifiable structural neuropathology and, in many cases, appear to be triggered and sustained by recognizable psychological factors. There is intriguing preliminary evidence to support the use of psychedelic-assisted therapy in a growing number of psychiatric illnesses, including FNDs.

The impact of dispositional optimism and depression on post-operative motor functioning following deep brain stimulation surgery for Parkinson's disease.

Introduction: The primary goal of subthalamic nucleus (STN) deep brain stimulation (DBS) for Parkinson's disease (PD) is to improve motor function. Dispositional optimism has been associated with better physical outcomes following a rehabilitation program in PD but has not been investigated in relation to STN-DBS. This study investigated the influence of dispositional optimism on motor outcomes following STN-DBS in individuals with PD.

Localization of motor and verbal fluency effects in subthalamic DBS for Parkinson's disease.

Introduction: Subthalamic nucleus deep brain stimulation (STN DBS) improves cardinal motor symptoms of Parkinson's disease (PD) but can worsen verbal fluency (VF). An optimal site of stimulation for overall motor improvement has been previously identified using an atlas-independent, fully individualized, field-modeling approach. This study examines if cardinal motor components (bradykinesia, tremor, and rigidity) share this identified optimal improvement site and if there is co-localization with a site that worsens VF.

Correspondence of optimal stimulation and beta power varies regionally in STN DBS for Parkinson disease.

Introduction: Subthalamic nucleus deep brain stimulation (STN DBS) for Parkinson disease (PD) normalizes neuronal hypersynchrony in the beta frequency range (13-30 Hz). The spatial correspondence of maximal beta power to the site of optimal stimulation along the DBS lead trajectory has been debated.

Methods: We determined the trajectory locations of the active contact, maximal beta power, and the dorsal border of the STN (DB-STN) in DBS patients.

Responsiveness to change over time and test-retest reliability of the PROMIS and Neuro-QoL mental health measures in persons with Huntington disease (HD).

Background: The majority of persons with Huntington disease (HD) experience mental health symptoms. Patient-reported outcome (PRO) measures are capable of capturing unobservable behaviors and feelings relating to mental health. The current study aimed to test the reliability and responsiveness to self-reported and clinician-rated change over time of Neuro-QoL and PROMIS mental health PROs over the course of a 24-month period.

Parkinson disease with mild cognitive impairment: Domain-specific cognitive complaints predict dementia.

Background: The presence of subjective cognitive complaints (SCC) as a predictor of cognitive impairment in Parkinson´s disease (PD) has shown conflicting results. Most previous studies only assessed complaints in the memory domain. We investigate the association of SCCs across cognitive domains with development of mild cognitive impairment (PD-MCI) and dementia (PDD) in PD and to assess agreement between SCCs and objective cognitive impairments in this population.