Factors influencing the outcome of deep brain stimulation: Placebo, nocebo, lessebo, and lesion effects.

Deep brain stimulation (DBS) is a well-established treatment option for movement disorders, especially for Parkinson's disease (PD). There is a need to determine the role of expectation of benefit and the use of placebo to better understand the effects of electrode placement including the (micro)lesion effect. These factors must be understood to better interpret and attribute the therapeutic value of DBS.

The relationship between balance confidence and control in individuals with Parkinson's disease.

Introduction: A broad range of subjective and objective assessments have been used to assess balance confidence and balance control in persons with Parkinson's disease (PD). However, little is known about the relationship between self-perceived balance confidence and actual balance control in PD. The purpose of this investigation was to determine the relationship between self-perceived balance confidence and objectively measured static/dynamic balance control abilities.

A Review and Update on Tourette Syndrome: Where Is the Field Headed?

Tourette syndrome (TS) is a childhood onset neurologic disorder with manifestations including multiple motor and phonic tics, and in most cases a variety of behavioral comorbidities such as attention deficit hyperactivity disorder, obsessive compulsive disorder, and other impulse control disorders. Although it is considered a hereditary disorder, likely modified by environmental factors, genetic studies have yet to uncover relevant causative genes and there is no animal model that mimics the broad clinical phenomenology of TS. There has been a marked increase in the number of neurophysiological, neuroimaging, and other studies on TS.

Tractography Activation Patterns in Dorsolateral Prefrontal Cortex Suggest Better Clinical Responses in OCD DBS.

Background: Medication resistant obsessive-compulsive disorder (OCD) patients can be successfully treated with Deep Brain Stimulation (DBS) which targets the anterior limb of the internal capsule (ALIC) and the nucleus accumbens (NA). Growing evidence suggests that in patients who respond to DBS, axonal fiber bundles surrounding the electrode are activated, but it is currently unknown which discrete pathways are critical for optimal benefit. Our aim was to identify axonal pathways mediating clinical effects of ALIC-NA DBS.

Mood Differences Among Parkinson's Disease Patients With Mild Cognitive Impairment.

Studies with healthy elderly adults suggest that apathy, depression, and anxiety are more common among individuals with mild cognitive impairment (MCI). This study examined differences in mood/amotivational symptoms among patients with Parkinson's disease (PD) with and without MCI. Patients with PD (N=214) underwent neurocognitive evaluations including assessment of apathy (Apathy Scale), depression (Beck Depression Inventory-II), and trait anxiety (State-Trait Anxiety Inventory trait scale).

Repetitive finger movement performance differs among Parkinson's disease, Progressive Supranuclear Palsy, and spinocerebellar ataxia.

Background: Differentiating movement disorders is critical for appropriate treatment, prognosis, and for clinical trials. In clinical trials this is especially important as effects can be diluted by inclusion of inappropriately diagnosed participants. In early disease duration phases, disorders often have overlapping clinical features, such as impairments in repetitive finger movement, making diagnosis challenging.

Gray and White Matter Contributions to Cognitive Frontostriatal Deficits in Non-Demented Parkinson's Disease.

Objective: This prospective investigation examined: 1) processing speed and working memory relative to other cognitive domains in non-demented medically managed idiopathic Parkinson's disease, and 2) the predictive role of cortical/subcortical gray thickness/volume and white matter fractional anisotropy on processing speed and working memory.

Methods: Participants completed a neuropsychological protocol, Unified Parkinson's Disease Rating Scale, brain MRI, and fasting blood draw to rule out vascular contributors. Within group a priori anatomical contributors included bilateral frontal thickness, caudate nuclei volume, and prefrontal white matter fractional anisotropy.

Impact of an Interdisciplinary Deep Brain Stimulation Screening Model on Post-Surgical Complications in Essential Tremor Patients.

Objective: To investigate the relationship of our interdisciplinary screening process on post-operative unintended hospitalizations and quality of life.

Background: There are currently no standardized criteria for selection of appropriate Deep Brain Stimulation candidates and little hard data exists to support the use of any singular method.

Methods: An Essential Tremor cohort was selected from our institutional Deep Brain Stimulation database.

Free-water imaging in Parkinson's disease and atypical parkinsonism.

Conventional single tensor diffusion analysis models have provided mixed findings in the substantia nigra of Parkinson's disease, but recent work using a bi-tensor analysis model has shown more promising results. Using a bi-tensor model, free-water values were found to be increased in the posterior substantia nigra of Parkinson's disease compared with controls at a single site and in a multi-site cohort. Further, free-water increased longitudinally over 1 year in the posterior substantia nigra of Parkinson's disease.

Memory Similarities Between Essential Tremor and Parkinson's Disease: A Final Common Pathway?

Objective: A growing body of literature supports the view that essential tremor (ET) involves alteration of cerebellar-thalamo-cortical networks which can result in working memory and executive deficits. In this study, we tested the hypothesis that individuals with ET would exhibit worse performance on memory tasks requiring more intrinsic organization and structuring (i.e.

Orthopedic Surgery and Post-Operative Cognitive Decline in Idiopathic Parkinson's Disease: Considerations from a Pilot Study.

Background: Post-operative cognitive dysfunction (POCD) demarks cognitive decline after major surgery but has been studied to date in "healthy" adults. Although individuals with neurodegenerative disorders such as Parkinson's disease (PD) commonly undergo elective surgery, these individuals have yet to be prospectively followed despite hypotheses of increased POCD risk.

Objective: To conduct a pilot study examining cognitive change pre-post elective orthopedic surgery for PD relative to surgery and non-surgery peers.

Motivational engagement in Parkinson's disease: Preparation for motivated action.

The current study investigated whether motivational dysfunction in Parkinson's patients is related to a deficit in preparing for motivated behavior. Based on previous studies, it was hypothesized that PD patients would show reduced preparation for action specifically when faced with threat (of loss) and that reduced action preparation would relate to self-report of apathy symptoms. The study measured an electrocortical correlate of preparation for action (CNV amplitude) in PD patients and healthy controls, as well as defensive and appetitive activation during emotional perception (LPP amplitude).

Association of Parkinson disease age of onset with DRD2, DRD3 and GRIN2B polymorphisms.

Introduction: Dopamine and glutamate are crucial neurotransmitters in Parkinson disease (PD). While recent large meta-analyses reported that genetic variation of dopamine (DRD2, DRD3) and glutamine (NMDA, GRIN2B) neurotransmitter receptors was not associated with PD risk, they could conceivably influence PD phenotype. We studied the association of these receptor polymorphisms relating to PD age of onset.

The Subthalamic Nucleus, Limbic Function, and Impulse Control.

It has been well documented that deep brain stimulation (DBS) of the subthalamic nucleus (STN) to address some of the disabling motor symptoms of Parkinson's disease (PD) can evoke unintended effects, especially on non-motor behavior. This observation has catalyzed more than a decade of research concentrated on establishing trends and identifying potential mechanisms for these non-motor effects. While many issues remain unresolved, the collective result of many research studies and clinical observations has been a general recognition of the role of the STN in mediating limbic function.

Association between antidepressants and falls in Parkinson's disease.

Parkinson's disease (PD) patients have an increased risk of falls resulting in important social and economical consequences. Risk factors for falls include the use of psychotropic drugs, which are used for the treatment of PD neuropsychiatric symptoms. We aimed to determine the association between psychotropic drug use and falls in a PD cohort.

A Polysomnographic Study of Parkinson's Disease Sleep Architecture.

Sleep disturbance is a common nonmotor phenomenon in Parkinson's disease (PD) affecting patient's quality of life. In this study, we examined the association between clinical characteristics with sleep disorders and sleep architecture patterns in a PD cohort. Patients underwent a standardized polysomnography study (PSG) in their "on medication" state.

Deep Brain Stimulation in a Case of Mitochondrial Disease.

Background: DBS has proven to be an effective therapy for Parkinson's disease, essential tremor, and primary dystonia. Mixed results have been reported in case series for other hyperkinetic disorders, and sparse data are available regarding secondary movement disorders. We report on the clinical effects of bilateral globus pallidus internus (GPi) DBS, a progressive mitochondrial cytopathy.

The treatment of gastroparesis, constipation and small intestinal bacterial overgrowth syndrome in patients with Parkinson's disease.

Introduction: Parkinson's disease (PD) affects the nerves of the entire gastrointestinal (GI) tract and may result in profound gastrointestinal (GI) dysfunction leading to poor patient outcomes. Common GI disturbances in patients with PD include gastroparesis (GP), constipation and small intestinal bacterial overgrowth syndrome (SIBO). In particular, GP is difficult to treat due to the limited options available and precautions, contraindications and adverse effects associated with the approved treatments.

Cystic Lesions as a Rare Complication of Deep Brain Stimulation.

DBS is a typically well-tolerated operation for treatment of Parkinson's disease, dystonia, and essential tremor (ET). Complications related to the surgical procedure and implanted hardware may occur. More commonly reported complications include hemorrhage, seizure, confusion, and infection.

Repetitive Transcranial Magnetic Stimulation (rTMS) Therapy in Parkinson Disease: A Meta-Analysis.

Objective: Several studies have reported repetitive transcranial magnetic stimulation (rTMS) therapy as an effective treatment for the control of motor symptoms in Parkinson disease. The objective of the study is to quantify the overall efficacy of this treatment.

Types: Systematic review and meta-analysis.

Novel targets and stimulation paradigms for deep brain stimulation.

Deep brain stimulation (DBS) is an accepted therapy for appropriately selected patients with movement disorders and psychiatric disease. The recent advances in lead technology and the advent of novel stimulation parameters have spurred a number of improvements that will likely be implemented in the clinical setting. Although the mechanisms and biology of DBS remain poorly understood, the progress in our understanding of network level dysfunction has driven the introduction of a variety of new targets and approaches to the treatment of human disease.

Capturing patients' experiences to change Parkinson's disease care delivery: a multicenter study.

Capturing patients' perspectives has become an essential part of a quality of care assessment. The patient centeredness questionnaire for PD (PCQ-PD) has been validated in The Netherlands as an instrument to measure patients' experiences. This study aims to assess the level of patient centeredness in North American Parkinson centers and to demonstrate the PCQ-PD's potential as a quality improvement instrument.

Update on deep brain stimulation in Parkinson's disease.

Deep brain stimulation (DBS) is considered a safe and well tolerated surgical procedure to alleviate Parkinson's disease (PD) and other movement disorders symptoms along with some psychiatric conditions. Over the last few decades DBS has been shown to provide remarkable therapeutic effect on carefully selected patients. Although its precise mechanism of action is still unknown, DBS improves motor functions and therefore quality of life.

Temporal Lobe and Frontal-Subcortical Dissociations in Non-Demented Parkinson's Disease with Verbal Memory Impairment.

Objective: The current investigation examined verbal memory in idiopathic non-dementia Parkinson's disease and the significance of the left entorhinal cortex and left entorhinal-retrosplenial region connections (via temporal cingulum) on memory impairment in Parkinson's disease.

Methods: Forty non-demented Parkinson's disease patients and forty non-Parkinson's disease controls completed two verbal memory tests--a wordlist measure (Philadelphia repeatable Verbal Memory Test) and a story measure (Logical Memory). All participants received T1-weighted and diffusion magnetic resonance imaging (3T; Siemens) sequences.

Distinct patterns of brain activity in progressive supranuclear palsy and Parkinson's disease.

The basal ganglia-thalamo-cortical and cerebello-thalamo-cortical circuits are important for motor control. Whether their functioning is affected in a similar or different way by progressive supranuclear palsy (PSP) and Parkinson's disease (PD) is not clear. A functional magnetic resonance imaging (fMRI) force production paradigm and voxel-based morphometry were used to assess differences in brain activity and macrostructural volumes between PSP, PD, and healthy age-matched controls.