Genetics Underlies Differences in Parkinson’s Disease Progression

MedicalResearch.com Interview with:

Rachel Saunders-Pullman, MD, MPH Associate Professor of Neurology Icahn School of Medicine at Mount Sinai Chief, Movement Disorders, Mount Sinai Beth Israel Co-Director Clinical/Translational Research and Research Mentoring Movement Disorders, Department of Neurology, Mount Sinai Beth Israel New York, NY 10003

Dr. Saunders-Pullman

Rachel Saunders-Pullman, MD, MPH
Associate Professor of Neurology
Icahn School of Medicine at Mount Sinai
Chief, Movement Disorders, Mount Sinai Beth Israel
Co-Director Clinical/Translational Research and Research Mentoring
Movement Disorders, Department of Neurology,
Mount Sinai Beth Israel
New York, NY 10003

MedicalResearch.com: What is the background for this study? What are the main findings? 

Response: There is a diversity in causes of Parkinson’s Disease (PD), and this may lead to heterogeneity in drug response. While LRRK2 PD due to G2019S mutations may fully mimic idiopathic PD (IPD), cross-sectional study suggests that the course may be slightly milder than IPD. Further, the pathology is heterogeneous with a minority not demonstrating Lewy bodies, and this may also correspond to less severe non-motor features.

To better understand the course of PD associated with the G2019S LRRK2 mutation (the most common LRRK2 mutation), we evaluated motor and cognitive progression in individuals enrolled in the LRRK2 Ashkenazi Jewish Consortium. Subjects were recruited from a Center in Tel Aviv, Israel, Sourasky Medical Center, and from two centers in New York, Columbia University and Mount Sinai Beth Israel. 144 participants were LRRK2 mutation carriers and 401 were not. We utilized all study visits, and constructed linear mixed-effects models to estimate the association between harboring the LRRK2 mutation and rate of change of both motor features- as assessed by the Unified Parkinson’s Disease Rating Scale (UPDRS), and cognition, as measured by the Montreal Cognitive Assessment Scale (MoCA). Models adjusted for sex, site, age, disease duration and (for the motor models) cognitive score.

We found a small but significant difference in rate of progression, with LRRK2 PD progressing at 0.69 points/year, and IPD at 1.06 points/year. While the cognitive decline was also less in the LRRK2 PD (-0.10 vs. -0.19 in the IPD, this difference was not statistically different (p=0.08).

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Study Finds Modest Survival Increase in Parkinson’s Patients Who Receive Deep Brain Stimulation

MedicalResearch.com Interview with:
Dr. Frances M. Weaver PhD
Hines VA Hospital
Center of Innovation for Complex Chronic Healthcare
Hines, IL 60141

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Research has shown that deep brain stimulation (DBS) for Parkinson’s disease (PD) improves motor function and this improvement is sustained. There is also improvement in quality of life after DBS. However, it is not known whether DBS also effects survival. A few studies that have examined survival have had mixed results.

In the current study we compared survival for a large cohort of persons with Parkinson’s disease who underwent DBS to a match group of persons with PD who were managed medically.

We found a modest improvement in survival for persons with Parkinson’s disease who underwent DBS compared to individuals who did not.

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Tapeworm Drug May Be Repurposed To Fight Parkinson’s Disease

MedicalResearch.com Interview with:

Dr. Youcef Mehellou PhD Lecturer in Medicinal Chemistry Cardiff School of Pharmacy and Pharmaceutical Sciences Cardiff University

Dr. Mehellou

Dr. Youcef Mehellou PhD
Lecturer in Medicinal Chemistry
Cardiff School of Pharmacy and Pharmaceutical Sciences
Cardiff University

MedicalResearch.com: What is the background for this study?

Response: Over the last decade or two, there has been many reports linking genetic mutations to the pathogenesis of Parkinson’s disease (PD). Among the proteins that have been found to be mutated in PD is a protein called PINK1. Indeed, PINK1 mutations that disturb its function in cells were found to be causal of PD in humans. Subsequent studies showed that PINK1 is a major player in maintaining healthy neurons. This is because it is one of the components involved in controlling the quality of the mitochondria, an organelle within the cell, and it does this by triggering the disposal of unhealthy mitochondria. Overall, studies into PINK1 indicated that the activation of PINK1 as a plausible strategy for maintaining health neurons and hence slowing down the development and progress of Parkinson’s disease.

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Diabetes Medication Exenatide Shows Promise In Treating Parkinson’s Disease

MedicalResearch.com Interview with:
Dr Dilan Athauda MRCP
Sobell Department of Motor Neuroscience and Movement Disorders
UCL Institute of Neurology & The National Hospital for Neurology and Neurosurgery
London

MedicalResearch.com: What is the background for this study?

Response: Exenatide is a synthetic version of a naturally occurring protein – exendin-4 – that was originally discovered by Dr John Eng in the early 1990’s in the saliva of the Gila Monster, a venomous lizard native to the Southwestern United states. He and his team were looking for bio-active peptides in insect and lizard venom that could be useful for people with Type 2 diabetes. They discovered that exendin-4 was extremely similar to a human hormone called Glucagon-like peptide-1 (GLP-1).  In humans, GLP-1 is secreted after you eat a meal to stimulate insulin secretion (and inhibit glucagon production) of which the end result is a lowering of blood sugar. Unfortunately human GLP-1 is rapidly broken down by a circulating enzyme called dipeptidyl peptidase IV (DPP-IV) and its effects only last minutes.

Importantly, it was discovered that exendin-4 is naturally resistant to the actions of this enzyme, meaning it’s effects on blood sugar control lasts much longer in the body.  These properties made it very attractive to people trying to treat people with Type 2 diabetes and following many successful randomised controlled trials of patients with Type 2 diabetes in 2005, exenatide was approved for use as a treatment.  During this time, work led by Nigel Greig’s group at the NIA showed that first evidence that exendin-4 had neuroprotective properties, and could protect neurons from a variety of stresses and could also improve growth and rescue degenerating cells. Over the next few years, various groups used exendin-4 in a variety of animal toxin models of Parkinson’s disease and showed that exendin-4 could halt the progression of Parkinsonism and prevent cell death in these models through beneficial effects on inflammation, mitochondrial function and cell survival.

Based on this encouraging pre-clinical data, Professor Foltynie supervised the first small, “open-label”, human trial of exenatide in patients with Parkinson’s disease.  The team found that patients treated with exenatide for 1 year (in addition to their usual medication) had less decline in their motor symptoms when assessed without their medication compared to the control group (just on their usual medication) and this advantage over the control group was still present 1 year after stopping the exenatide injections.  However, this trial was open-label – patients knew they were getting a (potentially beneficial) experimental therapy and so we couldn’t exclude the fact that placebo effects were explaining some of the results we saw.

As a result of the potentially beneficial results seen in this small open label trial we carried out a double-blind, placebo controlled trial.

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Extended-Release Amantadine Reduces Dyskinesia in Parkinson’s Disease

MedicalResearch.com Interview with:
Rajesh Pahwa MD
Department of Neurology
University of Kansas Medical Center, Kansas City, KS,

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Dyskinesia are one of the major unmet needs in Parkinson Disease patients. At the present time there are no approved medication for dyskinesia, however immediate release amantadine is used in PD patients with dyskinesia. ADS-5102 is a long acting, extended release capsule formulation of amantadine HCl administered once daily at bedtime. This study investigated the safety, efficacy and tolerability of ADS-5102 in Parkinson’s disease (PD) patients with levodopa-induced dyskinesia.

This was a randomized, double-blind, placebo-controlled study of Parkinson’s disease patients with levodopa-induced dyskinesia. In total, 126 patients were randomized to placebo or 274 mg ADS-5102 administered orally at bedtime. ADS-5102 was associated with a significant reduction in dyskinesia at 12 weeks compared with placebo, as measured by the mean change in Unified Dyskinesia Rating Scale (treatment difference, –7.9; P =.0009). OFF time was significantly reduced in ADS-5102 patients compared to placebo (treatment difference -0.9 hours, p=.017).

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Vagotomy May Point To Gut Origin of Parkinson’s Disease

MedicalResearch.com Interview with:

Karin Wirdefeldt, MD, PhD</strong> Associate professor Karolinska Institutet Stockholm, Sweden

Dr. Wirdefeldt

Karin Wirdefeldt, MD, PhD
Associate professor
Karolinska Institutet
Stockholm, Sweden

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: It has been hypothesized that Parkinson’s disease may start in the gut and spread to the brain via the vagal nerve. We found that people who had a truncal vagotomy (ie, the nerve trunk fully resected) at least 5 years earlier were less likely to develop Parkinson’s disease compared to people without vagotomy or people who had a selective vagotomy (ie, only branches of the nerve resected).

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Parkinson’s Disease Linked To Increase in Number of Inflammatory Markers

MedicalResearch.com Interview with:

Yong Cheng, PhD, post-doc fellow Section on Cellular Neurobiology Eunice Kennedy Shriver National Institute of Child Health and Human Development National Institutes of Health Bethesda, Maryland

Dr. Yong Cheng

Yong Cheng, PhD, post-doc fellow
Section on Cellular Neurobiology
Eunice Kennedy Shriver National Institute of Child Health and Human Development
National Institutes of Health
Bethesda, Maryland

MedicalResearch.com: What is the background for this study?

Response: Parkinson’s disease is the second most neurodegenerative disease after Alzheimer’s disease. The symptoms of the disease are typically movement related. However, the nonmotor features in PD are increasingly recognized. Evidence suggests that inflammation may play a role in the development of AD, and a substantial number of studies have demonstrated altered levels of peripheral blood inflammatory cytokines in patients with  Parkinson’s disease, but findings have been inconsistent for individual cytokines and between studies. Therefore, we undertook a systematic review of the scientific literature, using a meta-analysis to quantitatively summarize clinical data on blood cytokine levels in patients with PD, compared with healthy controls.

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Promising Study Evaluates Chemotherapy for Parkinson’s and Lewy Body Dementia

MedicalResearch.com Interview with:

Charbel Moussa MD. PhD Assistant Professor of Neurology Director- Laboratory for Dementia and Parkinsonism Clinical Research Director- National Parkinson's Foundation Center for Excellence Translational Neurotherapeutics Program Department of Neurology Georgetown University Medical Center Washington DC.

Dr. Charbel Moussa

Charbel Moussa MD. PhD
Assistant Professor of Neurology
Director- Laboratory for Dementia and Parkinsonism
Clinical Research Director- National Parkinson’s Foundation Center for Excellence
Translational Neurotherapeutics Program
Department of Neurology
Georgetown University Medical Center
Washington DC.

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: We conducted a pilot open label proof-of-concept study to evaluate the safety and tolerability of Nilotinib in participants with advanced Parkinson’s disease (PD) with dementia (PDD) or dementia with Lewy bodies (DLB). Our primary objective is to demonstrate that low oral daily doses of 150mg or 300mg Nilotinib (compared to 600-800mg in cancer) are safe and tolerated.

Our secondary objectives are that Nilotinib will cross the blood brain barier and may inhibit cerebral spinal fluid Abl. Based on preclinical data we also hypothesized that Nilotinib will increase DA levels. Motor and cognitive functions were also measured as exploratory clinical outcomes. Other exploratory outcomes are that Nilotinib may alter PD-related CSF biomarkers DJ-1 and α-synuclein. As most participants in this study had dementia we also explored the effects of Nilotinib on Alzheimer’s Disease-related CSF biomarkers, including Aβ40 and Aβ42, total tau and phosphorylated tau (p-tau).

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No Increased Risk of Parkinson’s From MRI Gadolinium Exposure

MedicalResearch.com Interview with:

Blayne Welk, MD, MSc,FRCSC Assistant Professor of Surgery Western University London, Canada

Dr. Blayne Welk

Blayne Welk, MD, MSc,FRCSC
Assistant Professor of Surgery
Western University
London, Canada

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Prior research has demonstrated that gadolinium, which may be used during MRI scans to help visualise the body organs, can be deposited in the body, and remain there for years. The US FDA released a notice last year stating that further research was needed to evaluate the clinical implications of these brain deposits. One of the areas that gadolinium is deposited is the brain, specifically in two regions which control voluntary movement (the globus pallidus and dentate nucleus). Damage to these areas could cause symptoms of Parkinsonism. We used administrative data from Ontario, Canada to evaluate whether people who underwent MRI scans with gadolinium had a higher risk of developing Parkinsonism in the future. In this study, we did not demonstrate an increased risk of Parkinsonism in patients exposed to gadolinium.

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Hip Fractures and Falls Increase Years Before Parkinson’s disease Diagnosed

MedicalResearch.com Interview with:

Helena Nyström MD, PhD Candidate Department of Community Medicine and Rehabilitation Umeå University Umeå, Sweden

Helena Nyström

Helena Nyström MD, PhD Candidate
Department of Community Medicine and Rehabilitation
Umeå University
Umeå, Sweden

Medical Research: What is the background for this study?

Response: Parkinson’s disease (PD) has an insidious onset and the prodromal phase, preceding the onset of the characteristic PD symptoms, may last for decades. Most prodromal signs previously reported are of non-motor type, such as sleep and mood disorders. However, recent studies have reported balance problems and an increased risk of accidental injuries in the last 3-5 years before diagnosis of Parkinson’s disease , and in a previous study we found a lower muscle strength at military conscription in men who were diagnosed with  Parkinson’s disease three decades later. In this study, we aimed to investigate if such subtle strength deficits may translate into an increased risk of fall-related injuries.

Medical Research: What are the main findings?

Response: The median study time was 20 years before the diagnosis of  Parkinson’s disease , and during this time more individuals with PD (18%) than controls (11.5%) had at least one fall-related injury. The risk was most increased in the last few years before the diagnosis of  Parkinson’s disease , but a difference between the groups appeared already a decade before the PD diagnosis. The risk of hip fracture was increased during the entire study time of 26 years before the diagnosis of Parkinson’s disease .

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