Common Noradrenergic Mechanisms in Parkinson´s Disease and L-DOPA Induced Dyskinesia (NORAPARK)

October 15, 2015 updated by: Adjmal Nahimi, Aarhus University Hospital

Common Noradrenergic Mechanisms in Parkinson´s Disease and L-DOPA Induced Dyskinesia and Healthy Age Matched Controls; [11C]Yohimbine and [11C]MeNER PET

The aims of this proposal include tests of hypotheses of the pathogenetic mechanisms of noradrenergic neurotransmission in Parkinson's disease in vivo, using positron emission tomography of patients with early and advanced Parkinson's disease with or without 3,4 L-dihydroxyphenylalanine (L-DOPA) - induced dyskinesia or co-morbid depression, and evaluation of whether these mechanisms can be influenced therapeutically.

Hypotheses:

  1. The investigators argue that release in human cortical and subcortical brain regions of norepinephrine (NE) derived from metabolism of exogenousL-DOPA is greater in Parkinson's disease patients with L-DOPA- induced dyskinesia than in patients without this complication. This hypothesis will be tested by measuring antagonist [11C]yohimbine binding to alpha-2 adrenoceptors before and after L-DOPA challenge.
  2. If so, it is argued that the greater rise of norepinephrine, measured as [11C]yohimbine displacement after L-DOPA challenge, is the result of down-regulation or loss of norepinephrine transporters. This hypothesis will be tested by measuring the binding of [11C]MeNER, a tracer of norepinephrine transporters.
  3. If so, the investigators argue that the greater decline of [11C]MeNER binding is significantly correlated to the symptoms of Parkinson's disease, as proof that patients with more severe loss of noradrenergic terminals exhibit more severe motor deficits.

Study Overview

Status

Unknown

Intervention / Treatment

Detailed Description

Introduction: The major source of NE in the central nervous system (CNS) is the locus coeruleus (LC), which sends projections to virtually all parts of the CNS, integrating cognitive and autonomic functions with the state of arousal (Sara SJ 2009).

With the onset of pathogenesis of PD in the lower brainstem, early symptoms of PD that include sleep disorder, cognitive deficits, and autonomic dysfunction, may appear prior to the motor symptoms of PD, and these symptoms have been linked to the degeneration of the LC and subsequent loss of noradrenergic innervations in the peripheral and central nervous systems (Rascol et al., 2009, Hawkes et al., 2010, Braak et al., 2003).

The loss of neurons in the LC exceeds that of the substantia nigra in some studies (Zarow et al. 2003), in which it is also argued that the loss may be related to the symptoms of endogenous depression in 40% of patients with PD. In these patients, the severity of motor symptoms also may be aggravated by loss of NE as release of dopamine (DA) and firing of dopaminergic neurons normally are both facilitated by activation of noradrenergic neurons.

Lesion of the LC and the subsequent loss of this facilitation reduces nigrostriatal DA release. Similarly, lesions to both dopaminergic and noradrenergic neurons induce more severe motor deficits, compared to lesions of dopaminergic neurons alone (Mavridis M et al., 1999). This relation suggests direct and indirect roles for NE in the emergence and severity of both motor and non-motor symptoms in PD, including depression.

The effects of NE are mediated by stimulation of the three receptor subtypes alpha-1, alpha-2, and ß. In the proposed studies, the investigators focus on alpha-2 and ß-receptors. Of the alpha-2 receptors, the alpha2C subtype is densely expressed in structures of the basal ganglia and therefore may mediate the direct effects of alpha-2 receptors on motor behavior.

However, in contrast to the possible beneficial effects of NE receptor activation in some brain regions, non-physiological increases of NE, after L- DOPA administration, may elicit dyskinesia (Buck et al., 2010) while fluctuations of NE concentration in other regions may contribute to generation of symptoms of depression (Zarow et al. 2003). Thus, several lines of evidence suggest that loss of NE may have direct and indirect roles in the appearance and severity of both motor and non-motor symptoms of PD and in LIDs.

Background:

Noradrenergic treatment of PD: The initial relief from symptoms of PD offered by DA agonist therapy is complicated by the manifestation of motor fluctuations, dyskinesia and psychiatric side effects following chronic treatment (Ahlskog et al., 2001, Fox et al., 2008).

The efficacy of conventional DA agonist therapy to reduce motor symptoms in PD is related to its ability to restore lost dopaminergic innervations. However, recent evidence suggests that activation of non- dopaminergic transmitter systems, including the noradrenergic system may play an important role in mediating the anti-parkinsonian effects of L-DOPA. L-DOPA and DA are sequential precursors of NE, and excitation of noradrenergic receptors following L-DOPA administration may contribute to the anti-parkinsonian effects of L-DOPA ( Schapira et al., 2008). Non-physiologically high release of NE derived from exogenous L-DOPA derived NE may contribute to both co-morbid depression and LID.

It further suggests that therapies that maintain L-DOPA- induced activation of NE receptors at physiological levels would reduce the severity of LID in patients. However, the underlying mechanisms of possible anti-parkinsonian and dyskinetogenic roles of NE remain unresolved. In this project, the investigators propose to identify the mechanisms through which NE conveys both beneficial and adverse effects of L-DOPA in a concerted attempt to help improve current treatment of PD by suggesting therapies that target the non-physiological L- DOPA-induced activation of the NE receptors as a potential contributor to LID.

The investigators developed and validated a novel PET tracer to be used in this project. Carbon-11 labelled yohimbine is an alpha-2 adrenoceptor antagonist and have been validated in studies with PET in pigs (Jakobsen et al., 2006, Landau et al. 2012) and approved for human use. To show that binding of [11C]yohimbine is sensitive to endogenously released NE, the investigators determined the binding before and after Vagus Nerve Stimulation in minipigs in vivo.

This group of researchers also developed the selective NET ligand, [11C]MeNER, for clinical PET studies in Denmark. Patients with PD and age-matched healthy controls will undergo PET-scans with the above-mentioned tracers to map pathological changes in noradrenergic transporters and receptors in-vivo.

Study Type

Observational

Enrollment (Anticipated)

45

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

  • Name: Michele Gammeltoft, Secretary
  • Phone Number: 0045 78461381
  • Email: michgamm@rm.dk

Study Locations

      • Aarhus C, Denmark, 8000,
        • Recruiting
        • Department of Nuclear Medicine and PET-Centre, Aarhus University Hospital
        • Contact:
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

50 years to 80 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Parkinson´s disease patients with/without L-DOPA induced dyskinesia and age-matched healthy controls.

Description

Inclusion Criteria:

  • 15 patients with PD in the age between 50 og 80, Hoehn og Yahr stage 2-3, never L-DOPA induced dyskinesia.
  • 15 patients with PD in the age between 50 og 80 år, Hoehn og Yahr stage 2-3, with established L-DOPA induced dyskinesia.
  • 15 age matched healthy controls.

Exclusion Criteria:

  • Psychiatric or neurological disease, not related to Parkinson´s disease.
  • Cancer and malignant disease.
  • Liver or kidney disease.
  • Alcohol or substance abuse.
  • Cardiac disease.
  • Treatment with antipsychotics or antiepileptics or other medications that affect the noradrenergic system. Medicines to treat Parkinson´s disease are allowed.
  • Patients treated with deep brain stimulation.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Cross-Sectional

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
PD_no_LID
Patients with Parkinson´s disease without dyskinesia
Patients and healthy controls are recruited to participate in [11C]yohimbine scans before and after L-DOPA challenge.
Other Names:
  • Sinemet
PD_LID
Patients with Parkinson´s disease with L-DOPA induced dyskinesia
Patients and healthy controls are recruited to participate in [11C]yohimbine scans before and after L-DOPA challenge.
Other Names:
  • Sinemet
HC
Health controls, age-mathced.
Patients and healthy controls are recruited to participate in [11C]yohimbine scans before and after L-DOPA challenge.
Other Names:
  • Sinemet

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Noradrenaline release
Time Frame: Up to 16 months
Quantification of noradrenaline release in patients with Parkinson´s disease and healthy controls after pretreatment with 150mg L-DOPA as evaluated with [11C]yohimbine positron. emission tomography.
Up to 16 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Noradrenaline transporters
Time Frame: Up to 16 months
Correlation of peripheral loss of noradrenaline in the heart with loss of central noradrenergic neurons in patients with Parkinson´s disease.
Up to 16 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

January 1, 2012

Primary Completion (Anticipated)

January 1, 2016

Study Completion (Anticipated)

January 1, 2016

Study Registration Dates

First Submitted

September 30, 2015

First Submitted That Met QC Criteria

October 15, 2015

First Posted (Estimate)

October 19, 2015

Study Record Updates

Last Update Posted (Estimate)

October 19, 2015

Last Update Submitted That Met QC Criteria

October 15, 2015

Last Verified

October 1, 2015

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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