Serotonin in Impulse Control Disorders in Parkinson's Disease

Impulse control disorders are frequent and troublesome in patients with Parkinson's disease. However, the cerebral functional alterations related to impulse control disorders in Parkinson's disease are poorly understood and may involve the serotoninergic system besides alterations in the dopaminergic system.

The primary objective of this study is to investigate the cerebral functional alterations in the serotoninergic system in patients with Parkinson's disease and impulse control disorders using Positron Emission Tomography with highly specific radiotracers of serotonin transporter (SERT) using \[11 Carbon\]-3-amino-4-(2-dimethylaminomethylphenylsulfanyl)-benzonitrile (\[11C\]-DASB) and of serotonin 5-Hydroxytryptamine 2A (5-HT2A) receptor using \[18 Fluorine\]-altanserin (\[18F\]-altanserin), in comparison to patients with Parkinson's disease without impulse control disorders and healthy volunteers.


Eligibility Criteria:
Inclusion Criteria:

Group 1 Patients with Parkinson's disease and impulse control disorders

* Patients with a diagnosis of clinically established or clinically probable Parkinson's disease according to the Movement Disorder Society (MDS) Clinical Diagnostic Criteria for Parkinson's Disease
* Patients aged ≥ 30 and ≤ 80 years old
* Patients presenting currently with impulse control disorders or having presented with impulse control disorders in the last 2 years (Ardouin Behavior Scale score ≥2 for one or more of the following items: eating behavior; compulsive buying; pathological gambling; hypersexuality) , following the diagnosis of Parkinson's disease
* Patients able to sign the consent document and willing to participate in all aspects of the study

Patients with Parkinson's disease and without impulse control disorders

* Patients with a diagnosis of clinically established or clinically probable Parkinson's disease according to the MDS Clinical Diagnostic Criteria for Parkinson's Disease
* Patients aged ≥ 30 and ≤ 80 years old
* Patients not currently presenting with impulse control disorders and other hyperdopaminergic behaviors and not having ever presented with impulse control disorders
* Patients able to sign a consent document and willing to participate in all aspects of the study

Group 2 : Healthy volunteers

Subjects aged ≥ 30 and ≤ 80 years old

* Subjects not currently presenting with impulse control disorders or hyperdopaminergic behaviors and not having ever presented with impulse control disorders
* Subjects able to sign a consent document and willing to participate in all aspects of the study

Exclusion Criteria:

Group 1 :

Patients with Parkinson's disease and impulse control disorders

* Patients with Montreal Cognitive Assessment score ≤24 or Frontal Assessment Battery score ≤14
* Patients not able to perform Positron Emission Tomography (PET) or Magnetic Resonance Imaging (MRI)
* Patients presenting with other severe medical condition or other parkinsonian syndrome
* Patients treated with Deep Brain Stimulation or levodopa pump
* Patients treated with drugs or consuming recreative drugs specifically interfering with the serotoninergic, noradrenergic or opiate systems in the last 3 months
* Patients presenting with substance dependence, except for tobacco
* Patients with Body Mass Index ≥ 35kilogram/meters2 (kg/m2)

Patients with Parkinson's disease and without impulse control disorders

* Patients with Montreal Cognitive Assessment score ≤24 or Frontal Assessment Battery score ≤14
* Patients not able to perform Positron Emission Tomography or Magnetic Resonance Imaging
* Patients presenting with other severe medical condition or other parkinsonian syndrome
* Patients treated with Deep Brain Stimulationor levodopa pump
* Patients treated with drugs or consuming recreative drugs specifically interfering with the serotoninergic, noradrenergic or opiate systems in the last 3 months
* Patients presenting with substance dependence, except for tobacco
* Patients with Body Mass Index ≥35kg/m2

Group 2 : Healthy volunteers

* Subjects with Montreal Cognitive Assessment score ≤24 or Frontal Assessment Battery score ≤14
* Subjects not able to perform Positron Emission Tomography or Magnetic Resonance Imaging
* Subjects presenting with neurologic, psychiatric or other severe medical condition
* Subjects treated with drugs or consuming recreative drugs specifically interfering with the serotoninergic, noradrenergic or opiate systems in the last 3 months
* Subjects presenting with substance dependence, except for tobacco
* Subjects with Body Mass Index ≥35kg/m2