Presence Hallucination in Parkinson's Disease

Study Overview
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Brief Summary
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Investigation on how robotically mediated sensorimotor stimulation induces and triggers presence hallucinations in patients with Parkinson disease

Detailed Description
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Parkinson's Disease (PD) is primarily known and characterized by motor symptoms such as tremor, rigidity and bradykinesia. However, a significant number of non-motor symptoms also accompany the unfolding of this disease. In fact, hallucinations are experienced by approximately 60% of the patients. The most common and amongst one of the earliest hallucinations in Parkinson's Disease, is the Presence Hallucination (PH), i.e., the strange sensation of perceiving someone behind when no one is actually there. In the present study the researchers aim at investigating the behavioural and neural mechanisms underlying symptomatic PH in PD. To do so the researchers intend to induce the PH in a repeated and controlled manner in the MRI scanner, with an extensively verified paradigm which gives rise to this sensation by means of robotically-mediated sensorimotor stimulation. This setup has in fact been shown to trigger the occurrence of symptomatic PH in these patients. The possibility to induce PH while the patient is in the MRI will allow the researchers to investigate online the brain networks associated with it. With analysis on the fine brain connectivity changes during PH-induction, the investigators intend to pinpoint the exact mechanism behind the appearance of this hallucination in these patients, in a similar fashion to previous work with the PH-induction in healthy individuals.

Official Title
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Unravelling Dysfunctional Brain Networks in Patients With Parkinson's Disease Suffering From Presence Hallucination

Conditions
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Parkinson Disease Psychosis

Intervention / Treatment
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* Other: Brain changes triggered by PH induction in Parkinson's disease patients with presence hallucinations


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diagnosed with Parkinson's disease Able to understand instructions and provide informed consent. Native speaking language of experimental site (or acquisition of language of experimental site before 6 years old). Montreal Cognitive Assessment (Nasreddine & Patel, 2016) with score ≥ 22. Able to manipulate the robotic device. Exclusion Criteria: Neurological comorbidities other than Parkinson's disease (e.g. Alzheimer's disease, vascular dementia, multiple sclerosis, stroke, traumatic brain injury, epilepsy, chronic migraine, etc.) History or current condition of substance abuse and/or dependence (e.g., alcohol, drugs). Suffering from or diagnosed with psychiatric illnesses according to DSM-V criteria (e.g., schizophrenia, bipolar disorders, autism, personality disorders, phobia etc.). Family history (1st and 2nd degree) of psychiatric disorders (e.g., schizophrenia or bipolar disorders). Severe somatic illnesses (e.g., cancer). Severe tremors or physical disability preventing optimal use of robotic device. Participating in a pharmacological study. Local or general anaesthesia 30 days prior experiment Inability to provide informed consent (legal guardianship) The following are due to the MRI scanner: body weight exceeding 160kg, implanted metallic devices, foreign metallic objects, unstable angina, cardio-vascular diseases, tattoos with metallic components, external metallic objects, claustrophobia, pregnancy.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Brain changes triggered by PH induction in Parkinson's disease<br>Clinical and neuropsychological evaluations + Sensorimotor task for PH-induction | Other: Brain changes triggered by PH induction in Parkinson's disease patients with presence hallucinations<br>* Parkinsonian patients will undergo a two distinct experimental sessions, conducted in two separate days. In day 1, they will complete a series of validated and lab-tailored clinical evaluations, alongside with semi-structured interviews. These tests are designed to assess, the extent of the movement disorder, the predominance of positive symptoms and presence hallucination, potential cognitive impairment, amongst other relevant measures, for sleep assessment, loneliness, apathy and depression. In day 2 patients will perform the described robotic manipulation task in the MRI.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| fMRI bold signal response during robotic manipulation | Analysis of changes of BOLD activity during the asynchronous condition as compared to the synchronous condition | Approximately 45 minutes during each participant's experimental session in arm 1 | 
| Sensitivity to the induction bodily illusions of Presence Hallucination, Passivity experiences, loss of agency, and control questions, through lab-tailored questionnaires (7-point Likert-scale) | Note that for the assessment of the sensitivity of each patient to the induction of the presence hallucination, passivity sensations, loss of agency, and control questions, the patients will perform two manipulations with the robotic system described in the introduction, in both the synchronous and asynchronous conditions | Approximately 5 minutes at the end of each participant's experimental session in arm 1 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Parkinson, fMRI, connectivity, hallucinations, psychosis, presence hallucination