Functional magnetic resonance imaging of Parkinson*s disease patients to investigate the effects of dopamine on visual attention.

Functional magnetic resonance imaging of Parkinson*s disease patients to investigate the effects of dopamine on visual attention. - PD and the role of dopamine in visual attention

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

NL-OMON

Registry ID

NL-OMON44476

Enrollment

Registered

2015-03-10

Start date

2015-08-09

Completion date

Unknown

Last updated

2024-04-23

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Parkinson's disease

Interventions

Cognitive performance measurements of PD patients when on L-DOPA medication and during a practically-defined off-medication state (i.e. following overnight withdrawal of dopamine medication).

Eligibility

Age

18 Years to 99 Years

Inclusion criteria

Inclusion criteria: -Diagnosis of idiopathic PD following UK Brain Bank criteria in Hoehn and Yahr -40-75 years old -Informed consent -Normal/corrected-to-normal vision

Exclusion criteria

Exclusion criteria: -Psychotropic medication (controls) other than L-DOPA or DA agonists (patients). If using psychotropic medication in the past, they must be at least 4 weeks off that medication. - Major somatic disorder or psychosis - Dementia (MoCA

Design outcomes

Primary

Measure	Time frame
Using fMRI analysis, we will identify regions of interest for all patients (VTA, SNpc, basal ganglia, LOC, V1-V4). These are associated with our hypotheses regarding reward contingencies and visual processing of the stimuli displayed in the task. In these regions, the processed brain activation data will be subjected to the following group-level analyses: 1. Within-subjects analyses, in which patients are compared in the withdrawal and the medicated condition. This will be carried out with repeated-measures ANOVAs. 2. Between-subject analyses, in which controls are compared both to patients in the withdrawal state, and to patients in the medicated condition, to identify whether patients in one or the other state are closer to normal as represented by controls. Alpha levels will be corrected for multiple comparison (Bonferroni; family-wise error correction; cluster threshold; permutation analysis; as appropriate). We will carry out whole brain analysis for the resting-state scans, using our regions of interest as seeds for independent component analysis (ICA). All analyses will be done using Python, FSL, Freesurfer, and SPSS.	—

Measure

Time frame

Using fMRI analysis, we will identify regions of interest for all patients (VTA, SNpc, basal ganglia, LOC, V1-V4). These are associated with our hypotheses regarding reward contingencies and visual processing of the stimuli displayed in the task. In these regions, the processed brain activation data will be subjected to the following group-level analyses: 1. Within-subjects analyses, in which patients are compared in the withdrawal and the medicated condition. This will be carried out with repeated-measures ANOVAs. 2. Between-subject analyses, in which controls are compared both to patients in the withdrawal state, and to patients in the medicated condition, to identify whether patients in one or the other state are closer to *normal* as represented by controls. Alpha levels will be corrected for multiple comparison (Bonferroni; family-wise error correction; cluster threshold; permutation analysis; as appropriate). We will carry out whole brain analysis for the resting-state scans, using our regions of interest as seeds for independent component analysis (ICA). All analyses will be done using Python, FSL, Freesurfer, and SPSS.

—

Secondary

Measure	Time frame
We will use results from the questionnaires and neuropsychological assessment of patients and investigate if these correlate with fMRI task activity in the identified regions of interest and with fMRI resting state activity.	—

Countries

Netherlands

Outcome results

None listed

Source: NL-OMON (via WHO ICTRP)