Written by an AI model from ClinicalTrials.gov eligibility criteria and checked on a sample basis. Please confirm against the original criteria.

Trial NCT04477785 – Eligibility in Plain Language

This trial includes several different groups of participants. The criteria for each group are listed separately below.

Group 1: Healthy Controls (people without Parkinson's disease)

Who might be able to join this trial:

• People aged 57 or older at the time of their screening visit
• People taking certain medications (alpha methyldopa, methylphenidate, amphetamine-based medicines, or modafinil) who are willing and medically able to stop taking them for a set period before a brain scan
• People whose screening brain scan (called a SPECT scan) confirms they meet the imaging requirements for the trial
• People who are able to give their own informed consent to participate
• Women of childbearing age who are not pregnant, not breastfeeding, not planning to become pregnant during the study, and who have a negative pregnancy test before their brain scan

Who may not be able to join:

• People who have a close biological family member (parent, brother, sister, or child) diagnosed with Parkinson's disease
• People who currently have, or have a history of, a significant neurological (brain or nerve) condition, as assessed by the trial doctor
• People whose previous MRI brain scan showed signs of a significant neurological condition, in the opinion of the trial doctor
• People who have taken certain medicines — including dopamine-blocking drugs (neuroleptics), metoclopramide, or reserpine — within the 6 months before their screening visit
• People currently taking blood-thinning medicines (such as warfarin/coumadin, heparin, or oral thrombin inhibitors) that could make a spinal fluid sample (lumbar puncture) unsafe
• People who have a back or spine condition, a bleeding disorder, or a blood-clotting problem that would make a lumbar puncture unsafe
• People with any other medical or mental health condition, or abnormal test results, that the trial doctor believes would prevent safe participation
• People who the trial doctor considers unsuitable for any other reason

Group 2: People with Parkinson's Disease (PD) — no specific genetic variant required

Who might be able to join this trial:

• People aged 30 or older at the time of their screening visit
• People who received a Parkinson's disease diagnosis 2 years ago or less at the time of their screening visit
• People who are not expected to need Parkinson's medication for at least 6 months from the start of the study
• People who have at least two of the following symptoms: resting tremor, slowness of movement (bradykinesia), or muscle stiffness (rigidity) — with resting tremor or slowness of movement being required; OR people who have resting tremor or slowness of movement that is noticeably worse on one side of the body
• People whose disease is assessed by the trial doctor as being at an early stage (Hoehn and Yahr stage I or II) at the start of the study
• People taking certain medications (alpha methyldopa, methylphenidate, amphetamine-based medicines, or modafinil) who are willing and medically able to stop taking them for a set period before a brain scan
• People whose screening brain scan (SPECT scan) confirms they meet the imaging requirements for the trial
• People who are able to give their own informed consent to participate
• Women of childbearing age who are not pregnant, not breastfeeding, not planning to become pregnant during the study, and who have a negative pregnancy test before their brain scan

Who may not be able to join:

• People currently taking Parkinson's medications such as levodopa, dopamine agonists, MAO-B inhibitors, or amantadine (except low-dose use for restless leg syndrome, with approval from the trial medical monitor)
• People who have taken levodopa, dopamine agonists, MAO-B inhibitors, or amantadine within 60 days before the start of the study
• People who have taken levodopa or dopamine agonists for more than 90 days in total before the start of the study
• People whose Parkinson's-like symptoms are caused by certain medications (such as metoclopramide, flunarizine, or neuroleptics), metabolic conditions (such as Wilson's disease), brain infection (encephalitis), or other brain diseases (such as progressive supranuclear palsy)
• People who have been clinically diagnosed with dementia, as determined by the trial doctor
• People whose previous MRI brain scan showed signs of a significant neurological condition, in the opinion of the trial doctor
• People who have taken dopamine-blocking drugs (neuroleptics), metoclopramide, or reserpine within the 6 months before their screening visit
• People currently taking blood-thinning medicines (such as warfarin/coumadin, heparin, or oral thrombin inhibitors) that could make a lumbar puncture unsafe
• People who have a back or spine condition, a bleeding disorder, or a blood-clotting problem that would make a lumbar puncture unsafe
• People with any other medical or mental health condition, or abnormal test results, that the trial doctor believes would prevent safe participation
• People who the trial doctor considers unsuitable for any other reason

Group 3: People with Parkinson's Disease and an LRRK2 or GBA Gene Variant

Who might be able to join this trial:

• People aged 30 or older at the time of their screening visit
• People who received a Parkinson's disease diagnosis 2 years ago or less at the time of their screening visit
• People who have at least two of the following symptoms: resting tremor, slowness of movement (bradykinesia), or muscle stiffness (rigidity) — with resting tremor or slowness of movement being required; OR people who have resting tremor or slowness of movement that is noticeably worse on one side of the body
• People whose disease is assessed by the trial doctor as being at an early stage (Hoehn and Yahr stage I or II) at the start of the study
• People who have a confirmed LRRK2 or GBA gene variant — either through genetic testing done as part of the trial screening process, or through previously documented genetic test results that meet the trial's requirements
• People taking certain medications (alpha methyldopa, methylphenidate, amphetamine-based medicines, or modafinil) who are willing and medically able to stop taking them for a set period before a brain scan
• People whose screening brain scan (SPECT scan) confirms they meet the imaging requirements for the trial
• People who are able to give their own informed consent to participate
• Women of childbearing age who are not pregnant, not breastfeeding, not planning to become pregnant during the study, and who have a negative pregnancy test before their brain scan

Who may not be able to join:

• People who have taken dopamine-blocking drugs (neuroleptics), metoclopramide, or reserpine within the 6 months before their screening visit
• People currently taking blood-thinning medicines (such as warfarin/coumadin or heparin) that could make a lumbar puncture unsafe
• People who have a back or spine condition, a bleeding disorder, or a blood-clotting problem that would make a lumbar puncture unsafe
• People with any other medical or mental health condition, or abnormal test results, that the trial doctor believes would prevent safe participation
• People who the trial doctor considers unsuitable for any other reason

Group 4: People with Parkinson's Disease and an SNCA or Rare Genetic Variant (such as Parkin or Pink1)

Who might be able to join this trial:

• People aged 30 or older at the time of their screening visit
• People who have a Parkinson's disease diagnosis at the time of their screening visit (no time limit on how long ago the diagnosis was given, unlike other PD groups)
• People who have at least two of the following symptoms: resting tremor, slowness of movement (bradykinesia), or muscle stiffness (rigidity) — with resting tremor or slowness of movement being required; OR people who have resting tremor or slowness of movement that is noticeably worse on one side of the body
• People whose disease is assessed by the trial doctor as being at an early to moderate stage (Hoehn and Yahr stage I, II, or III) at the start of the study
• People who have a confirmed SNCA or rare gene variant (such as Parkin or Pink1) — either through genetic testing done as part of the trial screening process, or through previously documented genetic test results that meet the trial's requirements
• People taking certain medications (alpha methyldopa, methylphenidate, amphetamine-based medicines, or modafinil) who are willing and medically able to stop taking them for a set period before a brain scan
• People whose screening brain scan (SPECT scan) confirms they meet the imaging requirements for the trial
• People who are able to give their own informed consent to participate
• Women of childbearing age who are not pregnant, not breastfeeding, not planning to become pregnant during the study, and who have a negative pregnancy test before their brain scan

Who may not be able to join:

• People who have taken dopamine-blocking drugs (neuroleptics), metoclopramide, or reserpine within the 6 months before their screening visit
• People currently taking blood-thinning medicines (such as warfarin/coumadin or heparin) that could make a lumbar puncture unsafe
• People who have a back or spine condition, a bleeding disorder, or a blood-clotting problem that would make a lumbar puncture unsafe
• People with any other medical or mental health condition, or abnormal test results, that the trial doctor believes would prevent safe participation
• People who the trial doctor considers unsuitable for any other reason

Group 5: Prodromal Participants (people who may be at risk of developing Parkinson's disease but do not yet have a diagnosis)

Who might be able to join this trial:

• People who meet centrally determined risk criteria, which include results from a smell identification test (UPSIT) — for people referred from the remote part of the study (PPMI Remote), referral to the clinic confirms this eligibility; for people identified directly by the clinic, eligibility may be based on factors such as having a close biological family member with Parkinson's, having a sleep behaviour disorder linked to PD risk (RBD), or having a gene variant associated with PD risk
• People aged 60 or older (or aged 30 or older for those with an SNCA or rare genetic variant such as Parkin or Pink1)
• People taking certain medications (alpha methyldopa, methylphenidate, amphetamine-based medicines, or modafinil) who are willing and medically able to stop taking them for a set period before a brain scan
• People who are able to give their own informed consent to participate
• Women of childbearing age who are not pregnant, not breastfeeding, not planning to become pregnant during the study, and who have a negative pregnancy test before their brain scan
• People whose screening brain scan (SPECT scan) confirms they meet the imaging requirements to continue to the main part of the trial (confirm with trial site, as selection involves a detailed process based on scan results and individual risk profile)

Who may not be able to join:

• People who already have a clinical diagnosis of Parkinson's disease, another parkinsonian condition, or dementia at the time of screening
• People who have taken dopamine-blocking drugs (neuroleptics), metoclopramide, or reserpine within the 6 months before their baseline (start-of-study) visit
• People currently taking blood-thinning medicines (such as warfarin/coumadin or heparin) that could make a lumbar puncture unsafe
• People who have a back or spine condition, a bleeding disorder, or a blood-clotting problem that would make a lumbar puncture unsafe
• People with any other medical or mental health condition, or abnormal test results, that the trial doctor believes would prevent safe participation
• People currently taking Parkinson's medications such as levodopa, dopamine agonists, MAO-B inhibitors, or amantadine (except low-dose use for restless leg syndrome, with approval from the trial medical monitor)
• People who have taken levodopa, dopamine agonists, MAO-B inhibitors, or amantadine within 60 days before their baseline visit (except low-dose use for restless leg syndrome, with approval from the trial medical monitor)
• People who the trial doctor considers unsuitable for any other reason

Important: Always verify eligibility with the trial site directly before applying.