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Open Imaging Index
MRI SPECT / nuclear medicine PET Brain

PPMI

Parkinson's Progression Markers Initiative (now Parkinson's Precision Medicine Initiative)

Longitudinal multi-site observational study of early untreated Parkinson's disease, prodromal and genetic at-risk people and healthy controls, with DaTscan SPECT, MRI including DTI, biofluids, genetics and clinical assessments shared through LONI.

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Overview

PPMI is an observational natural history study that follows people with Parkinson's disease, people at risk of it and healthy volunteers over many years to find markers of onset and progression for use in therapeutic trials. The Michael J. Fox Foundation launched it in 2010 together with academic and industry partners, and it has since been renamed the Parkinson's Precision Medicine Initiative. Clinical, imaging, biofluid, genetic and sensor data are released to approved researchers as they are collected, through the LONI Image and Data Archive.

Composition

The first phase enrolled 423 people with recently diagnosed, untreated Parkinson's disease, 196 healthy controls and 64 people whose clinical signs suggested Parkinson's but whose dopamine transporter scan was normal (SWEDD), at 24 sites in the US, Europe and Australia. About two thirds of each group were men, and mean age was around 61. The study has since added people with Parkinson's carrying LRRK2, GBA or SNCA variants (294 in the initial genetic phase), a prodromal cohort with risk features such as REM sleep behaviour disorder or reduced smell, and a further 600 untreated sporadic cases. The study design page plans about 5,500 clinical participants at around 50 sites. The counts in this entry cover the first phase only.

Acquisition

All participants had a brain MRI at baseline. Ten sites with a 3 T Siemens Trio followed a standardized protocol with a 3D MPRAGE and a cardiac-gated DTI sequence, repeated at follow-up for roughly half of the cohort; resting-state fMRI is flagged in the MRI metadata. Dopaminergic imaging used [123I]ioflupane SPECT (DaTscan), or [18F]AV-133 PET for VMAT-2 at the Australian site. Parkinson's participants were rescanned at 12, 24 and 48 months, healthy controls only at baseline.

Annotations

There are no voxel-level labels. The imaging core provides visual reads of each dopaminergic scan and striatal specific binding ratios for left and right caudate and putamen. Diagnoses, MDS-UPDRS and other clinical scores, biomarker results and genetic status are linked by participant number.

Known limitations

  • The database is updated continuously without version control, so analyses must record the download date.
  • Protocols, eligibility criteria and visit schedules changed between study phases.
  • Only part of the cohort has the standardized MRI protocol; other sites acquired MRI to exclude non-Parkinson pathology.
  • More than 90% of first-phase participants were white.

Cohort

Aggregate numbers from the sources below. Bars are relative to the 683 subjects.

Sex

  • Male 443 65%
  • Female 240 35%

Condition

subjects, values can overlap

  • Parkinson's disease 423 62%
  • Healthy control 196 29%

Country

subjects

  • United States 553 81%
  • Australia 6 <1%

License and access

Our reading of the license, not legal advice. Before you use the data, read the original license and confirm that your use is allowed. We take no responsibility for how you use a dataset. Full disclaimer

Access
Application

A research proposal is reviewed and approved

Access page

PPMI Data Use Agreement

Access for scientific investigation, teaching or planning clinical research after an online application reviewed by the PPMI Data and Publications Committee. No disclosure beyond the approved use, a review of every manuscript before submission, a required data acknowledgement, and no IP claims on the data or on inventions arising from it. Model training is allowed, but not on third-party AI services that retain inputs.

Original license text Version read: Version 5.0, April 2026, with Appendix A on AI tools Checked 2026-10-09

What you can do

  • Not stated
  • Not stated
  • Conditional
  • Yes
  • Conditional

What you can share

  • No
  • Conditional
  • Conditional

What you must do

  • Yes
  • Share alike No
  • Yes
  • Conditional
  • Yes
  • Release code No
  • Conditional
  • Delete after use No

Limits

  • Yes
  • No

Citation

State "Data used in the preparation of this article was obtained on [YYYY-MM-DD] from the Parkinson's Progression Markers Initiative (PPMI) database (www.ppmi-info.org/access-data-specimens/download-data), RRID:SCR_006431" and the funding statement from the PPMI Publication Policy. Cohort reference: Marek K, et al. The Parkinson Progression Marker Initiative (PPMI). Progress in Neurobiology 95(4):629-635 (2011). doi:10.1016/j.pneurobio.2011.09.005

All numbers

Every number on this page, as stored in stats.csv, with its source.

MeasureBreakdownValueSource
Subjectstotal
initial phase only: sum of the three disjoint enrollment cohorts (423 PD + 196 healthy controls + 64 SWEDD, scans without evidence of dopaminergic deficit), enrolled from June 2010 over about 32 months; later expansion cohorts are not counted
683marek2018
Table 1
Subjectscondition=parkinsons
untreated, within 2 years of diagnosis, with a dopaminergic deficit on DAT SPECT or VMAT-2 PET
423marek2018
Table 1
Subjectscondition=healthy 196marek2018
Table 1
Subjectssex=male
sum of 277 PD + 126 healthy controls + 40 SWEDD
443marek2018
Table 1
Subjectssex=female
sum of 146 PD + 70 healthy controls + 24 SWEDD
240marek2018
Table 1
Subjectscondition=parkinsons;sex=male 277marek2018
Table 1
Subjectscondition=parkinsons;sex=female 146marek2018
Table 1
Subjectscondition=healthy;sex=male 126marek2018
Table 1
Subjectscondition=healthy;sex=female 70marek2018
Table 1
Subjectscountry=US
enrolled at 18 US sites; a further 124 were enrolled at 5 European sites whose countries the paper does not list
553marek2018
Results
Subjectscountry=AU
enrolled at 1 Australian site
6marek2018
Results
Mean agecondition=parkinsons 61.7marek2018
Table 1
Minimum agecondition=parkinsons 33marek2018
Table 1
Maximum agecondition=parkinsons 85marek2018
Table 1
Mean agecondition=healthy 60.8marek2018
Table 1
Minimum agecondition=healthy 31marek2018
Table 1
Maximum agecondition=healthy 84marek2018
Table 1
Minimum agetotal
lowest of the three cohort minimums (PD 33; healthy controls 31; SWEDD 38)
31marek2018
Table 1
Maximum agetotal
highest of the three cohort maximums (PD 85; healthy controls 84; SWEDD 79)
85marek2018
Table 1

Sources

The keys used in the table above.