PPMI Ancillary Studies in Full Swing

PPMI offers scientists the flexibility to propose ancillary studies involving PPMI participants to add new study assessments that expand on the study data in a meaningful way. Several of the ancillary studies that have been proposed have been accepted and are actively underway as part of PPMI.


The goal of TAP-PD is to assess the feasibility of incorporating at home dexterity testing using a transportable computer-based device.  Historically, there has been a lack of reliable means for effectively tracking the progression of PD; the gold standard has been the Unified Parkinson?s Disease Rating Scale (UPDRS). But due to individual subjectivity, UPDRS is sometimes criticized for not being truly quantitative.

In a previous study, the computer-based device being used in TAP-PD was tested by individuals in their home environments and found to successfully detect changes in parkinsonian motor function.  However, the study also determined that the effectiveness of the device might best be optimized in a clinical setting. TAP-PD will test this hypothesis.

TAP-PD is being offered at three PPMI sites, where PPMI participants are completing the dexterity testing at home, and during their regular PPMI clinic visits. The device tests dexterity through finger tapping and peg transfer exercises meant to gauge speed and reaction time. Participants at those sites have the opportunity to opt into this study, but are not be required to do so.

The study in ongoing, however researchers are now beginning interim analysis of the TAP-PD data collected. The initial data indicates that the device was convenient and easy for PPMI participants to use at home. Additional analysis of the home dexterity testing relative to examiner-based measures such as the UPDRS is also planned.


PD subjects who fulfilled clinical criteria for inclusion in PPMI as PD subjects but did not show evidence of a dopamine transporter deficit on the baseline DaTSCAN have the opportunity to enroll in a parallel study.  This study evaluates the probability of change in clinical diagnosis of PD in subjects with Scans Without Evidence of Dopaminergic Deficit (SWEDD), and compares baseline characteristics of SWEDD to non-SWEDD PD subjects and healthy controls.

The SWEDD Study has now been fully incorporated into PPMI, and SWEDDs have been enrolled at 20 of PPMI?s 24 study sites.  As of March 31, 58 total SWEDDs have been enrolled in PPMI.

?This represents the largest prospective SWEDD study to date,? says PPMI Steering Committee member John Seibyl, MD, executive director and senior scientist at the Institute for Neurodegenerative Disorders. ?And it may ultimately aid in improving accurate diagnosis of idiopathic PD at the very early stages of motor symptoms.”

Resting State fMRI

The goal of this study is to add the acquisition of resting state fMRI data to the standard MRI protocol for the PPMI study. The availability of this data allows for a variety of analyses to examine functional brain networks, correlate these results with structural networks that can be measured using diffusion tensor imaging data, and correlate network changes with disease status, medication status and other biological markers being obtained in this study, including DAT imaging.

The collection of resting-state fMRI data has recently started at multiple MRI sites of PPMI and PD patients had their initial baseline scans. Since patients will have repeated MRI scans annually for 2-3 years, this fMRI study will be one of the largest of its kind to study changes in functional brain networks over time.

Tracking Mild Cognitive Impairment (MCI) and Dementia

This study is designed to complement the existing PPMI neuropsychological battery and clinical/demographic data with an annual diagnostic interview to be completed by a physician or neuropsychologist with expertise in PD cognition. The interview will allow serial (i.e., baseline + annually) categorization of PPMI patients as having normal cognition (PD-NC), mild cognitive impairment (PD-MCI), or dementia (PDD).

Like the SWEDD Study, Tracking MCI and Dementia has been fully incorporated into the PPMI study design on the whole. Each of the study sites is equipped to carry out the aforementioned tests.

 Physical Activity Scale for the Elderly

This is the newest ancillary study to be incorporated into PPMI. The Physical Activity Scale for the Elderly (PASE) measures participants? physical activity and how it relates to the clinical progression of their disease. PASE is a self-reported assessment and will be conducted at all 24 PPMI study sites for all subjects going forward.

Find out more about ongoing Ancillary Studies in PPMI.