New Serum Data Ready to Download

Serum analysis data from Maria Teresa Pellecchia, MD of the University of Salerno is now live in the PPMI database.  Qualified researchers can download this data at no cost.  Please refer to her abstract below for more details on her research.

This was one of the seven requests for PPMI biospecimen samples that was approved for usage.  Abstracts for all the approved specimen analyses can be found on Specimens Analysis.

Researchers interested in finding out more about gaining access to Parkinson’s and control data, imaging, and specimens are invited to join the PPMI Progress Update webinar, hosted by PPMI and The Michael J. Fox Foundation on Monday, December 15th at 12pm ET.  Register here.

Insulin-like growth factor-1 and DAT imaging as biomarkers of early cognitive impairment in Parkinson’s disease


Evidence supports that the protein insulin-like growth factor-1 (IGF-1) may be involved in cognitive deficits. An earlier study found that low serum IGF-1 levels significantly correlated to poor performance on executive tasks and verbal memory tasks. Separately, the role of dopamine nigrostriatal dysfunction in Parkinson’s disease (PD)-related cognitive deficits has been confirmed imaging studies. Both IGF-1 and dopamine transporter (DAT) imaging will be studied as possible biomarkers of cognitive dysfunction in early PD. This study will assess relationships between IGF-1 levels and DAT uptake (use) and cognitive performance to determine if variations of such biomarkers affect cognitive performances.


This study uses samples available from participants in the Parkinson’s Progression Markers Initiative (PPMI). Serum of 400 PD patients and 200 healthy controls enrolled in the PPMI study will be analyzed for IGF-1 levels. DAT imaging data from the same subjects will be analyzed. Finally, scores obtained from neuropsychological tasks (Montreal Cognitive Assessment, Hopkins Verbal learning Test, Benton Judgment of Line Orientation, semantic fluency, Letter Number Sequencing and Symbol Digit Modalities Test) will be used for the analysis.


Twenty-five percent of patients who have been newly diagnosed with PD may present some cognitive dysfunction. Cognitive function may decline over time, with many patients eventually developing dementia. However, some PD patients may exhibit early cognitive deficits that do not evolve into PD dementia or do so over an extended period. The development of cognitive impairment is a significant transition for patients and families, yet it is unpredictable. Thus, identification of one or more biomarkers able to track and predict cognitive dysfunction in PD is highly desirable. If this study confirms the association between IGF-1 levels and/or DAT uptake and cognitive performances in early PD and a predictive value of such biomarkers could be demonstrated by follow-up tests with the PPMI cohort, such biomarkers might be useful both as a clinical diagnostic tool and in the design of trials aimed at preserving cognition in PD.


The possibility that IGF-1 is involved in cognitive functions is supported by evidence from laboratory and clinical studies, but the relation between serum IGF-1 levels and cognitive functions in PD has poorly been studied. This study aims to identify a serum-based biomarker useful to track cognitive dysfunction. Moreover, researchers know that the pathophysiology of cognitive impairment in PD is complex, involving multiple neurotransmitter systems and diffuse neurodegeneration. This study also aims to expand knowledge about pathophysiological substrates of cognitive impairment.