Circulating levels of neurotrophic factors are unchanged in patients with Parkinson's disease.

There is great evidence linking neurotrophic factor (NF) dysfunction with Parkinson's disease (PD) pathophysiology. This study was conducted to evaluate plasma levels of NFs and their possible associations with clinical symptoms in PD. For this purpose, 40 PD patients and 25 controls were subjected to a clinical evaluation and peripheral blood draw.