Parkinson’s Disease Patients With Mild Cognitive Impairment Do Not Have Increased Brain Iron Concentrations As Compared To Patients Without Cognitive Impairment (P5.261)

Objective: To determine differences in deep gray matter (DGM) magnetic susceptibility using susceptibility-weighted imaging (SWI) in PD patients with- and without mild cognitive impairment (MCI). Associations of these indirect brain-iron measurements with clinical status were assessed. Background: Elevated brain-iron levels have been proposed to play an important role in the pathophysiology of neurodegenerative disorders including Parkinson9s disease (PD) and may influence clinical outcomes. Methods: Out of a total sample of 40 PD patients, 23 were classified as MCI, while 17 were not. MCI was defined as having a Hoehn & Yahr (HY suggestive of severe iron pathology) as well as structural volume measurements were derived of 10 DGM structures, including the caudate, putamen, substantia niagra pars compacta and pars reticulata. Clinical measures included were H&Y, CDR, MoCA, Mini-Mental State Exam (MMSE), and motor Unified Parkinson9s Disease Rating Scale (UPDRS). Although non-significant, because of slight differences between groups, age and gender were included as confounders in all statistical models (ANCOVA for group-wise comparisons, linear regression for associative analyses). Analyses were adjusted for multiple comparisons using the false discovery rate method. Results: MCI and non-MCI PD patients did not differ in DGM volumes, mean phase or MP-LPV (all p>.05). Neither the MCI nor the non-MCI group showed significant associations with H&Y, CDR, MoCA, MMSE, or motor UPDRS (p>.05). Conclusion: In contrast to previous accounts, the present study of PD patients with MCI did not show increased tissue magnetic susceptibility. No associations of these measures with clinical status were observed. Disclosure: Dr. Hagemeier has nothing to disclose. Dr. Gattuso has received personal compensation for activities with Teva Neuroscience as a speaker and advisory board member. Dr. Gattuso has received license fee payments from the University of Rochester. Dr. Bergsland has nothing to disclose. Dr. Heininen-Brown has nothing to disclose. Dr. Carl has nothing to disclose. Dr. Lichter has received personal compensation for activities with Teva Neuroscience and UCB Pharma. Dr. Zivadinov has received personal compensation for activities with Teva, Biogen Idec, EMD Serono, Novartis, Claret and Sanofi-Genzyme. Dr. Zivadinov has received research support from Biogen Idec, Teva Pharmaceuticals, Sanofi-Genzyme, Novartis and EMD Serono.