Title: Higher iron in the red nucleus marks Parkinson's dyskinesia.

Authors: Lewis, Mechelle M; Du, Guangwei; Kidacki, Michal; Patel, Nisargkumar; Shaffer, Michele L; Mailman, Richard B; Huang, Xuemei

Published In Neurobiol Aging, (2013 May)

Abstract: Dopamine cell loss and increased iron in the substantia nigra (SN) characterize Parkinson's disease (PD), with cerebellar involvement increasingly recognized, particularly in motor compensation and levodopa-induced dyskinesia (LID) development. Because the red nucleus (RN) mediates cerebellar circuitry, we hypothesized that RN iron changes might reflect cerebellum-related compensation, and/or the intrinsic capacity for LID development. We acquired high resolution magnetic resonance images from 23 control and 38 PD subjects (12 with PD and history of LID [PD+DYS]) and 26 with PD and no history of LID (PD-DYS). Iron content was estimated from bilateral RN and SN transverse relaxation rates (R2*). PD subjects overall displayed higher R2* values in both the SN and RN. RN R2* values correlated with off-drug Unified Parkinson's Disease Rating Scale-motor scores, but not disease duration or drug dosage. RN R2* values were significantly higher in PD+DYS compared with control and PD-DYS subjects; control and PD-DYS subjects did not differ. The association of higher RN iron content with PD-related dyskinesia suggests increased iron content is involved in, or reflects, greater cerebellar compensatory capacity and thus increased likelihood of LID development.

PubMed ID: 23177595

MeSH Terms: Biomarkers/metabolism; Female; Humans; Iron/metabolism*; Magnetic Resonance Imaging/methods*; Male; Middle Aged; Parkinson Disease/diagnosis*; Parkinson Disease/metabolism*; Red Nucleus/metabolism*; Tissue Distribution