title: Motor associations of iron accumulation in deep grey matter nuclei in Parkinson's disease: a cross-sectional study of iron-related magnetic resonance imaging susceptibility.
abstract: To determine whether iron deposition in deep brain nuclei assessed using high-pass filtered phase imaging plays a role in motor disease severity in Parkinson's disease (PD).
  
  
  
  Seventy patients with mild to moderate PD and 20 age- and gender-matched healthy volunteers (HVs) underwent susceptibility-weighted imaging on a 3 T magnetic resonance imaging scanner. Phase shifts (radians) in deep brain nuclei were derived from high-pass filtered phase images and compared between groups. Analysis of clinical laterality and correlations with motor severity (Unified Parkinson's Disease Rating Scale, Part III, UPDRS-III) were performed. Phase shifts (in radians) were compared between HVs and three PD subgroups divided according to UPDRS-III scores using analysis of covariance, adjusting for age and regional area.
  
  
  
  Parkinson's disease patients had significantly (P < 0.001) higher radians than HVs bilaterally in the putamen, globus pallidus and substantia nigra (SN). The SN contralateral to the most affected side showed higher radians (P < 0.001) compared to the less affected side. SN radians positively correlated with UPDRS-III and bradykinesia-rigidity subscores, but not with tremor subscores. ancova followed by post hoc Bonferroni-adjusted pairwise comparisons revealed that SN radians were significantly greater in the PD subgroup with higher UPDRS-III scores compared to both lowest UPDRS-III PD and HV groups (P < 0.001).
  
  
  
  Increased nigral iron accumulation in PD appears to be stratified according to disease motor severity and correlates with symptoms related to dopaminergic neurodegeneration. This semi-quantitative in vivo iron assessment could prove useful for objectively monitoring PD progression, especially in clinical trials concerning iron chelation therapies.
authors.affiliation: Centre for Neurodegeneration and Neuroinflammation, Division of Brain Sciences, Imperial College London, London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Martin-Bastida
authors.affiliation: Centre for Neurodegeneration and Neuroinflammation, Division of Brain Sciences, Imperial College London, London, UK.
authors.forename: N P
authors.initials: NP
authors.lastname: Lao-Kaim
authors.affiliation: Centre for Neurodegeneration and Neuroinflammation, Division of Brain Sciences, Imperial College London, London, UK.|Memory Research Group, Nuffield Department of Clinical Neurosciences, Medical Science Division, University of Oxford, Oxford, UK.
authors.forename: C
authors.initials: C
authors.lastname: Loane
authors.affiliation: Centre for Neurodegeneration and Neuroinflammation, Division of Brain Sciences, Imperial College London, London, UK.|Neurodegeneration Imaging Group, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.
authors.forename: M
authors.initials: M
authors.lastname: Politis
authors.affiliation: Centre for Neurodegeneration and Neuroinflammation, Division of Brain Sciences, Imperial College London, London, UK.
authors.forename: A A
authors.initials: AA
authors.lastname: Roussakis
authors.affiliation: John Van Geest Centre for Brain Repair, University of Cambridge, Cambridge, UK.
authors.forename: N
authors.initials: N
authors.lastname: Valle-Guzman
authors.affiliation: Sobell Department of Motor Neuroscience, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, London, UK.
authors.forename: Z
authors.initials: Z
authors.lastname: Kefalopoulou
authors.affiliation: Translational Neurology Group, Department of Clinical Sciences, Wallenberg Neuroscience Centre, Lund University, Lund, Sweden.
authors.forename: G
authors.initials: G
authors.lastname: Paul-Visse
authors.affiliation: Division of Neurology, Department of Clinical Sciences, Lund University, Skåne University Hospital, Lund, Sweden.
authors.forename: H
authors.initials: H
authors.lastname: Widner
authors.affiliation: Radiological Sciences, Division of Clinical Neuroscience, University of Nottingham, Queen's Medical Centre Nottingham, Nottingham, UK.
authors.forename: Y
authors.initials: Y
authors.lastname: Xing
authors.affiliation: Radiological Sciences, Division of Clinical Neuroscience, University of Nottingham, Queen's Medical Centre Nottingham, Nottingham, UK.
authors.forename: S T
authors.initials: ST
authors.lastname: Schwarz
authors.affiliation: Radiological Sciences, Division of Clinical Neuroscience, University of Nottingham, Queen's Medical Centre Nottingham, Nottingham, UK.
authors.forename: D P
authors.initials: DP
authors.lastname: Auer
authors.affiliation: Sobell Department of Motor Neuroscience, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, London, UK.
authors.forename: T
authors.initials: T
authors.lastname: Foltynie
authors.affiliation: Department of Clinical Neuroscience, University of Cambridge, Cambridge, UK.|MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK.
authors.forename: R A
authors.initials: RA
authors.lastname: Barker
authors.affiliation: Centre for Neurodegeneration and Neuroinflammation, Division of Brain Sciences, Imperial College London, London, UK.
authors.forename: P
authors.initials: P
authors.lastname: Piccini
mesh_terms: D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D004198:Disease Susceptibility; D005260:Female; D066128:Gray Matter / Q000000981:diagnostic imaging / Q000378:metabolism*; D006801:Humans; D018476:Hypokinesia / Q000209:etiology / Q000503:physiopathology; D007091:Image Processing, Computer-Assisted; D007501:Iron / Q000378:metabolism*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009069:Movement Disorders / Q000209:etiology / Q000503:physiopathology*; D009127:Muscle Rigidity / Q000209:etiology / Q000503:physiopathology; D010300:Parkinson Disease / Q000150:complications / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology*; D013378:Substantia Nigra / Q000000981:diagnostic imaging / Q000378:metabolism
chemical_list: D007501:Iron
keywords: 
  SWI
  ; Parkinson's disease; iron; motor severity; neurodegeneration