title: Brain pathway differences between Parkinson's disease patients with and without REM sleep behavior disorder.
abstract: OBJECTIVE
  REM (rapid eye movement) sleep behavior disorder (RBD) is characterized by increased muscle tone and violent limb movements and is a usual symptom of the early stages of Parkinson's disease (PD). PD patients with RBD represent faster motor and cognitive dysfunction progression. However, there are limited studies on possible structural brain changes underpinning this disorder.
  
  
  METHODS
  Diffusion magnetic resonance imaging (DMRI) was used to assess whether microstructural abnormalities in the brain of 23 RBD positive PD are detectable compared to 31 RBD negative PD. DMRI scans were analyzed without a prior hypothesis. Diffusion MRI connectometry was used to carry out group analysis between age and gender matched PD patients with and without RBD. Diffusion MRI connectometry is based on spin distribution function (SDF) which quantifies the density of diffusing water and is more sensitive to psychological differences between groups.
  
  
  RESULTS
  Patients with RBD positive showed microstructural white matter changes in the left and right cingulum, inferior front occipital fasciculus (IFOF), bilateral corticospinal tracts (CST), and middle cerebellar peduncles (MCPs), compared to patients without RBD.
  
  
  CONCLUSIONS
  White matter alterations in the cingulum, IFOF regions, and corpus callosum might explain faster cognitive deterioration in PD patients with RBD, in terms of visual recognition and visuospatial dysfunction and executive function. Disturbed brain structural tissue markers in CST in PD + RBD patients, could be justified in the light of faster motor progression in these patients.
authors.affiliation: Neuroimaging Network (NIN), Universal Scientific Education and Research Network (USERN), Tehran, Iran.|Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mina
authors.initials: M
authors.lastname: Ansari
authors.affiliation: Neuroimaging Network (NIN), Universal Scientific Education and Research Network (USERN), Tehran, Iran.|Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Farzaneh
authors.initials: F
authors.lastname: Rahmani
authors.affiliation: Neuroimaging Network (NIN), Universal Scientific Education and Research Network (USERN), Tehran, Iran.|Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mahsa
authors.initials: M
authors.lastname: Dolatshahi
authors.affiliation: Neuroimaging Network (NIN), Universal Scientific Education and Research Network (USERN), Tehran, Iran.|Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Atefe
authors.initials: A
authors.lastname: Pooyan
authors.affiliation: Basir Eye Health Research Center, Tehran, Iran. Mohammadhadiarabi@gmail.com.
authors.forename: Mohammad Hadi
authors.initials: MH
authors.lastname: Aarabi
mesh_terms: D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D060825:Cognitive Dysfunction / Q000000981:diagnostic imaging / Q000503:physiopathology; D063132:Connectome; D038524:Diffusion Magnetic Resonance Imaging; D018450:Disease Progression; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D020187:REM Sleep Behavior Disorder / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D012016:Reference Values
keywords: Connectometry; Diffusion MRI; Parkinson disease (PD); Quantitative anisotropic (QA); REM sleep behavior disorder (RBD); Spin distribution function (SDF)