title: Structural and functional imaging study in dementia with Lewy bodies and Parkinson's disease dementia.
abstract: BACKGROUND
  Dementia with Lewy Bodies (DLB) and Parkinson's disease with Dementia (PDD) are neurodegenerative disorders with complex clinical picture (parkinsonism, cognitive decline and neuropsychiatric disturbances). The conundrum of whether DLB and PDD represent the same or different entities is still under debate. Advanced neuroimaging techniques may represent a point of view to assess brain correlates in DLB and PDD. The study aimed at evaluating whether DLB and PDD may be labelled under the same disease entity or be considered distinctive pathologies. We compared DLB and PDD patients by assessing structural and functional brain imaging and including PD patients.
  
  
  METHODS
  Patients with diagnosis of PD, PDD, DLB and a group of healthy controls for neuroimaging comparisons were recruited and changes in structural and resting-state functional MR (Regional Homogeneity, ReHo) were studied.
  
  
  RESULTS
  No significant atrophy in VBM analysis was evident in PD. Conversely, PDD showed a significant bilateral frontal atrophy, whereas DLB was characterized by a predominant parietal, occipital atrophy; a similar involvement of subcortical regions in PDD and DLB was observed. ReHo demonstrated reduced local coherence of frontal regions in PD and in PDD, whereas DLB patients presented a reduced local connectivity in posterior regions.
  
  
  CONCLUSIONS
  Different brain areas are specifically involved in PDD and DLB. In the former group, greater atrophy of frontal regions with concomitant functional connectivity impairment was evident; conversely, structural and functional damage in the posterior regions characterized DLB. Despite an overlapping clinical spectrum, DLB and PDD have different networks involved and different underlying pathogenic pathways.
authors.affiliation: Centre for Ageing Brain and Neurodegenerative Disorders, Neurology Unit, University of Brescia, Italy. Electronic address: bborroni@inwind.it.
authors.forename: Barbara
authors.initials: B
authors.lastname: Borroni
authors.affiliation: Centre for Ageing Brain and Neurodegenerative Disorders, Neurology Unit, University of Brescia, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Premi
authors.affiliation: Centre for Ageing Brain and Neurodegenerative Disorders, Neurology Unit, University of Brescia, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Formenti
authors.affiliation: Centre for Ageing Brain and Neurodegenerative Disorders, Neurology Unit, University of Brescia, Italy.
authors.forename: Rosanna
authors.initials: R
authors.lastname: Turrone
authors.affiliation: Centre for Ageing Brain and Neurodegenerative Disorders, Neurology Unit, University of Brescia, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Alberici
authors.affiliation: Centre for Ageing Brain and Neurodegenerative Disorders, Neurology Unit, University of Brescia, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Cottini
authors.affiliation: S. Isidoro Hospital - FERB Onlus, Trescore Balneario, Bergamo, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Rizzetti
authors.affiliation: Neuroradiology Unit, University of Brescia, Brescia, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Gasparotti
authors.affiliation: Centre for Ageing Brain and Neurodegenerative Disorders, Neurology Unit, University of Brescia, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Padovani
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000098:blood supply* / Q000473:pathology*; D003704:Dementia / Q000209:etiology / Q000473:pathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D020961:Lewy Body Disease / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D010300:Parkinson Disease / Q000150:complications / Q000473:pathology*; D011569:Psychiatric Status Rating Scales; D012146:Rest; D012189:Retrospective Studies
chemical_list: D010100:Oxygen
keywords: Dementia with Lewy bodies; Parkinson's disease dementia; Resting state functional MRI; Voxel based morphometry