title: Structural brain abnormalities in patients with Parkinson's disease with visual hallucinations: a comparative voxel-based analysis.
abstract: The objective is to evaluate clinical characteristics and cerebral alterations in Parkinson's disease (PD) patients with diurnal visual hallucinations (VHs). Assessment was performed using magnetic resonance image (MRI) and voxel-based morphometry (VBM). Thirty-nine patients with PD (53.8%) and ten controls were studied. Voxel based morphology analysis was performed. Eleven patients presented diurnal VHs and among these, six had cognitive dysfunction. Patients with VHs performed worse in the mentation-related UPDRS I (p=0.005) and motor-related UPDRS III (p=0.02). Patients with VHs showed significant clusters of reduced grey matter volume compared to controls in the left opercula frontal gyrus and left superior frontal gyrus. PD without hallucinations demonstrated reduced grey matter volume in the left superior frontal gyrus compared to controls. Comparisons between patients with VHs regarding the presence of cognitive dysfunction showed that cases with cognitive dysfunction as compared to those without cognitive dysfunction showed significant clusters of reduced grey matter volume in the left opercular frontal gyrus. Cases without cognitive dysfunction had reduced grey matter substance in the left insula and left trigonal frontal gyrus. Judging from our findings, an abnormal frontal cortex, particularly left sided insula, frontal opercular, trigonal frontal gyrus and orbital frontal would make PD patients vulnerable to hallucinations. Compromise of the left operculum distinguished cases with VHs and cognitive dysfunction. Our findings reinforce the theoretical concept of a top-down visual processing in the genesis of VHs in PD.
authors.affiliation: Pós Graduação Ciências Médicas, Universidade Federal do Ceara, Fortaleza, Brazil.
authors.forename: Romulo Lopes
authors.initials: RL
authors.lastname: Gama
authors.affiliation: Pós Graduação Ciências Médicas, Universidade Federal do Ceara, Fortaleza, Brazil. Electronic address: veralice@superig.com.br.
authors.forename: Veralice Meireles Sales
authors.initials: VM
authors.lastname: Bruin
authors.affiliation: Pós Graduação Ciências Médicas, Universidade Federal do Ceara, Fortaleza, Brazil.
authors.forename: Daniel Gurgel Fernandes
authors.initials: DG
authors.lastname: Távora
authors.affiliation: Instituto de Psiquiatria, Hospital das Clínicas, Universidade de São Paulo, Brazil.
authors.forename: Fábio L S
authors.initials: FL
authors.lastname: Duran
authors.affiliation: Departamento de Psicobiologia, Universidade Federal de São Paulo, Brazil.
authors.forename: Lia
authors.initials: L
authors.lastname: Bittencourt
authors.affiliation: Departamento de Psicobiologia, Universidade Federal de São Paulo, Brazil.
authors.forename: Sergio
authors.initials: S
authors.lastname: Tufik
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002540:Cerebral Cortex / Q000473:pathology*; D005260:Female; D006212:Hallucinations / Q000209:etiology / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000473:pathology*
keywords: Insula; MRI; Operculum; Parkinson’s disease; Pre-frontal cortex; Visual hallucinations