title: Parkinson's disease is associated with hippocampal atrophy.
abstract: Patients with Parkinson's disease (PD) may have hippocampal atrophy compared with controls. We compared hippocampal, and extra-hippocampal volumes between PD, PDD (patients with PD who have mild cognitive impairment or dementia), Alzheimer's disease (AD) and controls using volumetric magnetic resonance imaging (MRI). Participants (10 patients with PD, 10 with PDD, 11 with AD, and 12 control subjects) had an informant interview, neurological examination, and psychometric testing. Established, reliable methods were used to measure the hippocampus, parahippocampal gyrus, temporal, frontal, and parieto-occipital lobes. Correction for intracranial volume was carried out before comparison. There was no age difference between groups (mean age, 74 years). On the Clinical Dementia Rating scale (CDR) cognitive impairment was mild (CDR = 0.5) in the majority of PDD and AD patients. Hippocampal (P < 0.0004) volumes were smaller in the patient groups. Effect sizes compared with the control group were: PD, 0.66; PDD, 1.22; and AD, 1.81. The other volumes did not differ significantly. Among PD and PDD patients, recognition memory (r = 0.54, P = 0.015) and Mini-Mental State Examination scores (r = 0.56, P = 0.01) correlated with left, but not right hippocampal volume. In conclusion, hippocampal volume showed a pattern (Control > PD > PDD > AD) suggesting progressive hippocampal volume loss in PD. Volumetric MRI imaging might provide an early marker for dementia in PD.
authors.affiliation: Department of Neurology, Oregon Health and Science University, Portland, Oregon, USA. rcamicio@ualberta.ca
authors.forename: Richard
authors.initials: R
authors.lastname: Camicioli
authors.forename: M Milar
authors.initials: MM
authors.lastname: Moore
authors.forename: Anthony
authors.initials: A
authors.lastname: Kinney
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Corbridge
authors.forename: Kathryn
authors.initials: K
authors.lastname: Glassberg
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Kaye
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis; D001284:Atrophy; D001921:Brain / Q000473:pathology; D002540:Cerebral Cortex / Q000473:pathology; D003704:Dementia / Q000175:diagnosis; D003937:Diagnosis, Differential; D018450:Disease Progression; D005260:Female; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008432:Mathematical Computing; D009460:Neurologic Examination; D009483:Neuropsychological Tests; D020534:Parahippocampal Gyrus / Q000473:pathology; D010300:Parkinson Disease / Q000175:diagnosis*; D012012:Red Nucleus / Q000473:pathology; D012016:Reference Values; D013477:Superior Colliculi / Q000473:pathology