title: Functional abnormalities of the visual processing system in subjects with mild cognitive impairment: an fMRI study.
abstract: Subjects with mild cognitive impairment (MCI) have a higher risk of developing Alzheimer's disease compared with healthy controls (HC). Sensory impairment can contribute to the severity of cognitive impairment. We measured the activation changes in the visual system between MCI and HC subjects. There were 16 MCI subjects with either amnestic MCI or multiple-domain+amnestic MCI and an HC group of 19 subjects. There were two tasks: (a) a face matching and (b) a location matching task. Brain activation was measured using functional magnetic resonance imaging. There were no differences in task performance. The HC group selectively activated the ventral and dorsal pathways during the face and location matching tasks, respectively, while the MCI group did not. The MCI group had greater activation than the HC group in the left frontal lobe during the location matching task. There were no areas of increased activation in the HC group compared with the MCI group. The MCI group, as a compensatory mechanism, activated both visual pathways and increased activation in the left frontal lobe during the location matching task compared with the healthy controls. To our knowledge, this is the first study that has examined visual processing in MCI.
authors.affiliation: Dementia and Neuroimaging Research Section, Alzheimer Memorial Center and Geriatric Psychiatry Branch, Department of Psychiatry, Ludwig-Maximilian University, Munich, Germany. Arun.Bokde@tcd.ie
authors.forename: Arun Lawrence Warren
authors.initials: AL
authors.lastname: Bokde
authors.forename: Patricia
authors.initials: P
authors.lastname: Lopez-Bayo
authors.forename: Christine
authors.initials: C
authors.lastname: Born
authors.forename: Wentian
authors.initials: W
authors.lastname: Dong
authors.forename: Thomas
authors.initials: T
authors.lastname: Meindl
authors.forename: Gerda
authors.initials: G
authors.lastname: Leinsinger
authors.forename: Stefan Johannes
authors.initials: SJ
authors.lastname: Teipel
authors.forename: Frank
authors.initials: F
authors.lastname: Faltraco
authors.forename: Maximilian
authors.initials: M
authors.lastname: Reiser
authors.forename: Hans-Jürgen
authors.initials: HJ
authors.lastname: Möller
authors.forename: Harald
authors.initials: H
authors.lastname: Hampel
mesh_terms: D000368:Aged; D001921:Brain / Q000503:physiopathology*; D003072:Cognition Disorders / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D012720:Severity of Illness Index; D014796:Visual Perception
chemical_list: D010100:Oxygen