Functional abnormalities of the visual processing system in subjects with mild cognitive impairment: an fMRI study.
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.
Bokde
Arun Lawrence Warren
AL
Dementia and Neuroimaging Research Section, Alzheimer Memorial Center and Geriatric Psychiatry Branch, Department of Psychiatry, Ludwig-Maximilian University, Munich, Germany. Arun.Bokde@tcd.ie
Lopez-Bayo
Patricia
P
Born
Christine
C
Dong
Wentian
W
Meindl
Thomas
T
Leinsinger
Gerda
G
Teipel
Stefan Johannes
SJ
Faltraco
Frank
F
Reiser
Maximilian
M
Möller
Hans-Jürgen
HJ
Hampel
Harald
H
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
D010100:Oxygen