Anosognosia in mild cognitive impairment: Relationship to activation of cortical midline structures involved in self-appraisal.
Awareness of cognitive dysfunction shown by individuals with Mild Cognitive Impairment (MCI), a condition conferring risk for Alzheimer's disease (AD), is variable. Anosognosia, or unawareness of loss of function, is beginning to be recognized as an important clinical symptom of MCI. However, little is known about the brain substrates underlying this symptom. We hypothesized that MCI participants' activation of cortical midline structures (CMS) during self-appraisal would covary with level of insight into cognitive difficulties (indexed by a discrepancy score between patient and informant ratings of cognitive decline in each MCI participant). To address this hypothesis, we first compared 16 MCI participants and 16 age-matched controls, examining brain regions showing conjoint or differential BOLD response during self-appraisal. Second, we used regression to investigate the relationship between awareness of deficit in MCI and BOLD activity during self-appraisal, controlling for extent of memory impairment. Between-group comparisons indicated that MCI participants show subtly attenuated CMS activity during self-appraisal. Regression analysis revealed a highly significant relationship between BOLD response during self-appraisal and self-awareness of deficit in MCI. This finding highlights the level of anosognosia in MCI as an important predictor of response to self-appraisal in cortical midline structures, brain regions vulnerable to changes in early AD.
Ries
Michele L
ML
Geriatric Research Education and Clinical Center, William S. Middleton VA Hospital, Madison, Wisconsin 53705, USA.
Jabbar
Britta M
BM
Schmitz
Taylor W
TW
Trivedi
Mehul A
MA
Gleason
Carey E
CE
Carlsson
Cynthia M
CM
Rowley
Howard A
HA
Asthana
Sanjay
S
Johnson
Sterling C
SC
D000368:Aged; D000369:Aged, 80 and over; D000377:Agnosia / Q000209:etiology* / Q000473:pathology*; D001931:Brain Mapping; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000098:blood supply / Q000473:pathology*; D003072:Cognition Disorders / Q000150:complications* / Q000523:psychology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D012044:Regression Analysis; D012649:Self Concept; D012720:Severity of Illness Index
D010100:Oxygen