Relationship between cognition and awareness of deficit in mild cognitive impairment.
OBJECTIVE
Although anosognosia is common in Alzheimer's disease (AD), limited research has investigated awareness among patients with mild cognitive impairment (MCI). The current study examined cognitive performance differences between MCI patients who were aware or unaware of their deficits.


METHODS
Participants were 65 patients who underwent a comprehensive neuropsychological evaluation and diagnosed with MCI according to Petersen's criteria. Participants were divided into groups based on clinician rating of awareness (aware n=30 or unaware n=35), which was determined following interview with the patient and family member. Neuropsychological measures were converted into z-scores based on sample mean and standard deviation and averaged across cognitive domains. Frontal behavioral ratings were also collected.


RESULTS
No significant differences were found between awareness groups for age, education, gender, or MMSE score. Individuals rated as unaware performed significantly worse in the learning domain and a trend for worse performance on the Dementia Rating Scale-II total score than those rated as aware. None of the other cognitive or behavioral domains differed between the groups. Clinician and informant ratings of anosognosia were only modestly correlated, and we found an unexpected pattern of relationships between informant ratings and cognitive performance.


CONCLUSIONS
Awareness deficits are common in MCI patients. Our results argue against the most common etiologic hypotheses in AD (i.e., executive and right hemisphere) and suggest that severity of encoding deficits underlie anosognosia in MCI.
Tremont
Geoffrey
G
Department of Psychiatry, Rhode Island Hospital, Providence, RI, USA. gtremont@lifespan.org
Alosco
Michael L
ML
D000368:Aged; D000369:Aged, 80 and over; D001364:Awareness; D003072:Cognition Disorders / Q000175:diagnosis / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D011569:Psychiatric Status Rating Scales; D012016:Reference Values