Multiple cognitive deficits in amnestic mild cognitive impairment.
OBJECTIVE
To determine if more widespread cognitive deficits are present in a narrowly defined group of patients with the amnestic form of mild cognitive impairment (MCI).


METHODS
From a larger sample of patients clinically diagnosed as meeting the criteria of Petersen et al. for amnestic MCI, we selected 22 subjects who had Clinical Dementia Rating scores of zero on all domains besides memory and orientation. These MCI subjects with presumably isolated memory impairments were compared to 35 age-matched normal controls and 33 very mild Alzheimer's disease (AD) patients on a battery of neuropsychological tests.


RESULTS
In addition to the expected deficits in episodic memory, the amnestic MCI group performed less well than the controls but better than the AD group on design fluency, category fluency, a set shifting task and the Stroop interference condition. Over half the amnestic MCI group (vs. none of the normal controls) scored at least 1 standard deviation below control means on 4 or more of the nonmemory cognitive tasks.


CONCLUSIONS
Isolated memory impairment may be fairly uncommon in clinically diagnosed amnestic MCI patients, even when the criteria for amnestic MCI are fairly narrow. Additional cognitive impairments are likely to include fluency and executive functioning. These more diffuse deficits argue for comprehensive cognitive assessments, even when the patient and family are reporting only memory decline, and are consistent with the increase in attention paid to the heterogeneity of MCI.
Kramer
Joel H
JH
San Francisco Medical Center, University of California, San Francisco, CA 94143, USA. kramer@itsa.ucsf.edu
Nelson
Adam
A
Johnson
Julene K
JK
Yaffe
Kristine
K
Glenn
Shenly
S
Rosen
Howard J
HJ
Miller
Bruce L
BL
D000368:Aged; D000647:Amnesia / Q000150:complications / Q000523:psychology*; D003072:Cognition Disorders / Q000150:complications / Q000523:psychology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D011597:Psychomotor Performance / Q000502:physiology