[Prediction of the development of Alzheimer disease in patients with mild cognitive impairment].
OBJECTIVE
Mild cognitive impairment (MCI) is considered to refer to a transitional zone between normal cognitive function and dementia. It comprises a heterogenous condition with a variety of clinical outcomes. The purpose of this study was to determine whether combined analysis of brain imaging studies, including MRI and single photon emission computed tomography (SPECT) , and assessment of awareness of memory deficits is useful in predicting Alzheimer disease (AD) in subjects with MCI.


METHODS
Thirty-nine patients with amnestic MCI [21 patients who had developed AD (MCI/AD) and 18 patients who did not develop AD (MCI/MCI) during a 2.5 to 3-year follow-up] and 19 patients with early AD were included in the study. The entorhinal cortex z-score in each patient was calculated using voxel-based morphometry with 3D T1-weighted MRI (software: VSRAD) . SPECT data were analyzed by the three-dimensional stereotactic surface projection method and posterior cortical hypoperfusion was qualitatively assessed. Awareness of memory deficits was evaluated with a standardized memory questionnaire system based on the Everyday Memory Checklist (EMC) . The discrepancy between these scores (caregiver rating-patient rating) was analyzed.


RESULTS
The MCI/AD group showed a tendency toward higher z-scores in the entorhinal cortex on MRI scan, a significantly higher frequency of posterior hypoperfusion on SPECT scan, and significantly more impaired awareness of memory deficits than in the MCI/MCI group. These findings were more severe and more frequent in the AD group than in the MCI/AD and MCI/MCI groups. A combined study of MRI, SPECT, and awareness of memory deficits yielded a higher level of discrimination between MCI/AD and MCI/MCI group results than in each separate study.


CONCLUSIONS
A combined study of brain imagings (MRI and SPECT) and an assessment of awareness of memory deficits may improve the prediction of the development of AD in subjects with amnestic MCI.
Kume
Kazumasa
K
Department of Geriatric Medicine, Tokyo Medical University.
Hanyu
Haruo
H
Sato
Tomohiko
T
Hirao
Kentaro
K
Kanetaka
Hidekazu
H
Shimizu
Soichiro
S
Sakurai
Hirofumi
H
Iwamoto
Toshihiko
T
D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis / Q000209:etiology*; D003072:Cognition Disorders / Q000150:complications* / Q000175:diagnosis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D015899:Tomography, Emission-Computed, Single-Photon