Volumetric MRI measurements can differentiate Alzheimer's disease, mild cognitive impairment, and normal aging.
BACKGROUND
Volumetric magnetic resonance imaging (MRI) has been extensively studied in the last decade as a method to help with the clinical diagnosis of Alzheimer's disease (AD). In recent years, researchers have also started investigating if that technique would be useful to identify individuals with mild cognitive impairment (MCI), differentiating them from AD patients and from normal elderly controls. This research project was planned to assess the accuracy of volumetric MRI to differentiate those groups of individuals.


METHODS
The investigation involved 39 patients with diagnosis of mild to moderate dementia in AD, according to the criteria of the NINCDS-ADRDA, DSM-III-R, and ICD-10; 21 subjects with complaints of cognitive decline without other psychiatric disorders (MCI); and 20 normal elderly controls. All the subjects were submitted to a standard protocol, including volumetric MRI evaluations.


RESULTS
The results indicated that all regions of interest measured (amygdala, hippocampus, and parahippocampal gyrus) were significantly different (p < .005) in AD patients compared to MCI subjects and controls. The left volumetric measures (amygdala, hippocampus, and parahippocampal gyrus) were also significantly different between the MCI subjects and controls (p < .05). The discriminant function analysis correctly classified 88.14% of the AD patients and controls, 81.67% of AD patients and MCI subjects, and 80.49% of the MCI subjects and controls.


CONCLUSIONS
The results suggest that measures of medial temporal lobe regions are useful to identify mild to moderate AD patients and MCI subjects, separating them from normal elderly individuals.
Bottino
Cássio M C
CM
Institute and Department of Psychiatry, University of São Paulo School of Medicine, Brazil. cbottino@usp.br
Castro
Cláudio C
CC
Gomes
Regina L E
RL
Buchpiguel
Carlos A
CA
Marchetti
Renato L
RL
Neto
Mário R Louzã
MR
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology*; D000544:Alzheimer Disease / Q000175:diagnosis*; D000679:Amygdala / Q000473:pathology; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000145:classification / Q000175:diagnosis*; D003937:Diagnosis, Differential; D016002:Discriminant Analysis; D005260:Female; D015577:Geriatric Assessment; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards; D008297:Male; D009483:Neuropsychological Tests; D020534:Parahippocampal Gyrus / Q000473:pathology; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013702:Temporal Lobe / Q000473:pathology