Comprehensive dissection of the medial temporal lobe in AD: measurement of hippocampus, amygdala, entorhinal, perirhinal and parahippocampal cortices using MRI.
BACKGROUND
Early pathological involvement of specific medial temporal lobe areas is characteristic for Alzheimer's disease (AD).


OBJECTIVE
To determine the extent of regional medial temporal lobe atrophy, including hippocampus, amygdala, and entorhinal, perirhinal, and parahippocampal cortices in mild AD patients and healthy controls, and to compare diagnostic accuracy across volumetric markers.


METHODS
We studied 34 patients with clinically probable AD and 22 healthy elderly control subjects. Regional volumetric measures were obtained from volumetric T1-weighted MRI scans after accounting for global brain atrophy using affine transformation into standard space.


RESULTS
Volumes of medial temporal lobe structures were significantly smaller in AD patients than in controls with exception of the left entorhinal cortex. The degree of atrophy was comparable between all structures. Diagnostic accuracy (number of correctly allocated cases divided by number of all cases) was highest for the right parahippocampal cortex with 85%, but only slightly lower for the right hippocampus and right entorhinal cortex with 82% and 84%. Using a linear combination of markers, the unilateral volumes of the right hippocampus, parahippocampal cortex and perirhinal cortex yielded an accuracy of 93%.


CONCLUSIONS
Extent of atrophy is similar between the different regions of the medial temporal lobe in mild AD.Volume measurements of medial temporal lobe structures in addition to the hippocampus only yield improved diagnostic accuracy if a combination of these structures is used.
Teipel
Stefan J
SJ
Alzheimer Memorial Center, Department of Psychiatry, Ludwig-Maximilian University, Nussbaumstrasse 7, 80336 Munich, Germany. Stefan.Teipel@med.uni-muenchen.de
Pruessner
Jens C
JC
Faltraco
Frank
F
Born
Christine
C
Rocha-Unold
Manoela
M
Evans
Alan
A
Möller
Hans-Jürgen
HJ
Hampel
Harald
H
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000473:pathology* / Q000503:physiopathology; D000679:Amygdala; D016001:Confidence Intervals; D018728:Entorhinal Cortex; D005260:Female; D006624:Hippocampus; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D016017:Odds Ratio; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013702:Temporal Lobe / Q000473:pathology* / Q000503:physiopathology