A comparison of beta-amyloid deposition in the medial temporal lobe in sporadic Alzheimer's disease, Down's syndrome and normal elderly brains.
The density of beta-amyloid (A beta) deposits was studied in the medial temporal lobe in non-demented individuals and in sporadic Alzheimer's disease (SAD) and Down's syndrome (DS). No A beta deposits were recorded in six of the non-demented cases, while in a further eight cases, these were confined to either the lateral occipitotemporal or parahippocampal gyrus. The mean density of A beta deposits in the cortex was greater in SAD and DS than in non-demented cases but with overlap between patient groups. The mean density of A beta deposits was greater in DS than SAD consistent with a gene dosage effect. The ratio of primitive to diffuse A beta deposits was greater in DS and in non-demented cases than in SAD and the ratio of classic to diffuse deposits was lowest in DS. In all groups, A beta deposits occurred in clusters which were often regularly distributed. In the cortex, the dimension of the A beta clusters was greater in SAD than in the non-demented cases and DS. The data suggest that the development of A beta pathology in the hippocampus could be a factor in the development of DS and SAD. Furthermore, the high density of A beta deposits, and in particular the high proportion of primitive type deposits, may be important in DS while the development of large clusters of A beta deposits may be a factor in SAD.
Armstrong
R A
RA
Aston University, Birmingham.
Cairns
N J
NJ
Myers
D
D
Smith
C U
CU
Lantos
P L
PL
Rossor
M N
MN
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism*; D000544:Alzheimer Disease / Q000378:metabolism* / Q000473:pathology; D016229:Amyloid beta-Peptides / Q000032:analysis / Q000378:metabolism*; D000704:Analysis of Variance; D004314:Down Syndrome / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008875:Middle Aged; D009928:Organ Specificity; D012016:Reference Values; D013702:Temporal Lobe / Q000254:growth & development / Q000378:metabolism* / Q000473:pathology
D016229:Amyloid beta-Peptides