O1‐01–02: Alzheimer's disease with relative hippocampal sparing: A distinct clinicopathologic variant
Year: 2008
Type: article
Study design: Observational Study
Abstract: Neuronal loss and neurofibrillary tangles (NFT) are characteristically severe in the medial temporal lobe, including the hippocampus (Hp), in Alzheimer's disease (AD). Atrophy of the Hp on antemortem structural imaging correlates with conversion of at-risk individuals to AD and clinical progression of AD. On the other hand, at autopsy a subset of AD cases have relative preservation of the Hp with respect to atrophy and NFT density. The Mayo Clinic Jacksonville brain bank database was queried for AD cases with complete quantitative data and a Braak NFT stage of V or VI. 718 AD cases were identified, including 305 men and 413 women, ranging in age from 37 to 103 years. They were subdivided into two groups based upon the relative density of NFT in the Hp and convexity cortices. Maximal NFT density was assessed at high magnification with thioflavin-S fluorescent microscopy in four sectors of hippocampus (endplate, CA2/3, CA1, and subiculum) and three association cortices (superior temporal, mid-frontal, and inferior parietal) and a primary cortex (visual cortex). A Braak NFT stage was assigned on each based upon the distribution of NFT. The AD/HpSp group (N=42) were significantly different from AD with respect to NFT densities in all but the primary visual cortex. They had significantly fewer NFT (p<0.01) in the endplate, CA2/3, CA1 and subiculum. In contrast, the NFT density in superior temporal, mid-frontal and inferior parietal cortices were all significantly (p<0.001) higher in AD/HpSp compared to AD. The AD/HpSp group was significantly younger (average 70 vs. 80 years) and the male:female ratio was greater in AD/HpSp than in AD (0.6 vs. 0.4). The APOE e4 carrier frequency was also lower in AD/HpSp (33% vs. 62%). Our data suggests that AD/HpSp is an uncommon variant of AD accounting for about 6% of AD cases at autopsy. These cases have disproportionately more cortical than Hp neurofibrillary pathology. They also tend to be men, to have a younger age at death, and to be negative for APOE e4. Future studies are needed to determine if these individuals have distinctive clinical and imaging features.
Source: Alzheimer s & Dementia
Authors: Melissa E. Murray, Dennis Dickson
Institutions: Mayo Clinic, Mayo Clinic in Florida
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2117616494