Year: 2008
Type: article
Abstract: Mild cognitive impairment is an intermediate cognitive state between normal aging and dementia. MCI subjects who transition to AD have been reported to have selective atrophy in hippocampal regions corresponding to the CA1 and subiculum. Objective: To compare the 3D hippocampal atrophy pattern of subjects with low, intermediate and advanced hippocampal atrophy measured with the visual quantitative medial temporal atrophy rating (MTA) method (range 0-no to 4-severe atrophy). We analyzed the baseline 3D MRI data of the 169 amnestic MCI participants (154 with MTA<2, mean MMSE = 27.6±1.8 and 15 with MTA≥2, mean MMSE= 26.6±2.1) from the imaging part of the ADCS Donepezil/Vitamin E trial. 60% of the MTA≥2 and 33.8% of the MTA<2 groups had converted to Alzheimer's disease at 3-year follow-up. Using the radial distance atrophy mapping approach we created 3D hippocampal mesh models. We mapped the radial distance from the medial core to each surface point, computed group average maps and subjected them to statistical comparisons. We also conducted quantitative comparisons of 5 subgroups divided based on their MTA scores in 0.5 increments relative to the MTA=0 group and developed a 4D animation sequence showing incremental atrophic changes with increasing MTA rating. The MTA≥2 group was older (p=0.001) and had lower MMSE scores (p=0.05). The 3D statistical maps revealed greater left sided hippocampal atrophy in MTA≥2 vs. MTA<2 (left p=0.0028, right p=0.3, corrected for multiple comparisons). The areas where significant between-group differences were seen showed 7–10% greater atrophy. The 4D animation of the incremental atrophy with worsening MTA rating can be viewed at http://www.loni.ucla.edu/∼lianaa/MTA_progression.mov. The hippocampal formations that had been assigned higher MTA scores demonstrated progressively greater atrophy of the subiculum and the CA1–3 subregions. Subjects with MTA≥2 have more advanced left-sided hippocampal atrophy localizing to the subiculum, CA1 and CA2/3 hippocampal subregions relative to subjects with MTA<2. Worsening MTA ratingassociates with greater hippocampal atrophy of the subiculum, and CA1–3 hippocampal subfields.
Source: Alzheimer s & Dementia
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2081497563