This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.
Abstract
Background: We tested if rates of brain atrophy accelerate in individuals with amnestic mild cognitive impairment (aMCI) as they progress to typical late onset Alzheimer disease (AD). We included comparisons to subjects with aMCI who did not progress (labeled aMCI-S) and also to cognitively normal elderly subjects (CN).
Methods: We studied 46 subjects with aMCI who progressed to AD (labeled aMCI-P), 46 CN, and 23 aMCI-S. All subjects must have had three or more serial MRI scans. Rates of brain shrinkage and ventricular expansion were measured across all available serial MRI scans in each subject. Change in volumes relative to the point at which subjects progressed to a clinical diagnosis of AD (the index date) was modeled in aMCI-P. Change in volumes relative to age was modeled in all three clinical groups.
Results: In aMCI-P the change in pre to post index rate (i.e., acceleration) of ventricular expansion was 1.7 cm3/year, and acceleration in brain shrinkage was 5.3 cm3/year. Brain volume declined and ventricular volume increased in all three groups with age. Volume changes decelerated with increasing age in aMCI-P, and to a lesser extent in aMCI-S, but were linear in the matched CN. Among all subjects with aMCI, rates of atrophy were greater in apolipoprotein E ε4 carriers than noncarriers.
Conclusions: Rates of atrophy accelerate as individuals progress from amnestic mild cognitive impairment (aMCI) to typical late onset Alzheimer disease (AD). Rates of atrophy are greater in younger than older subjects with aMCI who progressed to AD and subjects with aMCI who did not progress. We did not find that atrophy rates varied with age in 70- to 90-year-old cognitively normal subjects.
Glossary
- AD=
- Alzheimer disease;
- aMCI=
- amnestic mild cognitive impairment;
- aMCI-P=
- subjects with aMCI who progressed to AD;
- aMCI-S=
- subjects with aMCI who did not progress;
- APOE=
- apolipoprotein E;
- AVLT=
- Auditory Verbal Learning Test;
- CDR=
- Clinical Dementia Rating;
- CN=
- cognitively normal;
- FLAIR=
- fluid attenuated inversion recovery;
- MMSE=
- Mini-Mental State Examination;
- TE=
- echo time;
- TR=
- repetition time;
- TIV=
- Total intracranial volume;
- WAIS-R=
- Wechsler Adult Intelligence Scale–Revised;
- WMS=
- Wechsler Memory Scale.
AAN Members: Sign in with your AAN member credentials (e-mail or 6-digit Member ID number)
Non-AAN Member subscribers: Sign in with subscriber credentials
Log in using your username and password
Purchase access
Disputes & Debates: Rapid online correspondence
NOTE: All authors' disclosures must be entered and current in our database before comments can be posted. Enter and update disclosures at http://submit.neurology.org. Exception: replies to comments concerning an article you originally authored do not require updated disclosures.
- Stay timely. Submit only on articles published within the last 8 weeks.
- Do not be redundant. Read any comments already posted on the article prior to submission.
- 200 words maximum.
- 5 references maximum. Reference 1 must be the article on which you are commenting.
- 5 authors maximum. Exception: replies can include all original authors of the article.
- Submitted comments are subject to editing and editor review prior to posting.