Modifying Criteria for Amnestic MCI Dx Increases Prognostic Accuracy
Requiring impairment on two memory tests improves prediction of brain atrophy and progression to AD
WEDNESDAY, Dec. 19, 2018 (HealthDay News) -- Modifying diagnostic criteria to require impairment on at least two memory tests for mild cognitive impairment (MCI) diagnosis can improve prediction of medial temporal atrophy and conversion to Alzheimer's disease (AD), according to a study published online Dec. 4 in Brain Imaging and Behavior.
Eero Vuoksimaa, Ph.D., from the Institute for Molecular Medicine in Helsinki, and colleagues examined whether an MCI diagnostic requirement of impairment on at least two episodic memory tests improves three-year prediction of medial temporal lobe atrophy and progression to AD among 230 cognitively normal (CN) and 394 MCI individuals. MCI participants were further classified as having normal or impaired performance on the Rey Auditory Verbal Learning Test (AVLT+, 121 participants; AVLT−, 273 participants).
The researchers observed significant differences in the CN, AVLT+, and AVLT− groups on baseline brain and cerebrospinal fluid biomarkers; the AVLT− group was the most abnormal. Compared with the AVLT+ group, the AVLT− group had significantly more medial temporal atrophy and a substantially higher AD progression rate (51 versus 16 percent). Similar medial temporal trajectories were seen for the AVLT+ group and CN individuals. Even when restricted to individuals with above-average baseline medial temporal volume/thickness, the results were similar.
"The core clinical criteria defining amnestic MCI should incorporate the criterion of impaired performance on at least two memory measures," the authors write.
One author disclosed financial ties to CorTech Labs Inc.; data collection for the project was funded by the Alzheimer's Disease Neuroimaging Initiative, which was funded in part by pharmaceutical companies.