Utility of MRI in the identification of hippocampal sclerosis of aging.

IntroductionHippocampal sclerosis of aging (HS) is a common pathology often misdiagnosed as Alzheimer's disease. We tested the hypothesis that participants with HS would have a magnetic resonance imaging (MRI)-detectable hippocampal pattern of atrophy distinct from participants without HS, both with and without Alzheimer's disease neuropathology (ADNP).MethodsQuery of the National Alzheimer's Coordinating Center database identified 198 participants with MRI and autopsy. Hippocampal subfields were segmented with FreeSurfer v6. Analysis of covariance for subfield volumes compared HS+ participants to those without HS, both with ADNP (HS-/ADNP+) and without (HS-/ADNP-).ResultsHS+ participants (N = 27, 14%) showed atrophied cornu ammonis 1 (CA1; left P < .001, ηp 2  = 0.14; right P = .001, ηp 2  = 0.09) and subiculum (left P < .001, ηp 2  = 0.139; right P = .001, ηp 2  = 0.085) compared to HS-/ADNP+ (N = 100, 51%). Compared to HS-/ADNP- (N = 71, 36%), HS+ also had atrophy in subiculum (left P < .001, ηp 2  = 0.235; right P = .002, ηp 2  = 0.137) and CA1 (left P < .001, ηp 2  = 0.137; right P = .006, ηp 2  = 0.070).DiscussionSubiculum and CA1 atrophy from clinical MRI may be a promising in vivo biomarker for HS