Subjective cognitive failures and hippocampal volume in elderly with white matter lesions

Background: Subjective cognitive failures (SCF) and subjective memory failures (SMF) have been reported to be an early predictor of Alzheimer disease (AD) and have been attributed to white matter lesions (WML). Since AD is characterized by hippocampal degeneration, it is surprising that its relation with hippocampal atrophy has been investigated only sparsely. Previous studies on this are rare, limited in sample size, and did not adjust for WML. Objective: To determine the relation between SCF and hippocampal volume in strata of objective cognitive performance among elderly without dementia with incidental WML. Methods: The Radboud University Nijmegen Diffusion tensor and MRI Cohort study is a prospective cohort study among 503 subjects with WML aged between 50 and 85 years. All subjects underwent FLAIR and T1 MRI scanning. The amount of SCF and SMF was rated by the Cognitive Failure Questionnaire. Cognitive function was assessed by a cognitive screening battery. Volumetric measures of hippocampus and WML were manually performed. We assessed the relation between hippocampal volume and SCF and SMF adjusted for age, sex, education, depression, intracranial volume, and WML volume. Results: Subjects with SCF and SMF had lower hippocampal volumes than those without (p = 0.01 and p = 0.02). This was most noteworthy in subjects with good objective cognitive performance (p(trend) = 0.007 and p(trend) = 0.03), and not in those with poor objective cognitive performance. Conclusion: Subjective cognitive failures (SCF) are associated with lower hippocampal volume, even in subjects without objective cognitive impairment and independent of white matter lesions. SCF has a radiologic detectable pathologic-anatomic substrate.