The relationship between the apolipoprotein E e4 allele and hippocampal magnetic resonance imaging volume in community-dwelling individuals with mild Alzheimer's disease

Bernard Walsh,¹ Stuart Slater,² Balakrishnan Nair,³ John Attia<sup>3

1</sup>Department of Geriatric Medicine, John Hunter Hospital, Newcastle, Australia; ²Hunter Imaging Group, Cardiff, Australia; ³Centre for Clinical Epidemiology and Biostatics, University of Newcastle, Australia

Background: The degree of hippocampal magnetic resonance imaging (MRI) volume loss in Alzheimer's disease (AD) is commonly accepted as a marker of disease severity, yet remains expensive, unavailable, or not tolerated by many patients.
Aim: To examine whether the presence of one or more apolipoprotein E (ApoE) e4 alleles is associated with smaller hippocampal MRI volumes in a population of early AD patients.
Methods: A total of 88 consecutive patients attending a community-based memory disorders clinic who had both mild dementia on the Clinical Dementia Rating scale and Diagnostic and Statistical Manual of Mental Disorders criteria for probable AD were recruited. We examined the relationship between ApoE e4 allele load and hippocampal atrophy on MRI volumes.
Results: There was no association between the ApoE e4 load and hippocampal volume in this cohort.
Conclusion: This study suggests that the presence of one or more ApoE e4 alleles cannot be used to estimate pathological disease load in early AD.

Keywords: apolipoprotein E, Alzheimer's disease, MRI, hippocampus