A meta-analysis of hippocampal atrophy rates in Alzheimer’s disease Josephine Barnes a,* , Jonathan W. Bartlett b , Laura A. van de Pol c , Clement T. Loy d , Rachael I. Scahill a , Chris Frost a,b , Paul Thompson e , and Nick C. Fox a a Dementia Research Centre, University College London, Institute of Neurology, Queen Square, London, UK b London School of Hygiene and Tropical Medicine, London, UK c Department of Neurology, Alzheimer Center, Vrije Universiteit Medical Center, Amsterdam, The Netherlands d Prince of Wales Medical Research Institute, Sydney, Australia e Laboratory of Neuro Imaging, Department of Neurology, UCLA School of Medicine, Los Angeles, CA 90095, USA Abstract Hippocampal atrophy rates are useful in both diagnosing and tracking Alzheimer’s disease (AD). However, cohorts and methods used to determine such rates are heterogeneous, leading to differences in reported annualised rates. We performed a meta-analysis of hippocampal atrophy rates in AD patients and matched controls from studies reported in the peer-reviewed literature. Studies reporting longitudinal volume change in hippocampi in AD subjects together with controls were systematically identified and appraised. All authors were contacted either to confirm the results or to provide missing data. Meta-analysis and meta-regression were then performed on this data. Nine studies were included from seven centres, with data from a total of 595 AD and 212 matched controls. Mean (95% CIs) annualised hippocampal atrophy rates were found to be 4.66% (95% CI 3.92, 5.40) for AD subjects and 1.41% (0.52, 2.30) for controls. The difference between AD and control subject in this rate was 3.33% (1.73, 4.94). Keywords Meta-analysis; Hippocampus; Atrophy; AD; Alzheimer’s; Rates; Longitudinal 1. Introduction Alzheimer’s disease (AD) is a large and growing problem with increasing financial and social burdens to the individual, carers and society. AD affects over 5% of the population over 60 years (Dawbarn and Allen, 2001) and its prevalence doubles every 5–10 years above that age (Small et al., 1997). A definitive diagnosis of AD can only be given following pathologic examination of the brain, usually at post-mortem. The disease is pathologically characterised by the presence of microscopic extracellular neuritic plaques and intracellular neurofibrillary tangles. AD tangle pathology progresses from medial temporal lobe structures such as the © 2008 Published by Elsevier Inc. *Corresponding author at: Dementia Research Centre, Box 16, The National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK. Tel.: +44 845 155 5000x723804; fax: +44 207 676 2066. E-mail address: j.barnes@dementia.ion.ucl.ac.uk (J. Barnes). Disclosures None of the authors have any disclosures to make. NIH Public Access Author Manuscript Neurobiol Aging. Author manuscript; available in PMC 2010 November 1. Published in final edited form as: Neurobiol Aging. 2009 November ; 30(11): 1711–1723. doi:10.1016/j.neurobiolaging.2008.01.010. NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript