Hippocampal and diencephalic pathology in developmental amnesia

• Type of Material: Article
• Authors: Jocelyne Bachevalier, Emory University; Anna M Dzieciol, University College London; Kadharbatcha S. Saleem, National Institutes of Health; David G. Gadian, University College London; Richard Saunders, National Institutes of Health; W.K.Kling Chong, Great Ormond Street Hospital for Children; Tina Banks, Great Ormond Street Hospital for Children; Mortimer Mishkin, National Institutes of Health; Faraneh Vargha-Khadem, University College London
• Language: English
• Date: 2017-01
• Publisher: Elsevier
• Publication Version: Final Published Version
• Copyright Statement: © 2016 The Authors
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.cortex.2016.09.016
• Title of Journal or Parent Work: Cortex
• ISSN: 0010-9452
• Volume: 86
• Start Page: 33
• End Page: 44
• Grant/Funding Information: This work was supported by the Medical Research Council (programme grant numbers G03000117/65439 and G1002276-E01/1), and the Intramural Research Program of the National Institute of Mental Health, National Institutes of Health, and supported by the National Institute for Health Research Biomedical Research Centre at Great Ormond Street Hospital for Children NHS Foundation Trust and University College London.
• Keywords: Memory; Hippocampus; Mammillary bodies; Hypoxia-ischaemia; Thalamus
• Research Categories: Psychology, Clinical; Biology, Neuroscience; Health Sciences, Pathology

Abstract

Developmental amnesia (DA) is a selective episodic memory disorder associated with hypoxia-induced bilateral hippocampal atrophy of early onset. Despite the systemic impact of hypoxia-ischaemia, the resulting brain damage was previously reported to be largely limited to the hippocampus. However, the thalamus and the mammillary bodies are parts of the hippocampal-diencephalic network and are therefore also at risk of injury following hypoxic-ischaemic events. Here, we report a neuroimaging investigation of diencephalic damage in a group of 18 patients with DA (age range 11–35 years), and an equal number of controls. Importantly, we uncovered a marked degree of atrophy in the mammillary bodies in two thirds of our patients. In addition, as a group, patients had mildly reduced thalamic volumes. The size of the anterior-mid thalamic (AMT) segment was correlated with patients' visual memory performance. Thus, in addition to the hippocampus, the diencephalic structures also appear to play a role in the patients' memory deficit.