Hippocampal and diencephalic pathology in developmental amnesia

Cortex. 2017 Jan;86:33-44. doi: 10.1016/j.cortex.2016.09.016. Epub 2016 Sep 30.

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.

Keywords: Hippocampus; Hypoxia-ischaemia; Mammillary bodies; Memory; Thalamus.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Intramural

MeSH terms

  • Adolescent
  • Adult
  • Amnesia / diagnostic imaging
  • Amnesia / pathology*
  • Atrophy / diagnostic imaging
  • Atrophy / pathology
  • Child
  • Female
  • Hippocampus / diagnostic imaging
  • Hippocampus / pathology*
  • Humans
  • Male
  • Mammillary Bodies / diagnostic imaging
  • Mammillary Bodies / pathology*
  • Memory, Episodic
  • Memory, Short-Term
  • Young Adult