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Updated: Aug 14, 2026
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Investigations on Alterations of Hippocampal Circuit Function Following Mild Traumatic Brain Injury
Published on: November 19, 2012
Hippocampal amnesia
H J Spiers1, E A Maguire, N Burgess
1Institute of Cognitive Neuroscience and Department of Anatomy and Developmental Biology, 17 Queen Square, University College London, London WC1N 3AR, UK. h.spiers@ucl.ac.uk
Neurocase
|December 18, 2001
Summary
Bilateral hippocampal damage causes anterograde episodic memory loss but spares other memory types. Fornix lesions result in limited retrograde amnesia, highlighting specific memory system vulnerabilities.
Area of Science:
- Neuroscience
- Cognitive Psychology
- Neurology
Background:
- Amnesia is a complex memory disorder often linked to specific brain structures.
- Understanding the precise roles of the hippocampus and fornix in memory is crucial for diagnosing and treating amnesia.
Purpose of the Study:
- To review and synthesize findings from 147 cases of amnesia associated with hippocampal or fornix damage.
- To clarify consistent and controversial findings regarding memory deficits and lesion characteristics.
Main Methods:
- Systematic review of 179 publications reporting cases of amnesia.
- Tabulation of aetiology, mnestic abilities, and references for each of the 147 cases.
- Analysis of consistent and controversial findings across the reviewed cases.
Main Results:
- Bilateral hippocampal damage consistently correlates with deficits in anterograde episodic memory.
- Procedural and working memory remain largely intact following hippocampal damage.
- Lesions to the fornix are associated with limited retrograde amnesia.
Conclusions:
- Bilateral hippocampal damage specifically impairs the formation of new episodic memories.
- The fornix plays a role in retrograde memory, with lesions causing limited deficits.
- Further research is needed to resolve controversies regarding lesion size, laterality, and semantic memory impacts.
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