Brain lesion and lesion network analyses of anterograde and retrograde amnesia

Abstract

This thesis investigates lesion location and lesion network analyses in anterograde and retrograde amnesia using a systematic review of amnesia case reports and case series in the published peer-reviewed medical literature. We classified amnesia cases into three categories according to the severity of memory loss: predominately anterograde amnesia, predominately retrograde amnesia, and proportionate anterograde and retrograde amnesia. Advances in neuroimaging techniques have enabled us to locate and segment brain lesions with research-grade accuracy and answer questions about human brain disease and symptoms. In this thesis, we used brain lesion analysis to identify differential brain structures associated with anterograde and retrograde amnesias. We also employed lesion network mapping to localize functional and structural brain networks underlying anterograde and retrograde amnesias, lending insight into dissociable processes for encoding and retrieving episodic memory in humans. Our findings shed light on the specific brain networks contributing to anterograde and retrograde amnesias and provide insights into potential intervention targets for patients with memory disorders. Overall, this thesis work contributes to understanding the neural basis of episodic memory by elucidating discrete encoding and retrieval functions impacted in anterograde and retrograde amnesia. This brain network understanding of discrete episodic memory processes has translational implications for developing effective interventions and treatments for patients with memory disorders.