title: Anterograde and retrograde amnesia in a person with bilateral fornix lesions following removal of a colloid cyst.
abstract: AD, a 45-year-old man, presented with a severe and global anterograde amnesia following surgery for removal of a colloid cyst. Structural neuroimaging confirmed bilateral lesions to the fornix and a small lesion in the basal forebrain. Testing for remote episodic memory of autobiographical events, and for remote semantic memory of personal and public events, and of famous people, revealed that AD had a severe retrograde amnesia for autobiographical episodes that covered his entire lifetime, and a time-limited retrograde amnesia for semantic memory. Because the fornix and basal forebrain lesions disrupted major afferent and efferent pathways of the hippocampus, it was concluded that the integrity of the hippocampus and its projections are needed to retain and/or recover autobiographical memories no matter how old they are. By contrast, hippocampal contribution to semantic memory is time-limited. These findings were interpreted as consistent with Multiple Trace Theory, which holds that the hippocampal system is essential for recovering contextually rich memories no matter how old they are, but is not needed for recovering semantic memories.
authors.affiliation: Cleveland State University, Department of Psychology, Cleveland, OH 44115, USA.
authors.forename: Amir
authors.initials: A
authors.lastname: Poreh
authors.forename: Gordon
authors.initials: G
authors.lastname: Winocur
authors.forename: Morris
authors.initials: M
authors.lastname: Moscovitch
authors.forename: Matti
authors.initials: M
authors.lastname: Backon
authors.forename: Elinor
authors.initials: E
authors.lastname: Goshen
authors.forename: Zvi
authors.initials: Z
authors.lastname: Ram
authors.forename: Zeev
authors.initials: Z
authors.lastname: Feldman
mesh_terms: D020324:Amnesia, Anterograde / Q000503:physiopathology*; D000648:Amnesia, Retrograde / Q000503:physiopathology*; D001930:Brain Injuries / Q000150:complications / Q000209:etiology / Q000473:pathology*; D003560:Cysts / Q000601:surgery; D020712:Fornix, Brain / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D019635:Neurosurgical Procedures / Q000009:adverse effects