title: Congenital absence of the mammillary bodies: a novel finding in a well-studied case of developmental amnesia.
abstract: Individuals with developmental amnesia experience compromised development of episodic memory for details of personal life events, believed to relate to changes to the hippocampus after birth. Here we report the very rare discovery of aplasia of the mammillary bodies, hypogenesis of the fornix, and abnormal hippocampal shape and orientation in H.C., a well-documented case of selectively compromised episodic memory development who is the subject of numerous published empirical articles. These anatomical abnormalities are highly suggestive of disrupted extended hippocampal system development very early in gestation, despite an original diagnosis of developmental amnesia and assumed perinatal hypoxia. These findings provide a unique window into the normal function of the mammillary bodies, fornices, and related anterior nuclei of the thalamus bilaterally. The results also encourage re-examination of the pathological basis of developmental amnesia in other cases reported in the literature.
authors.affiliation: Department of Psychology, York University, Toronto, Ontario, Canada M3J 1P3; Rotman Research Institute Baycrest Health Sciences, Toronto, Ontario, Canada M6A 2E1. Electronic address: shaynar@yorku.ca.
authors.forename: R Shayna
authors.initials: RS
authors.lastname: Rosenbaum
authors.affiliation: LC Campbell Cognitive Neurology Research Unit, Brain Science Research Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada M4N 3M5.
authors.forename: Fuqiang
authors.initials: F
authors.lastname: Gao
authors.affiliation: LC Campbell Cognitive Neurology Research Unit, Brain Science Research Program, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada M4N 3M5.
authors.forename: Kie
authors.initials: K
authors.lastname: Honjo
authors.affiliation: Division of Neuroradiology, Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8; Department of Medical Imaging, University of Toronto, Toronto, Ontario, Canada M5T 1W7.
authors.forename: Charles
authors.initials: C
authors.lastname: Raybaud
authors.affiliation: Rotman Research Institute Baycrest Health Sciences, Toronto, Ontario, Canada M6A 2E1.
authors.forename: Rosanna K
authors.initials: RK
authors.lastname: Olsen
authors.affiliation: Rotman Research Institute Baycrest Health Sciences, Toronto, Ontario, Canada M6A 2E1; Department of Psychology, University of Toronto, Toronto, Ontario, Canada M5S 3G3.
authors.forename: Daniela J
authors.initials: DJ
authors.lastname: Palombo
authors.affiliation: Rotman Research Institute Baycrest Health Sciences, Toronto, Ontario, Canada M6A 2E1; Department of Psychology, University of Toronto, Toronto, Ontario, Canada M5S 3G3; Department of Medicine (Neurology), University of Toronto, Toronto, Ontario, Canada M4N 3M5.
authors.forename: Brian
authors.initials: B
authors.lastname: Levine
authors.affiliation: Rotman Research Institute Baycrest Health Sciences, Toronto, Ontario, Canada M6A 2E1; Department of Medical Imaging, University of Toronto, Toronto, Ontario, Canada M5T 1W7; Department of Medicine (Neurology), University of Toronto, Toronto, Ontario, Canada M4N 3M5.
authors.forename: Sandra E
authors.initials: SE
authors.lastname: Black
mesh_terms: D000328:Adult; D000647:Amnesia / Q000209:etiology*; D005260:Female; D006801:Humans; D008326:Mammillary Bodies / Q000002:abnormalities*; D061212:Memory, Episodic; D055815:Young Adult
keywords: Case study; Developmental amnesia; Episodic memory; Extended hippocampal system; Mammillary bodies