title: Neural Correlate of Anterograde Amnesia in Wernicke-Korsakoff Syndrome.
abstract: The neural correlate of anterograde amnesia in Wernicke-Korsakoff syndrome (WKS) is still debated. While the capacity to learn new information has been associated with integrity of the medial temporal lobe (MTL), previous studies indicated that the WKS is associated with diencephalic lesions, mainly in the mammillary bodies and anterior or dorsomedial thalamic nuclei. The present study tested the hypothesis that amnesia in WKS is associated with a disrupted neural circuit between diencephalic and hippocampal structures. High-density evoked potentials were recorded in four severely amnesic patients with chronic WKS, in five patients with chronic alcoholism without WKS, and in ten age matched controls. Participants performed a continuous recognition task of pictures previously shown to induce a left medial temporal lobe dependent positive potential between 250 and 350 ms. In addition, the integrity of the fornix was assessed using diffusion tensor imaging (DTI). WKS, but not alcoholic patients without WKS, showed absence of the early, left MTL dependent positive potential following immediate picture repetitions. DTI indicated disruption of the fornix, which connects diencephalic and hippocampal structures. The findings support an interpretation of anterograde amnesia in WKS as a consequence of a disconnection between diencephalic and MTL structures with deficient contribution of the MTL to rapid consolidation.
authors.affiliation: Laboratory of Cognitive Neurorehabilitation, Department of Clinical Neurosciences and Dermatology, Medical Faculty, University Hospitals of Geneva, Geneva, Switzerland. louis.nahum@hcuge.ch.|Division of Neurorehabilitation, Department of Clinical Neurosciences, University Hospitals of Geneva, Av. de Beau-Séjour 26, 1211, Geneva, Switzerland. louis.nahum@hcuge.ch.
authors.forename: Louis
authors.initials: L
authors.lastname: Nahum
authors.affiliation: Laboratory of Cognitive Neurorehabilitation, Department of Clinical Neurosciences and Dermatology, Medical Faculty, University Hospitals of Geneva, Geneva, Switzerland.|Division of Radiology, Department of Neuroscience and Department of Neurology, University Hospitals of Geneva, Geneva, Switzerland.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Pignat
authors.affiliation: Laboratory of Cognitive Neurorehabilitation, Department of Clinical Neurosciences and Dermatology, Medical Faculty, University Hospitals of Geneva, Geneva, Switzerland.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Bouzerda-Wahlen
authors.affiliation: Laboratory of Cognitive Neurorehabilitation, Department of Clinical Neurosciences and Dermatology, Medical Faculty, University Hospitals of Geneva, Geneva, Switzerland.
authors.forename: Damien
authors.initials: D
authors.lastname: Gabriel
authors.affiliation: Laboratory of Cognitive Neurorehabilitation, Department of Clinical Neurosciences and Dermatology, Medical Faculty, University Hospitals of Geneva, Geneva, Switzerland.
authors.forename: Maria Chiara
authors.initials: MC
authors.lastname: Liverani
authors.affiliation: Division of Radiology, Department of Neuroscience and Department of Neurology, University Hospitals of Geneva, Geneva, Switzerland.
authors.forename: François
authors.initials: F
authors.lastname: Lazeyras
authors.affiliation: Laboratory of Cognitive Neurorehabilitation, Department of Clinical Neurosciences and Dermatology, Medical Faculty, University Hospitals of Geneva, Geneva, Switzerland.|Division of Neurorehabilitation, Department of Clinical Neurosciences, University Hospitals of Geneva, Av. de Beau-Séjour 26, 1211, Geneva, Switzerland.
authors.forename: Radek
authors.initials: R
authors.lastname: Ptak
authors.affiliation: Division of Radiology, Department of Neuroscience and Department of Neurology, University Hospitals of Geneva, Geneva, Switzerland.|Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Standford, CA, USA.
authors.forename: Jonas
authors.initials: J
authors.lastname: Richiardi
authors.affiliation: Division of Radiology, Department of Neuroscience and Department of Neurology, University Hospitals of Geneva, Geneva, Switzerland.
authors.forename: Sven
authors.initials: S
authors.lastname: Haller
authors.affiliation: Division of Addictology, Department of Psychiatry, University Hopsitals of Geneva, Geneva, Switzerland.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Thorens
authors.affiliation: Division of Addictology, Department of Psychiatry, University Hopsitals of Geneva, Geneva, Switzerland.
authors.forename: Daniele F
authors.initials: DF
authors.lastname: Zullino
authors.affiliation: Laboratory of Cognitive Neurorehabilitation, Department of Clinical Neurosciences and Dermatology, Medical Faculty, University Hospitals of Geneva, Geneva, Switzerland.|Division of Neurorehabilitation, Department of Clinical Neurosciences, University Hospitals of Geneva, Av. de Beau-Séjour 26, 1211, Geneva, Switzerland.
authors.forename: Adrian G
authors.initials: AG
authors.lastname: Guggisberg
authors.affiliation: Laboratory of Cognitive Neurorehabilitation, Department of Clinical Neurosciences and Dermatology, Medical Faculty, University Hospitals of Geneva, Geneva, Switzerland.|Division of Neurorehabilitation, Department of Clinical Neurosciences, University Hospitals of Geneva, Av. de Beau-Séjour 26, 1211, Geneva, Switzerland.
authors.forename: Armin
authors.initials: A
authors.lastname: Schnider
mesh_terms: D000437:Alcoholism; D020324:Amnesia, Anterograde / Q000473:pathology; D016022:Case-Control Studies; D004027:Diencephalon / Q000473:pathology*; D005260:Female; D006624:Hippocampus / Q000502:physiology; D006801:Humans; D020915:Korsakoff Syndrome / Q000473:pathology / Q000503:physiopathology*; D008875:Middle Aged; D009415:Nerve Net / Q000503:physiopathology*; D009483:Neuropsychological Tests; D013702:Temporal Lobe / Q000473:pathology; D014899:Wernicke Encephalopathy