title: Selective neuronal vulnerability of human hippocampal CA1 neurons: lesion evolution, temporal course, and pattern of hippocampal damage in diffusion-weighted MR imaging.
abstract: The CA1 (cornu ammonis) region of hippocampus is selectively vulnerable to a variety of metabolic and cytotoxic insults, which is mirrored in a delayed neuronal death of CA1 neurons. The basis and mechanisms of this regional susceptibility of CA1 neurons are poorly understood, and the correlates in human diseases affecting the hippocampus are not clear. Adopting a translational approach, the lesion evolution, temporal course, pattern of diffusion changes, and damage in hippocampal CA1 in acute neurologic disorders were studied using high-resolution magnetic resonance imaging. In patients with hippocampal ischemia (n=50), limbic encephalitis (n=30), after status epilepticus (n=17), and transient global amnesia (n=53), the CA1 region was selectively affected compared with other CA regions of the hippocampus. CA1 neurons exhibited a maximum decrease of apparent diffusion coefficient (ADC) 48 to 72 hours after the insult, irrespective of the nature of the insult. Hypoxic-ischemic insults led to a significant lower ADC suggesting that the ischemic insult results in a stronger impairment of cellular metabolism. The evolution of diffusion changes show that CA1 diffusion lesions mirror the delayed time course of the pathophysiologic cascade typically observed in animal models. Studying the imaging correlates of hippocampal damage in humans provides valuable insight into the pathophysiology and neurobiology of the hippocampus.
authors.affiliation: Department of Neurology, Memory Disorders and Plasticity Group, University Hospital Schleswig-Holstein, Kiel, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Bartsch
authors.affiliation: Department of Neurology, Memory Disorders and Plasticity Group, University Hospital Schleswig-Holstein, Kiel, Germany.
authors.forename: Juliane
authors.initials: J
authors.lastname: Döhring
authors.affiliation: Department of Neurology, Memory Disorders and Plasticity Group, University Hospital Schleswig-Holstein, Kiel, Germany.
authors.forename: Sigrid
authors.initials: S
authors.lastname: Reuter
authors.affiliation: Department of Neurology, Charité Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Finke
authors.affiliation: Institute of Neuroradiology, University Hospital Schleswig-Holstein, Kiel, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Rohr
authors.affiliation: Department of Neurology, Memory Disorders and Plasticity Group, University Hospital Schleswig-Holstein, Kiel, Germany.
authors.forename: Henriette
authors.initials: H
authors.lastname: Brauer
authors.affiliation: Department of Neurology, Memory Disorders and Plasticity Group, University Hospital Schleswig-Holstein, Kiel, Germany.
authors.forename: Günther
authors.initials: G
authors.lastname: Deuschl
authors.affiliation: Institute of Neuroradiology, University Hospital Schleswig-Holstein, Kiel, Germany.
authors.forename: Olav
authors.initials: O
authors.lastname: Jansen
mesh_terms: D000328:Adult; D000368:Aged; D020236:Amnesia, Transient Global / Q000473:pathology; D002545:Brain Ischemia / Q000473:pathology; D056547:CA1 Region, Hippocampal / Q000473:pathology* / Q000503:physiopathology; D002561:Cerebrovascular Disorders / Q000145:classification / Q000473:pathology; D015331:Cohort Studies; D038524:Diffusion Magnetic Resonance Imaging; D004660:Encephalitis / Q000473:pathology; D005260:Female; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D002534:Hypoxia, Brain / Q000473:pathology; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009474:Neurons / Q000473:pathology*; D012307:Risk Factors; D013226:Status Epilepticus / Q000473:pathology