title: Cognitive state following mild stroke: A matter of hippocampal mean diffusivity.
abstract: The hippocampus is known to play a vital role in learning and memory and was demonstrated as an early imaging marker for Alzheimer's disease (AD). However, its role as a predictor for mild cognitive impairment and dementia following stroke is unclear. The main purpose of this study was to examine the associations between hippocampal volume, mean diffusivity (MD) and connectivity and cognitive state following stroke. Eighty three consecutive first ever mild to moderate stroke or transient ischemic attack (TIA) survivors from our ongoing prospective TABASCO (Tel Aviv Brain Acute Stroke Cohort) study underwent magnetic resonance imaging scans within 7 days of stroke onset. Hippocampal volume was measured from T1 weighted images, hippocampal mean diffusivity was calculated from diffusion tensor imaging and connectivity was calculated from resting state fMRI. Global cognitive assessments were evaluated during hospitalization and 6 and 12 months later using a computerized neuropsychological battery. Multiple linear regression analysis was used to test which of the hippocampi measurements best predict cognitive state. All three imaging parameters were significantly correlated to each other (|r's| >0.3, P's < 0.005), and with cognitive state 6 and 12 months after the event. Multiple regression analyses demonstrated the predictive role of hippocampal mean diffusivity (β = -0.382, P = 0.026) on cognitive state, above and beyond that of volume and connectivity of this structure. To our knowledge, the combination of hippocampal volume, mean diffusivity and connectivity in first ever post stroke or TIA patients has not yet been considered in relation to cognitive state. The results demonstrate the predictive role of hippocampal mean diffusivity, suggesting that these changes may precede and contribute to volumetric and connectivity changes in the hippocampi, potentially serving as a marker for early identification of patients at risk of developing cognitive impairment or dementia.
authors.affiliation: Functional Brain Center, the Wohl Institute for Advanced Imaging, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.|Imaging devision, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.|Neurology Department, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
authors.forename: Efrat
authors.initials: E
authors.lastname: Kliper
authors.affiliation: Neurology Department, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
authors.forename: Einor
authors.initials: E
authors.lastname: Ben Assayag
authors.affiliation: Imaging devision, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Amos D
authors.initials: AD
authors.lastname: Korczyn
authors.affiliation: Neurology Department, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
authors.forename: Eitan
authors.initials: E
authors.lastname: Auriel
authors.affiliation: Neurology Department, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
authors.forename: Ludmila
authors.initials: L
authors.lastname: Shopin
authors.affiliation: Neurology Department, Carmel Medical Center, Haifa, Israel.
authors.forename: Hen
authors.initials: H
authors.lastname: Hallevi
authors.affiliation: Neurology Department, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
authors.forename: Shani
authors.initials: S
authors.lastname: Shenhar-Tsarfaty
authors.affiliation: Neurology Department, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
authors.forename: Anat
authors.initials: A
authors.lastname: Mike
authors.affiliation: Functional Brain Center, the Wohl Institute for Advanced Imaging, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.|Imaging devision, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Moran
authors.initials: M
authors.lastname: Artzi
authors.affiliation: Functional Brain Center, the Wohl Institute for Advanced Imaging, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
authors.forename: Ilana
authors.initials: I
authors.lastname: Klovatch
authors.affiliation: Imaging devision, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.|Neurology Department, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
authors.forename: Natan M
authors.initials: NM
authors.lastname: Bornstein
authors.affiliation: Functional Brain Center, the Wohl Institute for Advanced Imaging, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.|Imaging devision, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.|Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Dafna
authors.initials: D
authors.lastname: Ben Bashat
mesh_terms: D000368:Aged; D060825:Cognitive Dysfunction / Q000175:diagnosis* / Q000453:epidemiology*; D015331:Cohort Studies; D056324:Diffusion Tensor Imaging / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D007557:Israel / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D020521:Stroke / Q000175:diagnosis* / Q000453:epidemiology*
keywords: MRI; TABASCO; cognition; hippocampus; stroke