title: Cognitive state following stroke: the predominant role of preexisting white matter lesions.
abstract: OBJECTIVE
  Stroke is a major cause of cognitive impairment and dementia in adults, however the role of the ischemic lesions themselves, on top of other risk factors known in the elderly, remains controversial. This study used structural equation modeling to determine the respective impact of the new ischemic lesions' volume, preexisting white matter lesions and white matter integrity on post stroke cognitive state.
  
  
  METHODS
  Consecutive first ever mild to moderate stroke or transient ischemic attack patients recruited into the ongoing prospective TABASCO study underwent magnetic resonance imaging scans within seven days of stroke onset and were cognitively assessed one year after the event using a computerized neuropsychological battery. The volumes of both ischemic lesions and preexisting white matter lesions and the integrity of the normal appearing white matter tissue were measured and their contribution to cognitive state was assessed using structural equation modeling path analysis taking into account demographic parameters. Two models were hypothesized, differing by the role of ischemic lesions' volume.
  
  
  RESULTS
  Structural equation modeling analysis of 142 patients confirmed the predominant role of white matter lesion volume (standardized path coefficient β =  -0.231) and normal appearing white matter integrity (β =  -0.176) on the global cognitive score, while ischemic lesions' volume showed no such effect (β = 0.038). The model excluding the ischemic lesion presented better fit to the data (comparative fit index 0.9 versus 0.092).
  
  
  CONCLUSIONS
  Mild to moderate stroke patients with preexisting white matter lesions are more vulnerable to cognitive impairment regardless of their new ischemic lesions. Thus, these patients can serve as a target group for studies on cognitive rehabilitation and neuro-protective therapies which may, in turn, slow their cognitive deterioration.
authors.affiliation: Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; 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: Jaime and Joan Constantiner School of Education, Tel Aviv University, Tel Aviv, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Tarrasch
authors.affiliation: Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Moran
authors.initials: M
authors.lastname: Artzi
authors.affiliation: 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: Shani
authors.initials: S
authors.lastname: Shenhar-Tsarfaty
authors.affiliation: Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
authors.forename: Orna
authors.initials: O
authors.lastname: Aizenstein
authors.affiliation: Neurology Department, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
authors.forename: Hen
authors.initials: H
authors.lastname: Hallevi
authors.affiliation: Neurology Department, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
authors.forename: Anat
authors.initials: A
authors.lastname: Mike
authors.affiliation: Neurology Department, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
authors.forename: Ludmila
authors.initials: L
authors.lastname: Shopin
authors.affiliation: 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; 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; D001921:Brain / Q000473:pathology*; D003071:Cognition; D003072:Cognition Disorders / Q000209:etiology / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D009483:Neuropsychological Tests; D011446:Prospective Studies; D020521:Stroke / Q000150:complications / Q000473:pathology*; D066127:White Matter / Q000473:pathology*