title: Narrative Organization Deficit in Lewy Body Disorders Is Related to Alzheimer Pathology.
abstract: Background:Day-to-day interactions depend on conversational narrative, and we examine here the neurobiological basis for difficulty organizing narrative discourse in patients with Lewy body disorders (LBD).Method:Narrative organization was examined in 56 non-aphasic LBD patients, including a non-demented cohort (n= 30) with Parkinson's disease (PD) or PD-Mild Cognitive Impairment PD-MCI,) and a cohort with mild dementia (n= 26) including PD-dementia (PDD) and dementia with Lewy bodies (DLB), with similar age and education but differing in MMSE (p< 0.001). We used a previously reported procedure that probes patients' judgments of the organization of brief, familiar narratives (e.g., going fishing, wrapping a present). A subgroup of 24 patients had MRI assessment of regional gray matter (GM) atrophy and cerebrospinal fluid (CSF) levels of biomarkers for Alzheimer's disease (AD) pathology, including beta amyloid (Aβ), total-tau (t-tau), and phosphorylated-tau (p-tau).Results:Mildly demented LBD patients had a significant deficit judging narratives compared to non-demented patients, but this deficit was not correlated with MMSE. Regression analyses instead related narrative organization to regions of frontal GM atrophy, and CSF levels of Aβ andt-tau associated with presumed AD pathology in these frontal regions.Conclusion:These findings are consistent with the hypothesis that CSF markers of AD pathology associated with frontal regions play a role in difficulty organizing narratives in LBD.
authors.affiliation: Departments of Neurology, University of Pennsylvania PA, USA.
authors.forename: Murray
authors.initials: M
authors.lastname: Grossman
authors.affiliation: Departments of Neurology, University of Pennsylvania PA, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Irwin
authors.affiliation: Departments of Neurology, University of Pennsylvania PA, USA.
authors.forename: Charles
authors.initials: C
authors.lastname: Jester
authors.affiliation: Departments of Neurology, University of Pennsylvania PA, USA.
authors.forename: Amy
authors.initials: A
authors.lastname: Halpin
authors.affiliation: Departments of Neurology, University of Pennsylvania PA, USA.
authors.forename: Sharon
authors.initials: S
authors.lastname: Ash
authors.affiliation: Departments of Neurology, University of Pennsylvania PA, USA.
authors.forename: Katya
authors.initials: K
authors.lastname: Rascovsky
authors.affiliation: Departments of Psychiatry, University of Pennsylvania PA, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Weintraub
authors.affiliation: Departments of Neurology, University of Pennsylvania PA, USA.
authors.forename: Corey T
authors.initials: CT
authors.lastname: McMillan
keywords: Lewy body disease; amyloid; cerebrospinal fluid; frontal lobe; narrative comprehension; tau