Objective: Patients with lewy body disords (LBSD) such as Parkinson's disease, Parkinson's disease with dementia, and dementia with bodies exhibit deficits in both marrative comprenhsion and narrative expression. The present research examinies the hypothesis that these impairments are due to a material neural deficit in organizational executive resocurces rather than to impairments of lenguage per se, We predicted that comprehension of narrative would be related to the same anatomic distribution of prefrontal disease. Method: We examined 29 LBSD patients and 26 heatly seniros on their comprehension and expression of narrative discourse. For comprehension. We maseured accuary and lactency in judging events with high and low associativity from familiar scirpts such as "going fishing". The expression task involved maintainig the connectedness of events while narrating a story from a wordless picture book. Results: LBSD patients were impaired on mesaures of narrative dorganization during both comprehension and expression relative to heatly seniors. Mesaures of organization during narrative expression and comprehension were significantly correlated with each other. These mesaures both correlated with each executive mesaures but not with neurosychological mesaures of lexical semantics or grammar. Voxel-based morphometry revaled overppong regressions relating frontal atrophy to narrative comprehension, narrative expression, and measures of executive control. Conclusions: Dificulty with narrative discours with narrative discours in LBSD stems in part from a deficit of organization common to comprehension and expression. This deficit is related to prefrontal cortical atrophy in LBSD.
