Investigating speech and language impairments in delirium: a preliminary case-control study

Green, S., Reivonen, S., Rutter, L.-M., Nouzova, E., Duncan, N., Clarke, C., MacLullich, A. M.J. and Tieges, Z. (2018) Investigating speech and language impairments in delirium: a preliminary case-control study. PLoS ONE, 13(11), e0207527. (doi: 10.1371/journal.pone.0207527) (PMID:30475831) (PMCID:PMC6261049)

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Abstract

Introduction: Language impairment is recognized as as part of the delirium syndrome, yet there is little neuropsychological research on the nature of this dysfunction. Here we hypothesized that patients with delirium show impairments in language formation, coherence and comprehension. Methods: This was a case-control study in 45 hospitalized patients (aged 65–97 years) with delirium, dementia without delirium, or no cognitive impairment (N = 15 per group). DSM-5 criteria were used for delirium. Speech was elicited during (1) structured conversational questioning, and (2) the "Cookie Theft" picture description task. Language comprehension was assessed through standardized verbal and written commands. Interviews were audio-recorded and transcribed. Results: Delirium and dementia groups scored lower on the conversational assessment than the control group (p<0.01, moderate effect sizes (r) of 0.48 and 0.51, resp.). In the Cookie Theft task, the average length of utterances (i.e. unit of speech), indicating language productivity and fluency, distinguished patients with delirium from those with dementia (p<0.01, r = 0.50) and no cognitive impairment (p<0.01, r = 0.55). Patients with delirium performed worse on written comprehension tests compared to cognitively unimpaired patients (p<0.01, r = 0.63), but not compared to the dementia group. Conclusions: Production of spontaneous speech, word quantity, speech content and verbal and written language comprehension are impaired in delirious patients compared to cognitively unimpaired patients. Additionally, patients with delirium produced significantly less fluent speech than those with dementia. These findings have implications for how speech and language are evaluated in delirium assessments, and also for communication with patients with delirium. A study limitation was that the delirium group included patients with co-morbid dementia, which precludes drawing conclusions about the specific language profile of delirium.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Nouzova, Eva and Clarke, Miss Caoimhe and Duncan, Nikki and Tieges, Dr Zoe
Creator Roles:
Nouzova, E.Conceptualization, Methodology, Supervision, Writing – review and editing
Duncan, N.Formal analysis, Methodology, Writing – review and editing
Clarke, C.Formal analysis, Methodology, Writing – review and editing
Tieges, Z.Conceptualization, Formal analysis, Methodology, Supervision, Visualization, Writing – original draft, Writing – review and editing
Authors: Green, S., Reivonen, S., Rutter, L.-M., Nouzova, E., Duncan, N., Clarke, C., MacLullich, A. M.J., and Tieges, Z.
College/School:College of Medical Veterinary and Life Sciences > School of Cardiovascular & Metabolic Health
Journal Name:PLoS ONE
Publisher:Public Library of Science
ISSN:1932-6203
ISSN (Online):1932-6203
Copyright Holders:Copyright © 2018 Green et al.
First Published:First published in PLoS ONE 13(11): e0207527
Publisher Policy:Reproduced under a Creative Commons License

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