Delirium in patients with dementia and in children: Overlap of symptoms profile and possible role for future diagnosis

Background: Delirium in the extremes of the age spectrum may show similarities in presentations, and these similarities may provide information to develop tools for the diagnosis of delirium superimposed on dementia (DSD). We sought to investigate the symptom profile and subtypes of delirium in patients with dementia, and in infants and preschool children. Methods: This was an exploratory analysis of previous prospective cohort studies that evaluated delirium with the DSM-IV criteria in patients with dementia, and in critically ill infants (< 2 years of age) and preschool children (2-5 years of age), respectively. Delirium subtypes were defined based on the Richmond Agitation-Sedation Scale. Results: We included 147 patients, 35 adult patients with delirium DSD, 80 infants, and 32 preschool children with delirium. Hypokinesia and apathy were common among both DSD (72%), infants (74%) and preschool children (75%) with delirium, whereas hallucinations and anxiety were less common in both adults with DSD (26%) and infants (10%) and preschool children (14%). Hypoactive delirium was most common delirium subtype among infants (68%) and preschoolers (76%), whereas RASS = 0 (alert) delirium was the most common among adult patients with DSD (55%). Conclusions: The study reports similarities in the symptoms profile of delirium in a cohort of patients with dementia and delirium, and in infants and preschool-aged children with delirium. These preliminary findings might be informative to design future studies adapting delirium assessments used in in infants and preschool-aged children to patients with dementia, especially in the moderate to severe stages.