Apathy ups risk of delirium in stroke patients
Prestroke apathy increases the risk of delirium in stroke patients and may predict other factors related to delirium, a recent study has shown.
“Apathy may be considered as a predisposing factor for poststroke delirium but can be also a marker of other conditions which contribute to delirium risk, such as undetected cognitive decline,” said researchers. “This needs clarification in future studies.”
Within the first seven days of admission, 750 adult stroke patients (median age 73 years; 53.1 percent female) were monitored for the development of delirium. Exclusion criteria included brain tumour, alcohol withdrawal syndrome, head trauma and vasculitis.
The final delirium diagnosis was based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Prestroke functional and neuropsychiatric status was determined using the modified Rankin Scale (mRS) and interviews with relatives and caregivers.
Of the 750 patients, 80.8 percent (n=606; median age 73 years; 53 percent female) had available prestroke neuropsychiatric status information. Delirium was reported in 28.2 percent (n=171) of the participants. [Sci Rep 2017;7:7658]
Diabetes, atrial fibrillation, prestroke cognitive decline, prestroke functional dependency, pneumonia and urinary tract infection were all significantly more common in those with delirium than in those without (p<0.01 for all).
Notably, of all the neuropsychiatric symptom, only apathy scores were significantly higher in patients with delirium (p=0.02). Moreover, multivariate analysis showed that only apathy was significantly correlated with higher risks of developing delirium (odds ratio [OR], 2.03; 95 percent CI, 1.17 to 3.50; p=0.01).
Apathy remained a significant independent predictor of delirium (OR, 2.22; 1.22 to 4.02; p=0.01) in the final statistical model, adjusted for all confounders and neuropsychiatric symptoms that were substantial in univariate analysis.
“Apathy is generally defined as a loss of motivation. It can be considered as a separate syndrome or as a symptom of other disorders [such as] depression,” explained researchers. “Apathy is associated with a higher risk of functional impairment, lower cognitive performance and dementia.” [Am J Psych 1990;147:22-30; Alzheimers Dement 2016;16:1-17]
“Apathy and delirium could be related to each other in several ways. First, structural disruption of common neuronal networks can be seen in apathy and delirium. Second, the same risk factors could be relevant for delirium and apathy. Neurodegenerative and vascular pathologies can predispose to both of them,” they added.
Apathy is also tied to depression and may be indicative of brain vulnerability, both of which up the risk of delirium, according to researchers.
Older age (OR, 1.02; 1.00 to 1.04; p=0.04), lesions in the right hemisphere (OR, 1.78; 1.15 to 2.75; p=0.01), diabetes mellitus (OR, 1.91; 1.21 to 3.02; p<0.01) and pneumonia (OR, 2.29; 1.34 to 3.94; p<0.01) were other predictors of delirium.
“Identification of patients with premorbid apathy symptoms might be important for a selection of persons who are at risk of delirium. These patients may demand extensive delirium prevention and closer monitoring for early detection and escalated treatment of delirium,” noted researchers.