Post-stroke delirium is associated with cognitive and psychiatric symptoms over time

Introduction

Delirium, an acute and fluctuating disturbance of attention, cognition, and consciousness, may occur in the acute phase of stroke. Research on long-term outcomes of stroke patients experiencing delirium is limited. Our previous findings suggested that patients experiencing acute delirium had increased cognitive and psychiatric symptoms in the chronic phase. In the current study, this was further examined in a larger sample, including measures of global cognition, as well as psychiatric symptoms.

Methods

As part of the Nor-COAST study, 373 stroke patients were screened for delirium using the Confusion Assessment

Methods

Patients were included in the study if they had available data from any of the follow-ups at three, 18 or 36 months, totaling 334 (44.6% women, mean (SD) age: 72.1 (12.5) years, 17 (5.1%) diagnosed with delirium). Global cognition was measured using the Montreal Cognitive Assessment (MoCA). Psychiatric symptoms were measured using the Hospital Anxiety and Depression Scale (HADS) and the Neuropsychiatric Inventory-Questionnaire (NPI-Q). Subscales of NPI-Q were used to measure specific psychiatric symptoms. Mixed-model linear regression was applied with MoCA, HADS, and NPI-Q, one at a time, as dependent variables. The independent variables were delirium, time as a categorical covariate, and their interaction. Mixed- model binary logistic regression was used to analyze differences in specific psychiatric symptoms.

Results

At three months, delirium was only significantly associated with a higher NPI-Q score (mean (SD) 2.9 (3.6) vs 1.4 (2.2)). At 18 and 36 months respectively, delirium was associated with a lower MoCA score (mean (SD) 19.7 (6.6) vs 24.3 (5.0), and 20.6 (7.6) vs 24.6 (4.8)), higher HADS anxiety symptoms (5.0 (4.3) vs 3.3 (3.3), and 5.9 (4.1) vs 3.4 (3.6)), higher HADS depression symptoms (7.2 (4.7) vs 3.4 (3.3), and 6.6 (5.1) vs 3.7 (3.7)), and higher NPI-Q score (2.4 (4.4) vs 1.7 (2.3), 2.6 (4.5) vs 1.0 (1.9)). Delirium significantly predicted the psychiatric symptoms hallucinations and agitation.

Discussion

Patients with delirium in the acute phase of stroke may be particularly vulnerable to developing cognitive and psychiatric symptoms in the chronic phase.