Knowns and Unknowns About Delirium in Stroke: A Review

Abstract

Delirium is a transient condition characterized by sudden and fluctuating disturbances in cognitive function. The condition can be considered a sign of the brain's vulnerability and diminished resilience to insult. Among the many clinical manifestations are cognitive, psychomotor, and sleep disturbances. Delirium is associated with longer hospital stays, worse functional outcomes, and higher mortality. Although up to 48% of patients who have had a stroke develop delirium, the condition has been studied much less in these patients than in general medicine, surgical, and intensive care patients. Coexisting neurologic deficits in patients with stroke limit the use of screening tools that are widely accepted in other populations. The variability of reported assessment methods highlights the need for delirium screening guidelines in stroke. Further, risk factors that are specific to stroke may play an important role in the etiology of delirium, along with such well-known factors as older age and infections. The delirium literature lacks data on differences in clinical manifestations and course in the various types of stroke. Here we review predisposing factors, diagnostic methods, and biomarkers of delirium in stroke and discuss aspects that need further research.

Delirium Monitoring in Neurocritically Ill Patients: A Systematic Review*

“…The neurocritically ill patient population is obviously more challenging than general medical and general surgical patients with respect to delirium assessment (59). Some are not testable for delirium due to decreased level of consciousness (i.e., coma) because of the primary neurological injury or due to deep sedation (Richmond Agitation-Sedation Scale<−3) for high intracranial pressures.…”

“…There have been broader and well-done reviews relevant to delirium in stroke (59, 61), and our work is uniquely limited by our focus on the critically ill patient affected by primary neurologic conditions. Additionally, we acknowledge our review excluded four studies of impure neurocritically populations (40–42, 50).…”

Subsyndromal delirium is associated with poor functional outcome after ischaemic stroke

“…In addition, symptoms of stroke may hinder delirium assessment. To minimize the risk of misdiagnosis, based on previous studies on the stroke population validated tools were used with follow‐up assessments interpreted in the context of stroke symptoms. Furthermore, patients with severe aphasia were excluded because available tools do not allow objective assessment of delirious symptoms in these patients.…”

Reduced ex vivo release of pro-inflammatory cytokines and elevated plasma interleukin-6 are inflammatory signatures of post-stroke delirium

“…Delirium is common among hospitalized elderly people and is associated with increased mortality and poor functional and cognitive outcome [ 1 ]. An estimated rate of delirium after stroke is 26% with a range of 10 to 48% [ 2 ].…”