The Prevalence and Prognostic Value of Neuroimaging Abnormalities in the Acute Phase of Sepsis-Associated Encephalopathy

Abstract

Objectives: Sepsis-associated encephalopathy (SAE)is the most common form of encephalopathy in the intensive care unit (ICU) today. However, little is known about the underlying pathogenesis and clinical significance of the brain changes associated with SAE. Using magnetic resonance imaging (MRI) and computed tomography (CT), the present study evaluated the spectrum of brain abnormalities in patients with SAE and examined whether these abnormalities predicted clinical features of SAE, ICU mortality, one-year mortality, and disability. Methods:We examined clinical and radiological data from 60 consecutive adults admitted to the medical ICU without preexisting neurological conditions, who met criteria severe sepsis or septic shock and subsequently developed SAE. Neuroimaging attributes were rated by two radiologists using a standardized protocol.Results: Common neuroimaging findings included periventricular and subcortical white matter lesions, cerebrovascular calcification, and lacunar infarction. By comparison, acute infarction, acute hemorrhage, cytotoxic edema, and vasogenic edema were less prevalent. Acutely altered mental status (e.g., delirium) was the most common form of SAE and was associated with greatercerebral atrophy (p=.029) and subcortical white matter lesion burden (p=.010) relative to patients presenting with new-onset of focal neurologic signs or new-onset seizure. Acute, but not chronic, neuroimaging findings were associated with risk for ICU mortality (p=.026), one-year mortality (p=.016), and disability (p=.032) after adjusting for potentially confounding variables. Discussion: Though less common than chronic neuroimaging findings, acute neuroimaging abnormalities have prognostic significance as predictors of disability and survival in the first year following the development of SAE.