Sepsis-Related Brain MRI Abnormalities Are Associated With Mortality and Poor Neurological Outcome in Pediatric Sepsis

Abstract

Background: It is not known whether brain magnetic resonance imaging (MRI) abnormalities in pediatric sepsis are associated with clinical outcomes. Study objectives were to (1) determine the prevalence and type of sepsis-related neuroimaging abnormalities evident on clinically indicated brain MRI in children with sepsis and (2) test the association of these abnormalities with mortality, new disability, length of stay (LOS), and MRI indication.

Methods: Retrospective cohort study of 140 pediatric patients with sepsis and a clinically indicated brain MRI obtained within 60 days of sepsis onset at a single, large academic pediatric intensive care unit (PICU). Two radiologists systematically reviewed the first post-sepsis brain MRI and determined which abnormalities were sepsis-related. Outcomes compared in patients with versus without sepsis-related MRI abnormalities.

Results: PICU mortality was 7%. Thirty patients had one or more sepsis-related MRI abnormality, yielding a prevalence of 21% (95% confidence interval 15%, 28%). Among those, 53% (16 of 30) had sepsis-related white matter signal abnormalities; 53% (16 of 30) sepsis-related ischemia, infarction, or thrombosis; and 27% (eight of 30) sepsis-related posterior reversible encephalopathy. Patients with one or more sepsis-related MRI abnormality had increased mortality (17% vs 5%; P = 0.04), new neurological disability at PICU discharge (32% vs 11%; P = 0.03), and longer PICU LOS (median 18 vs 11 days; P = 0.04) compared with patients without.

Conclusions: In children with sepsis and a clinically indicated brain MRI, 21% had a sepsis-related MRI abnormality. Sepsis-related MRI abnormalities were associated with increased mortality, new neurological disability, and longer PICU LOS.

Keywords: Brain; Critical care outcomes; Magnetic resonance imaging; Neuroimaging; Neurological outcomes; Pediatrics; Sepsis.

Figure 1:. Flow Diagram of Study Population

^&Coding errors included patients coded as severe sepsis or septic shock in VPS but did not meet criteria for severe sepsis or septic shock after chart review. CNS = central nervous system, MRI = magnetic resonance imaging, VPS = virtual pediatric systems.

Figure 2:. Representative Examples of Magnetic Resonance Imaging Abnormalities

Images A-D are examples of sepsis-related MRI abnormalities. Images E-H are examples of MRI abnormalities not related to sepsis. Images are axial views and sequences include: DWI (A, E), FLAIR (B, C, F), T1-weighted post-gadolinium contrast (D, G), and SWI (H). A: Areas of restricted diffusion within bilateral anterior and posterior watershed regions of the cerebral hemispheres, left greater than right (dashed arrows), representing watershed infarcts. B: 6 year-old female treated for pneumonia with depressed mental status post-extubation. Images show non-specific confluent areas of T2 signal hyperintensity within the left parietal cortical and subcortical white matter (**) and a few small scattered foci of hyperintensities within the left posterior frontal lobe in the perirolandic region. C and D: Confluent cortical and subcortical areas of FLAIR hyperintense signal (dashed oval) with nodular foci of contrast enhancement located in the parietal lobes (solid arrowheads) and posterior aspects of the cerebellar hemispheres (not shown) consistent with posterior reversible encephalopathy syndrome. Scattered areas of abnormal signal intensity are also noted in the frontal lobes, left more than right (dashed arrowheads). E: 14 year-old female with history of lupus with multiple predominantly cortical areas of restricted diffusion (ADC maps not shown) in the bilateral frontal lobes (arrows) and left cerebellar hemisphere (not shown) consistent with small areas of ischemia or seizure effect, which may be seen in lupus cerebritis and vasculitis. F: 11 year-old female with acute lymphoblastic leukemia on methotrexate chemotherapy. Images show a hyperintense lesion in the deep white matter of the left centrum semiovale (^^). This finding is characteristic of methotrexate-related leukoencephalopathy in the right clinical scenario and thus may not be related to sepsis in this context. G and H: 2 year-old male with an enhancing left frontal subdural collection (oval) with hemosiderin deposition along the left frontal lobe pial surface (curved arrow). The patient had a history of chronic bilateral subdural collections prior to the sepsis event, which indicates this finding is not related to sepsis. DWI = diffusion-weighted imaging, FLAIR = fluid-attenuated inversion recovery, MRI = magnetic resonance imaging, SWI = susceptibility-weighted imaging