(741) Variability of Pulsatility Index in Pediatric Cerebral Malaria and Neurologic Outcomes

Introduction: Cerebral Malaria (CM) is a severe form of the disease with neurologic implications and significant mortality. Children < 5 years old in Africa represent >95% of deaths. In CM, parasitemia leads to infected erythrocytes embedding in the vasculature causing obstruction, metabolic derangements, and an inflammatory response. Given that the parasite does not enter the parenchyma, further research is needed to determine how CM can cause significant neurologic injury. Transcranial Doppler (TCD) ultrasound can be used to measure cerebral blood flow (CBFV) and analyze flow to provide insight into the vasculature changes. The Gosling pulsatility index (PI) provides additional insight into CBFV. A novel use of PI, day-to-day (DTD) PI change, has been used to describe variability of CBFV. The purpose of this study is to compare variability of DTD PI change in children with CM.

Methods: A retrospective analysis of 122 children with CM treated at three hospitals in Malawi and Democratic Republic of the Congo who underwent daily TCD measurements was conducted. Data was collected between January 208 and June 2021. Inclusion criteria included ages 6mo-12yr and a diagnosis of CM. Exclusion criteria included developmental delay, sickle cell disease, severe malnutrition, and advanced HIV disease. Variability of DTD PI change was calculate and compared to neurocognitive outcomes, Brain Volume Score (BVS), and CM TCD phenotypes

Results: Participants with poor neurologic outcomes (neurologic sequelae or died) had higher variability of DTD PI change in the left and right middle cerebral artery (MCA). Participants with a higher BVS score also had higher variability of DTD PI change in the left and right MCAs. Previously described TCD CM phenotypes (hyperemia, isolated posterior hypertension, low flow, micro-obstruction, normal, and vasospasm) also demonstrated discrete variabilities in DTD PI change

Conclusions: Increased variability of DTD PI change in children with CM was associated with worse neurologic outcomes and increased BVS at presentation. Additionally, discreet variability of DTD PI change was seen in the six TCD phenotypes. Thus, DTD PI change as measured by TCD can help prognosticate neurologic outcomes of CM and support additional research of TCD as a point of care neuromonitoring device.