404 Mobile Pupillometry for Detection of Vasospasm, Delayed Cerebral Ischemia, and Neuro Exam Change in Subjects With Aneurysmal Subarachnoid Hemorrhage

Abstract

INTRODUCTION: The pupillary light reflex (PLR) parameters are quantitative biomarkers that can be used to detect neurological disease. Vasospasm complicates aneurysmal subarachnoid hemorrhage (aSAH) trajectory, causing morbidity and mortality. METHODS: We prospectively collected PLR parameters from patients with aSAH admitted to a neurological intensive care unit twice daily using quantitative smartphone pupillometry recordings. PLR parameters included: Maximum pupil diameter (MAX), minimum pupil diameter (MIN), percent change in pupil diameter (CHANGE), latency in beginning of pupil constriction to light (LAT), mean constriction velocity (MCV), maximum constriction velocity (MAXCV), mean dilation velocity (MDV). One-tailed t-tests were performed to determine changes in PLR parameters between the following comparisons: (1) patients with and without radiographic vasospasm (defined by computed tomography angiography (CTA) or digital subtraction angiography (DSA)); (2) patients with and without delayed cerebral ischemia (DCI); and (3) patients with and without neurological exam change due to vasospasm. RESULTS: 42 total subjects were enrolled. For patients with (n = 13) and without (n = 29) radiographic vasospasm, significant PLR parameter differences were observed in: MAX (p = .024) and MIN (p = .0018). For patients with (n = 14) and without (n = 28) DCI, significant PLR parameter differences were observed in: CHANGE (p = .008). For patients with (n = 13) and without (n = 29) neurological exam change due to vasospasm, significant PLR parameter differences were observed in: MIN (34.7 vs 31.7, p = .014), CHANGE (20.6 vs 24.7, p = .025), and LAT (.36 vs .2, p = .0002). All other PLR parameters were not significantly different between groups for the three comparisons. CONCLUSIONS: Quantitative smartphone pupillometry may be of clinical use in the detection of radiographic vasospasm, DCI, and neuro exam changes via separate and distinct parameters from the PLR.