Pupillary examination is one of the parameters we follow for
continuous neurological assessment in patients at risk of ICP
crisis in the neurological intensive care unit. In a patient with
malignant infarction at high risk of increased ICP due to cerebral
edema and herniation, a reliable and objective tool for pupillary
evaluation is essential. It allows time for triage whether a
decompressive hemicraniectomy is imminent or we can manage
with osmotherapy alone. Neurological Pupillary Index (NPi) is a
quantitative measurement of pupillary reactivity that can trend
deterioration from baseline allowing early intervention: an NPi
score equal to or above 3 means that the pupil measurement is
within normal pupil behavior.
<Representative case> A 76-year-old man presented with
aphasia, right hemiparesis and disturbed sensorium. Cranial CT
scan revealed hyperdensity of the left middle cerebral artery.
Initial pupillometer exam showed an NPi of 4.6 (right) and 4.8
(left). Cranial MRI done 12hrs later showed acute left
hemispheric infarct without signs of mass effect or midline shift.
Serial NPi trend remained normal until on the 28th hour of
admission left NPi started to decrease to 2.7 and became
unreactive on the 33rd hour without a change in sensorium
noted. Repeat Cranial CT scan at this time showed the mass effect and
midline shift to the right. The patient underwent extensive
frontoparietal lobectomy and regained left pupillary reactivity
12hrs post-op.
<Conclusion> Quantitative measurement of pupillary reactivity
using NPi provided useful guidance for the optimal timing of
follow-up CT and decompressive surgery in case of necessity.

USE OF NEUROLOGICAL PUPIL INDEX TREND FOR MONITORING PROGRESSIVE CEREBRAL EDEMA IN A MALIGNANT MIDDLE CEREBRAL ARTERY INFARCTION