Neurological Pupil Index as an Indicator of Irreversible Cerebral Edema: A Case Series

BACKGROUND: Assessing the pupillary light reflex is a core component of neurological assessments. Pupil size and reactivity can provide early warning about early neurological decline. Automated infrared pupillometry is noninvasive and easy to use and has greater reliability compared with manual assessments to obtain objective and consistent measurements of pupillary size and reactivity to light. METHODS: This is a case series of 3 patients who had poor baseline clinical neurological examinations. Because it would be more difficult to detect acute neurological deterioration, automated infrared pupillometry and the Neurological Pupil index (NPi) were used in addition to the clinical neurological examination. NPi values < 3.0 prompted further imaging. RESULTS: In each case, abnormal NPi values prompted emergent imaging that confirmed acute cerebral edema and resulted in a change in management and treatment plan. CONCLUSION: The automated infrared pupillometry is a noninvasive monitor that can provide additional objective data in patients with a poor baseline neurological examination in whom it may otherwise be difficult to detect neurological deterioration.

Automated summary

Assessing pupillary light reflex is crucial in neurological assessments. Automated infrared pupillometry, particularly in patients with poor baseline neurological examinations, can provide additional objective data to detect neurological deterioration that may otherwise be difficult to identify.