Elevated intracranial pressure and reversible eye-tracking changes detected while viewing a film clip

Abstract

OBJECTIVE The precise threshold differentiating normal and elevated intracranial pressure (ICP) is variable among individuals. In the context of several pathophysiological conditions, elevated ICP leads to abnormalities in global cerebral functioning and impacts the function of cranial nerves (CNs), either or both of which may contribute to ocular dysmotility. The purpose of this study was to assess the impact of elevated ICP on eye-tracking performed while patients were watching a short film clip. METHODS Awake patients requiring placement of an ICP monitor for clinical purposes underwent eye tracking while watching a 220-second continuously playing video moving around the perimeter of a viewing monitor. Pupil position was recorded at 500 Hz and metrics associated with each eye individually and both eyes together were calculated. Linear regression with generalized estimating equations was performed to test the association of eye-tracking metrics with changes in ICP. RESULTS Eye tracking was performed at ICP levels ranging from -3 to 30 mm Hg in 23 patients (12 women, 11 men, mean age 46.8 years) on 55 separate occasions. Eye-tracking measures correlating with CN function linearly decreased with increasing ICP (p < 0.001). Measures for CN VI were most prominently affected. The area under the curve (AUC) for eye-tracking metrics to discriminate between ICP < 12 and ≥ 12 mm Hg was 0.798. To discriminate an ICP < 15 from ≥ 15 mm Hg the AUC was 0.833, and to discriminate ICP < 20 from ≥ 20 mm Hg the AUC was 0.889. CONCLUSIONS Increasingly elevated ICP was associated with increasingly abnormal eye tracking detected while patients were watching a short film clip. These results suggest that eye tracking may be used as a noninvasive, automatable means to quantitate the physiological impact of elevated ICP, which has clinical application for assessment of shunt malfunction, pseudotumor cerebri, concussion, and prevention of second-impact syndrome.

Analysis of Normal High-Frequency Intracranial Pressure Values and Treatment Threshold in Neurocritical Care Patients

“…It is important to consider that numerous publications have suggested an ICP treatment threshold less than 20 mm Hg may be appropriate. [25][26][27][28][29] Analysis of our data suggests that an ICP threshold of 19 mm Hg is most strongly associated with patient outcome and that this threshold is robust across patient subgroups. However, our data suggest that ICP values as low as 10 mm Hg may be associated with harm.…”

Non-invasive detection of intracranial pressure related to the optic nerve

“…Kolecki et al performed eye tracking in 23 patients with ICP levels ranging from -3 to 30 mmHg 55 times. The results showed that eye-tracking measures related to cranial nerve function decreased linearly with the increase of ICP (P<0.001) (83). The main limitation of the method was the lack of continuous data in patients with high ICP records.…”

Eye tracking in extreme environments: from invention to new frontiers of human-machine teaming

“…Dawn Kernagis and a comprehensive literature review helped pinpoint critical oculometric and pupillometry measures utilized in medical diagnostics to detect neuro-cognitive and physiological states. This revealed a number of oculometric and pupillometry measures which have been used in medical diagnostics and scientific literature to detect neuro-cognitive and physiological states [4][5][6]7,12,14,15,16,[17][18][19]22,25,26]. These measures are outlined in the table below (Table 1).…”