Noninvasive ocular ultrasound dynamic assessment of intracranial pressure with encephalitis

Abstract

Abstract Background Patients with encephalitis and high intracranial pressure (ICP) may have increased optic disc height (ODH) and widened optic nerve sheath diameter (ONSD). This study investigated whether ONSD and ODH under ultrasound can dynamically evaluate the change of high ICP in encephalitis patients. Methods We recruited suspected high ICP patients who underwent lumbar puncture. The ODH and ONSD was measured before the lumbar puncture. ODH, ONSD and ICP were recorded at admission, two weeks followed up and one month followed up. We analyzed the correlation between ODH, ONSD, and ICP and its changes. The predicted fit was also compared by linear mixed-effects models. Results Totally, 56 headache patients with high ICP were enrolled. On admission, the correlation between ODH and ICP had an r value of 0.586 (P < 0.01), and between ONSD and ICP, an r value of 0.769 (P < 0.01). Two weeks followed up, no significant correlation between ODH change and ICP change (P = 0.536). But the change in ONSD was associated with changes in ICP (r = 0.572, P < 0.001). One month followed up, the correlation between ONSD change and ICP change were stronger than those between ODH change and ICP change (r = 0.667 vs. r = 0.435, P < 0.01). In linear mixed-effects model, ONSD had a better fitting value than ODH in the prediction model for ICP (P < 0.05). Conclusions Noninvasive ultrasonic ODH and ONSD are useful in assessing the presence of high ICP in encephalitis patients. ONSD is an earlier and more sensitive indicator for dynamically and noninvasively assessing the elevated ICP than ODH.