Optic Ultrasound Identifies Stroke Patient Mortality Risk

NASHVILLE — Among patients with stroke, optic nerve sheath diameter (ONSD), as measured by optic ultrasound (OUS), was significantly associated with in-hospital and six-month mortality.

Currently, neurologic exam deterioration is an early indicator of increasing intracranial pressure, but its accuracy is limited because of confounding factors, such as fluctuations in mental status and sedation/paralysis as part of the acute management.

The aim of the current study, according to Vishnumurthy S. Hedna, MD, study researcher with the University of Florida in Gainesville, Fla., was to identify early the increase in brain pressure in patients with stroke. “OUS is the easiest and fastest way to measure brain pressure noninvasively,” Hedna told Neurology Advisor. “OUS is easy to administer in the emergency department or by the bedside and can indicate early increasing brain pressure in patients.”

In the prospective convenience sample study, Hedna, who presented the findings at the International Stroke Conference 2015, and colleagues enrolled 86 patients with stroke from a tertiary care center. They used OUS to measure ONSD on the day of admission and subsequent day, taking longitudinal and transverse measurements of both eyes of each patient.

Paired t-tests and chi-square tests were used to compare means and proportions when appropriate, and regression analysis determined ONSD and patient outcome relationships.

Compared with patients who survived, those who died had increased ONSD in both ischemic stroke categories (0.582 vs. 0.533; P=.0092) and the intracerebral hemorrhage category (0.623 vs. 0.572; P=.0187).

With each ONSD increase of 0.1 cm, the odds of mortality increased 4.239 times among patients with ischemic stroke (95% CI, 1.317-13.642; P=.0155) and 6.222 times among patients with intracerebral hemorrhage (95% CI, 1.160-33.382; P=.0329). Furthermore, at 6 months, increased ONSD measurements correlated with poorer modified Rankin Scale scores (r=0.44; P<.0001).

“Increased ONSD measurements correlated with poor short-term (in-hospital) and long-term (6-month) mortality,” Hedna and colleagues concluded in the abstract. “OUS may be used as a screening tool to identify patients at risk of poor outcome from increased [intracranial pressure].”

Hedna further noted in an interview that OUS “is an noninvasive, reliable predictor of outcome in stroke patients, which needs to be tested in a larger stroke patient population.”

Hedna added that the findings will influence how he treats his stroke patients because OUS leads to a preemptive approach for treating increased brain pressure.

For more coverage of the International Stroke Conference 2015, go here. 

Reference

1. Hedna VS et al. Abstract W MP83. Presented at: International Stroke Conference 2015; Feb. 11-13, 2015; Nashville, Tennessee.