Researchers find how eye ultrasounds help detecting brain shunt failure in children

Washington: A recent study suggests that using an ocular ultrasound in the emergency room could help detect children with brain drainage tube failure quickly and safely.

Research presented at the Pediatric Academic Societies (PAS) 2024 Meeting in Toronto.

A ventricular shunt is a small plastic tube that is surgically placed to drain excess fluid and relieve pressure on the brain. Ventricular shunts are used on children to treat hydrocephalus, a disorder caused by improper brain fluid drainage or absorption from tumors, brain bleeds, and other sources. According to specialists, within two years following implantation, about 30 per cent of shunts break, become misplaced, or become clogged, and an additional 5 per cent fail annually after that.

When a patient visits the emergency department for potential shunt failure, their symptoms are often nonspecific, including headache, vomiting, and fatigue, according to researchers. Shunt failure is life threatening, and children with shunts typically undergo multiple computed tomography and magnetic resonance imaging scans per year, exposing them to excessive radiation and sedation. A backup of fluid causes the optic nerve sheath to swell, which researchers can measure with eye ultrasound.

The study found that comparing the diameter of the optic nerve when a patient is symptomatic to the diameter when they are well can help determine if a shunt is blocked.

"The research team is interested in finding ways to lessen radiation exposure and expedite diagnosing shunt failure in the emergency department," said Adrienne L. Davis, MD, MSc, FRCPC, pediatric emergency medicine research director at The Hospital for Sick Children (SickKids) and presenting author. "The study uses patients as their own controls by measuring the optic nerve when well and sick--a strategy that individualises this test for every patient and recognises that every patient with a shunt has a unique degree of shunt dependence and ability to tolerate high brain pressures."

The researchers studied 76 pairs of eye ultrasounds of nearly 60 children presenting to the Toronto hospital's emergency department with potential shunt failure. Researchers note that while findings are promising, results require further confirmation in a larger population of children with shunts across North America.