By Linda Carroll
(Reuters Health) – A preliminary study suggests that a new skin sensor could help avoid life-threatening crises for the millions of people living with hydrocephalus, a condition that causes fluid to accumulate in the brain.
When the disorder is diagnosed, a tube, called a shunt, is surgically inserted to drain excess fluid. The problem is that shunts frequently clog or develop kinks and then fluid accumulates.
The 10-year failure rate for shunts is 98 percent, said the study’s lead author Siddharth Krishnan, a Ph.D. candidate at Northwestern University’s McCormick School of Engineering. “When they fail, there’s no good way of quickly diagnosing it. The symptoms are non-specific: headache and nausea.”
Currently, the only way to diagnose a shunt failure is through brain scans and sometimes even surgery.
The perils of missing a shunt failure are enormous. “It can lead to coma, seizures and eventually death,” Krishnan said. “And the uncertainty that accompanies this can wreak havoc with families’ lives, because they know the next headache could be catastrophic.”
In the small pilot study, conducted in five patients, researchers determined that the new wireless, Band-Aid-shaped sensor could detect the difference between a shunt that was working and one that was not, according to the report published in Science Translational Medicine.
In other words, it could warn patients and doctors if the headache is a signal that the shunt that drains excess fluid from the brain has failed.
If the findings are proven in a larger trial, the device could possibly revolutionize the way hydrocephalus is managed, which could potentially save the U.S. health care system millions of dollars, said the study’s lead author Siddharth Krishnan, a Ph.D. candidate at Northwestern University’s McCormick School of Engineering.
Approximately one million Americans have hydrocephalus and one in every thousand babies is born with the condition, according to the Hydrocephalus Association. It’s often a complication of premature birth. In adults, some cases of hydrocephalus are related to traumatic brain injury or other neurologic conditions, Krishnan said.
“Most of us make about 12 ounces of cerebrospinal fluid a day,” Krishnan explained. “In a healthy person, it gets drained (or absorbed) about as fast as it is produced. In people with hydrocephalus, it doesn’t get absorbed well in the brain or the brain produces too much.”
When the fluid accumulates, pressure builds up on other parts of the brain.
The new device developed by Krishnan and his colleagues has a tiny heater in the middle and a sensor on either end. It’s placed on the skin over the spot where the shunt is located just below the surface. When the tiny heater brings the temperature of a small area of skin up a couple of degrees, it also heats the fluid inside the shunt at that spot. If the shunt is working, the sensors at either end will detect the heat from the warmed fluid as it moves down the shunt.
Krishnan and colleagues are planning a much larger study – involving 100 patients – in hopes that the early results will be replicated.
The researchers have taken a “step forward in a long journey,” said Dr. Shenandoah Robinson, a professor in the division of pediatric neurosurgery at Johns Hopkins Medicine. “Any step forward is important. It would be nice to have easier ways to diagnose shunt malfunction.”
Robinson can imagine possible issues that would interfere with the device in some patients: obesity, for example. Still, she said, “it is possible that it might be useful in a small fraction of patients. I think we’re going to have to have the validation studies to get a better sense” of how helpful will be.
SOURCE: http://bit.ly/2zywA42 Science Translational Medicine, online October 31, 2018.