Magnets in iPad2 May Alter Settings on Brain Shunt Devices: Study
TUESDAY June 26, 2012 -- Magnets embedded in the Apple iPad 2 can interfere with the settings of magnetically programmable shunt valves, which are critical devices to drain excess fluid from the brains of those with hydrocephalus and other conditions, a new study suggests.
Researchers from the University of Michigan decided to investigate the phenomenon after a 4-month-old patient with hydrocephalus was found to have a shunt malfunction three weeks after getting one implanted. The baby's mother had fed the child and used the iPad simultaneously, inadvertently placing the baby's head close to the tablet computer.
"Most times, technology has helped medical care significantly. This is one case . . . where we have to be concerned about these things," said Dr. Salvatore Insinga, a neurosurgeon at the Cushing Neuroscience Institute in Manhasset, N.Y., who was not involved in the study. "We do know programmable shunts are susceptible to magnetic field fluctuations -- MRIs, for instance, can change the settings of the shunts. [But] I don't think we know all of the devices that have a magnetic influence on these things."
The study is published online June 26 in advance of the August print issue of Journal of Neurosurgery: Pediatrics.
Hydrocephaly, brain swelling caused by the build-up of cerebrospinal fluid, can occur in children and adults due to a variety of medical conditions. Medical-grade magnets are used to change the settings on programmable shunt valves that allow the passage of extra fluid to other parts of the body.
Study author Dr. Cormac Maher, a pediatric neurosurgeon at the University of Michigan, and his colleagues tested the iPad 2 with and without an Apple Smart Cover, which contains additional magnets and is the most frequently used cover for the tablet.
Exposing 10 programmable shunt valves to the iPad/cover for 10 seconds at five different distances, Maher found that the settings changed in 58 percent of the valves at distances between 0 and 1 cm (about 0.4 inches); the settings changed in 5 percent of valves when the exposure distances lengthened to between 1 and 2.5 cm (up to 1 inch). After exposure at distances between 2.5 and 5 cm (1 to 2 inches), the settings changed in just 1 percent of shunt valves; no changes were observed at higher distances.
"Once we know a valve is dialed to an incorrect setting, it's easy to set back," Maher said, noting that his infant patient suffered no lasting effects. "The impact could potentially be serious if [the changed setting] is not recognized -- there could be complications from overdraining or underdraining."
Repeated calls to Apple headquarters in Cupertino, Calif., for comment on the findings were not returned.
Maher and other experts cautioned that those with programmable shunt valves, as well as their parents and/or caregivers, should be aware that an iPad placed within a couple of inches of patients' heads could produce such an effect.
"If a child uses an iPad, that's OK; they just shouldn't hold it near their head or sleep with it," Maher advised. "Routine use should be OK, people just need to be smart about it."
Dr. Jonathan Zhang, a neurosurgeon at Methodist Neurological Institute in Houston, recommended that more research be done to confirm a cause-and-effect between the iPad and programmable shunt valves.
"This is certainly a very intriguing and interesting finding," Zhang said. "As we use more and more technology, the world is changing and we certainly need to incorporate new findings into clinical practice. This is a cautionary tale."
The National Institute of Neurological Disorders and Stroke has more on hydrocephalus.
Posted: June 2012
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