Hearing Aid Magnets Could Interfere With Cerebrospinal Fluid Shunts, FDA Warns

Federal health officials are warning patients that certain magnetic hearing devices may cause unexpected problems with implantable cerebral spinal fluid shunt systems, increasing the risk of severe adverse health consequences.

The FDA sent a letter to healthcare providers on July 16, indicated that patients implanted with both programmable cerebrospinal fluid shunt system (CSF) and certain hearing implants that contain magnets may suffer complications due to magnetic interference.

Officials are warning that patients using cerebrospinal fluid shunt systems may experience unexpected and unintended changes to the CSF shunt valve settings, which could then over-or under-drain fluids.

The CSF systems are used to treat a condition known as hydrocephalus, which causes fluid to accumulate in the brain. The condition typically occurs in young children, causing their head to become enlarged. If the condition is not properly treated by regulating fluid accumulation it may cause swelling and brain damage.

The CSF shunt systems are implanted in the patient and drain excess fluid from the brain to another part of the body where fluid is absorbed as part of the circulatory process. The shunt systems consist of an in-flow tube, a valve that regulates the flow of fluid and an outflow catheter to carry fluid to other parts of the body.

According to officials, when a patients being treated for hydrocephalus has an implanted CSF shunt system, and also requires the use of hearing implants that contain magnets, the magnets may unintentionally alter the programmable CSF shunt valve settings. This could lead to excess draining or under draining of the cerebrospinal fluid from the patient’s brain.

Adverse reactions from magnetic interference could result in patients experiencing altered mental status, headaches, lethargy, irritability, vomiting, disrupted vision and difficulty balancing or walking. If the condition is left untreated or not recognized long enough, it could cause patients to experience loss of consciousness, seizures, hemorrhage, or even death.

FDA officials are advising all healthcare providers treating individuals with CSF shunt systems to be aware of the potential consequences that could result from a magnetic interference with implantable hearing devices such as cochlear implants, bone conducting hearing devices or middle ear hearing device.

Patients and healthcare providers are encouraged to report all adverse events with programmable CSF shunts and potential magnetic interference to the MedWatch Safety Information and Adverse Event Reporting program. For further questions regarding the warning, patients and healthcare providers may contact the FDA Division off Industry and Consumer Education (DICE) at 800-638-2041 or 301-796-7100.