CSF Shunt Hazard With Close Proximity to Hearing Devices, FDA Warns

Caroline Cassels


July 17, 2019

The US Food and Drug Administration (FDA) is warning healthcare providers about potential hazards from interactions between implanted programmable cerebrospinal fluid (CSF) shunts and hearing implants that contain magnets.

CSF shunt systems are used to treat hydrocephalus. Adverse magnetic interactions can occur when these devices and hearing implants are in close proximity to one another. Such interactions may lead to unintended changes to the programmable CSF shunt valve settings, resulting in overdrainage or underdrainage of CSF.

Patients may experience altered mental status, headaches, lethargy, irritability, vomiting, vision changes, and difficulty walking. Left untreated, such symptoms could progress to loss of consciousness, seizures, hemorrhage, or death.

The FDA's recommendations are as follows:

  • Educate patients and caregivers about this potential risk and what to do about it.

  • Check the programmable CSF shunt valve setting after placement or adjustment of other devices that contain magnets to ensure that the setting has not changed. Only a trained clinician, such as a neurosurgeon, should check the shunt valve setting and adjust the setting, if necessary.

  • Consider the location of placement of the programmable CSF shunt valve if the patient has other implanted devices known to contain magnets in close proximity. For example:

  • Consider placing the programmable CSF shunt valve on the contralateral side of a cochlear implant or implantable bone conduction hearing device, if the patient's anatomy and clinical picture permit such a strategy.

  • For patients who require bilateral hearing implants, which use magnets and a programmable CSF shunt, the implanting physician should position the CSF shunt valve and the ipsilateral hearing implant at a maximum distance from one another.

  • Contact the applicable device manufacturer for further information.

For more Medscape Neurology news, join us on Facebook and Twitter


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.