Reports of comas and other serious injuries in people with implanted neurologic stimulators incurred during MRI procedures have spurred the Food and Drug Administration to issue a reminder about these risks.
The agency has received “several” reports of coma, permanent neurologic impairment, and other serious injuries in patients who had deep brain stimulators and vagus nerve stimulators in place when they underwent MRI. “Similar injuries could be caused by any type of implanted neurologic stimulator,” such as spinal cord, peripheral nerve, and neuromuscular stimulators, according to the warning, issued by the FDA's Center for Devices and Radiological Health.
These injuries probably result when the electrodes at the end of the lead wires heat up, injuring the surrounding tissue, the statement said.
The FDA is recommending that physicians who implant or monitor neurologic stimulators explain to patients about MRI procedures, and stress that they must ask their monitoring physician, before having any MRI, whether it can be performed safely.
The notification includes a list of recommendations for radiologists and health care professionals who use MRI equipment. They include consulting with the referring physician and either reviewing the label or contacting the manufacturer of the specific model of implanted neurologic stimulator to learn the types and/or strengths of MRI equipment tested for the interaction with the device.
The notification also advises that patients be carefully screened for implanted devices before MRI procedures are performed, even if the device has been turned off, and should be asked about devices that have been removed, since some leads or portions of leads can remain in the body after removal and “may act as an antenna and become heated” during the MRI exam.