Overview
- University of Houston researchers report in Magnetic Resonance in Medicine that metallic vagus nerve cuff electrodes can enable unintended stimulation during MRI.
- Models show fast-switching gradient fields reduce nerve activation thresholds, with RF-induced heating further lowering thresholds for short pulse sequences.
- In some simulated cases, activation thresholds fell below peripheral nerve stimulation limits set in IEC 60601-2-33, raising concerns about patient discomfort or pain.
- The warning pertains to cuff electrodes used for conditions such as epilepsy, depression and inflammatory disorders, which are positioned around the vagus nerve.
- The authors stress the results are preliminary and call for broader validation across body models, imaging landmarks, implant pathways and polarizations, as they develop mitigation strategies and redesigned cuffs.