Positioning of vagal nerve stimulators: technical note

Area of Science:

• Neurology
• Biomedical Engineering

Background:

• Vagal nerve stimulation (VNS) is a key treatment for intractable seizures.
• Patients with VNS often require brain MRIs to monitor neurological conditions.
• Current implant techniques risk VNS deactivation during MRI scans.

Purpose of the Study:

• To identify an MRI-compatible positioning technique for VNS pulse generators.
• To prevent unintended deactivation of VNS devices during magnetic resonance imaging.

Main Methods:

• Assessed a VNS pulse generator model using an oscilloscope and LED in an MRI environment.
• Simulated device performance in various positions.
• Studied patients with implanted VNS devices to confirm stimulator activation.

Main Results:

• Placing the pulse generator with electrode inputs parallel to the body's long axis prevented deactivation in the MRI's magnetic field.
• This positioning maintained device function during supine scans.

Conclusions:

• Altering the VNS pulse generator's implant orientation is a simple solution to prevent MRI-induced deactivation.
• This allows for essential MRI and functional MRI (fMRI) scans without interrupting VNS therapy.