More on rTMS and VNS and MRI
I frequent poster, Herb, has introduced more information on the rTMS with VNS topic. Some doctors are saying it is possible. Additionally, if you read the whole thread, someone corrects me and notes that MRIs are possible with a VNS implant. This is, actually, true. Cyberonics has put together some physician information on this, copied below.
So it goes back to exactly what I said, no one really knows in the implications. Proceed at your own risk.
Additionally, if you read the whole thread, someone corrects me and notes that MRIs are possible with a VNS implant. This is, actually, true. Cyberonics has put together some physician information on this, copied below (no, I don’t know what this stuff means, sorry):
MAGNETIC RESONANCE IMAGING (MRI) ______
Caution: Magnetic resonance imaging (MRI) should not be performed with a magnetic resonance body coil in the transmit mode. The heat induced in the Lead by an MRI body scan can cause injury.
If an MRI should be done, use only a transmit and receive type of head coil. Magnetic and RF fields produced by MRI may change the Pulse Generator settings (change to reset parameters) or activate the device. Stimulation has been shown to cause the adverse events reported in the “Adverse Events” section in the indication-specific parts of the multi-part physician manuals. MRI compatibility was demonstrated using a 1.5T General Electric Signa Imager with a Model 100 only. The Model 102 and Model 102R are functionally equivalent to the Model 100. Testing on this imager as performed on a phantom1 indicated that the following Pulse Generator and MRI
procedures can be used safely without adverse events:
Pulse Generator output programmed to 0 mA for the MRI procedure, and afterward, retested by performing the System Diagnostics (Lead Test) and reprogrammed to the original settings
Head coil type: transmit and receive only
Static magnetic field strength: ≤2.0 tesla
Specific absorption rate (SAR): <1.3 W/kg for a 154.5-lb (70-kg) patient Time-varying intensity: <10 tesla/sec Use caution when other MRI systems are used, since adverse events may occur because of different magnetic field distributions. Consider other imaging modalities when appropriate. Caution: Procedures in which the RF is transmitted by a body coil should not be done on a patient who has the VNS Therapy™ System. Thus, protocols must not be used that utilize local coils that are RF-receive only, with RF-transmit performed by the body coil. Note that some RF head coils are receive-only, and that most other local coils, such as knee and spinal coils, are also RF receive-only. These coils must not be used in patients with the VNS Therapy System.
I can’t find the source on their annoying site, but for more info, contact Cyberonics.