The UF comprehensive epilepsy program is advancing clinical care of epilepsy with transcranial magnetic stimulation (TMS) to perform cortical language or motor mapping prior to brain surgery, which is FDA-approved. The preoperative mapping with TMS can be used to guide surgical decision.
TMS has the important advantage of being entirely noninvasive. TMS uses a small electromagnetic coil controlled by a computer program to deliver short bursts of magnetic energy focused precisely on the brain’s cortex. The TMS magnetic fields are the same type and strength as those produced by a magnetic resonance imaging (MRI) machine.
Functional MRI is currently the most commonly used noninvasive method for cortical mapping, but it is not ideal to use for every type of patient. Functional MRI requires patients to be awake and lie very still for long periods so that motor and language functions can be assessed. This makes it impractical for infants and young children and may pose challenges for adults who are claustrophobic or have difficulty lying still for long periods. Therefore, the TMS service may serve as more accessible alternative for those who may not be good candidates for functional MRIs. TMS can also be used to assess patients facing surgery for a brain tumor that may be near an eloquent area.
A TMS mapping session takes about one to two hours and is usually scheduled as a half-day outpatient visit. The primary contraindication is the presence of a non-removable metal-containing implant in the head, such as a cochlear implant, deep brain stimulator, responsive neurostimulation device or stent in the neck or brain.
TMS is safe enough to be used in the doctor’s office. Patients generally handle TMS well, and side effects are minimal. Some patients experience mild local pain and headache after a TMS session, but these symptoms are transient.