Transcranial magnetic stimulation is becoming a more common form of treatment and with this growth comes increased research and awareness of the safety of this procedure with respect to seizures. There are many factors that impact the probability of seizures during TMS treatments, and these factors must be considered before pursuing this form of treatment. Overall, in healthy patients, the risk of experiencing seizures due to TMS is rather low, <1% in most studies.
While the vast majority of patients who undergo Transcranial magnetic stimulation treatments will not experience any seizures, there are a number of risk factors, discussed below, that can increase the possibility of experiencing seizures.
Psychotropic medications have an interesting impact on the potential for seizures in TMS patients. Patients taking antipsychotic medications such as Olanzapine, Quetiapine, or Ziprasidone do have a slightly higher incidence rate of seizures independent of TMS treatments, but there is no concrete connection between these medications and seizures during TMS, as many have been used without incident. There is the potential for issues with switching medications prior to TMS treatments, as withdrawal can create a strong relative hazard. If you change medications while undergoing a course of TMS treatment, at Mid City TMS we always emphasize how important it is to redetermine the motor threshold and then the stimulus intensity is adjusted accordingly.
Traumatic Brain Injury Patients
Head injuries can increase the risk of seizures during TMS treatments. The severity of the brain injury is directly correlated with the risk of subsequent seizures, meaning that those with mild to moderate TBIs have a substantially lower risk of seizure compared to those with severe TBIs. A DovePress literature analysis found that while the risk of seizure from TMS alone was rather low, underlying neuropathy can greatly impact the risk.
Alcohol use can have a strong impact on a number of aspects of your health, and this includes TMS treatments. Excessive alcohol use can have a serious impact on the risk of seizures during TMS treatment, with alcohol withdrawal having similar effects. One study reported that 6 out of 31 patients who experienced TMS-related seizures had a history of increased alcohol intake. If you’re planning on undergoing this treatment, it is strongly recommended that alcohol intake not be altered prior to treatment.
In patients with epilepsy, sleep deprivation has long been identified as a trigger for seizures. With this in mind, it is likely that sleep deprivation may lead to increased risk of seizure during TMS treatments.
Patients with epilepsy are at the highest risk of experiencing seizures during TMS treatment, especially if they have any comorbidities with the risk factors listed thus far. That being said, many patients who have epilepsy undergo this treatment without any issue. The risk of seizures during the treatment itself is estimated to be around 2%, which is higher than the risk for patients without epilepsy, but remains relatively low.
Seizures have been identified as one of the most serious adverse effects of TMS therapy, but the risk of this side effect in healthy patients remains incredibly low. Some researchers have concerns about TMS therapy’s lasting impact on seizure thresholds. This is similar to the phenomenon known as “kindling”, where “repeated subconvulsive electrical cortical stimuli eventually result in seizure activity.” However, this phenomenon has been shown only in animals and not in humans despite the use of similar stimuli. Overall, researchers have found that TMS-induced seizures are almost always transient and self-limiting. Even when patients experience seizures during this treatment, they have not led to any long-term, repeated issues.
Transcranial Magnetic Stimulation Treatment at MidCity TMS
While there are certain risks involved in transcranial magnetic stimulation treatment with respect to seizures, the overall research suggests that this risk is minimal.
At MidCity TMS, we have seen incredibly positive results from TMS therapy in patients with depression. We offer expert care that goes above and beyond to ensure that our patients have the best possible experience. If you’re interested in pursuing TMS treatments, don’t hesitate to contact us for more information.