Brain Stimulation Contraindications and Seizure Considerations

Urgent guidance first

If someone has a seizure during or after brain stimulation, treat it as a medical emergency. In the United States, call 911. MedlinePlus states that a seizure is a medical emergency if it lasts longer than 5 minutes, or if a person has many seizures and does not wake up between them.[1] Do not wait to see whether it passes if either of those is true. Anyone who has a first-ever seizure should be seen by a clinician. If you are outside the United States, use your local emergency number.

This page is information only. It gives no stimulation settings and does not tell anyone to start, stop or change a treatment or medicine. Talk with the treating clinician.

Why seizures are discussed

Brain stimulation changes electrical activity in part of the brain. For magnetic stimulation (TMS), international expert guidelines call seizure theoretically the most serious risk. Their 2021 update concluded that the risk is low, even in people taking drugs that act on the central nervous system, at least with traditional stimulation parameters and focal coils for which large data sets exist.[2] "Low" is not "none," and the statement is limited to those conditions.

What counts as a contraindication

A contraindication is a reason a treatment is usually not offered. These examples come from specific documents, and lists differ between clinics and devices.

What is known about seizure frequency

• A systematic review found 25 seizures reported with repetitive TMS in the literature. Risk factors that emerged included sleep deprivation, multiple medicines and previous neurological injury. It concluded that the data did not support treating the antidepressant bupropion as a reason to withhold TMS, and it urged careful screening during consent.[5]
• A UK public summary of the NICE review (seven studies, over 6,000 patients) lists one partial seizure in one patient among the adverse events.[6]
• One NHS clinic leaflet gives a seizure risk of less than 1 in 30,000 to 50,000 and says the risk may be higher with its accelerated protocol, and that brain injury, alcohol use, sleep deprivation and some medicines may increase it.[3] This is one clinic's statement, not a pooled estimate.
• For low-intensity electrical stimulation (tDCS and related methods), an international review reported no serious adverse events in over 18,000 sessions, with skin burns from poor electrode-skin contact as a moderate event.[7] A separate review of conventional tDCS reported no serious adverse effect across more than 33,200 sessions in trials.[8] Trial settings include screening and supervision that home use does not have.

Other reported harms

Reported side effects include scalp discomfort, twitching, headache, temporary confusion or memory problems and temporary hearing loss with TMS.[6] With tDCS, headache, fatigue and prickling or burning sensations are the milder events, and very rare mania or hypomania was reported in depression patients (11 documented cases in one review).[7]

Who should check with a clinician first

Anyone with a seizure history, a head injury or stroke, an implanted device, metal in the head, skin conditions at the site, or a mood disorder such as bipolar disorder should speak with a clinician before any brain stimulation. Medicines and sleep loss may also matter, as the reviews above note.[5] Pregnancy, children and older adults need individual clinical advice. I did not verify device-specific rules for these groups.

Related guides: DIY brain stimulation risks, tDCS and tACS educational overview and risks, and neurological and psychiatric considerations for neurotechnology.