TMS Side Effects and Safety: A Montana Patient Guide

TMS Side Effects and Safety: A Montana Patient Guide

Transcranial magnetic stimulation (TMS) is a non-invasive treatment that uses magnetic pulses to stimulate specific areas of the brain. It is most commonly considered for major depressive disorder, particularly when other treatments have not provided enough relief or have caused difficult side effects.

TMS was cleared by the US Food and Drug Administration (FDA) for major depressive disorder in 2008, and for depression with comorbid anxiety in 2021. It does not involve surgery, anaesthesia or electrical current being passed directly through the brain. During treatment, a clinician places a magnetic coil against the scalp while you remain awake and seated.

For many people, the side effects of TMS are manageable and tend to be most noticeable early in treatment. However, TMS is still a medical treatment and requires proper screening. A clinician should review your health history, medicines and any implanted devices before treatment begins.

What a TMS session feels like

A TMS session usually involves repeated tapping or knocking sensations on the scalp. You may hear clicking sounds from the machine and will normally be offered hearing protection.

Before the main course begins, the treatment team will find an appropriate stimulation level for you. This is often done by checking for a small movement in your hand or fingers when a particular area of the scalp is stimulated. The setting may be adjusted over time if treatment feels too uncomfortable or if there are changes in your health or medication.

A standard course of TMS is often about 36 weekday sessions over six to nine weeks. Appointment length can vary according to the type of TMS protocol used. In Montana, it is sensible to ask a clinic about the likely treatment schedule, travel requirements and what support is available if you live some distance from the service.

Common side effects

The most common side effects are temporary scalp discomfort and headache. These can happen during treatment or shortly afterwards.

Scalp discomfort may feel like tapping, pressure, tingling or soreness where the coil rests. Some people find the sensation unusual at first, but become more accustomed to it after several sessions. The treatment team may be able to adjust coil placement, stimulation settings or positioning to improve comfort without compromising the treatment plan.

Headache is also relatively common, especially at the beginning of a course. It is usually mild to moderate and may settle as treatment continues. Your clinician can advise whether you can use an appropriate over-the-counter pain medicine, taking account of your other health conditions and medicines.

Other possible short-term effects can include:

• Facial muscle twitching during stimulation
• Temporary jaw discomfort
• Tiredness after an appointment
• Light-headedness or discomfort from sitting in one position
• Anxiety or frustration if the treatment sensation feels unfamiliar

These effects should be discussed rather than simply endured. Tell the treatment team if you are having pain, if headaches are worsening, or if you feel unable to continue a session comfortably.

The rare risk of seizure

Seizure is a rare but recognised risk of TMS. Clinics reduce this risk by screening carefully, using established treatment settings and reviewing changes in your health throughout the course.

A past seizure does not necessarily mean that TMS is impossible, but it is important information for the clinician assessing you. The same applies if you have epilepsy, a brain injury, a neurological condition, a history of fainting episodes, or a family history that may be relevant.

Certain circumstances can increase seizure risk. These may include severe sleep deprivation, heavy alcohol use or abrupt changes in alcohol intake, recreational drug use, and some medicines. Do not make changes to prescribed medicines on your own in preparation for TMS. Instead, tell the treating clinician and the prescriber managing your medication so they can advise you safely.

Seek urgent medical help if you or someone with you believes you have had a seizure or another serious medical event. Your TMS clinic should also be informed as soon as possible.

Who may not be suitable for TMS?

TMS is not suitable for everyone. A key safety consideration is the presence of certain implanted metal or electronic devices in or near the head.

For example, you should tell the clinician if you have, or may have:

• Metal fragments in or around the head, including from an injury or past work involving metal
• A cochlear implant
• Implanted brain stimulators or other neurostimulating devices
• Aneurysm clips, stents, electrodes or other implanted medical hardware
• A shunt or other device used in neurological treatment
• Permanent make-up, tattoos or dental work containing metal, if you are unsure of the materials used

Not all metal in the body automatically prevents TMS. For instance, some dental work or metal located well away from the treatment area may not be a problem. The important point is to provide complete information and allow the clinic to check the device or material involved.

Pregnancy, breastfeeding, significant hearing problems and certain neurological conditions should also be raised during assessment. A clinician can discuss what is known, what precautions may be needed and whether another approach is more appropriate for your circumstances.

What to tell your clinician before and during treatment

A thorough assessment is an important part of safe TMS care. Be open about your medical history, even if you are unsure whether something is relevant.

Before treatment, tell the clinician about:

• Previous seizures, epilepsy, concussion, stroke or brain injury
• Headaches or migraine, particularly if frequent or severe
• Bipolar disorder, psychosis, mania or hypomania
• Any implanted device, surgical clip or metal in or near your head
• Current medicines, including antidepressants, sleep medicines, stimulants, pain medicines, supplements and non-prescribed substances
• Alcohol use and any recent changes in drinking
• Recreational drug use
• Sleep difficulties, particularly significant lack of sleep
• Pregnancy, plans for pregnancy or breastfeeding
• Hearing concerns or sensitivity to noise

During the course, continue to report changes. This includes a new medicine, a dose change, a new diagnosis, a serious illness, a head injury, a change in alcohol or substance use, or a period of very poor sleep. These details may affect whether treatment should continue as planned or whether adjustments are needed.

It is also important to tell the team about changes in mood. TMS is used in depression care, but your clinician needs to know if you develop unusually elevated mood, agitation, impulsive behaviour, hallucinations, suicidal thoughts or a sense that you are becoming unsafe. If you are in immediate danger or may harm yourself, call emergency services or go to the nearest emergency department.

Questions worth asking a Montana TMS clinic

Choosing a clinic is not only about location. It is reasonable to ask how the service handles safety, comfort and communication with your wider care team.

You may wish to ask:

• Who will assess whether TMS is suitable for me?
• How will you review my medicines and medical history?
• What should I do if I develop a headache or discomfort between sessions?
• How will you communicate with my GP, psychiatrist or other prescriber?
• What happens if I miss an appointment because of weather, illness or travel difficulties?
• What should I do if I have a medication change during treatment?
• Which insurance plans do you work with, and what authorisation may be required?

Montana’s geography can make regular weekday attendance more complicated, particularly for patients travelling from outside larger population centres. TMS Therapy Montana currently lists clinics in Billings, Bozeman, Havre, Great Falls and Missoula. Asking about scheduling and missed-session policies before starting may help you plan a realistic course of care.

Coverage and prior authorisation rules can vary. Insurers commonly seen in Montana include Blue Cross and Blue Shield of Montana, PacificSource Health Plans, UnitedHealthcare, Aetna, Cigna, Allegiance Benefit Plan Management, Montana Medicaid and Medicare. A clinic may help verify benefits, but it is still wise to confirm your own cover, referral requirements and expected out-of-pocket costs with the insurer.

Getting help in Montana

TMS Therapy Montana’s directory includes 12 published clinic listings across Montana. Use the clinic listings to compare local options, read the insurance guide before contacting providers, and visit the contact page if you need help navigating the directory.

This is educational information, not medical advice.