Repetitive Transcranial Magnetic Stimulation rTMS

What is repetitive transcranial magnetic stimulation (rTMS)?

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive treatment that uses magnetic fields to perform brain stimulation. It is commonly used in the treatment of several psychiatric disorders including depression, particularly in individuals who have not responded well to standard treatments such as medication or psychotherapy.

How does rTMS work?

The procedure involves placing an electromagnetic coil against the scalp, typically near the forehead. This coil delivers repeated magnetic pulses that pass through the skull and into targeted brain regions involved in mood regulation and cognitive function. By modulating nerve activity, transcranial stimulation is thought to help improve symptoms in some patients.

Since rTMS does not require surgery or sedation, it is considered a relatively safe and well-tolerated electromagnetic therapy for depression. Treatment usually consists of multiple sessions spread over several weeks, and while results vary, some individuals experience significant symptom relief.

What are the uses of rTMS?

rTMS is used as a magnetic treatment for depression, particularly for individuals with major depressive disorder (MDD) who have not responded to standard treatments such as medication or psychotherapy. This is known as treatment-resistant depression, a condition that affects a significant number of patients despite multiple attempts at conventional treatment.

In addition to depression, rTMS has been approved for obsessive-compulsive disorder (OCD). It has also been investigated for use in a range of other disorders such as post-traumatic stress disorder, chronic pain, post-stroke recovery, autism spectrum disorder, substance dependence and anxiety disorders. Its use in these areas is still under clinical evaluation.

Who can benefit from rTMS?

rTMS may be considered for individuals who have not experienced sufficient symptom relief with antidepressants or psychotherapy, or who are unable to tolerate medications and may want to consider rTMS as an alternative treatment. The decision to pursue rTMS should be made in consultation with a healthcare provider based on individual suitability, medical history and treatment goals.

What are the benefits of rTMS?

rTMS offers a non-invasive, medication-free option for individuals with treatment-resistant depression and certain other conditions. While results vary, many patients experience significant symptom relief, making rTMS a viable alternative for those who have not responded well to traditional therapies.

1. Potential symptom improvement

For patients with depression, rTMS may help reduce persistent feelings of sadness, low energy and loss of motivation. Studies suggest that a proportion of individuals who undergo rTMS experience a noticeable reduction in depressive symptoms, and some achieve full remission. However, responses vary, and while some benefit after a few sessions, others may require the full treatment course before improvement is observed.

2. Non-invasive and well-tolerated

rTMS does not require surgery, anaesthesia or hospitalisation. Patients remain fully awake during treatment and can resume normal activities immediately after each session. While some individuals experience mild discomfort or headaches, these side effects are typically temporary and resolve as treatment progresses.

3. Long-term benefits and repeatability

For some individuals, the benefits of rTMS can last for months to years after completing a treatment course. If symptoms return, rTMS can be re-administered safely, making it a viable long-term management option for chronic conditions.

What are the side effects of rTMS?

rTMS is generally well-tolerated, but like any medical procedure, it can cause side effects. Most are mild and temporary, resolving on their own as the body adjusts to treatment. Serious complications are rare, but patients should be aware of potential effects before starting therapy.

Common, mild side effects

Most individuals undergoing rTMS may experience:

·       Headache — The most frequently reported side effect, usually mild and responsive to over-the-counter pain relief.

·       Scalp discomfort — Some patients feel tingling, warmth or sensitivity at the treatment site, which often improves over time.

·       Muscle twitching — Mild involuntary movements of the face or scalp during stimulation, typically harmless.

·       Light-headedness — Some individuals feel slightly dizzy or fatigued after a session, but this usually resolves quickly.

Simple painkillers (analgesics) such as paracetamol can help increase the tolerability of rTMS, which generally gets better over the course of the treatment.

Less common side effects

More serious side effects are uncommon, and following recommended safety measures helps reduce the likelihood of adverse events. They may include:

·       Seizures: The risk of seizures from rTMS is very low at less than 0.1% per treatment course in individuals without pre-existing neurological conditions. However, for patients with a history of epilepsy, brain injury or other seizure-related disorders, the risk may be slightly higher. To minimise this risk, rTMS is administered at safe stimulation parameters, and individuals are carefully screened for seizure susceptibility before starting treatment.

·       Temporary hearing discomfort: rTMS sessions generate a loud, repetitive clicking sound that may be uncomfortable or potentially impact hearing sensitivity. To minimise this, patients are typically provided with ear plugs during treatment.

·       Mild changes in mood or concentration: Some individuals, particular those with bipolar disorder[LW1] , report feeling temporarily irritable or having difficulty focusing after sessions.

What are the potential risks or complications of rTMS?

While rTMS is considered a safe and non-invasive treatment, it is not suitable for everyone. Certain individuals may face increased risks or complications, making them unsuitable candidates for the procedure.

1.      Individuals with metal or implanted medical devices in the body

Since rTMS uses strong magnetic fields, individuals with metal or electronic implants in or near the head should not undergo treatment. The magnetic pulses could interfere with or dislodge these devices. These include:

·       Cochlear implants (hearing devices)

·       Aneurysm clips or coils

·       Deep brain stimulators

·       Implanted electrodes or neurostimulators

·       Metal plates, screws or shrapnel in the skull

As an exception, dental fillings and braces are generally safe and do not pose a risk.

2.      Individuals with a history of seizures or epilepsy

rTMS may increase the risk of triggering a seizure, particularly in individuals with a personal or family history of epilepsy, brain injury or other seizure-related conditions. While the overall seizure risk from rTMS is very low, those at higher risk should discuss the procedure carefully with their healthcare provider.

3.      Individuals with other mental health conditions

rTMS is not recommended for individuals experiencing:
·       Uncontrolled or severe psychotic disorders — Individuals with conditions such as schizophrenia with active hallucinations or delusions may not be suitable for rTMS, as its effects on psychotic symptoms are not well established.

·       Untreated bipolar disorder — rTMS may induce mania in individuals with bipolar disorder if not properly managed with mood-stabilising medication. It should only be considered when bipolar disorder is well-controlled.

·       Severe suicidal thoughts or psychiatric instability — Patients in acute crisis may require more immediate or intensive interventions before considering rTMS.

4.      Pregnancy and certain medical conditions

In certain groups such as pregnant women, treatment outcomes and potential adverse effects should be closely monitored to ensure patient safety.

Screening and precautions

Before starting rTMS, patients are required to undergo a comprehensive medical assessment to determine suitability and minimise risks.

What can you expect during rTMS?

rTMS is an outpatient procedure that does not require anaesthesia or sedation. The recommended number of initial rTMS treatment sessions is 30 to 50. Each treatment session is approximately 30 to 60 minutes, during which patients remain awake and seated in a comfortable chair.

1.      Preparing for the session

• Before the first session, a medical evaluation is conducted to determine the appropriate stimulation settings.
• Patients are advised to remove any metallic accessories, such as jewellery, glasses with metal frames or hearing aids, before treatment.
• Earplugs are provided to protect against the clicking sound produced by the magnetic pulses.

2.      Placement of the magnetic coil

• The doctor or technician positions a magnetic coil on the patient’s scalp, usually near the forehead.
• Small test pulses are delivered to identify the motor threshold, which helps determine the appropriate intensity for stimulation.
• Once the correct intensity is set, treatment begins.
• This process is usually done only once and occurs during the first session. For all later treatments, the magnet is moved to the treatment position using the measurements from the first session.

3.      The stimulation process

• The machine delivers repetitive magnetic pulses to targeted brain areas, usually the prefrontal cortex.
• Patients may feel a tapping or tingling sensation on the scalp but no pain.
• Some individuals experience mild muscle twitches or discomfort during the first few sessions, which typically lessen over time.

Post-treatment and follow-up

• Patients can immediately return to normal daily activities after each session, including work or driving.
• A standard course of treatment consists of daily sessions (Monday to Friday) for four to six weeks. Each session takes 25 to 30 minutes.
• Follow-up assessments are conducted to monitor progress and determine if additional sessions are needed.

rTMS is a gradual process, and improvement in symptoms may take several weeks. Some patients experience relief early in treatment, while others may require the full course before noticing benefits. In cases where symptoms return, booster sessions may be recommended.