From the Guidelines
Transcranial Magnetic Stimulation (TMS) is generally safe but can cause several adverse effects, including headache, scalp discomfort, facial muscle twitching, lightheadedness, and neck pain, with the benefits of TMS for treatment-resistant depression (TRD) outweighing the harms, as indicated by the aggregate literature 1.
Adverse Effects of TMS
The adverse effects of TMS are typically mild to moderate and often resolve after the first few sessions. These include:
- Headache
- Scalp discomfort
- Facial muscle twitching
- Lightheadedness
- Neck pain More serious but rare adverse effects include seizures (risk <0.1%), hearing problems due to the loud clicking noise during treatment, and potential cognitive changes.
Administration Protocols of TMS
Standard TMS administration protocols typically involve:
- Daily sessions (5 days per week) for 4-6 weeks
- Each session lasting 20-40 minutes
- The most common protocol for depression uses high-frequency (10-20 Hz) stimulation to the left dorsolateral prefrontal cortex
- Delivering 3,000-5,000 pulses per session at 100-120% of motor threshold For conditions like OCD or anxiety, different brain regions may be targeted.
Precautions and Considerations
Before starting TMS, patients should undergo proper screening to exclude contraindications such as:
- Metallic implants in or near the head
- History of seizures
- Certain neurological conditions During administration, patients remain awake and seated while a magnetic coil is positioned against their scalp. The effectiveness of TMS depends on proper coil positioning, appropriate stimulation parameters, and consistent treatment adherence, as noted in the studies 1.
From the Research
Adverse Effects of TMS
- Common side effects of TMS include headache or local pain at the site of stimulation, which are typically mild 2
- Severe adverse effects, such as seizures, hearing impairment, or mania, are uncommon 2
- Certain populations, including adolescents, pregnant women, older adults, and those with metal/electronic implants, require special consideration when prescribing and monitoring treatment courses 2
Administration Protocols of TMS
- Repetitive TMS (rTMS) has been shown to be effective in treating depression, with response rates demonstrating efficacy of high-frequency rTMS over the left DLPFC 3
- Deep TMS is currently cleared for treating MDD in individuals 22-86 years old, but has also been shown to be safe and effective in adolescents and young adults suffering from MDD 4
- Theta-burst stimulation (TBS) and accelerated scheduling are newer forms of TMS that are faster and potentially more effective than conventional repetitive TMS 5, 6
- Considerations related to training, roles/responsibilities of providers, and documentation are important when administering TMS for depression 6
Special Considerations
- Adolescents, pregnant women, older adults, and those with metal/electronic implants require special consideration when prescribing and monitoring treatment courses 2
- TMS can be administered safely in a large proportion of depressed patients with adequate assessment and monitoring processes 2
- The use of TMS in special populations, such as adolescents and young adults, has been shown to be safe and effective, but further exploration of targeting methods and accelerated protocols is encouraged 4, 6