What Causes the Clicking Noise in rTMS Sessions?

Repetitive Transcranial Magnetic Stimulation (rTMS) is a non-invasive treatment used to stimulate specific areas of the brain. During an rTMS session, patients may hear a clicking noise. This article aims to explain what causes this sound, its frequency, and why it is normal and harmless.

How the Noise is Produced

The clicking noise during an rTMS session is a byproduct of the rapid switching of the magnetic coils, which are used to generate magnetic pulses. An rTMS device consists of an electromagnet with a coil that creates rapidly alternating magnetic fields.

When there is an electrical current flowing through the coil, it generates a magnetic field that penetrates the skull and stimulates specific brain regions. However, the mechanical action of the coil due to these rapidly changing magnetic fields causes the coil to expand and contract slightly, leading to the audible clicking sound.

The Frequency and Correlation with Stimulation

The frequency of this clicking sound is directly linked to the frequency of the magnetic pulses used during the stimulation. Inhibitory stimulation typically uses a frequency of 1 Hz (1 pulse per second), while excitatory stimulation may use frequencies as high as 10-20 Hz or higher.

Why It is Normal and Safe

The clicking noise is a byproduct of the technology used in rTMS and is not an indication of any malfunction or danger. Although the noise is generally harmless, it can sometimes be loud enough to cause mild discomfort. To reduce the impact of the noise, clinics often provide ear protection such as earplugs or noise-canceling headphones.

Does the Noise Affect Treatment Efficacy?

It is important to note that the clicking sound has no effect on the efficacy of the treatment. It is purely mechanical and unrelated to the magnetic fields' interaction with the brain. If you have concerns about the noise, it is advisable to discuss them with the clinic staff, who can ensure your comfort during the session.

Woodpecker Effect and Safety Measures

The rapid deformation of the magnetic coil can sometimes be referred to as the "woodpecker" sensation by both providers and patients. To ensure safety, earplugs or earbuds are required during the stimulation. These devices not only safeguard your hearing but also provide a more comfortable and peaceful experience during the treatment.

Conclusion

Understanding the clicking noise in rTMS sessions can help alleviate any concerns and ensure a more comfortable experience. By knowing that the noise is a normal part of the process and does not affect the treatment's efficacy, patients can focus on the benefits of the therapy without distraction.