Tinnitus is the perception of sound, such as ringing or buzzing, when no external sound is present. This condition can affect one or both ears, or seem to originate within the head, with intensity varying from a soft hum to a loud, persistent noise. While often described as “ringing in the ears,” tinnitus can also manifest as clicking, hissing, roaring, or whooshing sounds. Transcranial Magnetic Stimulation (TMS) is a non-invasive treatment being explored as a therapy for tinnitus.
Understanding Transcranial Magnetic Stimulation
Transcranial Magnetic Stimulation (TMS) uses magnetic fields to influence nerve cells in the brain. A stimulator generates electric pulses, delivered to a magnetic coil placed against the scalp. This coil produces a changing magnetic field that penetrates the skull.
The magnetic field induces an electrical current in the underlying brain tissue. This current can either excite or inhibit neurons, modulating their activity. TMS is a targeted form of brain stimulation, influencing specific brain regions without requiring surgery or electrode implantation.
The magnetic fields used in TMS are similar in strength to those produced by an MRI machine. These fields typically reach about 2 to 4 centimeters into the brain directly beneath the treatment coil, affecting superficial brain areas. Different coil types, such as the H-shaped coil used in “deep TMS,” can stimulate deeper and wider brain regions, up to 6 centimeters.
How TMS Addresses Tinnitus
Tinnitus is linked to abnormal neural activity, particularly in the auditory cortex, the part of the brain responsible for processing sound. In chronic tinnitus, this area may exhibit overactivity or disorganized neural patterns, contributing to perceived phantom sounds. The brain’s “noise-canceling” network, which helps filter unwanted sounds, may also not function optimally, leading to increased attention to the tinnitus.
TMS aims to modulate this irregular brain activity. By delivering magnetic pulses to the auditory cortex and associated regions, TMS can inhibit overactive neurons or stimulate underactive ones, restoring a more balanced neural state. For instance, low-frequency repetitive TMS (rTMS) often reduces hyperexcitability in the auditory cortex. This modulation can decrease the intensity and perception of tinnitus sounds.
The therapy also seeks to enhance the activity of brain networks that help individuals ignore unwanted sounds, reducing the distress and annoyance associated with tinnitus. While exact mechanisms are still being researched, the goal is to rebalance these brain networks to alleviate symptoms.
The Treatment Experience
A TMS treatment session for tinnitus is an outpatient procedure. Patients are usually seated comfortably in a reclining chair, and earplugs are provided to minimize the clicking sound produced by the magnetic pulses. There is no need for anesthesia, so the patient remains awake and alert throughout the session.
During the first session, a “brain mapping” process occurs where the technician locates the precise region of the brain to be targeted. An electromagnetic coil is then placed against the scalp over the targeted area, such as the auditory cortex, typically located above the left ear. The coil delivers magnetic pulses, which may cause a tapping sensation on the head and a clicking sound.
A typical session lasts around 20 minutes, though some protocols may extend to 40 minutes. The number of sessions usually ranges from 10 to 20 treatments, often administered daily over several weeks. Patients can generally drive themselves to and from appointments and resume their daily activities immediately after each session.
Outcomes and Important Considerations
The effectiveness of TMS for tinnitus varies among individuals. Research indicates that between 20% and 56% of patients receiving TMS for tinnitus experience some improvement in their symptoms. These benefits can last anywhere from several weeks up to six months or even longer after the treatment course concludes. Studies have shown reductions in tinnitus loudness, annoyance, and overall distress.
Potential side effects of TMS are generally mild and temporary. Common side effects include mild headaches, scalp discomfort or pain at the treatment site, tingling sensations, or twitching of facial muscles. These usually lessen over the course of treatment sessions. Rarely, more significant side effects like seizures can occur, although this is uncommon and often linked to administration errors. Hearing loss or exacerbation of tinnitus can also occur in rare instances if proper ear protection is not used during sessions.
Candidacy for TMS for tinnitus requires careful consideration. It is generally suitable for individuals with chronic subjective tinnitus, where the perceived sound is not caused by an external source and is heard only by the affected person. Individuals with certain medical implants, such as pacemakers or cochlear implants, may not be suitable due to the magnetic fields involved. Consulting with a healthcare professional is important to determine if TMS is an appropriate option, especially since insurance coverage for TMS specifically for tinnitus is currently limited, although it may be covered if depression is also present.