tDCS vs TMS: What’s the Difference?

What are tDCS and TMS Systems?

Transcranial magnetic stimulation, or “TMS”, targets certain areas of your brain to help improve brain function. Using a safe magnetic field generated over your scalp, the device passes gentle impulses into your brain to boost cell activity.

Transcranial direct current stimulation, or “tDCS”, uses electrical currents rather than magnetic energy. It involves passing harmless electrical currents into the brain to stimulate nerve activity.

Although both tDCS and TMS use brain stimulation techniques, they are completely different systems. To help you decide on the most effective treatment for your needs, here’s a look at tDCS vs TMS devices compared.

Size of TMS and tDCS Systems

TMS Devices

TMS devices come in a variety of sizes. Some units are the size of large microwaves, others can be as big as a mini fridge. Typically, they’re larger than direct current brain stimulation units.

• TMS units are wall-powered (220 V).
• These devices are heavy and usually sit on a cart.
• TMS is delivered in a clinical setting, rather than home treatment.

The most commonly used TMS coil resembles a figure-eight in appearance. This coil is placed on the subject’s head, and connected to the machine by a heavy-duty, high-voltage cable. This coil is held in place by a mechanical arm.

Additional equipment is available including a neuronavigation system, which uses a sophisticated infrared camera or magnetic trackers. This system can be used to aid in the accurate placement of the TMS coil over the targeted brain region.

Other additional equipment includes an EMG machine, which uses small, sticky electrodes placed on the hand to monitor muscle twitches. These twitches are a normal, temporary, and completely safe effect of using the TMS device.

tDCS Devices

tDCS devices are smaller than TMS devices. They’re portable and easy to use in different settings. They can be the size of a small microwave, or as compact as a cell phone.

• tDCS devices are usually battery-powered which makes them easy to operate.
• They’re light enough to carry or place on a normal table, so you can use them at home.
• tDCS can be delivered in a clinic, but it’s not a requirement.

To use a tDCS device, the subject must wear specialized headgear, which houses electrodes that administer the current in a safe and stabilized manner. These electrodes are either wet with saline or gel, depending on the system you are using. tDCS devices have small wires that run from the device to the wearer, which connect to these electrodes.

Bottom Line: tDCS devices are portable, battery-powered, and rely on specialized headgear. TMS systems, however, are wall-powered, heavier, and used in clinical settings. They use a coil held over the head as opposed to electrodes mounted to a headband.

Using tDCS and TMS devices

How to use TMS

TMS devices send a short, high-power electrical surge to the coil. This short pulse creates a magnetic field which in turn produces a safe, controlled electrical current that flows into and stimulates the subject’s brain through induction.

Depending on where the coil is held, different areas of the brain can benefit from the stimulation. The current produced can be above the threshold needed to make a neuron activate. When the coil is placed on the motor cortex, TMS makes the cells in the motor cortex active, leading to a finger twitch. A single short pulse or repetitive pulses can be administered depending on the clinician’s directive.

The latter is what is called repetitive TMS or rTMS. rTMS, features pulses that are delivered in a specific pattern to encourage a certain reaction in the brain. TMS is FDA cleared for the treatment of depression. This protocol involves treating the DLPFC (F3) with a 10 Hz frequency at 120 percent of the motor threshold.

TMS has also recently been cleared by the FDA for the treatment of OCD.

How to Use tDCS

tDCS uses a very low current, which is applied for several minutes.

The current passes through the head-mounted electrodes and targets certain brain areas. Although the currents are lower than the power generated by TMS devices, it can still improve brain tone, or “plasticity”. So, while TMS devices create more brain activity, tDCS systems can still:

• Activate certain brain cells (excitatory response, or anodal tDCS)
• Calm them down (inhibitory response, or cathodal tDCS).

In tDCS, there are typically two electrodes, an anode (red) and a cathode (black/grey). When using tDCS, it is important to position the electrodes in the correct location. Using the headstraps included in the starter kits, you can reference this electrode placement guide for assistane in determing the best electrode placement for your specific use case.

tDCS vs TMS Efficacy: TMS and rTMS make the brain active with every pulse. tDCS uses a sustained low power which can be adjusted depending on the desired response. They are both, however, effective at adjusting brain activity.

TMS vs tDCS Adverse Effects

TMS Side Effects

TMS can produce twitching in the scalp and some discomfort. However, this is completely safe and painless, and it subsides almost immediately after a session has been completed. The most serious side-effect of rTMS is the potential for seizures, but don’t let this frighten you. The chances of seizure are very low and your practitioner will know what the best course of treatment is for your needs.

tDCS Side Effects

The main known side-effects of tDCS are itching and tingling that happen under the electrode. Generally, people don't mind this and the sensation subsides as soon as the tDCS session stops. In that sense, there are no real side effects otherwise that should be a cause for concern

Transcranial Direct Current Stimulation vs TMS: The biggest difference between tDCS and TMS as far as side-effects are that TMS can be more uncomfortable. There is also a very low risk of a seizure occurring, so be sure to discuss with your doctor whether it’s a suitable treatment for you.

tDCS, on the other hand, has no long-term side effects, and the only immediate thing you’ll notice is temporary discomfort and irritation.

What works better, TMS or tDCS?

TMS

TMS has been investigated thoroughly, having been used in clinical trials and off-label for a range of different brain diseases. In the USA, TMS is currently cleared by the FDA for the treatment of major depressive disorder as well as for OCD. The magnetic field makes it more focal and targeted than tDCS.

tDCS

tDCS is also being investigated just as comprehensively and tested to identify effects on many different issues. Note that, in the USA, tDCS has not been approved for the treatment of any disease. In Europe and other countries, it has been approved for the treatment of depression and pain.

Bottom Line: So, what works better as a treatment, tDCS or TMS? This really depends on the intended use case and what you wish to accomplish with either device. It is not fair to recommend one or the other as both have their strengths and ideal use cases. What the disease is and whether there are any other personal factors that could affect performance are just a couple of factors that could influence your decision.

Also, just because the FDA has not approved a device for use in the treatment of a certain disease doesn’t mean it isn’t a good choice. This simply indicates that the FDA needs to perform further testing and/or isn’t ready to endorse it.

The best thing to do is perform ample research and then talk to your doctor about the best solutions for your situation.

When should you choose TMS or tDCS?

When to Use TMS

For TMS treatment, you‘ll first need to find a physician who provides TMS services in their clinic as these systems are not designed for at-home use. Access will vary depending on your country and region. You can find providers on various websites including via the Neuromodec "Find a TMS Provider" tool.

When to Use tDCS

tDCS is not a type of TMS. They are different treatments. tDCS that is intended for medical treatment is available only through a physician. Access will vary based on where you are located.

Alternatively, you can locate a tDCS provider on the Neuromodec "Find a tDCS Provider"tool.

tDCS devices that are not intended for medical purposes can be purchased online such as through Caputron. Always do your research first via resources such as our tDCS device comparison table.

Bottom Line: TMS will always be an in-clinic treatment. tDCS can theoretically be done at home, but only if for non-medical purposes. Furthermore, tDCS is in the investigational stage pending any endorsements.

If we compare tDCS vs TMS for depression, clinically-administered TMS has been FDA-cleared for the treatment of major depressive disorder and is reimbursable by insurance.

tDCS vs TMS: Which Is Best?

Is tDCS better than TMS? No – they both serve different purposes, that’s all. Arming yourself with knowledge and a deeper understanding of what’s best for your needs is the best way to experience safe, controlled, and effective TMS or tDCS treatments.

Be sure to discuss these solutions in further detail with your doctor and feel free to contact us at Caputron today for more information and setup tips.

*Disclaimer: Caputron provides top-quality EEG, TMS, CES, and tDCS devices and accessories from the leading device manufacturers. Some of the products offered are investigational devices and Federal (or United States) law limits such devices to investigational use.

The information provided here is not medical or legal advice. It is not an endorsement of any device, application or use. It is based entirely on information in the listed publications and information from manufacturer websites. Investigational devices are controlled and limited to researchers or medical doctors.

In order to obtain such products, certain information must be provided. To see if you are eligible to obtain an investigational device, please request a quote or contact us and an authorized representative will help guide you through the process.