Theta Burst Stimulation (TBS) Explained: iTBS, cTBS and Session Time
Theta Burst Stimulation (TBS) is a patterned form of rTMS that has changed how clinics schedule treatment, because it shortens sessions from over half an hour to a few minutes.
The pattern
- Bursts: 3 pulses at 50 Hz.
- Burst repetition: 5 Hz (theta frequency).
- Intermittent TBS (iTBS): 2-second trains repeated every 10 seconds. It is generally excitatory and is used over the left DLPFC for depression.
- Continuous TBS (cTBS): an uninterrupted train. It is generally inhibitory and is used in research and some protocols.
Why clinics like iTBS
A standard 10 Hz depression session can take around 37 minutes. An iTBS session of 600 pulses takes about 3 minutes. That means:
- More patients per day on one machine.
- Shorter visits for patients.
- Better use of staff time.
iTBS was cleared for depression in the United States in 2018, after a large randomised trial found it non-inferior to standard 10 Hz rTMS.
Equipment requirements
TBS demands rapid pulse delivery and good coil cooling. Both the MEDSTIM MS-50 and MS-100 include Theta Burst mode, continuous temperature monitoring and protocol memory.
Practical tips
- Set intensity from the motor threshold. See motor threshold basics.
- Warn patients that TBS may feel more intense at first.
- Keep consistent coil placement between sessions.
- Track outcomes with standard scales.
Accelerated protocols
Some newer protocols deliver several TBS sessions per day over a shorter period. These are evolving areas and should be adopted with care, following current evidence and guidelines.
To learn more, see what is rTMS or contact us for a Theta Burst demonstration.
MS-50 rTMS Machine
Indigenous rTMS with Theta Burst, 0.5–50 pps and dual coil support. ₹19 lakh – ₹24 lakh
Frequently Asked Questions
Is Theta Burst as effective as standard rTMS for depression?
A large randomised trial found iTBS non-inferior to 10 Hz rTMS for depression, supporting its use.
Does Theta Burst need special equipment?
The stimulator must support fast burst delivery; both MS-50 and MS-100 include Theta Burst mode.
Is TBS more uncomfortable?
Some patients feel it more intensely; tolerance usually improves.
This article is for general information for healthcare buyers and professionals and is not medical advice. Clinical decisions should be made by qualified practitioners.
