What does tFUS stand for?
tFUS stands for Transcranial Focused Ultrasound Sonication.
The form of tFUS that the Kuhn Lab (N³ Lab) utilizes may be also referred to in the current literature as the following: > Low-Intensity Focused Ultrasound Sonication (LIFUP or LIFU)
> Transcranial Focused Ultrasound (TFU)
> Focused Ultrasound Neuromodulation (FUN)
> Focused Ultrasound Sonication (FUS)
Is tFUS safe?
Though High-Intensity Focused Ultrasound Pulsation permanently ablates neural tissue, our studies use Low-Intensity Focused Ultrasound Pulsation which accurately and reversibly stimulates or inhibits neurons without damaging them. We likewise perform our tFUS studies within the FDA guidelines for safe, low intensity ultrasound of the brain.
Are there any side effects of tFUS?
Transcranial Focused Ultrasound is generally safe and well-tolerated based on preliminary safety studies by Pasquinelli et al. 2019, and like other non-invasive neuromodulation treatments in clinical use, may come with potential side effects which may include transient neck pain or headaches; scalp ting, discomfort, or irritation; transient muscle twitches; temporarily increased anxiety; or temporarily reduced attention.
How long does tFUS last for?
Preliminary research suggests that tFUS impact durations vary, with the current literature suggestion as brief as two hours and as long as two months. Our current longitudinal studies seek to study this duration more specifically.
How does tFUS work?
A concave plate placed outside of a participant’s head reverberates back and forth and creates longitudinal, pressure waves above the frequencies that humans can hear (ULTRAsonic!). These pressure waves are weak until they reach the targeted location inside the brain where they constructively interfere to create a stronger pulsation. This results in a mechanical vibration of the targeted brain area.
How new is tFUS?
Experiments with ultrasound on the brains of human subjects started in the 1950s, where they observed reversible changes in excitation of neurons. The ultrasound did not alter the neuronal structure of the brain. There have been studies performed in animals such as mice and monkeys since then supporting the safety of the technology, but over the years, the technique received little attention. As a result, the application of tFUS is largely unexplored. In recent years, ultrasound sonication has experienced a resurgence because of its specificity and ability to access deep brain structures.
What does tFUS feel like?
The participants cannot feel the ultrasound pulsations. However, they may be able to hear the pulsating device should they have excellent hearing, upon which they should notify the lab staff of the sensation.
What else is tFUS being used for?
tFUS has also been used in clinical trials to increase blood flow to areas in the brain, and ultrasound sonication is a verified technique used by surgeons to dissolve blood clots. Outside of the nervous system, tFUS has been used to speed up the healing process in bone tissue.
Is the MRI safe?
Unlike X-rays, there is no radiation put into the body, so there is no technical limit on how long a person can be in a scanner. Since an MRI works by changing the spin on hydrogen electrons with an induced electric field, no damage to human cells and tissues.
What are the risks of MRI?
There are three main safety concerns with an MRI machine. Because patients are in the scanner for around an hour and a half, if they are claustrophobic the tight-burhole can cause discomfort. Additionally, because an MRI is essentially a large magnet, no metal objects can be brought into the scanner. This includes metal implants such as knee replacements, cardiac pacemakers, shrapnel, and so on. Because some tattoo inks and permanent makeup can contain trace amounts of metal, participants can experience a slight irritation or heating on the area of their tattoo while they are in the scanner (though this does not happen in every case).
Can I sleep in the MRI scanner?
Although sleeping is not prohibited, we try to keep participants awake in order to check in regularly throughout the scan.
How long will I be in the MRI scanner?
For our study, the scans take approximately an hour to run, but with additional check-ins and ultrasound configuration, the process takes around an hour and a half.
Will I be able to see my scans afterwards?
No. We are currently unable to share scans with our study participants.
What is the age requirement to participate in your studiess?
Yes – please see our current study flyers for our recruitment criteria, which includes age limits.
Do I need to fast or are there any eating restrictions?
There are no eating or drinking restrictions; however, eating and drinking in large amounts before the scan increases the likelihood of bathroom breaks, which interrupts the flow of the scanning session and increases the time it takes to complete it.
How will these studies advance our knowledge of the brain?
These studies will elucidate the effects of low-intensity ultrasound sonication on various brain regions, which could evolve into treatments for psychiatric disease and/or increase our knowledge about the functionality of the stimulated brain regions. These are lofty goals; however, human-based LIFUP research is in its infancy and it remains difficult to discern whether this technique can become a proven clinical treatment method for neurodegenerative disorders.
Why is MRI being used with tFUS?
These technologies are compatible because they do not interfere with each other. tFUS is a stimulation technique, and MRI enables us to image the brain while tFUS is being applied. The visualization allows us to localize where and to what degree tFUS is taking effect.
Who is funding this study?
Our funds come from a variety of sources, depending on the exact study that is being conducted.
Is the study taking precautions with Covid-19? Is it safe to come in person?
Vaccinations are required by all participants and researchers dealing with subjects in person. We will employ extensive disinfectant protocols and covid screenings in order to ensure the safety of our participants.
Who can I talk to about the science behind tFUS, or this specific study if I have questions?
Please contact use at tFUS@mednet.ucla.edu or via our Contact Page.
Can my significant other or friend wait in the lobby?
Yes, absolutely. Unfortunately, they are not allowed within the testing or MRI scan room, but there is a designated area with a couch and cushioned chairs where they are more than welcome to wait.
How do I get paid and when?
Participants get paid in cash at the end of their complete session, or at the end of the last session if there are more than one.
Where can I read more?
Bystritsky, A., Korb, A. S., Douglas, P. K., Cohen, M. S., Melega, W. P., Mulgaonkar, A. P., DeSalles, A., Min, B. K., & Yoo, S. S. (2011). A review of low-intensity focused ultrasound pulsation. Brain stimulation, 4(3), 125–136.
Chen, H., & Jerusalem, A. (2021). A Framework for Low-Intensity Low-Frequency Ultrasound Neuromodulation Sonication Parameter Identification from Micromechanical Flexoelectricity Modeling. Ultrasound in medicine and biology, 47(7), 1985-1991.
Mehić, E., Xu, J. M., Caler, C. J., Coulson, N. K., Moritz, C. T., & Mourad, P. D. (2014). Increased anatomical specificity of neuromodulation via modulated focused ultrasound. PloS One, 9(2), e86939
Yu, K., Niu, X., Krook-Magnuson, E., & He, B. (2021). Intrinsic functional neuron-type selectivity of transcranial focused ultrasound neuromodulation. Nature Communications,12(2519).