Transcranial pulsed ultrasound

Most of the research as of 2010 revolved around projects to utilize TPU as a method of treating neural disorders and improving cognitive function. However, in 2012 Dr. Tyler also began research on ultrasound's potential to stopping seizures.[3] Dr. Tyler and his team still continue to improve their knowledge of brain stimulation therapy and hope to provide a strong foundation in the implementation of such methods.[4]

Conventional ultrasound used for anatomical analysis typically uses a wave frequency of about 20 MHz to penetrate the bodily tissue and produce images. In comparison, the low frequency of TPU has a sub-thermal exposure of about 5.7 MHz. By significantly reducing the wave frequency, excitable tissue can be manipulated without overexposure or detectable damage. Scientists have discovered that focusing on targeted brain regions in animals has been proven to alter their behavior, their cells' electrical properties (electrophysiology), and their synaptic plasticity, which is essentially the neuron's ability to function.[1]

For instance, when focused on the motor cortex of mice, TPU has been shown to induce paw movements without changing the structure or function of that area of the brain. This proves that this method is capable of controlling brain activity at a high cognitive level. It is clear that shorter waves are able to activate neuron activity while longer waves inhibit it. However, the mechanism responsible for this reaction is yet to be discovered. A recent leading hypothesis is the mechanical manipulation of stretch-sensitive membranes actually stimulates certain voltage-gated ion channels, such as sodium or calcium, thus modulating neuronal activity.[1]

Clinical trials have been used to determine any outstanding harmful effects. Although no subjects have displayed long-term neurological abnormalities as a result of these tests, this is a relatively new procedure and has not been studied enough to predict long term side effects. Even though it is a safer alternative to surgery because it is non-invasive, ultrasound always holds the potential to unintentionally disarrange the neurons in a harmful way and cause minor hemorrhages after long-term exposure.[8]

Opposing high-frequency ultrasound, LILFU holds the following benefits: lower absorption in tissue, greater physical penetration depth in tissue, stronger particle deflections, significantly better acoustic penetration and power in bone, greater influence in kinetic effects, immediate/short-term effect results, longer/persistent effects after procedure and a higher degree of patient safety.[9]