Study: Focused ultrasound reduced essential tremor symptoms for 3 years

In a recent study, Casey Halpern and  colleagues used ultrasound to relieve symptoms of essential tremor, for up to three years. The treatment is used when medication does not work.

76 people with an average age of 71 who had essential tremor for an average of 17 years were studied. 56  received focused ultrasound thalamotomy, and 20 had a sham therapy. After three months, those who received the sham were offered the treatment. 23 people left the study. The researchers believe that those who left did not respond as well as others to the treatment.

Hand tremors, level of disability and quality of life were measured at the start, and after six months, one year, two years and three years. After three years, on average, participants improved in hand tremors by 50 percent, disability by 56 percent, and quality of life by 42 percent.

No new side effects occurred. Existing side effects, which continued during the study, included numbness and tingling, imbalance and unsteadiness.  The researchers claimed that none worsened, and two were resolved, during the treatment.

Current recommended treatment for people with severe essential tremor responding insufficiently to medication is deep brain stimulation. Ultrasound is much less invasive, performed in one session. There is no need for follow-up visits, and there is immediate benefit.  Ultrasound does, however, produce an irreversible brain legion.

Cala Health has also developed a non-invasive therapy for essential tremor, using a neuromodulation wearable on the wrist. The device  stimulates nerves responsible for the tremor, interrupting circuits, to allow for better movement control.

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Focused ultrasound thalamotomy in Parkinson’s Disease

UVA’s Scott Sperling and Jeff Elias, who already used focused ultrasound to treat essential tremor, have just published the results of  a small study showing the efficacy of the technology in Parkinson’s Disease.

The sound waves were shown to interrupt brain circuits responsible for the uncontrollable shaking associated with the disease. The researchers claim that their study also offers “comprehensive evidence of safety” in its effect on mood, behavior and cognitive ability, which has not previously been studied.

According to Sperling, “In this study, we extended these initial results and showed that focused ultrasound thalamotomy is not only safe from a cognitive and mood perspective, but that patients who underwent surgery realized significant and sustained benefits in terms of functional disability and overall quality of life.”

27 adults with severe Parkinson’s tremor that had not responded to previous treatment were divided  into two groups. Twenty received the procedure, and a control group of seven (who were later offered the procedure) did not. Participants reported improved quality of life, including their ability to perform simple daily tasks, emotional wellbeing, and a lessened sense of stigma due to their tremor, at both three and twelve months.

The team found that mood and cognition, and the ability to go about daily life, ultimately had more effect on participants’ assessment of their overall quality of life than did remor severity or the amount of tremor improvement.

Cognitive decline was seen in some participants after the study, in that they were less able to name colors and think of and speak words. The cause of this was unclear, and must be investigated. The researchers suggested this could be a result of the natural progression of Parkinson’s.

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Ultrasound penetrates blood-brain barrier to treat brain tumor

Todd Mainprize at Sunnybrook Hospital has, for the first time,  delivered chemotherapy directly to a brain tumor, by breaking through the blood-brain barrier using tightly focused ultrasound.

The patient’s bloodstream was  infused with a chemotherapy drug, as well as microscopic bubbles, which are smaller than red blood cells and can pass freely through blood. MRI-guided, low intensity sound waves targeted blood vessels in the blood-brain barrier, near the tumor site. The ultrasound waves vibrated the microbubbles,  loosening the tight cell junctions of the blood-brain barrier. The loosened junctions allowed the chemotherapy drug to flow past the barrier and deposit within the targeted tumor site.

This breakthrough could also lead to new treatments for brain diseases such as Parkinson’s and Alzheimer’s.

Click to view Sunnybrook Hospital video.


Sonogenetics: Neuron stimulation via ultrasound

Salk‘s Sreekanth Chalasani‘s “sonogenetics” technique uses ultrasound to stimulate individual brain cells.  A nature paper describes the technology as tested on worms.  The goal is noninvasive stimulation of specific cell types or individual neurons in humans, with out using implanted electrodes or fiber-optic cables.

Current optogenetics therapies  rely on inserting light-sensitive channel proteins into neurons. When hit by the correct color of light, usually sent by a fiber-optic cable, the channels open, allowing ions to flood in.

The new technique relies on touch-sensitive  “channel” proteins, which can be added to specific brain cells through genetic engineering. The channels open when hit by an ultrasonic pulse, allowing ions to flood into a neuron and cause it to turn on.

Click to view Salk Institute video.

Ultrasound targets deep brain region, helps Parkinson’s symptoms

University of Maryland researchers are using MRI-guided focused ultrasound on the globus pallidus to treat Parkinson’s symptoms. The ExAblate Neuro system was developed by Israel’s Insightec.  The treatment is non-invasive, as it does not require a cut, but its ultrasound impacts a deep region of the brain, which is not with out risk.

Currently, drugs and (implanted) deep brain stimulation techniques treat  tremor, rigidity and dyskinesia in Parkinson’s patients.

According to Professor Howard Eisenberg, this  treatment could “help limit the life-altering side effects like dyskinesia to make the disease more manageable and less debilitating.”

During the  2-4 hour outpatient procedure, patients lie in an MRI scanner with a head-immobilizing frame fitted with a transducer helmet. Ultrasonic energy is targeted through the skull to the globus pallidus, and images acquired during the procedure give physicians a real-time map of the area being treated.  Patients are fully awake and able to interact with the treatment team, allowing the physicians to monitor immediate effects and make necessary adjustments.

Cheap, fast, precise, hand held ultrasound

Butterfly Network‘s Jonathan Rothberg wants to make a “super-low-cost version of a $6 million (ultrasound) machine, to make it 1,000 times cheaper, 1,000 times faster, and a hundred times more precise.”  This will depend on software and extensive AI image research to extract key features to automate diagnoses.

Butterfly’s patent applications describe compact, hand held ultrasound scanners that create 3D images in real time.  Rothberg want to create a cheap system that can be used in the poorest nations.

Current ultrasound machines use piezoelectric crystals or ceramics to generate and receive sound waves. They are wired and attached with cables to a signal processing box. Butterfly wants to  integrate ultrasound elements on a computer chip, cheaply produce them, and  simplify the creation of the arrays needed to produce 3D images.


Ultrasound improves virtual “touch”

Ultrahaptics uses ultrasound waves to make one feel as if he/she is  touching virtual objects and surfaces with bare hands.

It’s creator, a University of Bristol graduate student, claims that it improves upon touch-free interfaces such as Kinect and Leap Motion by reflecting air pressure waves off the hand to create different sensations for each fingertip.

Applications could include interacting with moving objects in virtual reality games, or improving navigation for the visually impaired by projecting the sensation of Braille letters onto fingers in midair.

Ultrasound combined with contrasting agent for radiation-free tumor detection

University of North Carolina Professor Nancy Klauber-Demore has improved the resolution and tumor-detecting ability of ultrasound scans.

Combining ultrasound with a contrast agent composed of tiny bubbles that pair with an antibody that many cancer cells produce at higher levels than do normal cells, Klauber-Demore was able to visualize lesions created by angiosarcoma.  By binding to the protein SFRP2, the contrast agent may help distinguish malignant from benign masses found on imaging.  Since SFRP2 is expressed in many cancers – including breast, colon, pancreas, ovarian, and kidney tumors – the technique could potentially be useful for a broad range of cancer types.  As the level of SFRP2 in tumors increases as tumors develop, the team will also investigate whether the technique can be used to track tumor growth.

Ultrasound stimulation enhanced sensory performance in human brain

Virginia Tech Carilion Research Institute scientists, led by Professor William Tyler, have demonstrated that ultrasound directed to a specific region of the brain can boost performance in sensory discrimination. This is the first example of low-intensity, transcranial-focused ultrasound modulating human brain activity to enhance perception.

The scientists delivered focused ultrasound to an area of the cerebral cortex that corresponds to processing sensory information received from the hand. To stimulate the median nerve, they placed an electrode on the wrist and recorded brain responses using EEG. Before stimulating the nerve, they began delivering ultrasound to the targeted brain region.  The ultrasound decreased the EEG signal and weakened the brain waves responsible for encoding tactile stimulation.

Subjects were then given two neurological tests: the two-point discrimination test, which measures a one’s ability to distinguish whether two nearby objects touching the skin are truly two distinct points, rather than one; and the frequency discrimination task, which measures sensitivity to the frequency of a chain of air puffs.  The subjects receiving ultrasound showed significant improvements in their ability to distinguish pins at closer distances and to discriminate small frequency differences between successive air puffs.

Sound waves detect disease related changes in red blood cell shape

Ryerson University investigators used photoacoustics to create detailed images to detect changing shapes of red blood cells associated with diseases including maria, sickle cell anemia and certain types of cancer.

A drop of blood is placed under a microscope that picks up sounds produced by the cells. Researchers then focus a laser beam on the samples. As the blood cells absorb energy from the laser pulse, they release some of it in the form of sound waves, enabling scientists to understand details about the shape of the cell.