Posts Tagged ultrasound

[NEWS] Focused ultrasound offers potential new epilepsy treatment

29 Jan 2019 Tami Freeman
Clinical trial
Researchers at the Ohio State University College of Medicine are studying how well focused ultrasound can treat medication-refractory lobe focal onset epilepsy. (Courtesy: Ohio State University)

Focused ultrasound treatments use multiple ultrasound beams focused deep within the body to provide non-invasive, targeted therapy for a wide range of clinical applications. Now, researchers at The Ohio State University College of Medicine have begun a clinical trial investigating the use of transcranial focused ultrasound to control a specific type of epilepsy in which seizures are not controlled by medication.

The study will enrol up to 10 patients with medication-refractory lobe focal onset epilepsy. Patients will receive MR-guided focused ultrasound through an intact skull to ablate tissue deep in the brain. The treatment works by passing 1024 ultrasound beams through the scalp, skull and brain tissue (without causing any harm) until they converge at a focal point to ablate a specific part of the brain involved in epilepsy.

“We’re pursuing this clinical trial because we know there’s a large unmet clinical need. More than 20 million people worldwide live with uncontrollable seizures because no available treatment works for them,” explains neurosurgeon Vibhor Krishna, who is leading the study. “Our goals are to test the safety of this procedure and study changes in seizure frequency in these patients.”

Earlier this month, a 58-year-old man became the first patient to be treated with focused ultrasound for epilepsy at Ohio State. During the three-hour surgery in an intraoperative MRI-surgical suite, he remained awake and alert, providing real-time feedback to the treatment team. His feedback helped the team safely ablate the brain region involved in spread of his epilepsy without causing undesirable side effects.

After treatment, the research team plan to monitor all the patients closely for one year. They will use neurological exams and neuro-psychological exams to assess language, memory and executive functioning.

“This is an important step in the evolution of focused ultrasound as a mainstream therapy for disorders affecting the brain,” said Neal Kassell, founder and chairman of the Focused Ultrasound Foundation, which is funding the clinical trial. “Ultimately, the results of this study could lead to new, more effective therapies for certain patients with epilepsy.”

 

 

via Focused ultrasound offers potential new epilepsy treatment – Physics World

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[WEB PAGE] Bionic exoskeleton could help people walk again

Researchers at University of Pittsburgh are combining this robotic technology of an exoskeleton with sensory technology to make paralyzed muscles work with the use of ultrasound. The team recently created a prototype hybrid exoskeleton. The hybrid aspect comes from the two types of technology being used in this project, with electrodes sending ultrasound noninvasively to make paralyzed muscles work while the battery-powered bionic exoskeleton provides additional support to promote movement. “We’re trying to create a situation where the patient controls the exoskeleton, not the other way around,” said Nitin Sharma, associate professor of mechanical engineering and materials science in Pitt’s Swanson School of Engineering and the team’s principal investigator.

Current rehabilitative technologies predict remaining muscle function and how much assistance is needed for muscle movement, a process called electromyography. Correctly measuring how much assistance any rehabilitative device should provide is a challenge with this method, as it is limited to large muscle groups.

However, Sharma’s research uses ultrasound, rather than electricity, delivered through sensors placed on the body. This aims to more accurately measure how much movement a target muscle group can generate. Ultrasound stimulates the tissue beneath the skin’s surface using high-frequency sound waves that cannot be heard by humans. While the ultimate goal is to coordinate muscle movement for the entire leg, Sharma’s team is focusing on the ankle for now because it is “much more complicated” than other parts of the leg, Sharma said. “Unlike the knee joint which moves in one direction, the ankle can be flexed in multiple directions and different muscles activate that joint,” Sharma said. “With electromyography, it’s very challenging because there is no correct place to put these sensors, so we want to use ultrasound to figure that out.”

Sensory technology

The prototype exoskeleton is being developed at Pitt’s Neuromuscular Control and Robotics Laboratory, also known as the Sharma Lab, and is wired to a power source. The final product will be able to function with a portable battery. In addition, the team is working on designs that will integrate these exoskeletons with wheelchairs other mobility technologies.

Sharma said the team will next find out whether the exoskeleton affects neurological behavior and muscle mass in the legs. The team also aims to slim down the 17 kilogram (37.5 pounds) prototype to make the exoskeleton more user friendly. “We added knee motors to the design, making it heavier. But we will be replacing many of our parts with aluminum and carbon fiber parts in the near future, so we are targeting a weight of under 12 kilograms (about 26.5 pounds) with the upgrades,” said Albert Dodson, a research associate in the Sharma Lab. “Exoskeletons are heavy, so what we’re proposing is that since people will be using their muscles, you don’t need these big exoskeletons,” Sharma said. “And if you use both your own muscles and these exoskeletons, you could also save power and walk for longer periods of time.”

Source: University of Pittsburgh

via Bionic exoskeleton could help people walk again – MedicalView

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[Abstract] Quantitative Ultrasound Imaging to Assess the Biceps Brachii Muscle in Chronic Post-Stroke Spasticity: Preliminary Observation

Abstract

We prospectively investigated the feasibility of using quantitative ultrasound imaging (QUI) to assess the biceps brachii muscle (BBM) in individuals with chronic post-stroke spasticity. To quantify muscle echogenicity and stiffness, we measured QUI parameters (gray-scale pixel value and shear wave velocity [SWV, m/s]) of the BBM in three groups: 16 healthy BBMs; 12 post-stroke, non-spastic BBMs; and 12 post-stroke, spastic BBMs. The QUI results were compared with the Modified Ashworth Scale and Tardieu Scale. A total of 20 SWVs were measured in each BBM, once at elbow in 90° flexion and again at maximally achievable extension using acoustic radiation force impulse imaging. BBM pixel value was measured in gray-scale images captured at 90° elbow flexion using ImageJ software. Statistical analyses included analysis of variance for examining the difference in SWV and pixel values among the three groups; Bonferroni correction for testing the difference in SWV and pixel values in a paired group; t-test for examining the difference in SWV values measured at two elbow angles; and Pearson correlation coefficient for analyzing the correlation of QUI to Modified Ashworth Scale and Tardieu Scale. SWV significantly differed between spastic BBMs and non-spastic or healthy BBMs. For pixel values, each of the three groups significantly differed from the others at elbow 90° flexion. The difference in SWV measured between the two elbow angles was also significant (p <0.01). A strong negative correlation was found between SWV and passive range of motion (R2 = −0.88, p <0.0001) in spastic upper limbs. These results suggest that the use of QUI is feasible in quantitative assessment of spastic BBM.

 

via Quantitative Ultrasound Imaging to Assess the Biceps Brachii Muscle in Chronic Post-Stroke Spasticity: Preliminary Observation

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[ARTICLE] Quantifying spasticity in individual muscles using shear wave elastography – Full Text

Abstract

Spasticity is common following stroke; however, high subject variability and unreliable measurement techniques limit research and treatment advances. Our objective was to investigate the use of shear wave elastography (SWE) to characterize the spastic reflex in the biceps brachii during passive elbow extension in an individual with spasticity. The patient was a 42-year-old right-hand-dominant male with history of right middle cerebral artery-distribution ischemic infarction causing spastic left hemiparesis. We compared Fugl-Meyer scores (numerical evaluation of motor function, sensation, motion, and pain), Modified Ashworth scores (most commonly used clinical assessment of spasticity), and SWE measures of bilateral biceps brachii during passive elbow extension. We detected a catch that featured markedly increased stiffness of the brachialis muscle during several trials of the contralateral limb, especially at higher extension velocities. SWE was able to detect velocity-related increases in stiffness with extension of the contralateral limb, likely indicative of the spastic reflex. This study offers optimism that SWE can provide a rapid, real-time, quantitative technique that is readily accessible to clinicians for evaluating spasticity.

Introduction

An estimated 795,000 Americans experience stroke every year [1], and stroke incidence is expected to increase as the population ages [2]. It is estimated that the prevalence of spasticity after stroke ranges from 18% to 39% [3], [4] and [5], and spasticity-associated functional limitations create significant burdens on survivors and caregivers [6]. Health care costs for individuals with stroke who develop spasticity are estimated to be fourfold higher than those without spasticity [7]. However, high subject variability and indeterminate measurement techniques limit research investigation and treatment advances [8] and [9].

Though classically considered to have increased stiffness resulting solely from the over-active velocity-dependent stretch reflex, chronically spastic muscles associated with stroke appear to also have increased nonreflex stiffness when compared to the side of the body ipsilateral to the lesioned hemisphere, as well as healthy controls [9] and [10]. Clinically, spasticity is diagnosed and monitored using the 5-point Modified Ashworth Scale (MAS): a simple technique that requires no equipment, though is subjective, qualitative, and varies widely with muscle groups [11] and [12]. Though the precise mechanism behind spasticity is not known, we now recognize a variety of biomechanical changes within skeletal muscle connective tissue that likely limit the effectiveness of a simplistic tool, such as the MAS, for evaluating spasticity in chronic stroke [13] and [14]. Electromyography or biomechanical measures may offer more reliable, quantitative information, though are impractical for routine clinical use [14], [15] and [16]. Furthermore, elevated muscle tone in persons with spasticity may not be related to activation of the muscle groups in question [17] and [18].

A variety of imaging-based elastography techniques have emerged with great promise for skeletal muscle evaluation, including ultrasound elastography and magnetic resonance elastography [18], [19], [20], [21] and [22]. Strain elastography, a qualitative measure of relative stiffness, is also available but offers little advantage over the MAS, as neither offers a quantitative, objective measure [21], [23] and [24]. The two quantitative imaging modalities, magnetic resonance elastography and ultrasound shear wave elastography (SWE), show good agreement in both phantoms and tissues, though SWE is especially promising for its flexibility, accessibility, and real-time results [25], [26] and [27]. For this reason, SWE may be uniquely suited for evaluating pathologic alterations in stiffness of individual muscles, especially for quantifying spasticity [18], [28], [29], [30] and [31].

This study evaluated the feasibility of using SWE to characterize the spastic reflex during passive elbow extension in an individual with spasticity caused by stroke. We hypothesized that SWE would capture heightened skeletal muscle stiffness, representing the spastic reflex, during passive elbow range of motion.

Continue —> Quantifying spasticity in individual muscles using shear wave elastography

Fig. 1. Shear wave speeds, ultrasound images, and elastograms for 60°/s ipsilateral elbow extension trials. (A) Ipsilateral biceps; (B) ipsilateral brachialis; (C) ultrasound images and elastograms from trial 1 with sample regions of interest demonstrated in the first panel.

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[Thesis] The road to optimized nerve reconstruction by Caroline A. Hundepool, 2016 – Full Text PDF

1. Introduction

Peripheral nerve injuries are devastating injuries, which can lead to severe disability. Nerve injuries are relatively common. It occurs with up to 3% of all patients admitted to Level I trauma centers. Most of the injuries to peripheral nerves occur in the upper extremities. Nerve injury will lead to significant impairment in motor function and causes sensory loss. Depending on the level of nerve injury the consequences can be devastating and have great impact on a patient’s life and ability to perform daily activities such as work and hobbies. Nerve injury not only causes physical disability. There is evidence it also has great consequences psychologically. Cognitive, emotional and behavioral aspects influence recovery. It is important these factors are recognized so that the quality of patient care can be improved[1]. The last decades both experimental and clinical research has been focused on optimizing the reconstruction of nerve injuries. The studies in this thesis are focused on the optimization of nerve reconstruction.

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[WEB SITE] UCLA researchers use noninvasive ultrasound technique to jump-start the brain of coma patient

A 25-year-old man recovering from a coma has made remarkable progress following a treatment at UCLA to jump-start his brain using ultrasound. The technique uses sonic stimulation to excite the neurons in the thalamus, an egg-shaped structure that serves as the brain’s central hub for processing information.

“It’s almost as if we were jump-starting the neurons back into function,” said Martin Monti, the study’s lead author and a UCLA associate professor of psychology and neurosurgery. “Until now, the only way to achieve this was a risky surgical procedure known as deep brain stimulation, in which electrodes are implanted directly inside the thalamus,” he said. “Our approach directly targets the thalamus but is noninvasive.”

Monti said the researchers expected the positive result, but he cautioned that the procedure requires further study on additional patients before they determine whether it could be used consistently to help other people recovering from comas.

“It is possible that we were just very lucky and happened to have stimulated the patient just as he was spontaneously recovering,” Monti said.

A report on the treatment is published in the journal Brain Stimulation. This is the first time the approach has been used to treat severe brain injury.

The technique, called low-intensity focused ultrasound pulsation, was pioneered by Alexander Bystritsky, a UCLA professor of psychiatry and biobehavioral sciences in the Semel Institute for Neuroscience and Human Behavior and a co-author of the study. Bystritsky is also a founder of Brainsonix, a Sherman Oaks, California-based company that provided the device the researchers used in the study.

That device, about the size of a coffee cup saucer, creates a small sphere of acoustic energy that can be aimed at different regions of the brain to excite brain tissue. For the new study, researchers placed it by the side of the man’s head and activated it 10 times for 30 seconds each, in a 10-minute period.

Monti said the device is safe because it emits only a small amount of energy — less than a conventional Doppler ultrasound.

Before the procedure began, the man showed only minimal signs of being conscious and of understanding speech — for example, he could perform small, limited movements when asked. By the day after the treatment, his responses had improved measurably. Three days later, the patient had regained full consciousness and full language comprehension, and he could reliably communicate by nodding his head “yes” or shaking his head “no.” He even made a fist-bump gesture to say goodbye to one of his doctors.

“The changes were remarkable,” Monti said.

The technique targets the thalamus because, in people whose mental function is deeply impaired after a coma, thalamus performance is typically diminished. And medications that are commonly prescribed to people who are coming out of a coma target the thalamus only indirectly.

Under the direction of Paul Vespa, a UCLA professor of neurology and neurosurgery at the David Geffen School of Medicine at UCLA, the researchers plan to test the procedure on several more people beginning this fall at the Ronald Reagan UCLA Medical Center. Those tests will be conducted in partnership with the UCLA Brain Injury Research Center and funded in part by the Dana Foundation and the Tiny Blue Dot Foundation.

If the technology helps other people recovering from coma, Monti said, it could eventually be used to build a portable device — perhaps incorporated into a helmet — as a low-cost way to help “wake up” patients, perhaps even those who are in a vegetative or minimally conscious state. Currently, there is almost no effective treatment for such patients, he said.

Source: University of California – Los Angeles

Source: UCLA researchers use noninvasive ultrasound technique to jump-start the brain of coma patient

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[REVIEW] Mobility and the Lower Extremity | EBRSR – Evidence-Based Review of Stroke Rehabilitation – Full Text PDF

Chapter 9

Mobility and the Lower Extremity

Rehabilitation techniques of sensorimotor complications post stroke fall loosely into one of two categories; the compensatory approach or the restorative approach. While some overlap exists, the underlying philosophies of care are what set them apart. The goal of the compensatory approach towards treatment is not necessarily on improving motor recovery or reducing impairments but rather on teaching patients a new skill, even if it only involves pragmatically using the non-involved side (Gresham et al. 1995). The restorative approach focuses on traditional physical therapy exercises and neuromuscular facilitation, which involves sensorimotor stimulation, exercises and resistance training, designed to enhance motor recovery and maximize brain recovery of the neurological impairment (Gresham et al. 1995).In this review, rehabilitation of mobility and lower extremity complications is assessed. An overview of literature pertaining to the compensatory approach and the restorative approach is provided. Treatment targets discussed include balance retraining, gait retraining, strength training, cardiovascular conditioning and treatment of contractures in the lower extremities. Technologies used to aid rehabilitation include assistive devices, electrical stimulation, and splints.

For evidence tables, please click here.

Source: Mobility and the Lower Extremity | EBRSR – Evidence-Based Review of Stroke Rehabilitation

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[WEB SITE] New head-scanning ultrasound technology could help diagnose brain injuries – Medical News Today

Patients’ lives could be saved or improved by new technology that enables medics to scan for bleeding in the brain using ultrasound.
[A scan of a brain hemorrhage]

The novel head-scanning technology could aid the diagnosis of brain injuries.

Software being developed by the University of Aberdeen and funded by the Defence Science and Technology Laboratory’s (Dstl) Centre for Defence Enterprise- part of the United Kingdom’s Ministry of Defence – could help battlefield medics create 3-D models of soldiers brains while on location, which can then be sent to an expert for swift diagnosis.

The technology is still at an early stage of development but has already been trialed on real hospital patients to test its viability.

In addition to military applications, the software could also be helpful in civilian life, helping paramedics record head ultrasound to diagnose brain hemorrhage as a result ofstroke or other causes. This could be particularly useful for patients living remotely, with a long distance to travel to hospital.

“Closed” brain injuries – for example, internal bleeding or other damage caused to the head by explosions or knocks – can cause death or have severe long-term implications. If identified early enough, emergency steps can be taken to prevent long-term damage, including drilling holes in the skull to relieve pressure, or taking medication.

Even minor head injuries that do not receive early treatment can result in complex long-term complications, including depression, memory problems, attention deficit, and othermental health issues.

Dr. Leila Eadie, a researcher at the Centre for Rural Health at the University of Aberdeen, said: “There is a clear need for this technology, as outlined by Dstl. Traumatic brain injury [TBI] is a big problem for the military, especially because it can be difficult to spot in the field and if left untreated, it can have long-term effects.”

“Ultrasound is not normally used for imaging the brain, but we hope to prove through further investigations that it is a viable method of making an early diagnosis of head injury whilst in the field,” she adds.

“Battlefield medics will not have CT or MRI scanners which are bulky and expensive, but they are likely to have ultrasound equipment already, so it is a case of extending the use of the kit they already have.”

Diagnosis in the field

The ultrasound image of the brain is acquired using existing hardware as found in any hospital. The information is captured using a movement sensor attached to an ultrasound probe, which is used to scan the brain from certain points on the skull where the bone is thinnest.

The probe captures up to 40 images per second, and the resulting 3-D image can be built up from around 2,000 individual photos.

The software is designed to guide a medic with only basic training in ultrasound to produce as detailed a scan of the brain as possible, by showing the user where it has already scanned, and where has yet to be scanned. Once completed, the file containing the brain scan can be sent to an expert for analysis and appropriate advice is fed back to the medical staff on the ground.

Because of the nature of battlefield scenarios, soldiers with “invisible” injuries could be overlooked, so having a relatively simple means of scanning the head for any problematic signs would be extremely helpful.

“U.K. Armed Forces operate in many remote locations and where personnel are injured we need to ensure that all conditions can be rapidly and correctly diagnosed to provide the best possible treatment and care.

Devices which are lightweight, easy to deploy and easy to use, such as the portable ultrasound scanning support system being developed by the University of Aberdeen, have the potential to enhance our capabilities on operations and enhance patient care.”

Neal Smith, Dstl’s capability advisor for medical sciences.

Read about a drug that shows promise for reducing brain inflammation in TBI.

Written by Matthew Driver, managing editor of The Journal of mHealth

Source: New head-scanning ultrasound technology could help diagnose brain injuries – Medical News Today

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[REVIEW] Mobility and the Lower Extremity | EBRSR – Evidence-Based Review of Stroke Rehabilitation – Full Text PDF

Abstract

Rehabilitation techniques of sensorimotor complications post stroke fall loosely into one of two categories; the compensatory approach or the restorative approach. While some overlap exists, the underlying philosophies of care are what set them apart. The goal of the compensatory approach towards treatment is not necessarily on improving motor recovery or reducing impairments but rather on teaching patients a new skill, even if it only involves pragmatically using the non-involved side (Gresham et al. 1995). The restorative approach focuses on traditional physical therapy exercises and neuromuscular facilitation, which involves sensorimotor stimulation, exercises and resistance training, designed to enhance motor recovery and maximize brain recovery of the neurological impairment (Gresham et al. 1995). In this review, rehabilitation of mobility and lower extremity complications is assessed. An overview of literature pertaining to the compensatory approach and the restorative approach is provided. Treatment targets discussed include balance retraining, gait retraining, strength training, cardiovascular conditioning and treatment of contractures in the lower extremities. Technologies used to aid rehabilitation include assistive devices, electrical stimulation, and splints.

Get Full Text PDF

via Mobility and the Lower Extremity | EBRSR – Evidence-Based Review of Stroke Rehabilitation.

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