A new ultrasound machine, used in conjunction with magnetic resonance imaging (MRI) allows neurosurgeons just burn small pieces of a malfunction of brain tissue without cutting the skin or opening in the skull. A preliminary study involving nine Swiss patients with chronic pain showed that the technology can be used safely in humans. Researchers are now aimed at testing in patients with other disorders such as Parkinson's disease. br The novel finding here is that you can make deep lesions in the skull intact brainthrough and skinwith extreme precision and accuracy and security, said Neal Kassell, a neurosurgeon at the University of Virginia. Kassell, who was not directly involved in the study, is president of Focused Ultrasound Surgery Foundation, a nonprofit organization based in Charlottesville, Va., which was founded to develop new applications of focused ultrasound. br HighIntensity Focused Ultrasound (HIFU) is different from that of ultrasound used for diagnostic purposes, such as prenatal diagnosis. Using a dedicated, highintensity ultrasound rays are concentrated in a small piece of diseased tissue, heating it and destroy it. The technology is currently used for the ablation of the uterus fibroidssmall benign tumors in the uterus and its clinical trials for the elimination of breast tumors and other cancers. Now InSightec, an ultrasound technology company based in Israel, has developed an experimental HIFU device designed to attack the brain. br The main challenge in the use of ultrasound in the brain is to find ways to direct the beams through the skull, which absorbs the energy of sound waves and distorts its path. InSightec The device consists of an array of more than 1,000 ultrasound transducers, each of which can be individually focused. You take a CT scan of the patient's head and adapted to focus acoustic beam through the skull, says Eyal Zadicario, chief of neurology InSightecs program. The device also has built a cooling system to prevent the head from overheating. br The ultrasound beams are focused at a specific point brainthe the exact location depends on the condition treatedthat that absorbs energy and converts it into heat. This raises the temperature to 130 degrees Fahrenheit andkills cells in a region of approximately 10 cubic millimeters in volume. The entire system is integrated with an MRI scanner, which enables neurosurgeons to ensure that they target the right part of brain tissue. Thermal images acquired in real time during treatment allows the surgeon to see where and to what extent the rise in temperature is achieved, says Zadicario. br The Swiss study, published this month in the Annals of Neurology, tested the technology in nine patients with chronic debilitating pain unresponsive to medication. Traditional treatment for these patients is one of two methods used to destroy a small portion of the thalamus, a structure that transmits messages between different brain areas. Surgeons or use radiofrequency ablation in which an electrode is inserted into the brain through a hole in the skull, or use focused radiosurgery, a noninvasive procedure in which a concentrated beam of ionizing radiation is delivered to the tissue target. Zadicario said HIFU has advantages over radiosurgery, because the effects of the death of tissue to radiation may take weeks or months, while the thermal approach is immediate. Add Kassell, precision and accuracy [are] much higher with ultrasound, which should in principle be safer in the long run. br In the new study, nine patients reported immediate pain relief after outpatient procedure and is approaching and soon afterward. Two patients had a glass of Prosecco [wine] with us, says Ernst Martin, director of the Center for Magnetic Resonance University Children's Hospital of Zurich and lead author of the study. Patients reported feeling a moment of tingling or dizziness, and in one case mild headache, as the heated tissue to be treated, he says. However, none had neurological problems or other side effects after surgery. br This will give much impetus to OEMs focused ultrasound interested in the brain, says Kassell. A pilot version of InSightecs ultrasound device being tested in five medical centers worldwide. In addition to use with patients suffering from Parkinson's and other movement disorders, the scientists plan to test the technology as a treatment for brain tumors, epilepsy and stroke. br A disadvantage of HIFU compared to neurosurgeries more invasive procedure performed with an electrode is that surgeons are not able to functionally test whether focused on the correct part of the brain. During traditional surgery of Parkinson's, for example, the neurosurgeon stimulates the target area with the electrode to ensure that he or she has identified the portion of the brain responsible for the problems of patients with motor, and then kill that piece of tissue. br neurosurgeon Not all accept this [new approach], because you can not do a test before the injury is made, says Ferenc Jolensz, director of the division of magnetic resonance imaging guided Therapy Program at Brigham and Women's Hospital in Boston. Jolensz and Yoo SeungSchik partner are developing ways of using HIFU to modulate brain activity in a localized area, allowing a test run of the target zone before it is destroyed. HIFU Jolensz also studying for brain surgery and has tested the technology in four patients with brain tumors, although results have not yet been published. br br
