Trial to test impact of MR-guided ultrasound on Parkinson's tremors

Non-invasive technology could provide new treatment option for tremor-dominant Parkinson's

Major advancements are being made in the treatment of Parkinson’s Disease (PD) with clinical trials beginning in America to test the impact of non-invasive MR-guided ultrasound technology.

Manufacturer, InSightec, has recently received approval from the US Food and Drug Administration (FDA) to begin a Phase I clinical trial evaluating the use of its ExAblate Neuro system for the treatment of patients with tremor-dominant PD.

If successful, the technology could be available in the UK within the next few years.

The device is the first clinical system to use magnetic resonance (MR) focused ultrasound to perform non-invasive transcranial treatment without the need for an incision or ionising radiation, helping to alleviate the clinical features of PD through deep lesioning of the brain.

While the concept has been recognised for many years, vast technical barriers had to be overcome to enable the technology to be developed.

There are many potential benefits of focused ultrasound treatment as this procedure is non-invasive, the therapeutic effect is immediate, and there is no associated ionizing radiation

It is hoped the ExAblate Neuro system could be the breakthrough scientists have been waiting for, enabling improved accuracy as MR images are used to reconstruct the skull and the data, in turn, used to configure the ultrasound beams to properly focus on the targeted lesion.

The clinical trial will be sponsored in collaboration with the Focused Ultrasound Foundation of Charlottesville, Virginia, where researchers have already treated 15 patients successfully. Preclinical studies conducted at the Focused Ultrasound Foundation as well as Arizona State University, UCLA, and Brigham and Women’s Hospital indicate the mechanical effects of ultrasound alone may be sufficient to both excite and suppress neuronal circuits.

PD is caused by the death of nerve cells in the brain, resulting in the ever-increasing impairment of cognitive and motor functions over time. A chronic, degenerative neurological disorder, it affects at least five million people worldwide, with the number of sufferers expected to double by 2030.

Currently there is no known cure and there are few therapies available to reduce the symptoms. Presently, most treatment options are limited to drug therapy and surgery, including deep brain stimulation and direct lesioning. While each of these approaches has been proven to show some symptomatic improvement, their effectiveness is limited and side effects discouraging. Drug therapy techniques, even at optimal intervals and dosages of medication, show diminishing effectiveness as the disease progresses and ultimately fail to promote good motor control in late-stage PD. Deep brain stimulation, or neurostimulation, is the most common surgical intervention used, but this technique is complicated as well as very invasive. Other options include radiofrequency ablation, another invasive technique; as well as radiosurgery, which has adverse side effects related to its use of ionising radiation.

As MRI machines become increasingly available to patients around the world, focused radiation offers a non-invasive means of accessing hard-to-reach areas of the body and it is expected that such techniques will become progressively more accurate and less expensive as technologies improve.

The technology is advantageous as it allows physicians to visualise the body anatomy, plan the procedure, adjust and control the treatment, and monitor the outcome – all in real time. As technologies develop, this treatment will have applications across multiple clinical disciplines

In 2010, the global neurostimulation market was valued at over $1.8billion and it is expected the market will grow at an annual rate of 14% to reach $4.7billion by 2017.

Commenting on the potential impact of the ExAblate Neuro system, GlobalData medical devices analyst, Rob Littlefield, told BBH : “There are many potential benefits of focused ultrasound treatment as this procedure is non-invasive, the therapeutic effect is immediate, and there is no associated ionizing radiation. Non-invasive procedures greatly reduce the patient’s risk of infection and closed-loop thermal feedback ensures focused ultrasound damages only the targeted tissue. This one-time procedure does not require subsequent surgery to replace batteries, does not involve implantation of a foreign object in the body, and greatly reduces collateral damage to the brain.”

Beyond working to treat indications of PD, additional research using magnetic resonance guided focused ultrasound is being conducted for chronic neuropathic pain, targeted drug delivery, uterine fibroids, adenomyosis, and sonothrombolysis for acute ischemic stroke.

Littlefield said: “The technology is advantageous as it allows physicians to visualise the body anatomy, plan the procedure, adjust and control the treatment, and monitor the outcome – all in real time. As technologies develop, this treatment will have applications across multiple clinical disciplines.”

Companies