MRI-guided focused ultrasound (MRgFUS) has emerged as a powerful, incision-less technique that permits precise treatment of neurological disorders. Through MRI guidance, focused ultrasound beams are delivered transcranially to create small therapeutic lesions in highly specific locations within the brain. These ablations can be used to effectively treat a variety of conditions by disrupting the neural circuitry that is propagating abnormal signals.
Interest in MRgFUS is rapidly increasing due to the utility of stereotactic intervention in medically refractory movement disorders, particularly where existing surgical options remain unsuitable for patients. Advances in feasibility and safety have lead to rapid growth in clinical applications and research investigations, particularly in the field of functional neurosurgery for movement disorders. The treatment is particularly applicable to patients with tremor, and MRgFUS thalamotomy has been shown to be an effective therapy for tremor.
St Vincent’s Hospital will become the first hospital in Australia and the southern hemisphere to deliver MRgFUS therapy. The $6.5 million dollar technology has been installed in St Vincent’s Hospital radiology department and MRgFUS treatment for tremor patients is scheduled to commence in late 2018.
Surgical intervention of deep structures of the brain movement disorders and psychiatric disease has a long history since the 1950’s. In particular thalamotomy and pallidotomy were effective to suppress movement disorders including tremor and dystonia by interrupting cortical, cerebellar and basal ganglia connections. Stereotactic lesions are usually created using focal heating from a radiofrequency (RF) electrode passed through the brain to the target structure. Electrical stimulation was often used to test the target area before committing to a permanent lesion, and these observations were seminal in later development of deep brain stimulation. With RF lesional surgery some patients experienced significant adverse events due to the inherent risks of passing instruments into the brain including stroke or haemorrhage and consequences of lesions encroaching nearby structures resulting in permanent neurological deficit. It was also observed that bilateral thalamotomy or pallidotomy carried a higher risk for deterioration in speech, swallowing and gait, and therefore most procedures were performed unilaterally to minimize side effects…