Restoring Neurological Physiology: The Innovative Role of High-Energy MR-Guided Focused Ultrasound (HIMRgFUS). Preliminary Data from a New Method of Lesioning Surgery.

BACKGROUND: Tremor is a disabling condition, common to several neurodegenerative diseases. Lesioning procedures and deep brain stimulation, respectively, of the ventralis intermedius nucleus for intentional tremor, and of the subthalamic nucleus for parkinsonian resting tremor, have been introduced in clinical practice for patients refractory to medical treatment. The combination of high-energy focused ultrasound (HIFUS) with sophisticated magnetic resonance (MR) instrumentation, together with accurate knowledge of the stereotactic brain coordinates, represents a revolution in neuromodulation.

METHODS: At the Neurosurgical Clinic and the Radiology Department of the University of Palermo,, two patients affected by severe and refractory forms of intentional tremor were treated by MRI-guided FUS (MRgFUS) with a unique 1.5 T MR scanner prototype that uses FUS. This apparatus is the only one of its type in the world."

FINDINGS: This is the first Italian experience, and the second in Europe, of treatment with MRI-gFUS for intentional tremor. But this is the very first experience in which a 1.5 T MRI apparatus was used. In both patients, the treatment completely abolished the tremor on the treated side, with results being excellent and stable after 7 and 5 months, respectively; no side effects were encountered.

CONCLUSION: MRgFUS, recently introduced in clinical practice, and widely used at several clinical centers, has been shown to be a valid therapeutic alternative in the treatment of tremor in several neurodegenerative diseases. It is virtually safe, noninvasive, and very efficacious. We report this technique in which a 1.5 T MR scanner was used. Further investigations with long-term follow up and larger clinical series are needed.