Safety Study Using Transcranial MR Guided Focused Ultrasound in the Treatment of Neuropathic Pain

MR-Guided Functional Ultrasound-Neurosurgery

The aim of this study is to asses the efficacy and the clinical safety of the transcranial magnetic resonance guided high intensity focused ultrasound system ExAblate 4000, InSightec Ltd. for functional neurosurgery. The treatments to be conducted in this study are non-invasive, i.e. without opening the skull, and will create micro-thalamotomies in specific target areas such as thalamus, subthalamus and pallidum. The data obtained in this study will be used to evaluate the basic safety aspects of this new treatment technology and will serve as a basis for the clinical introduction of MR-guided ultrasound-neurosurgery.

Inclusion Criteria:

1. Male and female patients 18 years and older
2. Clinical indication for a medial thalamotomy
3. Stereotactic targets within thalamus, subthalamus and pallidum
4. All targets supposedly accessible by TcMRgFUS
5. Physically and mentally able to understand the risks of participating in this study and to give written informed consent based on the patient information provided
6. Sufficient proficiency in one of the languages German, French, Italian or English to al-low for verbal communication during all phases of the study
7. Physically and mentally able to communicate the personal condition and all feelings during the TcMRgFUS treatment
8. Physically and mentally able to undergo the TcMRgFUS treatment

Exclusion Criteria:

1. Anomalies of brain anatomy, especially in or around thalamus or pallidum that will in-fluence the atlas-based navigation
2. Existing lesions in close proximity (<5mm) to planned ablation targets
3. Extended anomalies of scalp such as scars, inflammations, etc.
4. Clips or other implanted objects close to (< 3cm) target
5. Non-MRI-compatible cardiac pacemaker
6. Previous hemorrhages in the brain
7. Uncontrolled arterial hypertension
8. Any coagulopathy or patient under anticoagulant therapy
9. Sensitivity to MRI contrast agents
10. Contraindications to MRI such as non-MRI-compatible implanted devices
11. Large patients not fitting comfortably into the MRI unit (generally >110kg)
12. Difficulty to lie supine and still for up to 4 hours in the MRI unit or claustrophobia
13. Other known life-threatening systemic disease
14. Patients currently participating or participated in another clinical trial in the last 30 days