Focused Ultrasound Pallidotomy for Dyskinetic Cerebral Palsy in Pediatric and Young Adult Subjects

Inclusion Criteria:

• The treating physician has chosen GPi-DBS or pallidotomy for the treatment of thesecondary dystonia caused by cerebral palsy in this patient

• Patient and/or legal representative, if the patient is underaged or not capable togive consent himself, have chosen pallidotomy as treatment

• The consent to participate in the trial of the underaged patient, if he is capableto understand the study requirements, is required

• Age at enrolment 8-22 years

• Diagnosis of secondary dystonia due to cerebral palsy caused by perinatal hypoxicinjury

• Anti-dystonic pharmacotherapy insufficient

• Stable anti-dystonic medication over the last 30 days

• Globus pallidus internus (pars posterior) and thalamus (motor part) intact on MRI (not older than 2 years - if possible)

• No fixed severe skeletal deformations with loss of function, which need immediateorthopaedic surgical intervention

• Sufficient compliance of the patient or the legal representative if the patient isunderaged or not capable to give consent himself to take part in the study

• Informed consent to take part in the study from patient and/or legal representativeif the patient is underaged or not capable to give consent himself

• Patient and/or legal representative if the patient is underaged or not capable togive consent himself, understands the study requirements and the treatmentprocedures and provides written informed consent before any study-specific tests orprocedures are performed

Exclusion Criteria:

• Patients with known primary (e.g. DYT1) or idiopathic dystonia

• Severe axial hypotonia with total loss of head control (e.g. absence of control at "upper thoracic level" in the SATCo score) (medication effect excluded)

• Fixed hemi-dystonia

• Severe spasticity in knee- and elbow-flexors and -extensors (Modified Ashworth Scale >3)

• Fixed severe skeletal contractions with loss of function which require immediateorthopaedic surgical intervention

• Patients with other severe concurrent neurological disease (e. g. brain tumor,neurodegenerative diseases, trauma etc.)

• Condition likely to require use of MRI in the future

• Any intracranial abnormality or medical condition that would contraindicate DBSsurgery

• Any findings in neuropsychological screening assessments that would contraindicateDBS surgery

• Any current drug and / or alcohol abuse

• Any history of frequent grand-mal seizures without response to anticonvulsivetreatment

• Any other active implanted device (e.g. Cochlear implant, pacemaker), whether turnedon or off, would be allowed provided that they do not interfere with functioning ofthe device.

• The presence of DBS leads due the risks of these ferromagnetic devices in the MRIenvironment.

• A history of neurostimulation intolerance in any area of the body.

• Currently on any anticoagulant medications that cannot be discontinued duringperioperative period.

• Any significant medical condition that is likely to interfere with study proceduresor likely to confound evaluation of study endpoints, including any terminal illnesswith survival <24 months.

• Participation in another drug, device, or biologics trial concurrently or within thepreceding 30 days; any other trial participation should be approved by the PrincipalInvestigator.

• A female that is breastfeeding or of childbearing potential with a positive urinepregnancy test or - if a person is sexually active - not using sufficientcontraception with a Pearl Index of less than 1% including all forms of hormonalcontraception ("antibaby-pill", hormonal plaster, NuvaRing®, Implanon®, hormonaldepot injections, contraceptive coil), the tubal ligature (female sterilization).Alternatively, the female of child bearing potential is sexually abstinent.

• Subjects who have contraindications to anesthesia, in the judgment of the attendinganesthesiologist

• Subjects who are unwilling or unable to undergo general anesthesia

• Presence of a condition or abnormality that in the opinion of the Investigator wouldcompromise the safety of the subject or the quality of the data.

• Minimum head circumference < 49cm

• Skull Density Ratio (SDR) <0.40.