The main objective of this study is to evaluate the achievement of personalised short- and medium-term objectives of this selective treatment of hypertonia by ultrasound-guided perineural percutaneous cryoneurolysis at the shoulder and elbow, in a population of patients with cerebral palsy with spastic, dyskinetic or dyskinetic, or mixed disorders.

Inclusion Criteria:

• Patients with cerebral palsy treated at the CMCR des Massues, regardless of their functional status as defined by their gross motor function level on the GMFCS (Gross Motor Function Classification System) and their manual ability level on the MACS (Manual Ability Classification System).
• Presenting with disabling and/or painful muscle hyperactivity in the shoulder and/or elbow,
• Aged over 12 years,
• At a therapeutic impasse: contraindicated or refusing surgery, contraindication or insufficient efficacy of oral treatments (analgesics, baclofen, Artane), too short duration of efficacy of toxin injections (<3 months) and/or dose-weight limitation not allowing treatment of all necessary sites.
• Patient (and legal representatives in the case of a minor patient or guardian/curator in the case of an adult patient under legal protection measures) who has been informed and has signed the informed consent form for participation in the research,
• Patient affiliated with a social security scheme.

Exclusion Criteria:

• - Patients who have received a botulinum toxin injection (any location) within 3 months prior to inclusion.
• Change in analgesic and/or antispastic treatment within 5 weeks prior to inclusion - Refusal to allow the patient's medical data to be used for research purposes
• Contraindication to peripheral motor block and/or cryoneurolysis (haemostasis disorder, skin infection, Raynaud's syndrome, cryoglobulinaemia, cold urticaria).
• Pregnant/breastfeeding patients.
• Cognitive and/or behavioural disorders that prevent participation in the study or giving consent to participate