This multicenter observational study evaluates the safety and effectiveness of ultrasound-guided thermal radiofrequency applied to the musculocutaneous nerve in adult patients with focal elbow flexor spasticity secondary to central nervous system injury. Hypothesis: Thermal radiofrequency treatment of the musculocutaneous nerve in patients with spasticity resulting from damage to the central nervous system is a safe and effective treatment for spasticity.

Inclusion Criteria:

• Signed informed consent.
• Age 18 years or older.
• Diagnosis of spasticity secondary to central nervous system injury.
• Predominant elbow flexor spastic pattern dependent on the musculocutaneous nerve.
• Patients with severe spasticity refractory to conservative treatments who underwent thermal radiofrequency treatment of the musculocutaneous nerve during the study period.

Exclusion Criteria:

• No signed informed consent.
• Age under 18 years.
• Radiofrequency treatment applied to patients without central nervous system injury.
• Absence of follow-up after radiofrequency treatment, for any reason, for a minimum period of 2 months.

Individual participant data will not be shared due to privacy and confidentiality considerations.