Cryoneurolysis for Spasticity Treatment: Long-term Clinical Outcomes and Mechanisms in the Central Nervous System

Inclusion Criteria: * have increased range of motion or reduced spasticity with diagnostic nerve block, * have no undesired loss of function with a diagnostic nerve block, * score 2 or higher in the Modified Ashworth scale, * have at least flickers of movement in the upper extremity, * have not received botulinum-A neurotoxin within the past 3 months, * if on anti-spastic medication, maintaining anti-spastic medications on a stable schedule over the course of the follow up period, and * they can understand and follow instructions in English. Exclusion Criteria: * have contraindications to TMS (i.e., history of seizure, pregnancy) or 3T MRI (i.e., certain metallic implants), * are unable to provide informed consent (i.e., severe cognitive impairment), * receive any toxin injections for spasticity (Botulinum-A Toxin or equivalent) within 3 months of initial baseline assessments or at any time over the course of the follow-up period. * Have previously undergone any nerve-specific interventions (phenol neurolysis, radio-frequency ablation, or cryoneurolysis) for spasticity on a nerve that will be targeted for this study.