Investigating the effects of intrathecal baclofen and ventral-dorsal rhizotomy on dystonia in children with cerebral palsy (PREDICT-Dystonia): protocol for a prospective observational clinical trial.

INTRODUCTION: Dystonia, a form of elevated muscle tone in CP, significantly impairs function and quality of life. Multiple neurosurgical interventions are used to reduce dystonia, including intrathecal baclofen (ITB) and ventral dorsal rhizotomy (VDR). ITB is used most often for moderate to severe generalised dystonia in CP; however, the evidence supporting its effectiveness is weak due to patient variability and study limitations. Further, VDR is becoming more prevalent but there is minimal data available on its outcomes. This proposal aims to evaluate ITB and VDR's ability to reduce quantitative and functionally impactful dystonia as well as reduce spasticity, improve motor function, improve mood and improve quality of life. Secondary analysis will focus on identifying child characteristics of a positive response to ITB and VDR to allow for better patient selection.

METHODS AND ANALYSIS: We will conduct a prospective observational study of 52 children with CP and moderate-severe dystonia (Barry Albright Dystonia Scale (BADS) greater than 14) who receive ITB (n=35) and VDR (n=17). Children will be enrolled at three sites in the USA: Texas Children's Hospital (Houston), Lurie Children's Hospital (Chicago) and C.S. Mott Children's Hospital (Ann Arbor). Changes will be measured in dystonia, spasticity, gross and fine motor function and multiple patient-reported outcomes related to quality of life, participation, depression, anxiety and pain. Children enrolled in the study will undergo detailed characterisation of brain malformation and injury patterns. The primary analysis will use repeated measures models to estimate changes from baseline in BADS scores at 3, 6 and 12 months. Secondary analyses will apply the same strategies to the other outcome measures. Subgroup analyses will investigate unique characteristics of children with a positive response to either intervention. A multidimensional or composite measure will also be created.

ETHICS AND DISSEMINATION: Primary ethics approval was provided by the Baylor College of Medicine Institutional Review Board (H-54449). Primary caregivers of all participants were consented for the study. Participants with capacity were asked to assent. Results of the study will be disseminated via peer-reviewed presentations at scientific conferences and open access publication.

TRIAL REGISTRATION NUMBER: NCT06606574.