Equinovarus Foot

Poststroke spasticity significantly impairs function, particularly through the development of pes equinovarus. Botulinum toxin A (BoNT) injections into the medial gastrocnemius (MG) are a first-line treatment. Treatment outcomes and long-term responses to interventions can vary significantly between individual patients. Additionally, there is increasing concern about potential adverse effects on muscle morphology. Further research is essential to optimize treatment strategies and improve long-term outcomes in this population. Three-dimensional freehand ultrasound (3DfUS) and instrumented spasticity assessment (ISA) are two recently developed techniques that enable the evaluation of changes in muscle, tendon, and neural properties following BoNT injections for post-stroke spastic equinovarus. These methods hold promise for providing new insights into treatment effects. Before implementing these techniques in large-scale studies, a pilot study is required for accurate sample size calculations for a prospective observational study. This study includes a protocol for a non-blinded, non-randomized open-label longitudinal pilot study. The study was approved by the European Medicines Agency ( EU CT Number 2024-513158-32) by the University Hospitals Leuven ethical committee (ID S68672). Standard deviations and effect sizes of outcome measures obtained longitudinally with 3DfUS and ISA before and after BoNT injection into MG will inform sample size calculations for future research.

CRYOSTROKE study is designed : * to compare the efficacy and safety of percutaneous CryoNeurotomie (CN) versus surgical neurotomy (SN) on spasticity, 90 days after intervention, in post-stroke patients presenting with spastic equinovarus foot and, * to ensure that potential clinical effect/safety remain stable within time, with a 12-month follow-up.

Stroke is the leading cause of acquired disability in adults. Stroke causes death in 10% of patients, disability and functional handicap in 60% of cases. Sequelea of hemiplegia include spasticity resulting in great difficulty and slowness in walking, gait instability, increasing the risk of falls. Deambulation may need help (cane, crutch, tripod cane, walker). Lower limb spasticity includes hypertonia of extensors (gluteus maximus, quadriceps, posterior gastrocnemius) resulting in equinovarus. A neurology deficit may be present on ipsilateral lower limb flexors. Hence the patient walks with rubbing of the tip of the foot (tip-toeing gait), resulting in a "mowing wheatslike" movement of the leg as described in the French literature. Walking is then slowed down, unstable, with increased risk of falls. In post stroke, during the period of rehabilitation and beyond, it is advisable to wear sports shoes although custom-made shoes improve walking and are reimbursed by the French social security system after prior agreement. Most of patients only wear conventional shoes.