Long-term functional decline following upper limb botulinum toxin injections in children with unilateral cerebral palsy: A preliminary retrospective 5-year follow-up case-control study.

PURPOSE: To compare long-term upper extremity functional evolution in children with spastic cerebral palsy (CP) receiving upper limb botulinum toxin A (BoNT-A) injections versus physical therapy (PT) alone. METHOD: This retrospective cohort study included children aged 5-12 years at baseline with ≥2 Assisting Hand Assessment (AHA) evaluations over ≥3 years. The primary outcome was AHA score change. Secondary outcomes included changes in maximal wrist extension and forearm supination during functional tasks, measured from standardized videos by three blinded assessors. Changes were classified using minimal clinically important difference (MCID) thresholds: 5 units (AHA), 20° (wrist extension), and 30° (supination). RESULTS: Eleven patients with unilateral spastic CP (BoNT-A+PT, n=5; PT alone, n=6) were included. All BoNT-A+PT patients demonstrasted AHA deterioration (Δ = -3.6 ± 2.7), versus improvements in 5/6 PT patients (Δ = +9.0 ± 6.4). Wrist extension declined in all BoNT-A+PT patients (Δ = -53° ± 19°) versus 1/5 PT patients (Δ = -4° ± 8°). Supination deteriorated in 4/5 cases of BoNT-A+PT patients (Δ = -30° ± 7°) but remained stable in all PT patients (Δ = +2° ± 9°). CONCLUSION: Upper limb BoNT-A was associated with systematic long-term functional decline, while PT alone preserved or improved function. SIGNIFICANCE OF STUDY: These findings suggest that BoNT-A treatment may compromise long-term motor control and functional capacity, potentially influencing treatment algorithms in children with spastic cerebral palsy. LEVEL OF EVIDENCE: III (retrospective cohort study).