Functional classification systems and their association with botulinum toxin type a use in pediatric cerebral palsy.

Botulinum toxin type A (BoNT-A) is a key intervention for the management of spasticity in children with cerebral palsy (CP); however, the functional factors associated with its use remain incompletely defined. This cross-sectional study examined whether standardized functional classification levels across manual, motor, and communication domains are associated with BoNT-A administration in routine clinical practice. The study included 52 children with spastic hemiplegic and diplegic CP; children with quadriplegic involvement were excluded to enhance cohort homogeneity and focus on activity-oriented rehabilitation goals. Functional status was assessed using the Manual Ability Classification System (MACS), the Communication Function Classification System (CFCS), and the Korean-Modified Functional Severity Score (KMFSS). Children who received BoNT-A demonstrated significantly greater manual dysfunction than those who did not (median [IQR] MACS: 3.0 [2.0-4.0] vs. 2.0 [1.0-3.5]; p = 0.016), whereas no significant differences were observed for CFCS (p = 0.299) or KMFSS (p = 0.956). In multivariable logistic regression analysis adjusted for age and sex, MACS level was the only variable significantly associated with BoNT-A administration in this cohort(β = -0.721, p = 0.036). These findings suggest that BoNT-A use in pediatric CP may be more closely associated with upper limb functional impairment than with global motor or communicative classifications. This observation may reflect a potential "focal-to-global" gap in clinical assessment and warrants further investigation in larger, prospective studies.