Medial gastrocnemius muscle morphology in spastic cerebral palsy: A comparison between treatment naïve children and children with a treatment history

Abstract

In children with spastic cerebral palsy (SCP), conservative interventions such as physiotherapy, intra-muscular Botulinum Neurotoxin-A (BoNT-A) and serial casting are applied to counteract neuromuscular impairments [1]. The accumulated effects of these treatments on alterations in macroscopic muscle morphology are difficult to evaluate [2]. In Suriname, the access to these treatments for SCP-children is limited. Studying a cohort of treatment-naïve children, in comparison to a group of children with treatment history, can gain insight in the natural course of altered muscle morphology. Are the medial gastrocnemius (MG) macroscopic muscle morphology alterations different between treatment-naïve SCP children and SCP children with treatment history? In this cross-country comparison study, 20 treatment-naïve children from Suriname were case-control matched by age, GMFCS level and topographical description with 20 SCP-children with treatment history from Belgium. In addition, the data from 20 age-matched typically developing (TD) children from Belgium and 20 age-matched TD children from Suriname were assessed for comparison. A child was treatment-naïve if there was no previous 1) lower limb surgery, 2) serial casting in the last 3 years, 3) lower limb Botulinum Neurotoxin type A (BoNT-A) injection, 4) orthoses and 5) more than 10 physiotherapy sessions a year. SCP children had treatment history if they received usual care including orthoses and regular physiotherapy, and had access to BoNT-A treatment if clinically needed. Children with treatment history were excluded if they had 1) soft-tissue surgery, 2) BoNT-A injection in the last 10 months, 3) lower limb bony surgery in the last 2 years, 4) neurosurgery or 5) baclofen pump. Muscle-tendon unit (MTU) length, muscle length, tendon length and muscle volume were acquired from the MG with 3D freehand ultrasound measurement, which has proven reliability and validity [3]. Similar equipment, acquisition and processing procedures were used in both countries. The morphological alterations of the SCP child were calculated as a percentage of the morphology of the locally matched TD child. The medians and interquartile ranges of the deviation in morphology were defined, and treatment-naïve SCP-children and children with treatment history were compared by a Mann-Whitney U test. Both, the treatment-naïve and treatment-history groups showed alterations in their MG-muscle morphology compared to TD with greatest deviations in muscle volume (-47(19)% versus -31(30)%, Table 1). However, there were no significant differences in alterations for muscle volume, muscle length, tendon length and MTU length between treatment-naïve children and children with treatment history.Download : Download high-res image (167KB)Download : Download full-size image The natural course of pathological muscle morphology in treatment-naïve SCP-children seems comparable to SCP-children with treatment history. This may imply that the effect of interventions does not significantly influence the muscle pathomorphology. However, the heterogeneity in the data asks for caution with the interpretation. Further analysis may uncover the accumulated effects of these treatments on neuromuscular impairments and gait pathology.