Earliest age of onset are most affected
This study of three groups of 12 children – one group with HSP, one group with Cerebral Palsy and the third group made up of typically developing children – showed that muscle growth and development in HSP children overall is not significantly different to normal development.
However those children with the earliest age of onset exhibit the most difference in the muscle tested (medial gastrocnemius) and the most affected gross motor function overall.
Children with cerebral palsy did show significantly different muscle growth and development. Other aspects of muscle morphology and gait deviation, joint stiffness and spasticity were not assessed in this study.
Abstract
Hereditary spastic paraplegia (HSP) is a heterogeneous group of genetic disorders, characterised by altered muscle function. The clinical presentation is often similar to bilateral spastic cerebral palsy (SCP) but the etiology differs since HSP is defined by various ages of symptom onset [1]. Recent investigations highlighted the importance of impaired muscle growth in SCP [2].
Studies on muscle morphology in HSP however are lacking, and it can be questioned if age of symptom onset is related. Estimating the muscle properties of the medial gastrocnemius (MG) in an HSP, SCP and typically developing (TD) cohort, along with exploring the impact of age symptom onset in the subject with HSP, may therefore provide insight into altered muscle function in HSP.
Results
The HSP and SCP-cohort had smaller normalised muscle length nML and higher mean echo intensity EI than the TD-cohort, but differences were only significant for the SCP-cohort (nML p=0.014 and EI, p≤0.001). Mean nML and EI were not significantly different between the HSP and TD cohort. In the HSP-cohort, the early-onset group showed a tendency for higher GMFCS levels and greater alterations in MG nML and EI.
Discussion
This study investigated altered nML and EI of the MG in HSP children. Our results revealed that the HSP-cohort is less morphologically involved in comparison to the SCP cohort. The additional HSP cohort exploration suggests that the age of symptom onset may be a factor influencing the extent of morphological alterations. Further research should also focus on the other involved muscles and include other aspects of muscle morphology. In addition, a measure of gait deviation, ankle joint stiffness and spasticity may provide further insights into their potential aetiology.
References
[1] Salinas, et al., The Lancet Neurology (2008).
[2] Cenni, et al., Computer Methods and Programs in Biomedicine (2018).
SOURCE: Gait Posture. 2018 Jul 19. pii: S0966-6362(18)30811-7. doi: 10.1016/j.gaitpost.2018.06.083. [Epub ahead of print] PMID: 30033349
How comparable are the alterations in muscle morphology in age-matched children with hereditary spastic paraplegia and spastic cerebral palsy?
De Beukelaer N1, Schless SH2, Hanssen B2, Cenni F3, Peeters N2, Bar-On L2, Ortibus E4, Desloovere K2, Van Campenhout A5.
1 KU Leuven, Department of Rehabilitation Sciences, Leuven, Belgium. Electronic address: [email protected].
2 KU Leuven, Department of Rehabilitation Sciences, Leuven, Belgium.
3 KU Leuven, Department of Medical Engineering, Leuven, Belgium.
4 KU Leuven, Department of Development and Regeneration, Leuven, Belgium.
5 UZ Leuven, Department of Orthopaedic Surgery, Leuven, Belgium.