Support for similar treatment approaches
This Belgian study confirmed that children with HSP and cerebral palsy (CP) both have significantly smaller muscle volume in the inner head of the calf muscle and heightened reflexes. However, more children with HSP than CP have ankle clonus, which is more severe; while there is higher muscle activity in HSP vs CP as a result of faster stretches.
Overall it is thought that similar treatment approaches in the two groups are warranted.
Hereditary spastic paraplegia (HSP) is a neurological, genetic disorder that predominantly presents with lower limb spasticity and muscle weakness. Pediatric pure HSP types with infancy or childhood symptom onset resemble, in clinical presentation, children with bilateral spastic cerebral palsy (SCP). Hence, treatment approaches in these patient groups are analogous. Altered muscle characteristics, including reduced medial gastrocnemius (MG) muscle growth and hyperreflexia have been quantified in children with SCP, using 3D-freehand ultrasound (3DfUS) and instrumented assessments of hyperreflexia, respectively. However, these muscle data have not yet been studied in children with HSP.
Therefore, we aimed to explore these MG muscle characteristics in HSP and to test the hypothesis that these data differ from those of children with SCP and typically developing (TD) children. A total of 41 children were retrospectively enrolled including (1) nine children with HSP (ages of 9-17 years with gross motor function levels I and II), (2) 17 age-and severity-matched SCP children, and (3) 15 age-matched typically developing children (TD).
- Clinically, children with HSP showed significantly increased presence and severity of ankle clonus compared with SCP (p = 0.009).
- Compared with TD, both HSP and SCP had significantly smaller MG muscle volume normalized to body mass (p ≤ 0.001).
- Hyperreflexia did not significantly differ between the HSP and SCP group.
- In addition to the observed pathological muscle activity for both the low-velocity and the change in high-velocity and low-velocity stretches in the two groups, children with HSP tended to present higher muscle activity in response to increased stretch velocity compared with those with SCP.
This exploratory study is the first to reveal MG muscle volume deficits in children with HSP. Moreover, high-velocity-dependent hyperreflexia and ankle clonus is observed in children with HSP. Instrumented impairment assessments suggested similar altered MG muscle characteristics in pure HSP type with pediatric onset compared to bilateral SCP. This finding needs to be confirmed in larger sample sizes. Hence, the study results might indicate analogous treatment approaches in these two patient groups.
SOURCE: Front Neurol. 2021 Feb 26;12:635032. doi: 10.3389/fneur.2021.635032. eCollection 2021. PMID: 33716937 Copyright © 2021 De Beukelaer, Bar-On, Hanssen, Peeters, Prinsen, Ortibus, Desloovere and Van Campenhout.
Muscle Characteristics in Pediatric Hereditary Spastic Paraplegia vs. Bilateral Spastic Cerebral Palsy: An Exploratory Study
1. KU Leuven Department of Rehabilitation Sciences, Leuven, Belgium.
2. Clinical Motion Analysis Laboratory, University Hospitals Leuven, Leuven, Belgium.
3. Department of Rehabilitation Medicine, Amsterdam University Medical Center, Amsterdam, Netherlands.
4. Department of Orthopedics, University Hospitals Leuven, Leuven, Belgium.
5. KU Leuven Department of Development and Regeneration, Leuven, Belgium.