Spasticity is one of the most common secondary health conditions associated with SCI, especially when the level of injury is above the region of the conus medullaris/cauda equina. Spasticity can be a disabling condition, but with appropriate treatment and rehabilitation, its negative impact on patients’ quality of life can be significantly mitigated. There are several different definitions of spasticity, which can shed light on clinical diagnosis and evaluation. The most widely used definition in recent years is that spasticity is “disordered sensorimotor control, resulting from an upper motor neuron lesion, presenting as intermittent or sustained involuntary activation of muscles” (Pandyan et al. 2005). Literature on epidemiology, impact, measurement, and treatment of spasticity in the pediatric-onset SCI population will be reviewed.
Very few publications relating to pediatric SCI and spasticity were found.
In their study examining the prevalence of musculoskeletal and neurological complications of adults with pediatric-onset SCI, Vogel et al. (2002c) found that of the 216 patients who had been enrolled in the SCI programs of the Shriners Hospitals for Children, 57% had spasticity requiring medication; this rate is slightly lower than the prevalence of spasticity among adults who acquired SCI later in life (68%) (Levi et al. 1995). Vogel and colleagues (2002c) also observed that spasticity was associated with tetraplegia, lower American Spinal Injury Association motor scores, and lower total and motor Functional Independence Measure scores. It should be noted that based on these findings, conclusions cannot be drawn regarding whether spasticity has a direct impact on activities of daily living and/or participation.
In terms of the measurement and evaluation of spasticity in the pediatric SCI population, in most papers, only constructs of body structure/function were assessed (spasms, via the Spasm Score and Spasm Frequency Scale, and muscle tone via the Ashworth scale/Modified Ashworth scale) (Armstrong 1992; Johnston, Smith, et al. 2008b; Reynolds et al. 2014; Vogel et al. 2002c). One study used Functional Independence Measure (Vogel et al. 2002c), but not specifically to evaluate the impact of spasticity. Pierce et al. (2008a) evaluated passive torque as a discriminator for spasticity with an isokinetic dynamometer using different speeds from 5 deg/s to 180 deg/s. They compared 18 children with chronic SCI with 10 healthy children (Typical Development) but could not find any significant difference between the groups or correlation between passive torque and the clinical scales of Ashworth scale and Spasm Frequency Scale.
The literature search did not yield any controlled studies on spasticity treatment for patients with pediatric-onset SCI. Nevertheless, three case studies on this topic were found. The first study by Armstrong et al. (1992) reported the use of intrathecal baclofen in two children with severe spasms stemming from SCI who were ventilator-dependent and suggested that baclofen significantly reduced spasms. In another study, Reynolds et al. (2014) examined three children with SCI who underwent selective dorsal rhizotomy for their lower limb spasticity. Two of the children had good long-term relief in spasticity with decreased muscle tone and improved mobility. The third child had short-term reduction in spasticity but with full return of the problem after six months; he then received treatment with intrathecal baclofen with full resolution of the problematic spasticity. Lastly, Johnston and colleagues (2008a) work compared the effects of stationary cycling in home environment, either as FES or passive cycling, in four children with SCI. The participants cycled for 1 hour, 3 times per week, for 6 months. The findings revealed several positive health outcomes following the intervention, including improved bone mineral density (BMD), muscle volume, stimulated quadriceps strength, and lower resting heart rate; but no consistent change in spasticity was found.
To date, no studies have examined the development of spasticity in different age groups and over time and how it could interfere with musculoskeletal development. This represents a major gap in the literature and should be addressed in future research. In addition, no studies were found on the impact of spasticity on health-related quality of life. Spasticity has been shown to decrease health-related quality of life in adults with SCI (Adriaansen et al. 2016; Westerkam et al. 2011), but further research should validate whether this finding can be generalized to the pediatric SCI population. Systematic, controlled studies need to be conducted to inform clinical practice, guideline development, and the most optimal method for treating spasticity in this population. Until then, clinicians must rely on clinical experience as well as scientific evidence from spasticity treatment of other aetiologies in children and the adult SCI population to drive assessment and treatment.