Spasticity
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.
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Author, Year Country Study Design Sample Size |
Population Intervention Outcome Measure |
Results |
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(Johnston, Smith, et al., 2008b) USA Case Series* N=4 *Subjects were a subset from a larger RCT by (Johnston, Smith, et al., 2009) |
Population: Case 1: 7 yr, female, T4-T6, ASIA A SCI at 2 yr of age; Case 2: 9 yr, female, C7, ASIA A SCI at 4 yr of age; Case 3: 7 yr, male, T3, ASIA A SCI at 3 yr of age; Case 4: 11 yr, male, C7, ASIA A SCI at 3 yr of age. Intervention: Intervention Group: Functional Electrical Stimulation while cycling at 50 rpm while seated in wheelchair (pulse duration (150 ls) and frequency (33 Hz) were fixed; current amplitude (max 140 mA) increased automatically to generate sufficient force to maintain the cadence). Control Group: Passive cycling at 50 rpm. Sessions were conducted for 1 hr, 3 times/week for 6 mo. Outcome Measures: Bone mineral density (BMD) of the left femoral neck, distal femur, and proximal tibia; left quadriceps muscle volume, electrically stimulated strength of the left quadriceps, quadriceps and hamstrings muscles Ashworth scale scores; fasting lipid, profile via high density lipoprotein (HDL) and low-density lipoprotein (LDL); heart rate (HR); and oxygen consumption (VO2/kg). |
Case 1: FES Cycling 1.        Improvements in BMD at the femoral neck, distal femur, and proximal tibia; quadriceps muscle volume; stimulated strength of the quadriceps muscles; HDL cholesterol; resting HR; peak VO2/kg; and peak HR; however, cholesterol, LDL, and triglyceride levels and the cholesterol/HDL ratio increased compared to baseline. 2.       No changes in Ashworth scores, but parents reported decreased spasticity and looser muscles.  Case 2: FES Cycling 3.       Improvements in BMD at the femoral neck, distal femur, and proximal tibia; quadriceps muscle volume; stimulated quadriceps muscle strength; and hamstring muscle spasticity; however, cholesterol, LDL, HDL, and triglyceride levels and the cholesterol/HDL ratio worsened as compared to baseline. 4.       The parents reported bigger, firmer muscles; decreased bowel program completion times; increased appetite; and increased spasticity that did not require medical intervention.  Case 3: Passive Cycling 5.       Improvements in femoral neck BMD, hamstring spasticity, and triglyceride levels. 6.       Distal femur and proximal tibia BMD and stimulated quadriceps strength were lower as compared to baseline, and LDL levels and the cholesterol/HDL ratio were elevated. 7.       Parents reported decreased bowel accidents and new sensation in his knees and stomach.  Case 4: Passive Cycling 8.       Improvements in BMD at the femoral neck, distal femur, and proximal tibia; quadriceps muscle volume; stimulated quadriceps strength; hamstring spasticity; cholesterol; LDL cholesterol; resting HR; and peak VO2/kg. 9.       HDL cholesterol decreased as compared to baseline but the cholesterol/HDL ratio was unchanged. 10.     Parents reported decreased spasticity, looser muscles, increased energy, decreased lower extremity swelling, and increased appetite. |
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(Pierce et al., 2008b) USA Observational N=27 (N=18 SCI) |
Population: SCI: Age: 9.3±2.7 (5-13) yr; Gender: males=11, females=7; Time since injury: 5.3 yr; Severity of injury: AIS A=15, AIS B=3. Typical Development (TD; n=9): Age: 10.0±1.6 (7-12) yr; Gender=males=7, females=3. Intervention: None. Measurements. Outcome Measures: Ashworth Scale (AS), Spasm Frequency Scale (SFS), knee flexion and knee extension velocity and peak passive torque. |
1.        There were no significant differences in peak passive torque in any muscle group at any movement velocity between children with SCI and TD. 2.       For both the children with SCI and children of TD, velocity dependent increases in peak passive torque were found for the knee flexors (p<0.001) and knee extensors (p<0.001) at 15, 90, and 180 deg/s. 3.       Children with TD demonstrated significantly more reflex activity of the medial hamstrings during the assessment of knee flexor spasticity at all movement velocities than did children with SCI (p<0.05). 4.       There were no significant differences in vastus lateralis reflex activity between groups at any movement velocity during the assessment of knee flexor spasticity; however, children with TD demonstrated significantly more reflex activity of the medial hamstrings during the assessment of knee extensor spasticity with movements at 15 deg/s and 180 deg/s and significantly more reflex activity of the vastus lateralis during the assessment of knee extensor spasticity with movements at 180 deg/s (p<0.05). 5.       For AS of the knee flexors, 8 children were scored as 0, 8 children were scored as 1, 1 child was scored as 2, and 1 child was scored as 3. 6.       For AS of the knee extensors, 12 children were scored as 0, and 6 children were scored as 1. 7.       For the SFS, 4 children were scored as 1, 10 children were scored as 2, and 4 children were scored as 3. 8.       No significant relationships were found between the quantitative measurements of spasticity (peak passive torque at 15, 90, and 180 deg/s) and the clinical measurements (AS and SFS) for either muscle group with the exception of a significant relationship found between the SFS and peak passive torque of both the knee flexors and knee extensors with movements at 90 deg/s (p<0.05). 9.       During the assessment of knee flexor spasticity, positive correlations were found between comparisons of peak passive torque at 15 to 90 deg/s and 90 to 180 deg/s (p<0.05). 10.     During the assessment of knee extensor spasticity, positive correlations were found between measurements of peak passive torque at all movement velocities (p<0.05). 11.      There were no significant correlations between AS and SFS during the assessment of knee flexor and knee extensor spasticity. |
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(Vogel et al., 2002b) Part II USA Observational N=216 |
Population: Age at injury: 14.1±4.0 yr; Age at interview: 28.6±3.4 yr; Gender: males=150, females=66; Time since injury: 14.2±4.6 yr; Level of injury: tetraplegia=123, paraplegia=93. Severity of injury: C1-4 ABC=41, C5-8 ABC=67, T1-S5 ABC=82, tetra/para D=26. Intervention: None. Survey. Outcome Measures: Prevalence of spasticity. |
1.        Among the 216 subjects, 123 reported having spasticity requiring treatment. 2.       Spasticity was significantly associated with older age at injury (p=0.017), sports-related SCI (p=0.041), tetraplegia (p<0.001), lower ASIA Motor scores (p<0.001), and lower total FIM (p<0.001) and motor FIM scores (p<0.001). |
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Author, Year Country Study Design Sample Size |
Objective Statement |
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(Reynolds et al., 2014) USA Case Report N=3 |
Population: Case I: 9 yr, female, T2 AIS A SCI; Case II: 11 yr, female, high lumbar SCI; Case III: 13 yr, male, C2 tetraplegia SCI. Intervention: Selective dorsal rhizotomy. Outcome Measures: Spasticity. |
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(Armstrong et al., 1992) Canada Case Report N=2 |
Population: Case I: 13 yr, male, complete tetraplegia SCI, severe spasticity; Case II: 5 yr, female, C1 complete tetraplegia SCI, severe spasticity. Intervention: Intrathecal baclofen. Outcome Measures: Spasticity, pain, transfers, dressing, catheterizations, sleep, potential adverse effects. |
Discussion
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.
