Classification of pain in children with cerebral palsy

Chronic pain in children and young people with cerebral palsy: a narrative review of challenges, advances, and future directions

BACKGROUND

Cerebral palsy (CP), the most common physical disability of childhood, is often accompanied by a range of comorbidities including pain. Pain is highly prevalent in children and young people with CP, yet has been poorly understood, inaccurately assessed, and inadequately managed in this vulnerable population. This narrative review presents recent research advances for understanding and managing pain in children and young people with CP, focusing on chronic pain, and highlights future research directions.

MAIN BODY

Pain prevalence rates in CP vary due to different methodologies of studies. Recent systematic reviews report up to 85% of children experience pain; higher in older children, females, and those with dyskinesia and greater motor impairment. Research examining the lived experience perspectives of children and their families demonstrate that even those with mild motor impairments have pain, children want to self-report pain where possible to feel heard and believed, and management approaches should be individualized. Notably, many children with cognitive and communication impairments can self-report their pain if adjustments are provided and they are given a chance. Past inadequacies of pain assessment in CP relate to a focus on pain intensity and frequency with little focus on pain interference and coping, a lack of tools appropriate for the CP population, and an assumption that many children with cognitive and/or communication limitations are unable to self-report. Recent systematic reviews have identified the most reliable and valid assessment tools for assessing chronic pain. Many were not developed for people with CP and, in their current form, are not appropriate for the spectrum of physical, communication, and cognitive limitations seen. Recently, consensus and co-design in partnership with people with lived experience and clinicians have identified tools appropriate for use in CP considering the biopsychosocial framework. Modifications to tools are underway to ensure feasibility and applicability for the spectrum of abilities seen.

CONCLUSION

Recent research advances have improved our understanding of the prevalence, characteristics and lived experience of chronic pain, and refined assessment methods in children and young people with CP. However, the very limited evidence for effective and novel management of chronic pain in this population is where research should now focus.

Long-term outcomes of reconstructive treatment for painful dislocations in patients with cerebral palsy

Purpose

This report presents the long-term results of the hip joint reconstruction in patients with spastic hip disease through open reduction, proximal femur varus derotation osteotomy, and Dega transiliac osteotomy.

Methods

We analyzed retrospectively patients diagnosed with a spastic form of bilateral cerebral palsy with painful hip subluxation or dislocation. All patients underwent the same surgical procedure. The minimum follow-up time was 15 years. The study group comprised 15 patients (22 hips), classified with the Gross Motor Function Classification System as levels IV and V. The hip joint range of motion and anteroposterior X-ray examination at the final follow-up visit were compared with pre-operative data. The pain level was evaluated using the Visual Analogue Scale (VAS), and the femoral head shape was assessed using the Rutz classification. The patients' caregivers answered questions regarding pain during sitting, personal hygiene activities, and at rest. The caregivers' satisfaction with the treatment was also assessed with the Caregiver Priorities and Child Health Index of Life with Disabilities questionnaire.

Results

We observed a significant reduction of the hip joint pain and improvement in both radiological hip stability parameters and range of motion at the final follow-up visit. Based on the Rutz classification, one hip remained type B, while the other joints became type A. Reduced pain was reported in all three positions, with the most pronounced improvement during sitting and personal hygiene activities. Interestingly, patients with unilateral hip reconstruction were more prone to pain after reconstruction than those operated bilaterally.

Conclusion

Primary reconstruction of the painful hip joint neurogenic dislocation results in a stable joint reduction, pain decrease, and improved quality of life in patients with cerebral palsy.

Level of evidence

IV case series.

Foot and lower leg pain in children and adults with cerebral palsy: a population-based register study on 5,122 individuals

BACKGROUND

Pain is common in individuals with cerebral palsy (CP) and the most reported pain site is the foot/lower leg. We analyzed the prevalence of pain in the foot/lower leg and the associations with age, sex, gross motor function, and clinical findings in individuals with CP.

METHOD

This was a cross-sectional register-study, based on data reported to the Swedish Cerebral Palsy Follow-up Program (CPUP). All participants in CPUP, four years-of-age or older, were included. Pearson chi-square tests and logistic regression were used to analyze the prevalence and degree of pain in the foot/lower leg.

RESULTS

In total, 5,122 individuals were included from the CPUP database: 58% were males and 66% were under 18 years-of-age. Overall, 1,077 (21%) reported pain in the foot/lower leg. The odds ratios (ORs) of pain were higher in females (OR 1.31, 95% confidence interval (CI) 1.13-1.53), individuals who could ambulate (Gross Motor Function Classification System Level I (OR 1.84, CI 1.32-2.57) and II (OR 2.01, CI 1.46-2.79) compared to level V), and in individuals with decreased range of motion of the ankle (dorsiflexion 1-10 degrees (OR 1.43, CI 1.13-1.83) and ≤ 0 degrees (OR 1.46, CI 1.10-1.93) compared to ≥ 20 degrees). With increasing age the OR of pain increased (OR 1.02, CI 1.01-1.03) as well as the reported pain intensity (p < 0.001).

CONCLUSIONS

Pain in the foot and lower leg appears to be a significant problem in individuals with CP, particularly in those who walk. As with pain in general in this population, both pain intensity and frequency increase with age. The odds of pain in the foot and lower leg were increased in individuals with limited dorsiflexion of the ankle. Given the cross-sectional design causality cannot be inferred and it is unknown if pain causes decreased range of motion of the ankle or if decreased range of motion causes pain. Further research is needed on causal pathways and importantly on prevention.

Influence of musculoskeletal pain during gait on kinematics and selective motor control in individuals with spastic cerebral palsy: A pilot study

BACKGROUND

Individuals with cerebral-palsy commonly present with altered kinematics and selective-motor-control during gait, and may also experience musculoskeletal pain. This pilot study aims to investigate if the immediate experience of musculoskeletal pain during gait influences kinematics and selective-motor-control in individuals with spastic cerebral-palsy.

METHODS

Retrospective treadmill-based gait-analysis data for 145 individuals with spastic cerebral-palsy were screened. Participants were asked about experiencing lower-extremity musculoskeletal pain immediately during gait, with 26 individuals (18%) reporting this was the case (pain-group; mean 11.55 ± 3.15 years, Gross-Motor-Function-Classification-System levels I/II/III n = 5/13/8, Uni/bilateral involvement n = 11/15). Of the 77 individuals who did not report any pain, a no-pain group (n = 26) was individually matched. Kinematics were evaluated using the Gait-Profile-Score and spatiotemporal parameters (dimensionless-walking-speed, single-leg-support percentage and step-time). Selective-motor-control was assessed using the Walking-Dynamic-Motor-Control index.

FINDINGS

In the pain-group, 58% reported experiencing pain in their more-involved leg, 8% in the less-involved leg and 34% in both legs. Regarding the pain location, 38% of the pain-group reported experiencing pain in multiple locations. On a more specific level, 35%, 46% and 54% reported pain around the hip/thigh, knee/calf and ankle/ft, respectively. No significant differences were observed between the pain and no-pain groups for any of the outcome measures, in each leg or bilaterally.

INTERPRETATION

No significant differences in kinematics and selective-motor-control during gait were found between individuals with spastic cerebral-palsy, with and without musculoskeletal pain. This suggests that the individuals in this study may not present with obvious antalgic gait patterns, which may relate to the pre-existing altered kinematics and selective-motor-control.

A scoping review on muscle cramps and spasms in upper motor neuron disorder-two sides of the same coin?

Background

Muscle cramps are typically regarded as benign muscle overactivity in healthy individuals, whereas spasms are linked to spasticity resulting from central motor lesions. However, their striking similarities made us hypothesize that cramping is an under-recognized and potentially misidentified aspect of spasticity.

Methods

A systematic search on spasms and cramps in patients with Upper Motor Neuron Disorder (spinal cord injury, cerebral palsy, traumatic brain injury, and stroke) was carried out in Embase/Medline, aiming to describe the definitions, characteristics, and measures of spasms and cramps that are used in the scientific literature.

Results

The search identified 4,202 studies, of which 253 were reviewed: 217 studies documented only muscle spasms, 7 studies reported only cramps, and 29 encompassed both. Most studies (n = 216) lacked explicit definitions for either term. One-half omitted any description and when present, the clinical resemblance was significant. Various methods quantified cramp/spasm frequency, with self-reports being the most common approach.

Conclusion

Muscle cramps and spasms probably represent related symptoms with a shared pathophysiological component. When considering future treatment strategies, it is important to recognize that part of the patient's spasms may be attributed to cramps.

Pain coping and catastrophizing in youth with and without cerebral palsy

OBJECTIVES

The aim of this study is to compare the use of pain coping strategies and pain catastrophizing in youth with and without cerebral palsy (CP), and to examine how these two groups differ with respect to the associations between pain coping, catastrophizing, and measures of psychological function and sleep disturbance.

METHODS

Twenty-seven individuals with CP and 49 healthy controls aged 15-22 were included in this cross-sectional observational study. Pain was assessed using a semi-structured interviews and participants completed measures of pain coping, pain catastrophizing, psychological function, and sleep.

RESULTS

Youth with CP used information seeking and problem solving (p = 0.003, Cohen's d (d) = -0.80) and sought social support (p = 0.044, d = -0.51) less often, and used internalizing as a coping strategy more often (p = 0.045, d = 0.59) than healthy controls. The use of information seeking and problem solving correlated more strongly with measures of depression (p = 0.023, Cohen's f (f) = 0.08) and sleep disturbance (p = 0.022, f = 0.08), while behavioral distraction correlated more strongly with measures of anxiety (p = 0.006, f = 0.11) and sleep disturbance (p = 0.017, f = 0.09) in youth with CP, compared to healthy controls.

CONCLUSIONS

The study findings raise the possibility that youth with CP may benefit more in terms of psychological function and sleep quality from coping training interventions that focus on behavioral distraction, information seeking, and problem solving. Research to test these ideas in additional samples of youth with CP is warranted.

Effect of virtual reality combined with repetitive transcranial magnetic stimulation on musculoskeletal pain and motor development in children with spastic cerebral palsy: a protocol for a randomized controlled clinical trial

PURPOSE

This trial aims to investigate the efficacy and safety of virtual reality (VR) combined with repetitive transcranial magnetic stimulation (rTMS) for improving musculoskeletal pain and motor development in children with unilateral spastic cerebral palsy (CP).

METHODS

This study protocol is for a randomized controlled trial consisting of 2 treatment sessions (3 days/week for 4 weeks in each session, with a 1-week interval between sessions). We will recruit children aged 3-10 years with unilateral spastic CP (Gross Motor Function Classification System level I or II). Participants will be randomly divided into 3 groups: the VR + rTMS group (immersive VR intervention, rTMS and routine rehabilitation therapy), rTMS group (rTMS and routine rehabilitation therapy), and control group (sham rTMS and routine rehabilitation therapy). VR therapy will involve a daily 40-minute movement training session in a fully immersive environment. rTMS will be applied at 1 Hz over the primary motor cortex for 20 min on the contralateral side. The stimulation intensity will be set at 90% of the resting motor threshold, with 1200 pulses applied. A daily 60-minute routine rehabilitation therapy session including motor training and training in activities of daily living will be administered to all participants. The primary outcome will be pain intensity, assessed by the Revised Face, Legs, Activity, Cry, and Consolability Scale (R-FLACC). The secondary outcomes will include motor development, evaluated by the 66-item version of the Gross Motor Function Measure (GMFM-66) and Fine Motor Function Measure (FMFM); balance capacity, measured by the interactive balance system; activities of daily living; and quality of life, measured by the Barthel index and the Chinese version of the Cerebral Palsy Quality of Life scale for Children (C-CP QOL-Child). Safety will be monitored, and adverse events will be recorded during and after treatment.

DISCUSSION

Combined application of VR therapy and rTMS may reveal additive effects on pain management and motor development in children with spastic CP, but further high-quality research is needed. The results of this trial may indicate whether VR therapy combined with rTMS achieves a better analgesic effect and improves the motor development of children with spastic CP.

TRIAL REGISTRATION

Registration number: ChiCTR230069853. Trial registration date: 28 March 2023. Prospectively registered.

Ultrasound findings in painful spastic hip. Muscle thickness in children with cerebral palsy

BACKGROUND

In cerebral palsy (CP), spasticity is the dominant symptom and hip pain is one of the most common secondary conditions. Aetiology is not clear. Musculoskeletal ultrasound (MSUS) is a low-cost, non-invasive imaging technique that allows assessment of structural status, dynamic imaging, and quick contralateral comparison.

OBJECTIVE

A retrospective case-matched-control study. To investigate associated factors with painful spastic hip and to compare ultrasound findings (focusing on muscle thickness) in children with CP vs. typically developing (TD) peers.

SETTING

Paediatric Rehabilitation Hospital in Mexico City, from August to November 2018.

PARTICIPANTS

21 children (13 male, 7 + 4.26 years) with CP, in Gross Motor Function Classification System (GMFCS) levels IV to V, with spastic hip diagnosis (cases) and 21 children age- and sex-matched (7 + 4.28 years) TD peers (controls).

CHARACTERISTICALLY DATA

Sociodemographic data, CP topography, degree of spasticity, mobility arch, contractures, Visual Analog Scale (VAS), GMFCS, measurements of the volumes of eight major muscles of the hip joint and MSUS findings of both hips.

RESULTS

All children with CP group reported chronic hip pain. Associated factors for hip pain (high VAS hip pain score) were degree of hip displacement (percentage of migration), Ashworth Level, GMFCS level V. No synovitis, bursitis or tendinopathy was found. Significant differences (p < 0.05) were found in muscle volumes in all hip muscles (right and left) except in the right and left adductor longus.

CONCLUSION

Though possibly the most important issue with diminished muscle growth in CP children is the influence on their long-term function, it is likely that training routines that build muscle size may also increase muscle strength and improve function in this population. To improve the choice of treatments in this group and maintain muscle mass, longitudinal investigations of the natural history of muscular deficits in CP as well as the impact of intervention are needed.

Parental perspectives of outcomes following very preterm birth: Seeing the good, not just the bad

AIM

To describe parental perspective on health and developmental outcomes of their preterm child in relation to level of neurodevelopmental impairment (NDI).

METHODS

A parental survey about their children aged 15-36 months corrected age born ˂29 weeks' gestation investigated parental concerns and positive attributes. Parental responses in relation to their child's level of NDI were examined using Kruskal-Wallis and chi-square for trend tests.

RESULTS

One hundred ninety-nine parental responses were obtained for 163 children, including 44% with NDI. Vast majority of parents reported their children were developing well with good physical health. All parents, irrespective of NDI, reported their children were happy and had a positive personality. Appreciation of social interactions was higher for parents of children without versus with NDI (96% vs. 87%, p = 0.039). Parents of children with NDI were more likely to express concerns than those without NDI. Overall, development was the most common area of concern (45%), followed by the child's future (40%) and physical health (35%).

CONCLUSION

Parents of preterm children report many positive points and concerns, some of which are not examined in neonatal follow-up data. These parental perspectives could be used to inform parents of preterm infants, both antenatally and in the neonatal unit.

Prevalence and determinants of hip pain in non-ambulatory cerebral palsy children: a retrospective cohort study

BACKGROUND

Hip pain is common in cerebral palsy children, particularly at Gross-Motor Function Classification System level IV-V. It is associated to hip displacement and relates to the migration percentage. Recent literature suggested early reconstructive bone surgery, as the best approach to prevent hip luxation, then hip pain. Still, high rates of hip pain are reported.

AIM

To investigate prevalence and determinants of hip pain in an Italian cerebral palsy sample.

DESIGN

Single-center retrospective cohort study.

SETTING

Inpatient and outpatient.

POPULATION

Patients with spastic or dyskinetic cerebral palsy, Gross-Motor Function Classification System level IV or V, age 0-18.

METHODS

A chart review was implemented to report hip pain, as a dichotomous variable (pain/no pain), age, sex, cerebral palsy subtype, Gross-Motor Function level, lumbar scoliosis, migration percentage, previous orthopedic surgery, or botulinum injections, oral or intrathecal baclofen, drug-resistant epilepsy, assistive devices for standing or walking. Descriptive statistics and a multivariate logistic stepwise regression were performed.

RESULTS

A total of 504 subjects were included: 302 level V, 209 females, 432 spastics. The mean length of follow-up was 6 years. The overall prevalence of hip pain was 8.9% (6.3% were at level V) and of hip dislocation was 19% (15.9% were at level V). Just 39% of dislocated hips were painful. Children at spastic subtype and level V were predominantly affected. Botulinum and soft tissue surgery related to lower rates of hip pain, without statistical significance. Age (OR 1.19, 95%CI 1.14-1.25, P value 0.000), sex (OR 1.72, 95%CI 1.18-2.52, P value 0.005), migration percentage (OR 1.02, 95%CI 1.02-1.03, P value 0.000) and lumbar scoliosis (OR 1.32, 95%CI 0.86-2.01, P value 0.200) resulted significant independent determinants of hip pain.

CONCLUSIONS

Hip pain relates with the migration percentage, but not all dislocated hips become painful. Hip pain may be transient and requires a targeted and individualized approach. Children at spastic subtype and level V were predominantly affected. Age and sex are confirmed as determinants. Specific validated measures are to be implemented to assess hip pain.

CLINICAL REHABILITATION IMPACT

Considering severe non-ambulatory cerebral palsy patients, pain and quality of life should be considered as outcomes, in the management of hip luxation.

Multisystem compensations and consequences in spastic quadriplegic cerebral palsy children

Spastic quadriplegic cerebral palsy (CP) is a permanent neuromuscular disorder causing limitation on all four limbs following a lesion on the developing brain. Most children with spastic quadriplegic CP are identified to be Gross Motor Function Classification System (GMFCS) level V, thus they have more comorbidities compared to other types at lower levels. Spastic quadriplegic CP is characterized by weak and inactive postural muscles of the neck and trunk, hence, they will undergo a total body extension as a compensatory mechanism leading to an atypical movement pattern, that give rise to multisystem consequences that reduce their quality of life. The relationship between atypical movement patterns, compensatory strategies, and multisystem consequences have not yet been explored. In fact, these multisystem consequences aggravate their condition and make movement much more atypical, forming a vicious cycle. This review aimed to provide a summary and highlight the mechanism of atypical movement pattern, multisystem compensations, and consequences in spastic quadriplegic CP children. It is true that central nervous system (CNS) lesion in CP is non-progressive, however the multisystem consequences may impair overall function over time. An understanding of how compensatory strategy and multisystem consequences in spastic quadriplegic CP offers the opportunity to intervene as early as possible to improve their quality of life.