Factors associated with bone density in different skeletal regions in children with cerebral palsy of various motor severities

Lifelong Fitness in Ambulatory Children and Adolescents with Cerebral Palsy I: Key Ingredients for Bone and Muscle Health

Physical activity of a sufficient amount and intensity is essential to health and the prevention of a sedentary lifestyle in all children as they transition into adolescence and adulthood. While fostering a fit lifestyle in all children can be challenging, it may be even more so for those with cerebral palsy (CP). Evidence suggests that bone and muscle health can improve with targeted exercise programs for children with CP. Yet, it is not clear how musculoskeletal improvements are sustained into adulthood. In this perspective, we introduce key ingredients and guidelines to promote bone and muscle health in ambulatory children with CP (GMFCS I-III), which could lay the foundation for sustained fitness and musculoskeletal health as they transition from childhood to adolescence and adulthood. First, one must consider crucial characteristics of the skeletal and muscular systems as well as key factors to augment bone and muscle integrity. Second, to build a better foundation, we must consider critical time periods and essential ingredients for programming. Finally, to foster the sustainability of a fit lifestyle, we must encourage commitment and self-initiated action while ensuring the attainment of skill acquisition and function. Thus, the overall objective of this perspective paper is to guide exercise programming and community implementation to truly alter lifelong fitness in persons with CP.

Bone Mineral Density in Adults With Cerebral Palsy

Low bone mineral density (BMD) is an emerging health issue in adults with cerebral palsy (CP). This cross-sectional study aimed to describe the characteristics of BMD in adults with CP, and to elucidate the risk factors for low BMD in this population. People aged ≥20 years and diagnosed with CP were recruited from February 2014 to November 2014. We assessed BMD using dual-energy X-ray absorptiometry (DXA) for the lumbar spine, femoral neck, and total femur. Moreover, the body composition was assessed using DXA. We included a total of 87 adults with CP (mean age 42.01 years; 52 men). The prevalence of low BMD was 25.3%. Male sex and age were associated with lower BMD. BMD was significantly lower in the non-ambulatory group than that in the ambulatory group for both lumbar spine and femoral neck. The total fat mass demonstrated a positive correlation with the Z-score and BMD for the femur neck and total femur. Body mass index (BMI) and total fat mass were positively correlated with BMD in the lumbar spine, femoral neck, and total femur. However, the Gross Motor Function Classification Scale levels were negatively correlated with BMD at the aforementioned three sites. In conclusion, adults with CP revealed decreased BMD, which was associated with male sex, age, decreased gross motor function, loss of ambulatory function, low BMI, decreased total fat mass, and decreased total fat-free mass.

A Comparison of Lumbar Spine and Lateral Distal Femur Bone Density in Girls With Rett Syndrome

Patients with Rett syndrome (RS) are at risk for low bone mineral density (BMD) and femoral fractures. In patients with RS, assessment with lateral distal femur (LDF) dual-energy X-ray absorptiometry (DXA) is recommended and clinically relevant. This study is the first to assess LDF BMD in girls with RS, and to compare LDF BMD results with lumbar spine BMD results in RS. Method Eleven girls (mean age 8.4 yr) with molecularly diagnosed RS and clinical DXA scan(s) were identified; medical charts were retrospectively reviewed. Baseline and serial lumbar spine and LDF BMD Z-scores were evaluated based on patients' ambulation status, presence of epilepsy, and mutation type. Results At the time of first scan, 8 of 11 patients had normal lumbar spine BMD and low LDF BMD Z-scores. Two patients had fracture history. Fully ambulatory (3) patients had higher lumbar spine and LDF BMD than partially (5) and nonambulatory (3) patients. Patients with epilepsy had lower average BMD at all sites. No difference was seen in lumbar spine or LDF BMD in patients with high-risk BMD mutations. Seven patients had serial DXA scans with an average observation of 5.1 yr (range 3.1 yr to 6.2 yr). Lumbar spine BMD over time was variable, while LDF bone mass accrual occurred at a lower rate than typically developing girls. Conclusion Females with RS exhibited lower BMD Z-scores at the LDF than at the lumbar spine. LDF and lumbar spine results were discordant. Ambulatory status and the presence of epilepsy were related to BMD. LDF BMD accrual deviated from normal as patients aged.

The Utility of DXA Assessment at the Forearm, Proximal Femur, and Lateral Distal Femur, and Vertebral Fracture Assessment in the Pediatric Population: 2019 ISCD Official Position

Dual-energy X-ray absorptiometry (DXA) is widely used in the evaluation of bone fragility in children. Previous recommendations emphasized total body less head and lumbar spine DXA scans for clinical bone health assessment. However, these scan sites may not be possible or optimal for all groups of children with conditions that threaten bone health. The utility of DXA scans of the proximal femur, forearm, and radius were evaluated for adequacy of reference data, precision, ability of predict fracture, and applicability to all, or select groups of children. In addition, the strengths and limitations of vertebral fracture assessment by DXA were evaluated. The new Pediatric Positions provide guidelines on the use of these additional measures in the assessment of skeletal health in children.

Densidad mineral ósea e indicadores bioquímicos y hormonales en niños con parálisis cerebral cuadripléjica

Introduction: children with cerebral palsy (CP) have multiple risk factors for low bone mineral density or osteoporosis. Objective: to explore the association between bone mineral density (BMD) and biochemical and hormonal indicators of bone metabolism in children with quadriplegic cerebral palsy (CP). Methods: a cross-sectional analytical study included 59 participants from six to 18 years of age with quadriplegic CP. Serum concentrations of calcium, phosphorus, 25OHD metabolite, parathyroid hormone (PTH), alkaline phosphatase, and thyroid hormones were determined using standardized methods. The BMD measurement was obtained from the lumbar spine expressed in g/cm2 and Z-score. Unpaired Student's t-test, Chi-square test, odds ratio and Pearson's correlation were performed. Results: participants with CP and malnutrition had lower serum concentrations of calcium, phosphorus and alkaline phosphatase. Those who had low BMD showed lower serum concentrations of calcium, phosphorus and alkaline phosphatase. Most participants with low and normal BMD had vitamin D deficiency (27.1% and 10%) and insufficiency (35.4% and 30%), respectively. There was a significant correlation between BMD and serum concentrations of calcium, phosphorus, alkaline phosphatase, vitamin D and thyroid-stimulating hormone (TSH). There were no differences in the biochemical and hormonal indicators by level of gross motor function, use of anticonvulsants and oral versus enteral feeding method. Conclusion: malnutrition and alteration of vitamin D nutritional status were associated with low BMD and alterations of biochemical indicators of bone metabolism in pediatric patients with quadriplegic CP. The relationship between BMD and biochemical indicators of bone metabolism in children with quadriplegic CP was also demonstrated.

Low bone mineral density in ambulatory persons with cerebral palsy? A systematic review

Purpose: Non-ambulatory persons with cerebral palsy are prone to low bone mineral density. In ambulatory persons with cerebral palsy, bone mineral density deficits are expected to be small or absent, but a consensus conclusion is lacking. In this systematic review bone mineral density in ambulatory persons with cerebral palsy (Gross Motor Function Classification Scales I-III) was studied. Materials and methods: Medline, Embase, and Web of Science were searched. According to international guidelines, low bone mineral density was defined as Z-score ≤ -2.0. In addition, we focused on Z-score ≤ -1.0 because this may indicate a tendency towards low bone mineral density. Results: We included 16 studies, comprising 465 patients aged 1-65 years. Moderate and conflicting evidence for low bone mineral density (Z-score ≤ -2.0) was found for several body parts (total proximal femur, total body, distal femur, lumbar spine) in children with Gross Motor Function Classification Scales II and III. We found no evidence for low bone mineral density in children with Gross Motor Function Classification Scale I or adults, although there was a tendency towards low bone mineral density (Z-score ≤ -1.0) for several body parts. Conclusions: Although more high-quality research is needed, results indicate that deficits in bone mineral density are not restricted to non-ambulatory people with cerebral palsy. Implications for Rehabilitation Although more high-quality research is needed, including adults and fracture risk assessment, the current study indicates that deficits in bone mineral density are not restricted to non-ambulatory people with CP. Health care professionals should be aware that optimal nutrition, supplements on indication, and an active lifestyle, preferably with weight-bearing activities, are important in ambulatory people with CP, also from a bone quality point-of-view. If indicated, medication and fall prevention training should be prescribed.

Bone mineral density and nutritional status in children with quadriplegic cerebral palsy

This study demonstrated the relationship of low bone mineral density (BMD) with the degree of motor impairment, method of feeding, anthropometric indicators, and malnutrition in children with quadriplegic cerebral palsy (CP). The control of these factors could optimize adequate bone mineralization, avoid the risk of osteoporosis, and would improve the quality of life.

PURPOSE

The purpose of the study is to explore the relationship between low BMD and nutritional status in children with quadriplegic CP.

METHODOLOGY

A cross-sectional analytical study included 59 participants aged 6 to 18 years with quadriplegic CP. Weight and height were obtained with alternative measurements, and weight/age, height/age, and BMI/age indexes were estimated. The BMD measurement obtained from the lumbar spine was expressed in grams per square centimeter and Z score (Z). Unpaired Student's t tests, chi-square tests, odds ratios, Pearson's correlations, and linear regressions were performed.

RESULTS

The mean of BMD Z score was lower in adolescents than in school-aged children (p = 0.002). Patients with low BMD were at the most affected levels of the Gross Motor Function Classification System (GMFCS). Participants at level V of the GMFCS were more likely to have low BMD than levels III and IV [odds ratio (OR) = 5.8 (confidence interval [CI] 95% 1.4, 24.8), p = 0.010]. There was a higher probability of low BMD in tube-feeding patients [OR = 8.6 (CI 95% 1.0, 73.4), p = 0.023]. The probability of low BMD was higher in malnourished children with weight/age and BMI indices [OR = 11.4 (1.3, 94), p = 0.009] and [OR = 9.4 (CI 95% 1.1, 79.7), p = 0.017], respectively.

CONCLUSION

There was a significant relationship between low BMD, degree of motor impairment, method of feeding, and malnutrition. Optimizing these factors could reduce the risk of osteopenia and osteoporosis and attain a significant improvement of quality of life in children with quadriplegic CP.

Low bone mineral density and fractures are highly prevalent in pediatric patients with spinal muscular atrophy regardless of disease severity

Patients with Spinal Muscular Atrophy (SMA) are at risk for poor bone health. The prevalence of fractures, low areal bone mineral density (aBMD; Z-score ≤-2.0) of the lateral distal femur and of osteoporosis by SMA subtype is not known. We aimed to describe the natural history of bone health in patients with SMA prior to bisphosphonate treatment. We reviewed data from 85 eligible patients with SMA ages 12 months to 18 years, seen at a single institution between January 2005 and July 2016. Fracture history was reported at annual clinic visits. aBMD was obtained from dual energy x-ray absorptiometry scans of the lumbar spine, total body, and lateral distal femur. 85% of patients had aBMD Z-scores ≤-2.0 SD and were progressively lower with worsening SMA severity. Longitudinal aBMD Z-scores of the lateral distal femur decreased with age. Fractures occurred in 38% (32/85) of patients with the femur being the most common location (25 of 57 fractures). Thirteen percent of patients fulfilled criteria for osteoporosis. Low aBMD and femur fractures are highly prevalent in all SMA subtypes from a young age; however, few patients met the criteria for osteoporosis. Poor bone health may be an under-recognized comorbidity of SMA.

Bone mineral density and vitamin D status in ambulatory and non-ambulatory children with cerebral palsy

This study assessed distal femur and lumbar spine bone mineral density (BMD) Z-scores in children with cerebral palsy. BMD z-score was lower in non-ambulatory than in ambulatory children. Somewhat surprisingly, among ambulatory children, those with better walking abilities had higher BMD z-score than those with more impaired walking ability.

INTRODUCTION

Children with cerebral palsy (CP) have increased risk for low bone mineral density (BMD). The aim was to explore the difference in BMD at the distal femur and lumbar spine between ambulatory and non-ambulatory children with CP and the relationship between vitamin D status and BMD.

METHODS

Fifty-one children (age range 8-18 years; 20 girls) with CP participated. Their BMD Z-scores were measured in the lumbar spine and the distal femur using dual X-ray absorptiometry, and 25-hydroxy-vitamin D (25-OHD) concentrations were measured in serum. Children with GMFCS level I-III were defined as 'walkers' while children with level IV-V were defined as 'non-walkers.

RESULTS

Non-walkers had lower mean BMD Z-scores (range -1.7 to -5.4) than walkers at all sites (range -0.8 to -1.5). Among walkers, BMD Z-scores at the distal femur were lower in those with GMFCS level II than with level I (p values < 0.004). A similar difference was found between the affected and unaffected limb in children with hemiplegia. Mean 25-OHD concentration was 45 nmol/L (SD = 18); lower in walkers (mean = 41 nmol/L; SD = 18) than in non-walkers (mean = 53 nmol/L; SD = 19; p = 0.041). There were no correlations between 25-OHD and BMD z-scores.

CONCLUSIONS

The main predictor of low BMD Z-scores in the distal femur was the inability to walk, but the results suggest that the degree of the neuromotor impairment may also be a significant predictor. Vitamin D status did not correlate with BMD z-scores.

Low bone turnover phenotype in Rett syndrome: results of biochemical bone marker analysis

BACKGROUND

Patients with Rett syndrome (RTT) are at risk of having low bone mass and low-energy fractures.

METHODS

We characterized bone metabolism by both bone formation and resorption markers in blood in a RTT population of 61 girls and women and 122 well-matched healthy controls. Levels of N-terminal propeptides of collagen type 1 (P1NP), C-terminal telopeptide cross links (CTX), osteocalcin (OC), and bone-specific alkaline phosphatase (B-ALP) were compared between RTT patients and controls in regression models adjusted for BMI, vitamin D status, volumetric bone mineral apparent density of the lumbar spine (vBMAD spine), and femoral neck (vBMAD neck). We examined biochemical bone marker levels overall and stratified to persons younger than age 25 y or equal to or older than age 25 y.

RESULTS

The RTT patients had reduced levels of all biochemical bone markers (P < 0.05), which remained significant in persons younger than 25 y (P ≤ 0.001) regarding P1NP, CTX, and OC. Bone marker levels were not significantly associated to methyl-CpG-binding protein 2 (MECP2) mutation group, walking ability, or previous low-energy fractures.

CONCLUSION

Our findings of a low bone turnover state in girls with RTT suggest critical attention to medical treatment of low bone mass in young RTT patients.

Efficacy of home-based virtual cycling training on bone mineral density in ambulatory children with cerebral palsy

The 12-week home-based virtual cycling training (hVCT) improved lower limb muscle strength and areal bone mineral density (aBMD) than the control program in children with cerebral palsy (CP). A muscle strengthening program, rather than general physical activity, is more specific in enhancing aBMD for these children. A novel hVCT is an effective and efficient strategy that enhances lower limb bone density in these children.

INTRODUCTION

This is the first study to assess the efficacy of a novel hVCT program on bone density for children with spastic CP using a well-designed randomized controlled trial.

METHODS

Twenty-seven ambulatory children with spastic CP, aged 6-12 years, were randomly assigned to the hVCT group (n=13) or control group (n=14). Outcome measures-motor function [Gross Motor Function Measure-66 (GMFM-66)], muscle strength (curl up scores and isokinetic torque of knee extensor and flexor muscle) and aBMD of the lumbar and distal femur-were administered before and immediately after the 12-week intervention.

RESULTS

Analysis of covariance results show that the hVCT group had greater distal femur aBMD and isokinetic torques of knee extensor and flexor muscles than the control group at posttreatment (p<0.05). However, curl up scores, GMFM-66, and lumbar aBMD at posttreatment did not differ between the two groups.

CONCLUSIONS

Analytical findings suggest that the muscle strengthening program is more specific in enhancing bone density for children with CP than general physical activity. Thus, the proposed 12-week hVCT protocol is an effective and efficient strategy for improving lower limb aBMD in these children.

Relationships of muscle strength and bone mineral density in ambulatory children with cerebral palsy

SUMMARY

This work explores the relationships of muscle strength and areal bone mineral density (aBMD) in ambulatory children with cerebral palsy (CP). The knee extensor strength, but not motor function, was related to aBMD. Thus, muscle strength, especially antigravity muscle strength, was more associated with aBMD in these children than motor function.

INTRODUCTION

Muscle strength is related to bone density in normal children. However, no studies have examined these relationships in ambulatory children with CP. This work explores the relationships of muscle strength and aBMD in ambulatory children with CP.

METHODS

Forty-eight ambulatory children with spastic CP, aged 5-15 years, were classified into two groups based on Gross Motor Function Classification System levels: I (n = 28) and II (n = 20). Another 31 normal development (ND) children were recruited as the comparison group for the aBMD. Children with CP underwent assessments of growth, lumbar and distal femur aBMD, Gross Motor Function Measure-66 (GMFM-66), and muscle strength of knee extensor and flexor by isokinetic dynamometer.

RESULTS

The distal femur aBMD, but not lumbar aBMD, was lower in children with CP than in ND children (p < 0.05). Children with level I had greater knee flexor strength and GMFM-66 scores than those with level II (p < 0.001). However, the knee extensor strength and distal femur and lumbar aBMD did not differ between two groups. Regression analysis revealed the weight and knee extensor strength, but not GMFM-66 scores, were related positively to the distal femur and lumbar aBMD (adjusted r (2) = 0.56-0.65, p < 0.001).

CONCLUSIONS

These results suggest the muscle strength, especially antigravity muscle strength, were more associated with the bone density of ambulatory children with CP than motor function. The data may allow clinicians for early identifying the ambulatory CP children of potential low bone density.

Aging and bone health in individuals with developmental disabilities

Low bone mass density (BMD), a classical age-related health issue and a known health concern for fair skinned, thin, postmenopausal Caucasian women, is found to be common among individuals with developmental/intellectual disabilities (D/IDs). It is the consensus that BMD is decreased in both men and women with D/ID. Maintaining good bone health is important for this population as fractures could potentially go undetected in nonverbal individuals, leading to increased morbidity and a further loss of independence. This paper provides a comprehensive overview of bone health of adults with D/ID, their risk of fractures, and how this compares to the general aging population. We will specifically focus on the bone health of two common developmental disabilities, Down syndrome (DS) and cerebral palsy (CP), and will discuss BMD and fracture rates in these complex populations. Gaining a greater understanding of how bone health is affected in individuals with D/ID could lead to better customized treatments for these specific populations.