Children with pediatric neuromuscular disorders experience common complications, primarily due to immobility and weakness. Musculoskeletal complications include hip dysplasia with associated hip subluxation or dislocation, neuromuscular scoliosis, and osteoporosis and resulting fractures. Constipation, gastroesophageal reflux, and obesity and malnutrition are commonly experienced gastrointestinal complications. Disordered sleep also is frequently observed, which affects both patients and caregivers.
Key points
- •
Children with pediatric neuromuscular disorders suffer from common complications.
- •
The complications are related to immobility and weakness.
- •
Scoliosis, hip dysplasia, and osteoporosis are common musculoskeletal complications.
- •
Constipation, gastroesophageal reflux, obesity, and malnutrition are common gastrointestinal complications.
- •
Disordered sleep affects both the children and their caregivers.
- •
Screening for these common complications can lead to healthier children with pediatric neuromuscular disorders and a resulting higher quality of life.
Introduction
Nature of the Problem
There are several pediatric neuromuscular disorders (pNMDs), such as cerebral palsy (CP), myelomeningocele, spinal cord injury, chromosomal abnormality, acquired brain injury, acquired and hereditary neuropathy, myopathy, and motor neuron disorders that all share common complications. Immobility and weakness are the primary etiologies for most of these commonly seen conditions. Musculoskeletal complications in pNMDs include hip dysplasia with associated hip subluxation or dislocation, neuromuscular scoliosis, and osteoporosis and resulting fractures. Constipation and gastroesophageal reflux (GER), along with obesity and malnutrition, are commonly experienced gastrointestinal (GI)-related complications. Disordered sleep also is frequently observed, and this affects not only the patients but also caregivers.
Introduction
Nature of the Problem
There are several pediatric neuromuscular disorders (pNMDs), such as cerebral palsy (CP), myelomeningocele, spinal cord injury, chromosomal abnormality, acquired brain injury, acquired and hereditary neuropathy, myopathy, and motor neuron disorders that all share common complications. Immobility and weakness are the primary etiologies for most of these commonly seen conditions. Musculoskeletal complications in pNMDs include hip dysplasia with associated hip subluxation or dislocation, neuromuscular scoliosis, and osteoporosis and resulting fractures. Constipation and gastroesophageal reflux (GER), along with obesity and malnutrition, are commonly experienced gastrointestinal (GI)-related complications. Disordered sleep also is frequently observed, and this affects not only the patients but also caregivers.
Musculoskeletal complications
Musculoskeletal complications, such as limb contractures, hip dislocation or subluxation, and scoliosis are common in pNMDs ( Table 1 ). They contribute to increased disability due to decreased motor performance, mobility limitations, reduced functional range of motion, loss of function for activities of daily living (ADLs), decreased quality of life (QOL), and increased pain.
Musculoskeletal Complications | Cerebral Palsy | Myelomeningocele | Duchenne Muscular Dystrophy | Spinal Cord Injury | Charcot- Marie-Tooth | Spinal Muscular Atrophy |
---|---|---|---|---|---|---|
Scoliosis, % | 38–64 | 20–94 | 63–90 | 100 a | 10 | 70–100 |
Hip dysplasia, % | 2–60 | 1–28 | 35 | 29–82 | 6–8 | 11–38 |
Scoliosis in pNMDs leads to multiple problems, including poor sitting balance, difficulty with upright seating and positioning, pain, and preclusion of the ability to sit upright in a wheelchair. Screening for spinal deformities is important because it can have several clinical implications. Unfortunately, spinal deformity is neither preventable nor responsive to nonsurgical modalities such as bracing. Unlike idiopathic scoliosis, neuromuscular scoliosis almost always progresses. Early detection and screening are crucial for proper and ideal management of scoliosis.
The Adam forward-bend test is the primary screening test for neuromuscular scoliosis and should be performed on all patients with pNMDs. The screening examination is performed by having the patient bend forward as far as possible, flexing the cervical and thoracolumbar spine. If a patient is unable to stand, this can be performed in the seated position. Some patients will require postural support if they are unable to sit independently. The patient is viewed from behind focusing on the rib cage. The examiner is looking for one side of the rib cage to be higher than the other next to the vertebral column. The convex side of the scoliosis is the side with the rib hump. In obese patients, smaller curves can be missed, especially in the lower lumbosacral spine.
If a spine curve is detected or the patient’s body habitus precludes the test’s sensitivity, spinal radiographs should be performed. Anteroposterior (AP) and lateral spinal radiographs with the patient either sitting or standing, based on the individual’s function, are generally sufficient. On the AP film, the Cobb angle is measured. Serial measurements should be performed using the same anatomic landmarks to ensure comparable measurements ( Fig. 1 ).
Hip subluxation and dislocation due to hip dysplasia are frequently encountered in children with pNMDs. Hip dysplasia is a condition of the hip that may be present at or shortly after birth with inadequate acetabular formation. At birth, neonates have a shallow acetabulum. As they grow, the acetabulum usually deepens and contours around the femoral head. When infants have decreased muscle tone, strength, and movement, the acetabulum remains shallow due to the reduced force applied to the acetabulum by the femoral head. Hip dysplasia is most commonly seen in pNMDs with congenital or early-onset paresis, such as myelomeningocele, CP, congenital myopathies, congenital muscular dystrophies, and spinal muscular atrophy types 1 and 2. The presence of hip dysplasia predisposes children with pNMDs to progress toward hip subluxation and eventually dislocation. The primary physical examination maneuver screening for hip subluxation or dislocation is the Galeazzi sign or Allis sign. The maneuver is performed by laying the patient supine, flexing the hips and knees, and examining the knee heights. If the knees are not at the same level, the test is positive. The pathologic side is the lower knee height and subluxation is often associated with decreased hip abduction range of motion ( Fig. 2 ). In the setting of complete dislocation, hip abduction can be reduced, normal, or excessive. If the Galeazzi sign is positive, an AP radiograph of the pelvis should be obtained.
In addition to joint complications, bone health also is significantly affected in pNMDs. There are several factors contributing to poor bone health in pNMDs, such as decreased mobility, muscle weakness, and medication side effects, such as glucocorticoid treatment for Duchenne muscular dystrophy (DMD). The consequences of osteoporosis in pNMDs can be long-bone fractures and vertebral compression fractures that can result in bone pain and a reduced QOL. Fractures can occur with minimal trauma, such as during transfers or with rotation, such as forearm supination to start a peripheral intravenous line. Osteoporosis is more severe in nonambulatory children with pNMDs. Sufficient vitamin D levels are required for normal skeletal development and mineralization. A recent study found that 97% of children with myelomeningocele had vitamin D levels in the insufficient range (<30 ng/mL) and 48.5% had levels less than 10 ng/mL. There was a significant correlation between serum 25-hydroxyvitamin D (25[OH]D) and osteoporosis, concluding that vitamin D supplementation may be helpful. There is insufficient evidence that weight-bearing activities are an effective intervention to improve bone density; however, there is also inadequate evidence to support the use of vitamin D supplementation to decrease fractures. A general rule is to supplement with double the recommended dietary allowance amount for age ( Table 2 ). Serum levels of 25(OH)D should be screened in late winter, as levels reach their nadir in the northern hemisphere due to shortened daylight and the supplemental vitamin D3 (cholecalciferol) dose should be adjusted accordingly to achieve the desired level.