Cerebral palsy is a heterogeneous disorder that is characterized by a static lesion (eg, injury, congenital defect) to the immature motor cortex of the brain.

The natural history of neuromuscular scoliosis in cerebral palsy is relentless progression. Progression is most common in spastic quadriplegic cerebral palsy. The rate of progression can be severe in adolescent years (2 to 4 degrees per month).

Progression also occurs after skeletal maturity. In curves greater than 40 degrees, it may occur at a rate of 2 to 4 degrees per year.²⁵

Curves in the 60- to 90-degree range begin to effect sitting balance, arm control, and head control. Further progression may prevent the child from sitting in an upright position.

Conservative treatment with chair modifications and bracing is only a temporary treatment and does not stop curve progression. Conservative treatment is especially helpful in the younger child with a flexible scoliosis to temporarily maintain upright sitting posture. This will allow the spine to grow to its maximum size (to achieve maximum sitting height) so that the resulting fusion can correct the spinal deformity without limiting growth.

Duchenne muscular dystrophy is a sex-linked recessive disorder involving a defect on the Xp21.2 locus of the X chromosome resulting in a marked decrease or absence of the protein dystrophin.¹¹

Affected children become progressively weaker with age, eventually becoming nonambulatory.

Death typically occurs in the second or third decade secondary to pulmonary or cardiac failure.

Scoliosis is almost universal when the child becomes nonambulatory, and curve progression correlates strongly with a decline in respiratory function.

In the past, the prevalence of scoliosis approached 100%.²² For this reason, surgery was previously recommended soon after the child became nonambulatory before an irreversible
decline in forced vital capacity occurred. Now with the advent of corticosteroids, the life expectancy of children with Duchenne muscular dystrophy is extended with a reported delay or prevention of the severity of scoliosis with long-standing use of corticosteroids.^{1, 13, 15} The risk of progression decreases if the scoliosis develops after 14 years of age.³¹ Pulmonary function decreases as the natural history of the disease and scoliosis magnitude progresses. Scoliosis surgery should be done before the forced vital capacity decreases to less than 30%.

Myelomeningocele, a congenital malformation of the nervous system, is due to a neural tube defect and results in a spectrum of sensory and motor deficits.

Although the level of the spinal cord defect influences the clinical presentation of the condition, neurologic deterioration may occur at any age owing to hydrocephaly, hydrosyringomyelia, Arnold-Chiari deformity, and tethered cord syndrome.

In general, the higher the level of the defect, the higher the prevalence of scoliosis. Almost 100% of thoracic level paraplegic patients develop scoliosis.²⁶

A long C-shaped curve is associated with a high level of paralysis and usually occurs at a young age.

Hydromyelia and tethered cord syndrome may also be associated with scoliosis and should be suspected if the scoliosis onset is more sudden and associated with other symptoms of acute neurologic deterioration.

Bracing in younger children can be attempted to slow progression, but it does not stop eventual progression.

Spinal muscular atrophy is an autosomal recessive disorder resulting in spinal cord anterior horn cell degeneration. Two genes on the chromosome 5q locus have been found to be associated with this disorder: survival motor neuron (SMN) gene and neuronal apoptosis inhibitory (NAIP) gene.²⁴

Clinically, progressive muscular weakness occurs and eventual pulmonary compromise is common.

Three forms of the disease exist:

Most children with the early form of the disease die at an early age and therefore do not require treatment.

Most children with the intermediate and late type who survive into adolescence develop a progressive spinal deformity. The curvature typically develops in the first decade. Thoracolumbar and thoracic patterns are most common.

One-third of patients have an associated kyphosis in the sagittal plane. Bracing is ineffective at preventing curve progression but may delay progression in the very young patient to allow further growth of the spine.²

This autosomal recessive disorder results in a slowly progressive spinocerebellar degeneration. A defect on chromosome 9 has been identified.

The incidence of scoliosis is 100%, and progression is related to the age of disease onset. When disease onset is prior to age 10 years and scoliosis onset is before 15 years, scoliosis progression is usually greater than 60 degrees.

Progressive scoliosis requiring surgery occurs in about 50% of patients.¹⁴

Orthotic treatment may slow but usually does not prevent progression.

This is an X-linked disorder that affects females almost exclusively. Some children have a mutation on the MECP2 gene.²¹ The child’s development is normal until 6 to 18 months of age, followed by rapid deterioration in cognitive and motor function.

After the initial deterioration in function, the neurologic picture may become relatively static for years. The clinical spectrum is variable, with some children remaining ambulatory and others becoming wheelchair bound.

Rett syndrome may be mistaken for cerebral palsy.

Scoliosis has been reported in up to 80% of patients.¹²

A long C-shaped thoracolumbar pattern is common. Bracing is usually ineffective, and curve progression is common. Surgical stabilization allows maintenance of sitting balance.

Spinal cord injury in the skeletally immature child is associated with a nearly 100% incidence of scoliosis.⁷

The predominant curve type is a long C-shaped curvature. The younger the child, the higher the progression.

Prophylactic bracing may be effective in smaller curves (under 20 degrees). There are no data to support that bracing is effective in preventing progress in established curves greater than 20 degrees.