Scoliosis Comorbid Disorders
By definition, idiopathic scoliosis is not associated with a known cause for the spinal deformity. The diagnosis of idiopathic scoliosis is arrived at if there is a normal neurologic examination, no unusual presenting symptoms, such as persistent or night pain, and no evidence of boney fusion or hemivertebrae in the spine. This diagnosis will comprise over 80% of all cases of pediatric scoliosis; however, suspicion of a comorbid disorder needs to be evaluated with appropriate screening as discussed below. Idiopathic scoliosis can be further divided into three areas: infantile (newborn up to 3 years of age), juvenile (3-9 years of age) and adolescent (10 years of age until skeletal maturity). Patients in the infantile and juvenile categories need to pay special attention to their work-up as this is a less common presentation of idiopathic scoliosis than the adolescent variety and, thus, presents a higher chance of a comorbid disorder. Patients under 9 years of age should have a spinal survey with an MRI scan to rule out any intrinsic neurologic abnormality and to confirm the diagnosis of idiopathic scoliosis.
Congenital scoliosis is defined as either a failure of formation or a failure of segmentation of a portion of the spine. This results in mis-shapen or fused bones that can develop into a scoliosis. This type of scoliosis has a high association with other abnormalities owing to the fact that the embryonic development of the spine is closely timed with that of the spinal cord and mesoderm.[1,15,16] Therefore, central lesions, such as intraspinal anomalies, heart defects and bowel and bladder disorders, would be expected.[1,17,18,19,20] The congenital scoliosis may present with any or all of the defects alone or in the setting of a syndrome, such as the vertebral anomalies, anal atresia, tracheosophageal fistula, renal and vascular anomalies (VACTERYL) syndrome. Owing to the timing of development of these systems around the same time in the uterus, if one defect is found, the others should be actively sought.
Patients will often present at a young age with a family complaint of a curvature to the spine. Radiographs may demonstrate abnormal vertebrae that are either fused or partially formed. In this young age group (often less than 5 years of age), obtaining additional imaging studies, such as an MRI, requires sedation. It has therefore been recommended in the literature to selectively order an MRI on patients who may need surgical correction in cases with neurologic changes or cases of progressive deformity.
A congenital scoliosis may also be diagnosed during the work-up of a plagiocephally (flattening of the skull bones on one side) or a tilted rotational position of the head, termed torticollis. Either of these conditions can be associated with a congenital spinal abnormality.
Intraspinal anomalies have been noted in 20-40% of cases[1,8,10,15,16,17,18,19,20,22,23,24,25] and include spinal tumors, diastematomyelia, tethered cord syndrome, syringomyelia and Arnold-Chiari malformation. Congenital heart defects, such as atrial or ventral septal defects, patent ductus arteriousus and Tetrology of Fallot, may be observed in up to 30% of patients.[1,15,17,19,20,22,25] Screening echocardiograms should be performed on any patient undergoing surgery and any patient with a heart murmur, with a higher suspicion in patients with cervical or thoracic spinal deformities.[15,19,20,25] An additional area of concern is the genotourinay tract, which may show abnormalities in up to 20% of patients. These anomalies may include hypoplastic or unilateral kidneys, obstruction of a ureter or possibly hypospadius, among others. The work-up for genitourinary defects should be performed by ultrasound if the patient is not scheduled for an MRI, or by MRI at the same time as the spinal MRI, if ordered.
Any child with congenital scoliosis may also be at risk for chest wall deformities. The most devastating are those that have fusions of multiple ribs in young patients as the chest wall restriction inhibits growth and development of the lungs. Idiopathic scoliosis has not been demonstrated to affect overall lifespan; however, congenital scoliosis, especially in the setting of a chest wall restriction, has in fact been demonstrated to significantly shorten a patient's lifespan. The chest wall restriction may need to be addressed individually or as a component of corrective spinal surgery depending on the amount of restriction and its effect on pulmonary function. This can be evaluated and followed with pulmonary function testing in patients who are old enough to comply with testing.
Neuromuscular scoliosis is defined as a spinal curvature in the setting of a neuromuscular disease, such as cerebral palsy, muscular dystrophy, spina bifida, poliomyelitis, Friedreich's ataxia, familial dysautonomia (Riley-Day syndrome) or Werdnig-Hoffmann disease.[1,25,27,28,29,30,31,32] Any of these conditions require spinal radiographs for evaluation of scoliosis; however, many of these children are already followed by an orthopedist for their baseline condition who may already be following their spine. MRI scans may also have already been performed for evaluation of their neurologic condition and may not be necessary.
Scoliosis may be encountered as a component of a number of genetic syndromes or conditions. The two most commonly associated conditions are Marfan's syndrome, affecting 60% of patients[33,34,35,36,37] and neurofibromatosis, affecting 10-50% of patients.[1,38,39] Patients with neurofibromatosis almost universally require an MRI and/or a CT scan prior to surgical intervention to evaluate the spinal cord, dural ectasia and Chiari malfromations.[1,40] Patients with one of these comorbid disorders may also have evidence of a slippage between two lower lumbar vertebra, termed a spondylolisthesis, which may or may not need treatment.[33,38,41]
Scoliosis may also be noted in patients who have had chest wall surgery, such as thoracotomy for congenital heart defect repair. Although there is a high association of congenital heart defects and scoliosis, the association is higher after patients undergo thoracotomy with a higher association being observed in those who had surgery at a younger age (<18 months).
Pediatr Health. 2009;3(5):451-456. © 2009 Future Medicine Ltd.
Cite this: Scoliosis in Pediatric Patients: Comorbid Disorders and Screening - Medscape - Oct 01, 2009.