1) Distinguish the epidemiology and pathophysiology of neural tube defects
2) Identify the common sensorimotor deficits and associated comorbidities of myelomeningocele
3) Identify and help physical therapists choose optimal treatment interventions for children with myelomeningocele
CASE A, PART I
Dylan is a 15-year-old male with myelomeningocele. His birth history includes myelomeningocele (see Figure 19-1) identification from an ultrasound at 20 weeks of gestation. He was born via scheduled C-section at 38 weeks gestational age. He had postnatal surgery to close the lesion 24 hours later, and during surgery, the highest lesion level identified was L1/L2; he had a second surgery to implant a ventriculoperitoneal shunt at 3 weeks of age. He wore a Pavlik harness for his first 6 months of life for bilateral hip dysplasia. He has had multiple episodes of physical therapy care throughout his lifetime. Dylan does not ambulate but wore braces up to the age of six to facilitate standing and home ambulation with a walker. Currently, he is s/p spinal fusion for scoliosis and has restrictions, including no flexion of his trunk and no pushing or pulling with his arms; he has been fitted with a thoracolumbosacral orthosis (TLSO) to prevent trunk flexion during recovery. Dylan is unable to push or pull with his legs. His ankle ROM is lacking 5 degrees bilaterally, and 20+ degrees of hip flexion contractures were corrected as part of his scoliosis surgery. In the past year, he has also had an increased weight gain of 30 pounds, and now weighs 150. Dylan will be starting high school in 2 months. He is currently in a manual wheelchair that he has had for 2 years. His current chair is too small, and he cannot propel it with the restrictions from the surgery. Right now his mom pushes him in the manual chair, and in school, a student peer is pushing him from one class to another.
Myelomeningocele is one of a group of disorders, referred to as neural tube disorders (NTDs). To understand NTDs, we will start with a discussion of the formation of the nervous system, during gestation, and how disruption of this formation results in a variety of defects of the CNS. NTDs are the second most frequent congenital anomaly with only heart defects occurring more frequently.1 Since these occur during early gestation, they can result in complex sequelae, associated with the site and extent of the defect; some are so severe that they result in miscarriages, or even if birth occurs, life cannot be sustained.
Illustration of myelomeningocele and Arnold–Chiari defects. The spinal defect (myelomeningocele) typically presents in the thoracolumbar spine as a bulging sac with neural and meningeal contents; the associated Arnold–Chiari malformation is illustrated at the craniocervical flexure with the cerebellum herniating down into the foramen magnum.