6.2 Flashcards
(12 cards)
- What is spina bifida and how does it develop?
Spina bifida is a neurodevelopmental disorder classified as one of the neural tube defects. It occurs when the caudal portion of the neural tube fails to close properly between 26–28 days of embryogenesis, resulting in maldevelopment of the vertebral column, spinal cord, and associated nerves.
- What is the pathophysiology of spina bifida?
The central pathology in spina bifida is the incomplete formation of the vertebral arches, which may lead to a defect in the protective bony enclosure of the spinal cord. This defect can cause exposure of the neural tissue or result in abnormal positioning, leading to neurological deficits and associated functional impairments.
- What are the major subtypes of spina bifida?
The three primary subtypes are: Spina bifida occulta (a mild form with isolated vertebral non-closure and minimal or no protrusion), Meningocele (where a sac containing cerebrospinal fluid and meninges protrudes through the vertebral defect without involving the spinal cord), and Myelomeningocele (the most severe form, in which both the meninges and spinal cord tissue protrude through the defect).
- What are the key features of spina bifida occulta?
Spina bifida occulta is the mildest form characterized by incomplete closure of one or more vertebrae—commonly at L5 or S1—with no visible protrusion of the spinal cord. It may be identified by subtle cutaneous markers at the lesion level and can sometimes be associated with conditions like tethered cord syndrome or syringomyelia.
- How does meningocele differ from myelomeningocele?
In meningocele, a sac-like cyst composed of meninges and cerebrospinal fluid protrudes through the vertebral defect, but the spinal cord remains in place and is typically not involved. In contrast, myelomeningocele involves both meninges and neural tissue (spinal cord) protruding through the defect, leading to more severe neurological impairment, including paralysis and sensory loss.
- What are some common neurological complications associated with myelomeningocele?
Patients with myelomeningocele often develop significant complications such as Chiari II malformation (herniation of parts of the cerebellum and brainstem), hydrocephalus (ventricular enlargement due to CSF accumulation), syringomyelia (fluid-filled cysts within the spinal cord), and various brainstem anomalies, which contribute to the overall morbidity and impact on quality of life.
- What are the common treatments and management approaches for spina bifida?
Treatment is largely palliative. For myelomeningocele, surgical repair is typically performed prenatally or soon after birth to close the defect and reduce infection risk. Long-term management relies on a multidisciplinary approach—including neurosurgery, urology, orthopedics, physical rehabilitation, and psychological support—to manage complications such as hydrocephalus, neurogenic bladder, motor dysfunction, and to optimize quality of life.
- How is prenatal diagnosis of spina bifida achieved?
Prenatal diagnosis is commonly made via ultrasound imaging—often in the first trimester—and may be supported by maternal serum alpha-fetoprotein (AFP) level screening. An elevated AFP can indicate a neural tube defect such as spina bifida.
- What is the key environmental risk factor for spina bifida, and why is it important in public health management?
Maternal folate (vitamin B9) deficiency is a key environmental risk factor because adequate folate is crucial for neural tube closure during early embryogenesis. Folate deficiency can markedly increase the risk of spina bifida and related neural tube defects.
- How has public health management addressed the risk factor of folate deficiency to reduce spina bifida rates?
Many countries, including Australia, have implemented policies for folic acid fortification of wheat flour and cereal products, coupled with public health campaigns advising women of childbearing age to take folic acid supplements. These measures have significantly reduced the incidence of spina bifida by improving maternal folate status.
- What multidisciplinary approaches are essential for the long-term care of individuals with spina bifida?
Long-term care for spina bifida patients involves coordinated management by multiple specialties—including neurology, neurosurgery, urology, orthopedics, rehabilitation medicine, psychological support, and assistive services—to address motor deficits, cognitive challenges, bladder and bowel dysfunction, and other complications over the patient’s lifetime.
- Why is early intervention and public health policy important in spina bifida prevention and management?
Early diagnosis through prenatal screening and timely surgical intervention can greatly mitigate complications and improve outcomes. Additionally, public health policies such as folic acid fortification not only reduce the incidence of neural tube defects but also alleviate future healthcare burdens, improve quality of life, and contribute to better societal health.
