Neural Tube Defects http://www.youtube.com/watch?v=86NDMfxU4ZU&feature=related
Neural Tube Development Normal embryological development • Neural plate development -18th day • Cranial closure 24th day (upper spine) • Caudal closure 26th day (lower spine)
What is Spina Bifida? A midline defect of the • bone, • skin, • spinal column, &/or • spinal cord. • http://www.youtube.com/watch?v=Jl1PlvM9HZQ&feature=related • http://www.youtube.com/watch?v=6Ii_v3t9hpU&feature=relmfu
Clinical Considerations Note this chart illustrates WEEKS of gestation (pregnancy). Does the mother generally know she is pregnant when the neural tube is developing?
Clinical considerations: At what point could health professionals prevent the development of neural tube defects? http://www.youtube.com/watch?v=qRtspxmhYnA&feature=relmfu http://www.youtube.com/watch?v=XOviMfHaYmI http://www.youtube.com/watch?v=N_MaRhpBo6A
Spina Bifida or "Open Spine." • Incomplete development of a baby's spine • Encephalocele: • Incomplete closing of the skull, with a varying amount of brain protruding from the skull. • Anencephaly: • A fatal defect. Incomplete growth of a baby's brain. NEURAL TUBE DEFECTS
Clinical Considerations What factors contribute to neural tube defects?
Why Folic Acid is So Important • NEURAL TUBE DEFECTS RISK FACTORS • Mother's Health • Pregnancy History • Ethnic Background • Other/Unknown
Consumption of the B Vitamin Folic Acid for the Prevention of Birth Defects
Foods That are Either Good Sources of Natural Folate or Which Contain Synthetic Folic Acid
Making a Few Simple Choices About What You Eat Can Do a Lot to Improve the Quality of Your Diet
FOLATE COOKING AND STORAGE TIPS • Do not over cook vegetables • Steam, microwave, or stir-fry vegetables • Refrigerate produce, but use as soon as possible.
Lowered Folate Use in Body • Prescribed Drugs • Over the Counter Drugs • Health Conditions • Smoking • Alcohol Abuse
Preconceptional Use of Folic Acid for Reduction of the Risk of Birth Defects
Myelomeningocele (MMC) Open neural tube defect • Most common & severe CNS congenital anomaly • Affects ~ 1500 fetuses in U.S. annually • Severity varies depending on level of lesion • Significant morbidity and mortality • Life-long disabilities
Complications Hydrocephalus Need for ventriculoperitoneal shunting Motor & cognitive impairments Bladder & bowel incontinence Social & emotional challenges
Preventive Care • The United States Public Health Service recommends that: "All women of childbearing age in the United States who are capable of becoming pregnant should consume 0.4 mg of folic acid per day for the purpose of reducing their risk of having a pregnancy affected with spina bifida or other neural tube defects." Folic acid is a "B" vitamin that can be found in such foods as: cereals, broccoli, spinach, corn and others, and also as a vitamin supplement.
Types of Myelodysplasia* • Spina bifida occulta • Lipomeningocele • Meningocele • Myelomeningocele = Spina Bifida *defective development of the spinal cord
Neurologic pathology Spina bifida occulta (occulta = closed) A condition involving nonfusion of the halves of the vertebral arches without disturbance of the underlying neural tissue
Neurologic pathology Lipomeningocele (lipo = fat) lipoma or fatty tumor located over the lumbosacral spine. Associated with bowel & bladder dysfunction Lipomeningocele
Neurologic pathology Meningocele (cele = sac) Fluid-filled sac with meninges involved but neural tissue unaffected
Types of Myelodysplasia Myelomeningocele or spina bifida: meninges and spinal tissue protruding through a dorsal defect in the vertebrae
Incidence and Prevalence • Incidence • 1/1000 • Prevalence • Increased incidence in families of Celtic and Irish heritage (genetic or environmental?) • Increased incidence in minorities (genetic or environmental?) • Increased incidence in families
Etiology Neural Tube defects may result from: • Combination of environmental and genetic causes • Teratogens – Cause developmental defects • Nutritional deficiencies - notably, folic acid deficiency
Diagnosis and Detection • Amniocentesis AFP - indication of abnormal leakage • Blood test Maternal blood samples of AFP • Ultrasonography For locating back lesion vs. cranial signs
Prognosis Spina bifida is a: • static • non-progressive defect • with worsening from secondary problems. The prognosis for a normal life span is generally good for a child with good health habits and a supportive family/caregiver.
Impairments associated with Spina Bifida Physiological changes below the level of the lesion generally include: abnormal nerve conduction, resulting in: • somatosensory losses • motor paralysis, including loss of bowel and bladder control
Impairments associated with Spina Bifida Physiological changes below the level of the lesion generally include: abnormal nerve conduction, resulting in: changes in muscle tone* *Note: Muscle tone can range from flaccid to normal to spastic; may have UMN signs with/without true spastic paraparesis; progression of neurologic dysfunction or change in neurologic status most concerning
Impairments associated with Spina Bifida Anatomical changes below the level of lesion: • musculoskeletal deformities (scoliosis) • joint and extremity deformities (joint contractures, club foot, hip subluxations, diminished growth of non-weight bearing limbs) • osteoporosis • abnormal or damaged nerve tissue
Impairments associated with Spina Bifida Anatomical changes associated with a cervical lesion: An enlarged head caused by hydrocephalus (“water on the brain”) Hydrocephalus
Arnold Chiari Malformation Arnold Chiari type II Malformation: • cerebellar hypoplasia (hypoplasia = reduced growth) • with caudal displacement of the hindbrain through the foramen magnum • usually associated with hydrocephalus
Health Problems associated with the Arnold Chiari syndrome • Cranial Nerve Palsies • Visual Deficits • Pressure from the enlarged ventricles affecting adjacent brain structures (See Tecklin, page 166, for symptoms associated with Arnold Chiari syndrome.)
Health Problems associated with the Arnold Chiari syndrome Cognitive and perceptual problems: • Potential for lower intellect • Memory deficits • Distractibility • “Cocktail party personality” (chattering speech - with limited content) • Visual perceptual deficits
Health Problems associated with Arnold Chiari syndrome Motor dysfunction: • Upper limb incoordination: halting and deliberate movement instead of smooth continuous movement • Spasticity: related to upper motor neuron lesions
Complications leading to progressive neurological dysfunction • Syringobulbia (syringes occurring in the brainstem) • Syringomyelia (syringes anywhere in the spinal cord) • Bowel and/or Bladder Dysfunction: potential for neurogenic bowel and/or bladder (requires clean, intermittent catheterization on a regularly timed schedule) Tubular cavitation called a syrinx
Other Complications • Hydrocephalus • Hydromyelia • Tethering of the spinal cord: fixation or tethering of the distal end of the spinal cord causing intermittent bowstringing of the spinal cord between the normal cephalic attachment and the point of tether • Seizures
Related Problems • Skin Breakdown • Decubitus ulcers and other types of skin breakdown • Obesity • Latex Allergy