Neural tube defects and spinal dysraphism

Your progress

Saved on this device.

Target exams

Red flags

• A sac on the back of a newborn that leaks cerebrospinal fluid is a myelomeningocele needing neurosurgical closure within 24 to 72 hours to prevent infection and preserve function
• A low-lying conus below L2 with progressive leg weakness, foot deformity, or bladder deterioration is a tethered cord until proven otherwise
• Atypical midline back skin stigmata including a hair tuft, a lipoma, a haemangioma, a dermal sinus, or a deviated gluteal cleft mark an occult spinal dysraphism that demands spinal magnetic resonance imaging
• The Chiari II malformation in myelomeningocele may present with stridor, swallowing difficulty, apnoea, or arm weakness from brainstem compression and is a neurosurgical emergency
• A shunted child with myelomeningocele and new drowsiness or vomiting has a shunt malfunction until proven otherwise, because hydrocephalus complicates most cases
• Latex allergy is common in spina bifida and can cause anaphylaxis, so every procedure from birth onward must use a latex-free environment
• Maternal serum alpha-fetoprotein more than two and a half multiples of the median at 15 to 20 weeks raises an open neural tube defect until ultrasound and amniocentesis resolve it

Life stages

Care settings

Clinical exam formats

Board mappings

• Defines neural tube defects as failures of neural tube closure in the third and fourth week of embryogenesis, spanning the open defects of anencephaly and myelomeningocele and the closed defects of spina bifida occulta and the occult dysraphic states
• States that periconceptional folic acid at 400 micrograms daily for all women and 4 milligrams daily for the high-risk woman prevents most neural tube defects, and that food fortification lowers population prevalence
• Recognises the cutaneous stigmata of occult spinal dysraphism, including the hair tuft, the lipoma, the dermal sinus, and the deviated gluteal cleft, and refers for spinal magnetic resonance imaging
• Applies the open and closed classification to the clinical, imaging, and surgical approach, and relates the Chiari II malformation and the near-universal hydrocephalus to the myelomeningocele phenotype
• Distinguishes myelomeningocele from meningocele, lipomyelomeningocele, diastematomyelia, dermal sinus, and tethered cord syndrome, and justifies the choice of neurosurgical closure, untethering, and urological management
• Integrates the Management of Myelomeningocele Study evidence for prenatal repair before 26 weeks into the prenatal counselling, and manages the lifelong multidisciplinary burden of neurogenic bladder, latex allergy, and shunt dependence
• The periconceptional folic acid doses of 400 micrograms for the general population and 4 milligrams for the high-risk woman, and the window of at least one month before conception through the first trimester
• The maternal serum alpha-fetoprotein and the fetal ultrasound that make the prenatal diagnosis, and the alpha-fetoprotein threshold of two and a half multiples of the median at 15 to 20 weeks
• The cutaneous stigmata of occult dysraphism and the spinal magnetic resonance imaging criteria for tethered cord, including a conus below L2 and a filum thicker than 2 millimetres
• Runs the neonatal resuscitation and neurosurgical referral of a newborn with a myelomeningocele, including the latex-free environment, the sterile covering of the sac, and the closure within 24 to 72 hours
• Coordinates the multidisciplinary management of the child with spina bifida across neurosurgery, urology, orthopaedics, and rehabilitation, and the lifelong surveillance for tethering, shunt malfunction, and latex sensitisation
• Counsels the family on the cause, the prenatal and postnatal management, the prognosis for ambulation and continence, and the recurrence risk and the folic acid dose for a future pregnancy
• Level 1: Recognition that neural tube defects arise from failed neural tube closure and that folic acid prevents most cases, and identification of the back lesion and the skin stigmata
• Level 2: Application of the open and closed classification, the maternal serum alpha-fetoprotein and fetal ultrasound, and the neurosurgical closure of myelomeningocele, with timely referral
• Level 3: Coordination of the prenatal counselling, the operative closure or untethering, the neurogenic bladder and latex allergy management, and the longitudinal multidisciplinary follow-up
• The embryology of neural tube closure in the third and fourth week and the open and closed classification of neural tube defects, and the epidemiology and the primary prevention by folic acid and food fortification
• The Chiari II malformation and the near-universal hydrocephalus of myelomeningocele, the maternal serum alpha-fetoprotein and fetal ultrasound, and the Management of Myelomeningocele Study of prenatal repair
• The cutaneous stigmata of occult dysraphism, the spinal magnetic resonance imaging criteria for tethered cord, and the neurogenic bladder management with clean intermittent catheterisation
• Structured neonatal assessment of a newborn with a back lesion including the level of the lesion, the motor and sensory level, the head circumference, and the signs of Chiari II
• Distinguishing myelomeningocele from meningocele and the occult dysraphic states, and identifying the skin stigmata that demand spinal imaging
• Communication of the diagnosis, the multidisciplinary plan, the prognosis for ambulation and continence, and the folic acid advice for a future pregnancy
• Neural tube defects as failures of neural tube closure presenting with anencephaly, myelomeningocele, meningocele, and the occult dysraphic states, and prevented by periconceptional folic acid
• The neonatal presentation of a back lesion and the cutaneous stigmata of occult dysraphism, and the urgent neurosurgical referral for closure
• The Chiari II malformation and the hydrocephalus of myelomeningocele and the multidisciplinary management of the neurogenic bladder and the latex-free environment
• Recognition of the open and closed neural tube defects and the folic acid prophylaxis at 400 micrograms for the general population and 4 milligrams for the high-risk woman
• Structured neonatal assessment and the cutaneous stigmata of occult dysraphism, with timely neurosurgical referral for closure or untethering
• The multidisciplinary management of neurogenic bladder, shunt dependence, latex allergy, and the transition to adult care
• Canadian approach to the primary prevention of neural tube defects by folic acid supplementation and mandatory food fortification of white flour
• Distinguishing the open and closed defects and the occult dysraphic states, and the role of maternal serum alpha-fetoprotein, fetal ultrasound, and spinal magnetic resonance imaging
• The Management of Myelomeningocele Study evidence for prenatal repair and the lifelong multidisciplinary management of the child with spina bifida