A review of neural tube defects specially spina bifida for medical students.

1. NEURAL
TUBE
DEFECTS
Dr. Farrukh Javeed
Consultant Neurosurgeon
JPMC, Karachi.

2. OUTLINE
• Embryology
• Types of neural tube defects
• Possible Risk Factors
• Clinical features
• Investigation
• Associated anamolies
• Management

6. TYPES
• Open
– anencephaly, encephalocele, spina bifida, hydrencehaly,
iniencephaly.
• Closed
– lipomyelomeningocele, lipomeningocele, and tethered cord.

7. ENENCEPHALY
• There is absence of cranial vault with cerebral hemispheres
completely absent or greatly reduced in size.

8. CRANIOSCHISIS
• A skull defect through
which neural tissue
protrudes.

9. EXANCEPHALY
• A protrusion of brain and meninges out of the skull.

10. RACHISCHISIS
• Meninges and spinal cord are exposed through a fissure in the
vertebral column.

11. INIENCEPHALY
• There is retroflexion of the head without a neck and severe
distortion of the spine.

12. HYDRENCEHALY
• The cerebral hemispheres are absent and replaced by sacs
filled with cerebrospinal fluid.

13. ENCEPHALOCELE
• A protrusion of brain and meninges into a fluid filled sac
through a skull defect.

16. SPINA BIFIDA
• Incomplete closing of the
spine and membranes around
the spinal cord

18. RISK FACTORS
• Low intake of folic acid
• Ingestion of folate antimelabolities
• Gestational diabetes
• Obesity during pregnancy
• Arsenic poisoning
• Radiation
• Cigarette smoking

25. CLINICAL FEATURES
• Paralysis of the legs
• Partial or total lower
body weakness
• Learning disabilities
• Visual impairment
• Stunted growth
• Mental retardation
• Difficulty in movement
• Facial defects
• Increased muscle tone
• Respiratory issue
• Progressive enlargement of the
head
• Vomiting
• Nausea
• Coma
• Urinary and bowel dysfunction
• Cardiac abnormalities

26. WORKUP

28. PRENATAL DETECTION
SERUM ALPHA-FETOPROTEIN (AFP)
• A high maternal serum AFP (≥ 2 multiples of the median for
the appropriate week of gestation) between 15–20 weeks
gestation carries a relative risk of 224 for neural tube defects

29. ULTRASOUND
• Prenatal ultrasound will detect 90–95% of cases of spina bifida
• In cases of elevated AFP, it can help differentiate NTDs from
non-neurologic causes of elevated AFP (e.g. omphalocele), and
can help to more accurately estimate gestational age.

30. AMNIOCENTESIS
• Amniotic fluid AFP levels are elevated with open neural tube
defects, with a peak between weeks 13–15 of pregnancy.
• Amniocentesis also carries a ≈ 6% risk of fetal loss in this
population.

31. ASSOCIATED ANOMALIES

35. UROGENITAL & ORTHOPEDIC

36. TREATMENT
• Perinatal management
– In utero repair
• Conventional Surgery/ Open repair

37. IN UTERO REPAIR; OPEN REPAIR

38. IN UTERO REPAIR; ENDOSCOPIC REPAIR

39. POST-NATAL REPAIR

41. POST-OP COMPLICATIONS
• Wound infection
• Meningitis
• Sepsis
• Hydrocephalus
• Chiari malformation
• Tethered cord
• Scoliosis
• Dermoid cyst
• Latex allergy
• Death

42. THANK YOU