Neural Tube Defects for Undergraduate Medical Students

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

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

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

5. CRANIOSCHISIS A skull defect through which neural tissue protrudes.

6. EXANCEPHALY A protrusion of brain and meninges out of the skull.

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

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

9. HYDRENCEHALY T he cerebral hemispheres are absent and replaced by sacs filled with cerebrospinal fluid.

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

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

12. RISK FACTORS Low intake of folic acid Ingestion of folate antimelabolities Gestational diabetes Obesity during pregnancy Arsenic poisoning R adiation Cigarette smoking

13. 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

14. WORKUP

15. 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

16. 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.

17. 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.

18. ASSOCIATED ANOMALIES

19. UROGENITAL & ORTHOPEDIC

20. TREATMENT Perinatal management In utero repair Conventional Surgery/ Open repair

21. IN UTERO REPAIR; OPEN REPAIR

22. IN UTERO REPAIR ; ENDOSCOPIC REPAIR

23. POST-NATAL REPAIR

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

25. THANK YOU