Neural Tube defects ( NTD )

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Neural Tube defects ( NTD )

Neuropores 

• Anterior - normally closes at 25 days
• Posterior - normally closes at 27 days

NTD due to failure of closure.

• Anterior nonclosure - Ancephalocele , Encephalocele
• Posterior nonclosure - Spina Bifida , Meningocele , Meningomyelocele

Risk factor :

1. Maternal folic acid deficiency (Most important)
2. Maternal Zn deficiency
3. Materanl Malnutrition
4. Maternal Alcohol , Diabetes , Radiation
5. Maternal Anticonvulsan (Valproate , phenytoin)

Thus Start folic acid 1 month before conception to 3 months after conception. -> 400microg

To prevent recurrence : give 4mg Folic acid (i.e 10 times)

Meningocele : Herniation of meninges

Meningomyelocele : Herniation of meninges + nerve roots

if Lumbosacral Meningomyelocele - Complications

1. Paraplegia /parasis
2. Posterior dislocation of hip
3. Bowel and bladder incontinence
Do MRI head - because 80% will have obstructive hydrocephalus , because of Arnold Chiari type 2 malformation.

Encephalocele : Herniation of brain tissue. 

Occipital is more common than frontal.

Earliest Congenital anomaly that can be diagnosed by USG : Anencephaly (at 10-11 wks)

Tests for NTD

1. Amniocentesis : Acetyl cholinesterase and Alpha feto protein
2. Maternal Serum : AFP (MSAFP)

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