Exencephaly is a lethal congenital fetal brain developmental anomaly (neural tube defect).
- maternal serum alpha feto protein (MSAFP) levels are highly elevated (x 2.5 MoM)
Imaging features have some overlap with that of anencephaly except that there is some brain tissue presence:
- cranial vault is absent or poorly formed, cephalad to orbits
- nasal bone may be absent in most cases
- brain tissue is herniating or dangling in amniotic fluid
- brain tissue may be attached to the amniotic membrane
Treatment and prognosis
Exencephaly is a precursor to anencephaly, and essentially a lethal condition. Advise and counselling for abortion is to be given to the parents.
- 1. Wilkins-haug L, Freedman W. Progression of exencephaly to anencephaly in the human fetus--an ultrasound perspective. Prenat. Diagn. 1991;11 (4): 227-33. - Pubmed citation
- 2. Bianchi DW, Crombleholme TM, D'Alton ME. Fetology, diagnosis & management of the fetal patient. McGraw-Hill Professional. (2000) ISBN:0838525709. Read it at Google Books - Find it at Amazon
- 3. Timor-tritsch IE, Greenebaum E, Monteagudo A et-al. Exencephaly-anencephaly sequence: proof by ultrasound imaging and amniotic fluid cytology. J Matern Fetal Med. 5 (4): 182-5. doi:10.1002/(SICI)1520-6661(199607/08)5:4<182::AID-MFM4>3.0.CO;2-G - Pubmed citation
- 4. Papp Z, Csécsei K, Tóth Z et-al. Exencephaly in human fetuses. Clin. Genet. 1986;30 (5): 440-4. - Pubmed citation
- 5. Merz E, Bahlmann F. Ultrasound in obstetrics and gynecology. Thieme Medical Publishers. (2005) ISBN:1588901475. Read it at Google Books - Find it at Amazon