Thursday, 15 August 2019

Anencephaly: A lethal malformation -Its diagnosis & teatemnt


Refresh your knowledge on Anencephaly  :Need not read any books: look  at my head: My grandson & granddaughters particularly have eaten half of my head by not getting chocolates -As such I have become anencephalic!!!
Defn:-Anemophily is characterized by the absence of the cranial  vault and telencephalon. Necrotic remnants of the brain stem and rhomboencephalic structures are covered   by a vascular membrane.
What may be associated malformations outside the head?? Ans:- Associated malformations are common and include   spina bifida cleft lip / palate clubfoot and  omphalocele 
When to clinically  suspect in pre USG era? (Prior to 1980)?? . We used to think of this D/D in 1967-1981 (when first USG machine was installed at Eden Hospital,  Medical College Kolkata) as anencephaly is frequently associated with Polyhydramnios. Now after widespread  availability  of USG centers at every lane and bye lane : The diagnosis is easy in the second  and third  trimester and relies on the demonstrations of the absence  of the cranial vault

Pathogensis ?? .Anencephaly is considered to be the final stage of acrania as a consequence of disruption of abnormal brain tissue unprotected by  the calvarium . Although  the term  acrania  is often used in conjunction with anencephaly the term  implies  absence of the  entire skull including  the skull  base which is not true in anencephaly. The skull base is present  in anencephaly and the calvarium is absent  

How early anencephaly can be picked up?? Ans:-The fetal head can be positively identified by vaginal sonography as early  as the 7th week of gestation the diagnosis may be difficult in the first trimester . But one caveat. The absent   calvarial  mineralizataion before  10 to 12  weeks gestation makes  the differentiation of normal  and abnormal  brain  difficult. Therefore a cephalic pole  albeit overtly abnormal  is usually  present in early gestation and may be difficult to identify  and differentiate from the normal  brain before  11 weeks gestation  .

No comments:

Post a Comment