Encephalocele is characterized by a protrusion of the brain and/or meninges through a defect in the skull that is covered with skin. It is one of the most severe neural tube defects with a prevalence estimated to be 0.8 to 5/10 000 births [
A 26-year-old woman, secundigravida, presented for a first medical visit to our department at 22 weeks of gestation for a prenatal exam. She had a sonographic examination four days later. The ultrasound showed a single viable fetus with a regularly shaped, heterogenic, midline, facial cystic mass with no vascular supply (Figure
Sonographic examination showing a regularly shaped, midline, facial cystic mass.
Prenatal MRI showing a small round midline lesion with herniation of brain parenchyma (arrow).
Prenatal MRI showing a well-defined osseous defect in the underlying calvarium (arrow).
Under the diagnosis of fetal isolated encephalocele, counseling by pediatric specialists (neurosurgeons and neonatologists) the mother and the husband followed regarding the prognosis, progress, and postnatal treatment. The parents were informed that even though the survival rate had increased in the anterior defects, the bigger the herniated sac is (in this case 44 mm), the greater the neurological and physical deficits are with or without surgery.
The mother has voiced understanding of the very limited clinical information concerning the long-term effect of such an anomaly on central nervous system development, and she also is aware of the uncertainty of the long-term neurologic outcome with such structural abnormalities and decided for termination of her pregnancy.
The assisted abortion was agreed on by the maternity center of ethics committee. The medical termination of her pregnancy by induction of labor was carried out at 25 weeks of gestation. The procedure started by an intracardiac KCl injection followed by misoprostol administration 400
Fetal macroscopic examination showing the sincipital encephalocele.
Anterior encephaloceles result from a herniation of intracranial contents through a cranial skull defect with a persistent connection to the subarachnoid space. Based on the location, they can be classified as occipital (75%), sincipital (15%) or basal (10%) [
The sincipital meningoencephalocele is typically divided into 3 types [ Frontoethmoidal (subdivided into nasofrontal (40–60%), nasoethmoidal (30%), and nasoorbital (10%)). Interfrontal. Those associated with craniofacial clefts.
Frontoethmoidal encephalocele is the most common of the anterior encephaloceles, followed by the nasopharyngeal and orbital types [
The Foetopathology Department of Maternity Center of Tunis, Tunisia, drains all of the capital malformed fetuses. Roughly 800 fetopathological exams per year are carried out in this center. Two interfrontal encephalocele cases were detected in 7 years, which estimates the frequency of the disease at 3.6 per 10 000 malformed cases.
Prenatal diagnosis of encephalocele is commonly accomplished by maternal screening of serum
With two-dimensional ultrasound (2D US), encephalocele appears as a defect in the calvarium containing a cystic or solid mass with a gyral pattern that is in continuity with the brain [
Prenatal US, usually, can define the calvarial deficiency, but difficulties might be incurred if the defect is small, fetal head position is poor, or defect is contiguous with nasal cavity [
MRI is increasingly used to evaluate the fetal brain, particularly when an abnormality has been detected on prenatal US or when a fetus is at increased risk for neurodevelopment anomalies. Fetal MRI has several advantages over US. It has higher contrast resolution and is not affected by the shadowing from the calvarium or by low amniotic fluid volume; it allows a larger field of view and can easily be performed using ultrafast T2-W sequences [
In terms of the sincipital encephalocele, fetal MRI can provide superior definition of brain and vascular structure images involved and their relative relationship. It can also detect additional central nervous system malformations. Therefore, it can provide important prognostic information for prenatal management. Fetal MRI is also useful in differentiating small cephaloceles from subcutaneous skull cysts and cranial hemangiomas [
Encephalocele is frequently associated with other malformations that may be part of recognized syndromes. The most common of the associated syndromes is Meckel-Gruber syndrome which includes occipital encephalocele, microcephaly, microphthalmia, polycystic kidneys, ambiguous genitalia, polydactyly, cleft lip and cleft palate, and other malformations. Other cerebral malformations are often associated with encephalocele such as hydrocephalus, corpus callosal abnormalities, and cerebral dysgenesis [
If the size of the sac is important and encephalocele is bulky, with severe microcephaly or other lethal anomalies, termination of pregnancy may be the choice due to the severe morbidity and mortality [
Specific information on the outcome of a child with a cephalocele can be difficult to find and interpret. French reported that 83% of patients with encephaloceles had mental handicap and/or physical impairment [
Sincipital encephalocele is rare and should be suspected on the basis of any anterior midline mass. The diagnosis can be made by US. Fetal magnetic resonance imaging (MRI) may provide superior detail of central nervous system (CNS) anomalies. The extent of cerebral tissue involvement in an encephalocele is also better defined with MR imaging, which aids in prognosis and surgical planning. The prognosis of babies with encephalocele is variable. Babies with an encephalocele at the back of the head have a 55 percent survival rate. Long-term prognosis for survival becomes less likely if there are other complications. Approximately 75 percent of these infants who do survive have varying degrees of mental deficit.
The authors declare that there is no conflict of interests.