|Year : 2020 | Volume
| Issue : 3 | Page : 257-260
Giant anterior fontanel encephalocoele: A rare case report and review of literature
Bikash R Behera1, Sanjib Mishra1, Manmath K Dhir1, Jyotirmayee Biswal2, Siba N Bhujabal1
1 Department of Neurosurgery, Srirama Chandra Bhanja Medical College & Hospital, Cuttack, Odisha, India
2 Department of Pediatrics, Peerless Hospital, Kolkata, West Bengal, India
|Date of Submission||28-Aug-2016|
|Date of Decision||17-May-2017|
|Date of Acceptance||25-May-2020|
|Date of Web Publication||06-Nov-2020|
Dr. Bikash R Behera
B/L-29, VSS Nagar, P.O. Sahid Nagar, Bhubaneswar, Odisha.
Source of Support: None, Conflict of Interest: None
| Abstract|| |
An encephalocoele is a spectrum of cranial dysraphism caused due to defective closure of neural tube during early embryonic life, leading to formation of a cerebrospinal fluid (CSF)–filled sac containing brain tissue and meninges, all herniated through a bony defect of the skull. Anterior encephalocoeles, though rare in the Western world, are relatively common in southeast Asia, including some parts of India. Among anterior encephalocoeles, fronto-ethmoidal type is the most common followed by orbital encephalocoeles. Giant encephalocoeles are rare with few published short series, which are mostly located in occipital region. Giant interfrontal encephalocoele through a wide anterior fontanel is the rarest one and is limited to three case reports, including this index case. Here we report a case of giant anterior fontanel encephalocoele in a 20-day-old neonate and discuss various aspects of its management.
Keywords: Cranial dysraphism, giant encephalocoele, wide anterior fontanel
|How to cite this article:|
Behera BR, Mishra S, Dhir MK, Biswal J, Bhujabal SN. Giant anterior fontanel encephalocoele: A rare case report and review of literature. J Pediatr Neurosci 2020;15:257-60
| Introduction|| |
With an incidence of 1:40,000 in all live births, anterior encephalocoeles usually present as a swelling in front of coronal suture, extending up to nasal/orbital cavity. When an encephalocoele presents as a mass, larger than the head itself, it is known as a giant encephalocoele. An interfrontal encephalocoele arising from the widened anterior fontanel in the midline is the rarest form among all encephalocoeles.
Multiple other congenital anomalies associated with this neural tube defect usually prognosticate the overall survival of these babies. In most of the cases of giant encephalocoeles, brain matter herniates into the sac cavity, resulting in a relatively small head size.
Here we present an unusual case of giant anterior fontanel encephalocoele and discuss the critical aspects of its management.
| Case Description|| |
A 20-day-old newborn male child presented to our department with a huge pedunculated swelling over the midline in the anterior aspect of head since birth. The baby was delivered at term by lower segment cesarean section (LSCS) due to obstructed labor at a district headquarters hospital and was referred to our institute. As per record, the baby had a birth weight of 2.5kg, with an Apgar score of 4 and 7 at 1 and 5min, respectively, along with a history of delayed crying and floppiness in all four limbs.
There was no history of consanguineous marriage, intrauterine infection, radiation exposure, or any history of drug intake (including iron and folic acid) during prenatal period. This was the only child of the parents, and no family history of any congenital malformation was reported.
On local examination, a globular, pedunculated, soft, cystic, fluctuant, and brilliantly transilluminant mass with ulcerated fundus was found protruding out from the widened anterior fontanel having a circumference of 48 cm, which was way bigger than the size of the head (32 cm) [Figure 1]A–[Figure 1]C. No other associated congenital anomalies were detected.
|Figure 1: (A) Lateral view of giant encephalocoele with the pedicle attached to the midline anterior aspect of a relatively small head. (B) Brilliantly transilluminant encephalocoele with skin necrosis at fundus. (C) Top view of the baby with the giant encephalocoele. (D–F) NCCT brain axial, sagittal, and coronal views, respectively, showing compact, undifferentiated brain matter with no visible ventricle along with an encephalocoele filled with CSF and minimal brain tissue. (G and H) 3D reconstruction of the skull showing widened anterior fontanel with forced separated suture lines|
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On neurological examination, the baby was lethargic and hypotonic but was able to suck mother’s milk with no apparent cranial nerve abnormality.
Owing to financial constraints, the parents could not afford a magnetic resonance imaging (MRI) and MR venogram (MRV), compelling us to proceed with a noncontrast computed tomography (NCCT) scan with three-dimensional (3D) reconstruction of skull bone. The 3D reconstruction of skull bone revealed a wide separation of sagittal, coronal, lambdoid, and metopic sutures along with a large defect at anterior fontanel making way for the brain matter to herniate into the giant encephalocoele [Figure 1]G and [Figure 1]H. NCCT of brain revealed a densely packed undifferentiated intracranial brain matter with no clearly visible ventricular system, along with a huge pedunculated swelling, proceeding from anterior fontanel, containing cerebrospinal fluid (CSF) with some herniated brain tissue [Figure 1]D–[Figure 1]F.
Important intraoperative challenges such as patient positioning, difficult endotracheal intubation, hypothermia, blood loss, CSF loss causing fluid and electrolyte imbalance, and venous sinus repair, if encountered, were kept in mind well before surgery. Under general anesthesia, an elliptical incision was made encircling the pedicle to raise a flap over the bony defect [Figure 2]A. Before opening the dura, approximately 500mL of yellowish fluid was slowly aspirated over 10 min to slowly decompress the sac. Herniated dural sac was identified and opened. Part of the herniated gliosed neural tissue along with redundant dura was excised. No major veins and sinuses were encountered during the procedure. Watertight dural closure followed by a layered skin closure was meticulously performed to complete the procedure [Figure 2]B.
|Figure 2: (A) Intraoperative image showing herniated gliotic brain matter within the sac. (B) Postoperative image showing primary repair of encephalocoele defect over anterior fontanel|
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Postoperative recovery was uneventful with no evidence of CSF leak or wound dehiscence. Continuous head circumference charting was found to be normal in follow-up visits. Prognosis of this baby with a possible need of a future shunting procedure was explained to the parents along with the importance of folic acid intake in periconceptional period for next pregnancy.
| Discussion|| |
Nonseparation of the surface ectoderm from neuroectoderm in early embryonic life results in a specific type of cranial dysraphism known as encephalocoele. However, rupture of a well-formed neural tube at a later date could explain the well-formed skin cover over the encephalocoele, as seen in our case.
Encephalocoeles are fairly common in pediatric neurosurgical practice, with the occipital type (75%) being the most common, followed by fronto-ethmoidal type (13%–15%). Interfrontal encephalocoeles are the least common types described in world literature. Pure interfrontal encephalocoeles without an associated anomaly are extremely rare and limited to only four case reports in medical literature.,,, Our case is probably the fifth one in literature. But when it comes to a “giant interfrontal encephalocoele,” we could only find two case reports in the world literature, excluding our case.,
Periconceptional intake of folic acid has shown to prevent this cranial dysraphism. Regular monitoring of obstetric scan with maternal serum alfa-fetoprotein (MSAFP) level, amniocentesis, and fetal MRI (if necessary) helps in prenatal diagnosis of encephalocoeles with other anomalies. In our case, neither the mother had taken folic acid nor she underwent any obstetric scans during perioperative periods.
Factors responsible for poor long-term prognosis are associated congenital anomalies, microcephaly, hydrocephalus, amount of herniated brain matter, large size of sac, and CSF leak., Our case was fortunate to have minimal herniation of brain tissue with no associated anomalies and hydrocephalus.
MRI, along with MRV, is necessary to delineate the relationship between the herniated brain matter and superior sagittal sinus (SSS), thus improving the safety margin for excision of an anterior fontanel encephalocoele. The 3D reconstruction of skull has an advantage of producing a clear picture of bony defect and for planning of an expansile cranioplasty, if necessary.
Surgical strategies in these young neonates largely depend on the size of the sac, amount of herniated neural tissue, site of encephalocoele, state of CSF pathway, and relationship of superior sagittal sinus with the herniated sac., Intraoperative complications such as blood loss, hypothermia, and electrolyte imbalance can be avoided by delaying the surgery for 7–8 months, which is not always possible, especially in the presence of CSF leak and in giant encephalocoeles, which ultimately end up in skin erosion with CSF leak., To prevent bradycardia and cardiac arrest in a neonate due to sudden loss of CSF, slow controlled tapping of CSF is recommended. Management of postoperative hydrocephalus is of utmost importance, to prevent postoperative CSF leak and wound dehiscence. The index case neither had preoperative hydrocephalus nor did it appear postoperatively.
It is not the neurosurgical procedure but the underlying brain involvement and associated congenital anomalies that predict the long-term outcome of the baby.
| Conclusion|| |
This “giant anterior fontanel encephalocoele” is perhaps the third case reported in medical literature. As it is technically difficult for the mother to breastfeed these babies in their lap for long periods, along with the chance of CSF leak with meningitis, these babies should be operated as soon as possible. Counseling the parents about the fate of these babies with proper advice to take folic acid in their next periconceptional period is of paramount importance.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]