A Rare Triad of Giant Occipital Encephalocele with Lipomyelomeningocele, Tetralogy of Fallot, and Situs Inversus

Anomalies of the Mesenchyme (Meninges and Skull)—Defects of Neural Tube Closure: Cephalocele and Other Calvarial and Skull Base Defects; Intracranial Lipomas; Arachnoid Cysts; Nonsyndromic and Syndromic Craniosynostoses

Within the embryonic head, a layer of mesenchyme envelops the brain beneath the surface ectoderm. This cranial mesenchyme is responsible for the formation of the meninges, the calvaria (upper portion of the skull), and the scalp's dermis. Irregular development of these structures, particularly the meninges and the calvaria, is associated with notable congenital defects in humans, such as defects in neural tube closure. Anencephaly is the most common neural tube defect (NTD) and one of the most severe malformations of the central nervous system; it consists in the complete or partial absence of the brain, associated with the absence of the bones of the cranial vault. Iniencephaly is an uncommon congenital NTD characterized by abnormalities in the occipital region, including rachischisis of the cervicothoracic spine and a fixed retroflexion deformity of the head. Unlike anencephaly, in iniencephaly, there is a skull cavity and a normal-looking skin that entirely covers the head and the medullary retroflex area. Cephaloceles are congenital abnormalities distinguished by the protrusion of meninges and/or brain tissue through a naturally occurring defect in the skull bone. This anomaly is typically covered by skin or mucous membrane. Intracranial lipoma is a relatively uncommon and generally benign tumor that occurs in an abnormal location within the brain; it probably represents a disturbance of the differentiation of the primordial meninges: for unknown causes, the meningeal mesenchyme can differentiate into adipose tissue. Arachnoid cysts are sacs filled with cerebrospinal fluid (CSF) situated between the brain or spinal cord and the arachnoid membrane. Typically, these cysts originate within CSF cisterns and gradually expand their boundaries. Craniosynostosis is the early fusion of one or more cranial sutures. It can occur spontaneously, be associated with a syndrome, or have a familial connection. It can involve one or multiple cranial sutures. Pfeiffer's, Crouzon's, and Apert's syndromes are among the more prevalent syndromic craniosynostoses.

The outcome of surgical management for the patient with giant occipital encephalocele: a case illustration and systematic review

PURPOSE

Occipital encephalocele (OE) is one of congenital malformation of the central nervous system. However, giant OE, mostly defines as bigger-than-head OE, is extremely rare and carries a worse prognosis. Here, we presented our systematic review of the management of the giant OE and illustrated our case.

METHOD

The systematic review was carried out under PRISMA guidelines. Publications were searched under "occipital encephalocele" from 1959 to April 2021. Our primary area of interest was the outcome of patients who have undergone surgery for giant OE. Variables of interest included age, sex, size of the sac, presentations, associated anomalies, management, outcome, and follow-up period were collected.

RESULT

We collected 35 articles, consisting of 74 cases (including 1 case from our illustrative case), to perform a systematic review. The mean age at the time of surgery was 3.53 ± 8.22 months. The mean circumference of the sac was 52.41 ± 18.6 cm. The three most common associated anomalies were microcephaly, corpus callosal agenesis/dysgenesis, and Chiari malformation. After the surgery, survival was reported in 64 (90.1%) patients. Postoperative complications were reported in 14 cases (16 events). Age above 1 month at the time of surgery was significantly associated with survival (p = 0.02) but not with complication (p = 0.22). In contrast, the type of surgery was not associated with survival (p = 0.18) or complications (p = 0.41).

CONCLUSION

Despite a rare condition with a poor prognosis, our reported case and systematic review revealed promising outcomes of surgery regardless of surgical strategies, especially in patients older than 1 month. Thus, appropriate planning is essential for the treatment of this condition.

Occipital Encephalocele: Cause, Incidence, Neuroimaging and Surgical Management

AIMS

To review and present the current knowledge of incidence, signs and symptoms, diagnosis and treatment of the occipital encephalocele.

BACKGROUND

Encephalocele (E) is a defect of the neural tube that refers to congenital malformations featured by skull defect and dura with extracranial spread of intracranial structures. Occipital encephalocele (OE) are the most common form of this congenital disorder and are manifested as a swelling of different sizes over the occipital bone in the midline. Proper diagnosis and treatment is highly important in the management of this congenital malformation of brain.

OBJECTIVE

To review and present the current knowledge of incidence, signs and symptoms, diagnosis and treatment of the occipital encephalocele.

METHODS

We conducted a search of case reports or case-series of patients by the use of electronic databases: Pub Med, Medline, Index Medicus, Scorpus. The key words were: encephalocele, occipital encephalocele, neural tube defect, congenital malformation. The search was updated to December 31, 2018. Papers published in English were the only source of information.

RESULTS

Occipital encephalocelle are more frequent in females than in males. The incidence is between 1 in 3000 to 1 in 10,000 live births; approximately 90% of them involve the midline. Magnetic resonance imaging is the method of choice in diagnosis and surgery is the best option for the treatment of OE. Overall morbidity and mortality is still high in spite of advenced surgical management, but have been significantly improved in recent years thanks to sophisticated highresolution imaging, adequate and proper surgical treatment and decent post-operative care.

CONCLUSION

Occipital encephalocele is the most common form of encephalocele. The diagnosis is mostly based by the use of neuroimaging techniques. Operation is the best option for treatment. Overall morbidity and mortality is still high, but have been significantly improved in recent years thanks to sophisticated high-resolution imaging, adequate and proper surgical treatment and decent post-operative care.