In 1855, the Finnish physician Karl Benedikt Mesterton described a congenital malformation characterized by the herniation of the meninges and cerebral tissue through a defect in the anterior cranium. He classified this pathological entity, now known as fronto-ethmoidal meningo-encephaloceles (MEC) into three types according to its location: nasofrontal, nasoethmoidal and naso-orbital.

In1854 Spring wrote an excellent monograph on the subject, which was probably the first major work about this condition. He made a distinction between a Meningocele and Cerebral hernia.

Globally, neural tube defects are among the top five most serious birth defects. Approximately 300,000 new cases of neural tube defects occur annually.

The neural tube develops into the brain and the spinal cord of the embryo. These defects result from failure of the neural tube to close during the third and fourth weeks of gestational age.

The most common forms of neural tube defects include Anencephaly, Spina bifida, and Encephalocele. These are the congenital anomalies of the Central Nervous System.

Encephalocoele-overview

Hydrocephalus is a common complication of both Spina bifida and Encephalocele.

The incidence of Encephalocoele is 1/35000 live births. The diagnosis is evident at birth. The predominant type is the Frontoethmoid type encephalocoele, followed by Transethmoidal nasopharyngeal type and Orbital encephaloceles.

Frontoethmoidal type is associated with hypertelorism which might affect vision if not operated before visual fixation develops. Nasal obstruction is common in nasopharyngeal type.

The causative mechanism of neural tube defects remains poorly understood though genetic factors, nutritional factors, environmental factors, or a combination of these, are known to play a role in its development. Collaborate evidence of nutritional factor comes from research studies which have documented that Folic acid can reduce the risk of neural tube defects by 50-70% if taken before conception.

The effectiveness of folic acid fortification of staples foods in the prevention of neural tube defects has been well documented in the United States, Canada, Costa Rica and Chile, where folic acid fortification of staples has been implemented since 1998.

Encephalocoele-diagnosis-img1

Encephalocoele-diagnosis-img2 Imaging using Computed Tomography and Magnetic Resonance helps in delineating the exact site of herniation of the Encephalocoele, the contents of the sac and the presence of hydrocephalus. The immediate anatomical relationship to the venous sinuses and skull base may be important consideration during surgery.

Needless to say, all Encephaloceles need surgery. Meticulous planning is necessary for surgery, depending on the type and size of Encephalocele and associated Hydrocephalus.

Encephalocoele-treatment

By and large, emergency operation is avoided unless there is leaking encephalocele, where it is a must to prevent meningitis.