Nasal encephaloceles: A review of etiology, pathophysiology, clinical presentations, diagnosis, treatment, and complications

Introduction: Encephaloceles are considered by most to be a type of neural tube defect characterized by a herniation of the brain and meninges through structural weaknesses in the bony structures of the skull. Discussion: Many different types of encephaloceles have been classified according to the location of the bony defect. Basal and frontoethmoidal encephaloceles constitute a nasal subclass of encephaloceles, which are herniations from the skull base and ethmoid bone, respectively. Basal encephaloceles are usually occult and can herniate into nasal structures causing obstruction. Frontoethmoidal encephaloceles usually present as a protrusion that is visible at birth and enlarges during crying. Both of these entities are rare with an incidence ranging from 1 in 5,000 to 1 in 40,000 live births around the world with the majority of cases localized in Southeast Asia. Conclusion: Although cases have been recorded since the sixteenth century, there is still a scarcity of knowledge on the exact causes and factors associated with the development of the disease. Many studies have determined these to be caused by a combination of genetic and environmental factors. Most cases are nonlife threatening and the preferred method of treatment is surgical removal after diagnosis is confirmed with computerized tomography or magnetic resonance imaging. Prognosis is generally positive, especially in the subset of patients with frontoethmoidal encephaloceles.