Nasal encephalocoeles are in most cases a form of neural tube defect particularly common in Southeast asia. They are are herniation of cranial content through a bony defect in the anterior skull base into the nasal area.
Nasal encephaloceles usually present at birth with symptoms of obstruction or other complications. It presents as an external swelling on the nose. The swelling is usually soft, with normal overlying skin, and increases in size on coughing/straining. Symptomatic patients usually present with obstruction or rhinorrhea.
Nasal encephalocoeles are typically identified in association with a discernible cranial bone defect.
Nasal encephalocoeles are anterior encephalocoeles where meningeal herniation occurs through a midline defect in the floor of the anterior cranial fossa.
CT is good for delineating bony abnormalities but not for detecting an intracranial component.
MRI is better for delineating soft tissue details, including any intracranial connection. It also minimises the level of exposure to ionising radiation
Treatment and prognosis
When a midline nasal swelling is present, no invasive procedures nor operations are performed until an intracranial connection has been excluded using CT scanning or MRI, due to the risk of meningitis or cerebrospinal fluid leakage.
General imaging differential considerations include other midline nasal region lesions:
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