Basal encephalocele

Basal encephalocele is a rare congenital neural tube defect in which brain tissue and meninges herniate through a defect in the base of the skull (the skull base or basicranium). Unlike other encephaloceles that present as visible external masses, basal encephaloceles protrude internally, often into the nasal cavity, nasopharynx, or orbit, making them more difficult to detect at birth. They may also be referred to as transethmoidal, transsphenoidal, or sphenoethmoidal encephaloceles depending on the precise location of the bony defect. Because of their hidden location, basal encephaloceles can present with nasal obstruction, a nasal or nasopharyngeal mass, recurrent meningitis, cerebrospinal fluid (CSF) rhinorrhea, or visual disturbances. Some patients may also develop hormonal abnormalities if the pituitary gland or hypothalamus is involved in the herniation. The condition primarily affects the central nervous system and craniofacial structures. Clinical features can include hypertelorism (widely spaced eyes), broadened nasal bridge, midface abnormalities, and in some cases developmental delay or intellectual disability depending on the extent of brain tissue involvement. Diagnosis is typically made through neuroimaging, including CT and MRI, which can delineate the bony defect and the contents of the herniation. Basal encephaloceles must be carefully distinguished from nasal polyps or other intranasal masses to avoid inadvertent biopsy, which could lead to CSF leak or meningitis. Treatment is primarily surgical, involving repair of the skull base defect and repositioning or removal of herniated tissue. The surgical approach may be transcranial, transnasal (endoscopic), or transfacial depending on the size and location of the defect. Outcomes depend on the amount of brain tissue involved and the presence of associated anomalies. Early diagnosis and intervention are important to reduce the risk of complications such as meningitis and to optimize neurodevelopmental outcomes. Long-term follow-up is recommended to monitor for recurrence, CSF leaks, and any neurological or endocrine complications.

Common questions about Basal encephalocele