[A case of transethmoidal encephalocele]

A case of a 3-year-old boy with transethmoidal encephalocele is presented. The patient was found to have bacterial meningitis, which responded well to an intravenous antibiotics therapy. No physical anomaly was evident on examination but plain skull X-ray film showed cloudiness of the left nasal antrum. Coronal CT scan disclosed a defect in the left cribriform plate and soft tissue mass in the left nasal cavity. MRI showed an anterior basal encephalocele protruding into the nasal cavity. Hypothalamic-pituitary system and the optic nerves appeared normal in the sagittal image. CSF rhinorrhea was confirmed by RI cisternography. An operation was performed transcranially. After a left frontal craniotomy, a unilateral bony defect in the cribriform plate and protrusion of the brain was observed subfrontally. The crista galli was intact. The herniated brain substance was transected and partially removed and the bony defect plugged by temporal muscle and covered by lyofirized dura. Microscopic examination of the herniated brain mass revealed gliosis and capillary proliferation. The patient recovered well and there has been no recurrence of CSF rhinorrhea or meningitis. Basal encephalocele is a very rare congenital anomaly. It is reported to constitute 1 to 10% of all encephaloceles. Incidence is estimated as 1 in every 35,000 to 40,000 live births. The anomaly is classified into two subtypes; transethmoidal (TE) and transsphenoidal (TS).(ABSTRACT TRUNCATED AT 250 WORDS)