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Letters to the Editor Indian Pediatrics 1999;36: 1182-1183 |
Anterior Encephalocele Mimicking Choanal Atresia |
| Anterior encephalocele is an infrequent congenital malformation of the central nervous system with a reported incidence of 1 in 35,000 live births(1). Transethmoidal encephaloceles (TEE), a subtype of basal anterior encephalo-cele, is the protrusion of a part of brain tissue through a bony defect in the cribriform plate into the anterosuperior nasal cavity. A 1800 g preterm (36 weeks) male was born to a third gravida mother by normal vaginal delivery. The baby cried immediately after birth and there was no perinatal asphyxia. Soon after birth the baby developed respiratory distress with mild cyanosis. Attempts to pass a nasogastric tube through the nose were un-successful. Esophageal atresia was ruled out by passing an oro-gastric tube. A provisional diagnosis of bilateral choanal atresia was made. Routine laboratory investigations were normal. The chest X-ray and X-ray naso-pharyngeal region lateral view did not show any abnormality. Ultrasound cranium was normal. A CT scan of the paranasal sinus region and skull showed a bony defect in the floor of anterior cranial fossa in the region of the cribriform plate with brain parenchyma extend-ing into the nasoethmoidal region (Fig.). These findings suggested the diagnosis of trans-ethmoidal encephalocele as the cause of nasal obstruction.
Fig. CT (Coronal View) showing bony defect in cribriform plate and protruding brain tissue (arrow). Basal anterior encephaloceles are sub-classified into four types depending on the site of the bony defect sphenoethmoidal, trans-ethmoidal, transphenoidal and spheno-orbital. Clinically, TEE can present with signs and symptoms of nasal obstruction, hyperteleorism, CSF leakage and recurrent meningitis(2). In the present case TEE presented as nasal obstruction mimicking choanal atresia, the common cause of nasal obstruction in newborns. The aware-ness of this lesion in differential diagnosis of choanal atresia is of practical importance because failure to recognize this lesion can lead to surgical misadventure. The advent of CT scanning and MRI has made the diagnosis simple. These scans help to delineate the extent and characteristics of the anomaly. The aim of surgery is to excise the encephalocele, repair the dural defect and correct the facial and orbital deformity(3). The ideal age for surgery is around 6-9 months. Early surgery leads to better cosmetic results and prevents CSF leak(1). Ramesh Kumar, References 1. Mahapatra AK. Anterior encephaloceles. Indian J Pediatr 1997; 64: 699-704. 2. Hayashi T, Utsanomiya H, Hashimoto T. Transethmoidal encephalocele. Surg Neurol 1985; 24: 651-655. 3. Mahapatra AK, Tandon PN, Dhawan IK, Khazanchi RK. Anterior encephaloceles. A report of 30 cases. Childs Nervs Syst 1994; 10: 501-504. |
