Interfrontal encephalocele: a rare feature of forehead in hydrocephalic myelomeningocele patients. Clinical feature, probable mechanisms, and management.

Objective: Myelomeningocele is a complex central nervous system malformation mostly associated with other neural and extraneural anomalies. A rare special feature of the forehead and skull was observed in myelomeningocele. Here, we present several patients with myelomeningocele, severe hydrocephalus, and interfrontal encephalocele accompanied by metopic suture widening and abnormally shaped frontal bones.

Methods: Five children with this feature were enrolled in this series. The age, sex, location of myelomeningocele sac, neurological deficits, hydrocephalus and history of shunt surgery, and follow-up period were evaluated.

Results: Patients were aged from 1 to 12 months (mean, 6 months). All patients were male. Most sacs were located in lumbar and lumbosacral areas. Neurological deficits varying from only sphincter problem to paraplegia were found in all patients. Hydrocephalus was found in all children that needed a shunt procedure. Asymptomatic Chiari malformation, interfrontal encephalocele, and corpus callosum agenesis were evident in five, five, and three patients, respectively.

Conclusion: Anterior fontanel anomalies known as interfrontal encephalocele associated with myelomeningocele have been reported before. The patients have an open metopic suture extending widely to the nasal radix producing hypertelorism accompanied by interfrontal herniation of frontal lobes. The associated hydrocephalus exaggerates the anomaly. Treatment of accompanying hydrocephalus is advised to decrease the severity of frontal lobe herniation. Some patients may need frontal bone reconstruction surgery to provide cosmetic correction at the place of the midline frontal bone defect.