Encephalocele

Classification

System based on Suwanwela and Suwanwela

• Occipital: Often involves vascular structures.
• Cranial vault: Accounts for approximately 80% of encephaloceles in the Western hemisphere. Subtypes include:
  • Interfrontal
  • Anterior fontanelle
  • Interparietal: Often involves vascular structures.
  • Temporal
  • Posterior fontanelle
• Fronto-ethmoidal (Sincipital): Represents 15% of encephaloceles. External opening into the face can occur in three regions:
  • Nasofrontal: External defect in the nasion.
  • Naso-ethmoidal: Defect between nasal bone and nasal cartilage.
  • Naso-orbital: Defect in the antero-inferior portion of the medial orbital wall.
• Basal: Represents 1.5% of encephaloceles. Subtypes include:
  • Transethmoidal: Protrudes into the nasal cavity through a defect in the cribriform plate.
  • Spheno-ethmoidal: Protrudes into the posterior nasal cavity.
  • Transsphenoidal: Protrudes into the sphenoid sinus or nasopharynx through the patent craniopharyngeal canal (foramen cecum).
  • Fronto-sphenoidal or spheno-orbital: Protrudes into the orbit through the superior orbital fissure.
• Posterior fossa: Typically contains cerebellar tissue and a ventricular component.