Parietal Encephalocele in a Two-Year-Old Child: Clinical Presentation and Management

The image depicts a two-year-old child with a parietal encephalocele, visible as a prominent protrusion from the superior aspect of the skull. Encephalocele is a rare congenital neural tube defect characterized by the herniation of brain tissue and meninges through a defect in the cranium. This case is notable as most encephaloceles are surgically addressed in early infancy, but this child appears to have reached two years of age with the condition still present. The sac appears well-vascularized with a reddish, taut appearance, suggesting active blood supply to the herniated tissues. This condition requires comprehensive neurosurgical evaluation and intervention to prevent further complications and optimize developmental outcomes.

The image does not contain specific labels, but clearly shows a child with a substantial parietal encephalocele on the top of the head, with the child’s face partially visible in profile.

Understanding Encephalocele: Types and Epidemiology

Encephalocele is a severe neural tube defect that occurs in approximately 1 in 5,000 to 12,000 live births worldwide. The incidence varies significantly by geographical region and genetic background. This condition results from failure of the neural tube to close properly during early embryonic development, specifically during the fourth week of gestation.

The persistence of encephalocele to the age of two years, as shown in this image, is relatively uncommon in developed healthcare settings as surgical intervention is typically performed in early infancy. This case highlights the importance of access to specialized neurosurgical care and the challenges in management of complex congenital neurological conditions in resource-limited settings.

Classification by Anatomical Location

Encephaloceles are classified according to their anatomical location on the skull, with each type presenting distinct clinical challenges and surgical considerations. Understanding the specific location is crucial for appropriate surgical planning.

Major classifications include:

• Occipital encephalocele: Most common in Western populations (75%), occurring at the back of the skull through the occipital bone
• Frontoethmoidal encephalocele: More common in Southeast Asian populations, protruding through the frontal and ethmoidal bones
• Basal encephalocele: Occurring through the base of the skull, often not visible externally
• Parietal encephalocele: As seen in this image, occurring through the parietal bones at the top of the skull; these are relatively rare, accounting for only 10-20% of all encephaloceles

The image clearly depicts a parietal encephalocele, which presents unique challenges due to its location at the vertex of the skull and potential involvement of critical venous structures, particularly the superior sagittal sinus.

Pathophysiology and Embryological Basis

Encephalocele represents a failure in the process of primary neurulation during embryonic development. Neural tube formation and closure is a complex process that occurs between days 18 and 28 post-conception, proceeding in a zipper-like fashion from the future cervical region both rostrally and caudally.

The pathogenesis involves multiple factors:

• Genetic predisposition: Mutations in genes involved in neural tube closure and folate metabolism
• Environmental factors: Maternal folate deficiency, hyperthermia, certain medications (anticonvulsants), and maternal diabetes
• Mechanical factors: Abnormal cranial development and abnormal adhesion between neural ectoderm and surface ectoderm

At the molecular level, disruption of signaling pathways involving sonic hedgehog (SHH), bone morphogenetic proteins (BMPs), and WNT proteins have been implicated in the development of neural tube defects including encephalocele.

Content of Encephalocele Sac

The contents of an encephalocele sac can vary significantly and directly impact surgical approach and prognosis:

• Meningocele: Contains only meninges and cerebrospinal fluid, with no brain tissue
• Meningoencephalocele: Contains meninges, cerebrospinal fluid, and brain tissue
• Meningoencephalocystocele: Contains meninges, brain tissue, and part of the ventricular system

Based on the image, this appears to be a substantial parietal encephalocele, likely containing both neural tissue and meninges, though definitive determination would require neuroimaging studies such as MRI.

Clinical Evaluation and Diagnostic Approach

When evaluating a child with encephalocele, as in this case of a two-year-old with a parietal defect, comprehensive assessment is essential to guide management decisions and predict outcomes.

Physical Examination

The physical examination should include:

• Assessment of the encephalocele sac: Size, location, skin coverage, signs of inflammation or rupture
• Neurological examination: Developmental milestones, cranial nerve function, motor and sensory function
• Evaluation for associated anomalies: Particular attention to craniofacial, cardiac, and genitourinary systems
• Head circumference measurement: Assessing for microcephaly or macrocephaly (associated with hydrocephalus)

In the image, the encephalocele appears to have intact skin coverage but shows significant vascularity and prominence, suggesting considerable volume and potential neural tissue involvement.

Neuroimaging Studies

Neuroimaging is essential for characterizing the defect and planning surgical intervention:

• Magnetic Resonance Imaging (MRI): Gold standard for assessing neural tissue involvement, ventricular system, and associated brain anomalies
• Computed Tomography (CT): With 3D reconstruction to delineate the bony defect for surgical planning
• MR venography: Particularly important for parietal encephaloceles to evaluate the relationship to major venous sinuses
• Functional MRI: In older children, may help determine if eloquent cortex is contained within the sac

Associated Anomalies and Syndromes

Encephaloceles can occur as isolated defects or as part of genetic syndromes. Common associations include:

• Meckel-Gruber syndrome: Occipital encephalocele, polydactyly, and polycystic kidneys
• Walker-Warburg syndrome: Encephalocele with lissencephaly and ocular abnormalities
• Knobloch syndrome: Occipital encephalocele with retinal degeneration
• Amniotic band syndrome: Encephalocele due to disruption by amniotic bands

Surgical Management Considerations

The surgical management of encephalocele, particularly in a child who has reached the age of two years as shown in the image, presents unique challenges. Ideally, repair is performed in early infancy to minimize developmental impact and reduce complications.

Preoperative Considerations

Before surgical intervention in a case like this, several key considerations must be addressed:

• Neuroimaging: Detailed mapping of the sac contents and relationship to critical structures
• Venous drainage patterns: Especially important in parietal encephaloceles due to potential involvement of the superior sagittal sinus
• Presence of hydrocephalus: May require simultaneous or staged CSF diversion procedures
• Anesthetic considerations: Including positioning challenges and blood loss management
• Nutritional optimization: Ensuring adequate nutritional status to support wound healing

Surgical Approach

The surgical management aims to:

1. Remove non-functional neural tissue while preserving viable tissue
2. Achieve watertight dural closure
3. Reconstruct the bony defect
4. Provide adequate soft tissue coverage

For parietal encephaloceles as shown in this image, the surgical approach typically involves:

• Careful circumferential dissection of the sac from surrounding tissues
• Opening of the sac with preservation of any viable neural tissue
• Identification and management of associated venous structures
• Watertight dural closure, often requiring duraplasty with autologous or synthetic materials
• Cranioplasty to repair the bony defect, which may involve autologous bone grafts or synthetic materials
• Scalp reconstruction, which may require local flaps or tissue expansion in cases with significant skin deficiency

Postoperative Care and Complications

Following surgical repair, meticulous postoperative care is essential:

• Neurological monitoring: For signs of increased intracranial pressure or new deficits
• Wound care: To prevent infection and CSF leak
• Positioning: To avoid pressure on the surgical site
• Management of hydrocephalus: If present, may require permanent CSF diversion with a ventriculoperitoneal shunt
• Early rehabilitation: To address any developmental delays

Common complications following repair include:

• Cerebrospinal fluid leak
• Wound dehiscence
• Meningitis
• Progressive hydrocephalus
• Seizures
• Sunken flap syndrome if a large volume was contained in the sac

Developmental Outcomes and Prognosis

The long-term prognosis for children with encephalocele varies significantly based on several factors. For a child who has reached two years of age with an untreated parietal encephalocele, careful assessment of current developmental status is crucial for predicting post-surgical outcomes.

Prognostic Factors

Key factors affecting long-term outcomes include:

• Location and size: Parietal encephaloceles generally have intermediate prognosis between frontal (better) and occipital (worse) locations
• Neural tissue involvement: The amount of functional brain tissue in the sac significantly impacts neurological outcomes
• Microcephaly: Often associated with poor neurodevelopmental outcomes
• Hydrocephalus: Present in approximately 40% of cases, may impact cognitive development
• Associated brain anomalies: Particularly corpus callosum dysgenesis, cortical dysplasia, or cerebellar abnormalities
• Age at repair: Earlier repair generally associated with better outcomes, though the optimal timing remains controversial

Neurodevelopmental Outcomes

The spectrum of developmental outcomes is broad:

• 30-50% of children with encephalocele develop normal or near-normal intelligence
• Motor deficits are common, particularly with significant brain tissue involvement
• Visual impairment occurs in 25-50% of cases
• Seizure disorders develop in approximately 30% of patients
• Speech and language delays are common, requiring targeted intervention

For a child with a persistent encephalocele at age two, comprehensive developmental assessment and early intervention services are essential to maximize functional outcomes.

Recent Advances and Future Directions

Management of encephalocele continues to evolve with technological advances improving outcomes:

• Advanced neuroimaging: Functional MRI and tractography allow better delineation of eloquent tissue
• Minimally invasive approaches: Endoscopic techniques for selected cases
• 3D modeling and virtual surgical planning: Allowing customized approaches to complex defects
• Novel biomaterials: For dural and cranial reconstruction
• Neural stem cell research: Potential future applications for neural tissue regeneration

The multidisciplinary approach remains the cornerstone of effective management for these complex cases, with coordination between neurosurgery, plastic surgery, neurology, developmental pediatrics, and rehabilitation medicine.

1. Parietal Encephalocele in a Two-Year-Old: Clinical Presentation and Surgical Management
2. Late-Presenting Encephalocele: Diagnostic Evaluation and Treatment Options in Older Children
3. Congenital Cranial Herniation: A Comprehensive Review of Parietal Encephalocele Management
4. Pediatric Encephalocele Beyond Infancy: Surgical Challenges and Developmental Considerations
5. Persistent Cranial Defects: Managing Untreated Encephalocele in Toddlers