Pediatric Neurosurgery
What you must own
Understand the common congenital and acquired conditions. Hydrocephalus: causes (obstructive versus communicating), presentation by age (bulging fontanelle, sunset eyes, macrocephaly in infants; headache, vomiting, papilloedema in older children), and treatment (shunt versus endoscopic third ventriculostomy).
Neural tube defects: myelomeningocele (antenatal folate reduces risk), Chiari malformations (type I versus type II with myelomeningocele), and tethered cord. Understand the difference between Chiari I (asymptomatic or syrinx) and Chiari II (associated with myelomeningocele and hydrocephalus).
Paediatric tumours: medulloblastoma (posterior fossa, midline, drop metastases), pilocytic astrocytoma (cyst with mural nodule), ependymoma (fourth ventricle, floor), craniopharyngioma (suprasellar, calcified).
Trauma: non-accidental injury patterns and growing skull fracture. Know the differences between paediatric and adult brain (higher water content, thinner skull, open sutures).
Traps
Questions test Chiari I versus II, and whether a posterior fossa mass is midline (medulloblastoma) or eccentric (pilocytic astrocytoma). Another trap: assuming a shunt malfunction presents with headache only - in infants it may present with irritability and vomiting.
Rule of thumb
Posterior fossa tumour in a child: midline + drop metastases = medulloblastoma; cyst with mural nodule = pilocytic astrocytoma; fourth ventricle floor = ependymoma.
Worked example
A child with a midline cerebellar mass and hydrocephalus: medulloblastoma is most likely, and staging of the neuraxis is required because of the risk of drop metastases.