A 3-month-old infant presents with progressive head enlargement (head circumference crossing centiles), bulging anterior fontanelle, and dilated scalp veins. Transillumination of the skull is positive. CT head shows massive dilation of all four ventricles. The MOST likely etiology of communicating hydrocephalus in this age group is:
- A Aqueductal stenosis
- B Post-hemorrhagic hydrocephalus from germinal matrix bleed ✓
- C Dandy-Walker malformation
- D Choroid plexus papilloma
Correct answer: B. Post-hemorrhagic hydrocephalus from germinal matrix bleed
Explanation
Post-hemorrhagic hydrocephalus following intraventricular hemorrhage (IVH) from germinal matrix bleeds is the most common cause of communicating hydrocephalus in preterm/young infants. Blood products obstruct the arachnoid granulations, impairing CSF reabsorption (communicating type). Aqueductal stenosis causes non-communicating (obstructive) hydrocephalus. Dandy-Walker involves fourth ventricle cystic malformation. All four ventricles being dilated suggests a communicating cause rather than obstruction.
Reference: Ghai Essential Pediatrics, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.