MRI of a 4-year-old child with rapidly progressive head enlargement shows periventricular rim of T2 hyperintensity with effaced sulci and dilated ventricles. This periventricular signal change represents:

• A Infarction of deep perforator territories from venous congestion
• B Transependymal migration of CSF into the periventricular white matter ✓
• C Demyelination from nutritional deficiency
• D Reactive gliosis secondary to prior infection

Explanation

In acute obstructive hydrocephalus, rising intraventricular pressure forces CSF across the ventricular ependymal lining into the surrounding white matter, producing interstitial edema that appears as periventricular T2 hyperintensity. This transependymal seepage explains why ventricular enlargement with sulcal effacement accompanies the signal change. Deep venous congestion, demyelination, and gliosis would not track the ventricular margins so uniformly nor resolve promptly after shunting.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

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Written and medically reviewed by the StethoPrep medical team.