1. 13 month old female Jason Dowling Radiology Elective April 21, 2005

2. Presentation n 13 month old female with no significant PMH n HPI: Pt presents with 2-3wk h/o increased head circumference, fussiness, lethargy, and refusal to stand. PMI: NSVD without hydrocephalous at birth, otitis media, RSV infection n FH: brittle bone disease n Labs: CBC and BMP normal n Work-up: CT at outside hospital showed non-communicating hydrocephalous involving lateral and 3rd ventricle.

3. Radiology - axial T2

4. Radiology - sagital T1 n Findings: dilatation of the lateral and third ventricles with periventricular fluid –normal fourth ventricle –distal aqueduct stenosis

5. Hospital Course n Pt received a endoscopic third ventricular ventriculostomy n MRI showed marked decrease in ventricular size post-op

7. Aqueduct of Sylvius Stenosis n Most common cause of hydrocephalus (20% of cases) n Incidence: 0.5-1.0 per 1000 births n Can be congenital or acquired following inflammatory or neoplastic event n X-linked recessive form (rare) n Associated with spina bifida

8. Radiographic findings n Marked enlargement of the lateral ventricles, with interstitial edema n Outpouching of the suprasellar recesses of the third ventricle n “Ventricularization” of the proximal aqueduct just above the level of obstruction n Normal size and configuration of the fourth ventricle Differntial Diagnosis n Congenital malformation n Post-infectious n Post-hemorrhage n Tumors n Other causes of hydrocephalus: communicating hydrocephalus, malformations (Chiari type II, Dandy-Walker, Vein of Galen)

9. References n Behrman: Nelson Textbook of Pediatrics. 17th ed. Elsevier: 2004. Pg 1990. n Grainger & Allison's Diagnostic Radiology: A Textbook of Medical Imaging, 4th ed. 2001 Churchill Livingstone, Inc. pg 2403. Nard, JA. Abnormal head size and shape. In: Gartner, JC, Zitelli, BJ. Common Chronic Symptoms in Pediatrics, Mosby, St. Louis, 1997.