Cisterna magna clot and subsequent post-hemorrhagic hydrocephalus

Background. Posthemorrhagic hydrocephalus (PHH) is an ominous complication of intraventricular hemorrhage (IVH) in premature infants. Previous studies have correlated lateral intraventricular clot with subsequent PHH, but the re are no studies assessing the outcome of clot in the cisterna magna (CM). Objective. The purpose of this study was to determine if the identification of clot in the CM on the initial positive cranial ultrasound for intravent ricular hemorrhage increased the risk of subsequent PHH. Materials and methods. A review of ultrasound records over a 4-year period identified 41 neonates with at least grade 2 IVH who had specific CM views prospectively performed. Results. Thirty-six survived more than 3 months. Overall, 22 (61%) develope d hydrocephalus. On the initial positive cranial ultrasound, CM blood was i dentified in 21 (58%). Of these 18 (86%) developed hydrocephalus [odds rati o (OR) 16.5, confidence interval (CI) 2.5-125.7, P < 0.001] and 14 (67%) re quired intervention or remained dilated (OR 28.0, CI 2.8-1265.8). All patie nts that required permanent shunt placement had initial CM clot (P < 0.01). Initial ventriculomegaly was not a significant predictor of subsequent hyd rocephalus, but a dilated third ventricle (greater than or equal to 8 mm) w as (OR 9.0, CI 1.2-103.3, P < 0.04). Asymmetric intraventricular clot filli ng of more than 50% was not predictive of hydrocephalus, but symmetric clot of more than 50% was (OR 10.8, CI 1.4-61.6, P < 0.01). Nine neonates had c oncomitant parenchymal damage with varying outcomes (three shunted, two per sistent ventriculomegaly, four resolved with normal sized ventricles). Conclusion. In this study CM clot significantly increased the risk and was a better predictor of posthemorrhagic hydrocephalus than initial hydrocepha lus.