Ventricle wall movements and cerebrospinal fluid flow in XXXX .

@entity1 @entity67 @entity2841 @entity1276
OBJECT: The dynamics of fluid flow in normal pressure @entity1276 (NPH) are poorly understood. Normally, @entity2841 flows out of the brain through the ventricles. However, @entity67 during NPH may be caused by @entity2841 backflow into the brain through the ventricles. A previous study showed this reversal of flow; in the present study, the authors provide additional clinical data obtained in @entity1 with NPH and supplement these data with computer simulations to better understand the @entity2841 flow and ventricular wall displacement and emphasize its clinical implications. METHODS: Three NPH @entity1 and 1 @entity1 with @entity1276 underwent cine phase-contrast MR imaging (cine MR imaging) for measurement of @entity2841 flow and ventricle wall movement during the cardiac cycle. These data were compared to data previously obtained in 8 healthy volunteers. The @entity2841 flow measurements were obtained at the outlet of the aqueduct of Sylvius. Calculation of the ventricular wall movement was determined from the complete set of cine MR images obtained axially at the middle of the lateral ventricle. The data were obtained before and after @entity2841 removal with a ventriculoperitoneal shunt with an adjustable valve. To supplement the clinical data, a computational model was used to predict the transmural pressure and flow. RESULTS: In healthy volunteers, net @entity2841 aqueductal flow was 1.2 ml/minute in the craniocaudal direction. In @entity1 with NPH, the net @entity2841 flow was in the opposite direction--the caudocranial direction--before shunt placement. After shunting, the magnitude of the abnormal fluid flow decreased or reversed, with the flow resembling the normal flow patterns observed in healthy volunteers. CONCLUSIONS: The authors' MR imaging-based measurements of the @entity2841 flow direction and lateral ventricle volume size change and the results of computer modeling of fluid dynamics lead them to conclude that the directional pattern and magnitude of @entity2841 flow in @entity1 with NPH may be an indication of the disease state. This has practical implications for shunt design and understanding the mechanisms that produce @entity1276 .
