The management of normal pressure hydrocephalus (NPH) is challenging due to diagnostic uncertainties and high treatment risks. To date, there are no evidence-based treatment guidelines for this disorder. Our long-term goal is to improve the outcome of NPH by lowering complications related to shunt valves and by increasing our understanding of how different shunt designs influence cerebrospinal fluid (CSF) hydrodynamics. This investigation uses a three-tiered shared-subject study design.
The Specific Aims are to 1) determine which of two adjustable valve designs, one with a siphon control device and one without, is superior for the treatment of NPH with regard to lowering the complication rate, 2) compare the intracranial pressure (ICP) physiological response of a standard differential pressure valve, with and without a siphon control device, in the treatment of NPH, and 3) determine whether intracranial hemo/hydrodynamic variables, measured before and after a shunt operation, support the tuned-dynamic absorber model, of intracranial pressure dynamics. We hypothesize that siphon control devices increase the incidence of shunt under-drainage, manifesting as a lack of both neurological improvement and ventricular size reduction. Furthermore, we hypothesize that current hydrocephalus models are over- simplistic and that shunt-induced hydrodynamics are better modeled based on ICP waveform characteristics and the application of novel dynamic models. All of the studies will be performed as part of a prospective, randomized clinical trial assessing two existing, FDA-approved, adjustable valves. The outcome analysis will be useful for clinicians wishing to apply evidence-based guidelines in the management of NPH. From a viewpoint of better understanding the ICP physiology of CSF shunts, the comprehensive hydrodynamic studies will provide valuable information that will be useful in selecting the optimal valve pressure or type for individual patients. In addition, we foresee the information being used by shunt valve manufacturers to improve current valve designs. Documenting definitive evidence of the tuned-dynamic absorber model could have fundamental implications to all ICP disorders.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS054881-04
Application #
7761319
Study Section
Clinical Neuroscience and Disease Study Section (CND)
Program Officer
Morris, Jill A
Project Start
2007-02-15
Project End
2012-01-31
Budget Start
2010-02-01
Budget End
2012-01-31
Support Year
4
Fiscal Year
2010
Total Cost
$334,590
Indirect Cost
Name
University of California Los Angeles
Department
Neurosurgery
Type
Schools of Medicine
DUNS #
092530369
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Xu, Peng; Hu, Xiao; Yao, Dezhong (2013) Improved wavelet entropy calculation with window functions and its preliminary application to study intracranial pressure. Comput Biol Med 43:425-33
Kasprowicz, Magdalena; Bergsneider, Marvin; Czosnyka, Marek et al. (2012) Association between ICP pulse waveform morphology and ICP B waves. Acta Neurochir Suppl 114:29-34
Hamilton, Robert B; Baldwin, Kevin; Vespa, Paul et al. (2012) Subpeak regional analysis of intracranial pressure waveform morphology based on cerebrospinal fluid hydrodynamics in the cerebral aqueduct and prepontine cistern. Conf Proc IEEE Eng Med Biol Soc 2012:3935-8
Hu, Xiao; Hamilton, Robert; Baldwin, Kevin et al. (2012) Automated extraction of decision rules for predicting lumbar drain outcome by analyzing overnight intracranial pressure. Acta Neurochir Suppl 114:207-12
Hamilton, Robert; Baldwin, Kevin; Fuller, Jennifer et al. (2012) Intracranial pressure pulse waveform correlates with aqueductal cerebrospinal fluid stroke volume. J Appl Physiol 113:1560-6
Scalzo, Fabien; Bergsneider, Marvin; Vespa, Paul M et al. (2012) Intracranial pressure signal morphology: real-time tracking. IEEE Pulse 3:49-52
Asgari, Shadnaz; Bergsneider, Marvin; Hamilton, Robert et al. (2011) Consistent changes in intracranial pressure waveform morphology induced by acute hypercapnic cerebral vasodilatation. Neurocrit Care 15:55-62
Kim, Sunghan; Bergsneider, Marvin; Hu, Xiao (2011) A systematic study of linear dynamic modeling of intracranial pressure dynamics. Physiol Meas 32:319-36
Asgari, Shadnaz; Subudhi, Andrew W; Roach, Robert C et al. (2011) An extended model of intracranial latency facilitates non-invasive detection of cerebrovascular changes. J Neurosci Methods 197:171-9
Kim, Sunghan; Hu, Xiao; McArthur, David et al. (2011) Inter-subject correlation exists between morphological metrics of cerebral blood flow velocity and intracranial pressure pulses. Neurocrit Care 14:229-37

Showing the most recent 10 out of 29 publications