Normal Pressure Hydrocephalus Studies
In collaboration with Mayo Clinic's Department of Neurosurgery, the Memory Disorders Laboratory established a database of over 400 cases with normal pressure hydrocephalus (NPH). Research based on this data shows that when the lumbar puncture pressure is much lower than the opening pressure on the shunt valve, over drainage complications such as subdural hematoma, hygroma and postural headache are more likely to occur. As a result, surgeons have started setting the valve opening at the lumbar puncture pressure, decreasing over drainage complications.
In collaboration with David S. Knopman, M.D., in the Atherosclerosis Risk in Communities (ARIC) study, Dr. Graff-Radford's lab found that systolic blood pressure and pulse pressure are associated with increase in ventricle size 10 years later.
Dr. Graff-Radford published a hypothesis as to why cerebrospinal fluid (CSF) biomarkers in NPH can be misleading. He found the Ab42 is low in NPH as in Alzheimer's disease, but it turns out most of the CSF proteins are low.
The Memory Disorders Lab collaborates with Ronald C. Petersen, M.D., Ph.D., and using data from the Mayo Clinic Study of Aging, the lab found that volumetric measures of the ventricle are strongly related cross-sectionally and longitudinally to measures of gait and cognition. Research also shows that certain features are associated with increased ventricle size, the strongest being a CSF dynamic abnormality, which is an extra ventricular marker of hydrocephalus.
The Memory Disorders Lab published autopsy findings of a person with the radiological features of extra ventricular hydrocephalus that was mistaken for degeneration-causing atrophy, but found to be due to NPH. Dr. Graff-Radford's lab also has an ongoing collection of DNA from people with NPH to facilitate a genetic study of this disorder.