Normal-Pressure Hydrocephalus Studies

In collaboration with Mayo Clinic's Department of Neurosurgery, the Memory Disorders Laboratory established a database of over 400 people with normal-pressure hydrocephalus. Research based on this data shows that when the lumbar puncture pressure is much lower than the opening pressure on the shunt valve, overdrainage 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 overdrainage complications.

In collaboration with David S. Knopman, M.D., in the Atherosclerosis Risk in Communities (ARIC) Study, the Memory Disorders Lab found that systolic blood pressure and pulse pressure are associated with an increase in ventricle size 10 years later.

Dr. Graff-Radford published a hypothesis as to why cerebrospinal fluid biomarkers in normal-pressure hydrocephalus can be misleading. He found that Ab42 is low in normal-pressure hydrocephalus as in Alzheimer's disease, but it turns out most of the cerebrospinal fluid proteins are low.

The Memory Disorders Lab collaborates with Ronald C. Petersen, M.D., Ph.D. 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 feature is a cerebrospinal 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 extraventricular hydrocephalus that was mistaken for degeneration-causing atrophy but was found to be due to normal-pressure hydrocephalus. Dr. Graff-Radford's lab also has an ongoing collection of DNA from people with normal-pressure hydrocephalus to facilitate a genetic study of this condition.

We are identifying people with normal-pressure hydrocephalus, with the subset of people with large heads, indicating congenital factors. We also have studied the CWH43 gene that accounts for 16% of people with normal-pressure hydrocephalus. The results of this study were published in Neurology Genetics in 2023.

Related publications