New Technique Non-invasively Measures Intracranial Pressure in Brain Disorder

A new advanced magnetic resonance imaging technique developed at the University of Illinois at Chicago for the diagnosis and treatment of neurological problems, such as Chiari malformations, hydrocephalus and brain injury, will be evaluated for clinical use through a $1.4 million National Institutes of Health Bioengineering Research Partnership grant.

The project, which draws on bioengineering, radiology and neurosurgery, will determine the clinical potential of a non-invasive measurement of intracranial pressure to the diagnosis and treatment of patients with Chiari malformation.

The new technique relies on a novel algorithm that determines "intracranial compliance" from the change in fluid volume and pressure occurring with each heartbeat as blood and cerebral spinal fluid flow in and out of the cranium. Intracranial compliance is the ability of the intracranial compartment to accommodate an increase in volume without a large increase in pressure.

"We believe that in Chiari malformation both the severity of symptoms and the likely success of surgery are related to intracranial compliance," said Noam Alperin, UIC associate professor of medical physics and head of the MRI research laboratory. "This new method gives us a non-invasive way to study a relatively common and poorly understood neurological problem."

Chiari malformation is a condition where lower parts of the brain, the brainstem and the cerebellum, protrude downward into the spinal column. In the past, it was estimated that the condition occurs in about seven in every 1,000 births, but the increased use of diagnostic imaging has shown that it may be much more common. It can also occur later in life.

Chiari malformation can cause a wide range of symptoms, including severe headache, poor balance, dizziness, muscle weakness, numbness, and vision problems. In its most severe aspect, Chiari malformation can result in permanent neurological damage, including paralysis. Although medications can relieve pain, surgery is the only treatment currently available, and doctors have not been able to predict who will benefit, said Alperin, who is principal investigator on the project. One of the goals of the study, he said, is to improve prediction of whether surgical treatment will alleviate symptoms.

The non-invasive measurement may be useful in a range of neurological disorders, including hydrocephalus, brain injury, hemorrhages, stroke and brain tumors, Alperin said.

Swelling, which is a common response to all injury, can be fatal in brain injury, because in the restricted cranial space it increases pressure and reduces blood perfusion, Alperin said. "This technique will give us a better understanding of an individual's ability to tolerate swelling or any other space occupying processes."

Alperin's collaborators on the project include Terry Lichtor and Robert Glick of Rush University and the John H. Stroger, Jr. Hospital of Cook County; Doris Lin and Jon Weingart of Johns Hopkins University; and Masoud Hemmati, professor and head of radiology at UIC. Frank Loth, associate professor of mechanical and industrial engineering at UIC, was co-principal investigator on a completed NIH-funded project and contributed to the development of the method.

CONTACT: Jeanne Galatzer-Levy, (312) 996-1583, jgala@uic.edu