CINCINNATI—A University of Cincinnati (UC) researcher has won a prestigious award for new investigators from the American Stroke Association (ASA) for his study of the location of intracranial aneurysms within families.
Jason Mackey, MD, a second-year stroke fellow in the department of neurology and a member of the UC Neuroscience Institute, won the Mordecai Y.T. Globus New Investigator Award for the study, "Familial Intracranial Aneurysms: Is Anatomic Vulnerability Heritable?” He will receive the award and present his study at the ASA’s International Stroke Conference (ISC) 2011 in Los Angeles Thursday, Feb. 10.
Intracranial aneurysms are "blisters” which form within the arteries of the brain. A rupture of an aneurysm may lead to subarachnoid hemorrhage, which occurs in about 30,000 people annually in the United States with 35 percent dying within the first 30 days. Most of the deaths from subarachnoid hemorrhage are due to rapid and massive brain injury from the initial bleeding, so prevention of aneurysm formation is important.
Identification of susceptible genes in the formation and rupture of intracranial aneurysms would help researchers understand how aneurysms develop and could lead to the development of improved screening, diagnosis and prevention.
Mackey and colleagues at UC analyzed data from the Familial Intracranial Aneurysm (FIA) study, a collaborative research effort of investigators throughout the United States, Canada, Australia and New Zealand. Sponsored by the National Institutes of Health (NIH), the study is examining genetic and other environmental risk factors for intracranial aneurysm. Families in the study have at least three affected members or one affected sibling pair. Joseph Broderick, MD, Albert Barnes Voorheis Chair of Neurology at UC, is principal investigator of the FIA study.
Seeking to test the hypothesis that anatomic vulnerability in families might be inherited, Mackey and colleagues examined 324 families for the study. They then evaluated the four major arterial territories in the brain—internal carotid, middle cerebral, anterior cerebral and vertebrobasilar—by comparing FIA location within families and between randomly selected families.
Concordance (presence of the same trait) was greater within families than between families in the internal carotid distribution (56 percent vs. 47 percent)) and the vertebrobasilar distribution (26 percent vs. 12 percent). The overall concordance was 53.1 percent within families and 43.1 percent between families.
"As we suspected, genetics plays a role in where your aneurysm might develop if you have a family history of intracranial aneurysm,” says Mackey, adding that future studies of aneurysm genetics should consider breaking out results by location.
In a second oral presentation at ISC 2011, Mackey will present another study of familial aneurysms and aneurysm location. In that study, he and colleagues compared FIA families with subjects from the International Study of Unruptured Intracranial Aneurysms (ISUIA). ISUIA subjects with a family history of aneurysms were excluded, effectively allowing a comparison of subjects with a strong familial predisposition to IA to be compared with subjects without a family history of IA.
Mackey and his colleagues found that the subjects with a strong familial disposition were more likely to have multiple aneurysms and an aneurysm in the middle cerebral territory than subjects without a family history of IA.
"These findings underline the importance of ongoing investigations into the underlying mechanism of aneurysm formation,” Mackey says.