Skin Test May Detect Subarachnoid Hemorrhage Risk

A skin test can detect a tissue disorder that may increase the risk of intracranial aneurysm, which can lead to stroke, according to a pilot study published in the September issue of Stroke: Journal of the American Heart Association.

Researchers found defects in the structural matrix of skin tissue in 33 percent of study patients with intracranial aneurysms. Aneurysms are weakened sections of blood vessels that balloon out from the artery wall. When they rupture, they can cause a type of stroke known as subarachnoid hemorrhage -- bleeding in the brain.

"Our findings suggest that people with multiple aneurysms have a predisposing connective tissue disorder, leading to a weakness of the artery wall," says Caspar Grond-Ginsbach Ph.D. "This disorder can be diagnosed by a skin test."

Grond-Ginsbach, a geneticist and Holger Schnippering, M.D., a neurosurgeon, both at the University of Heidelberg in Germany, are lead authors of the report.

About 3 percent to 6 percent of adults age 30 and older have unruptured aneurysms and about 20 percent of them have multiple artery weaknesses, they say. Genes play a role in the development of some intracranial aneurysms, but why these aneurysms develop remains unknown. The findings suggest a genetic cause for two connective tissue defects.

Several years ago, the researchers discovered connective tissue defects in patients with cervical artery dissections, another vascular defect that causes stroke. They initiated this study because dissections and aneurysms might be related, they say.

Biopsies from the arterial wall of patients are rarely available, Grond-Ginsbach explains. Skin is considered a window to heritable connective tissue disorders, so researchers took skin samples from patients' upper arms. They used an electron microscope to examine the collagen and elastic fibers of the skin.

The team took skin biopsies from 21 patients with intracranial aneurysm (average age 44) without signs of connective tissue disorders. Seventeen of them had suffered a subarachnoid stroke.

They found that seven patients had connective tissue mutations. These tissue alterations were not found in 10 patients who did not have intracranial aneurysms or in a database of more than 3,000 patients who had skin biopsies to diagnose dermatological problems. Four patients were classified as normal, although their electron microscope examinations seemed somewhat abnormal. So these findings might be an underestimation.

The researchers caution however, that the test is a scientific test rather than a screening tool for patient management.

Co-authors are Ingrid Hausser, Ph.D.; Ralf Weber, M.D.; Inge Werner; Hans H. Steiner, M.D., Nina Luttten, M.D.; Otto Busse, M.D.; Armin Grau, M.D.; and Tobias Brandt, M.D.