WEDNESDAY, Dec. 26, 2007 (HealthDay News) -- Brief bouts of amnesia or confusion raise a person's risk of having a stroke or developing dementia, Dutch scientists suggest.
The findings, which add to previous research linking "mini-strokes" to full-fledged strokes, make sense to Dr. Argye Beth Hillis, a professor of neurology at Johns Hopkins University School of Medicine.
In the United States, some doctors typically take memory loss seriously, she said. But elsewhere in the world, "there are places where any kind of [brief neurological difficulty] is not taken seriously. That's changing, and it should," she added.
Neurologists like Hillis are very familiar with transient ischemic attacks, also known as "mini-strokes," which typically last about a minute and can cause a variety of sudden stroke-like symptoms, such as numbness, confusion, headache and difficulty seeing or walking. These attacks happen when clots briefly block blood flow to a specific part of the brain.
In the new study, the researchers looked at a different category of brief neurological problems -- confusion or brief amnesia that doesn't seem to be caused by a problem in a single region of the brain. "Damage to different areas can interfere with memory or level of alertness," she said.
Hillis said she sees such cases about once a month. "It usually is very transient and lasts less than a day, several hours during which people just don't remember what they did or said during that period. Generally, they never do remember that time period," she said. "I saw someone yesterday who had decorated a tree very nicely, and later that day he came down and said, 'Who decorated the tree?' He couldn't remember doing it at all."
In such cases, physicians often prescribe aspirin to thin the blood, she said.
In this latest study, researchers looked at 6,062 subjects who were 55 years or older when they entered the study between 1990 and 1993. The subjects were followed until 2005.
The findings were published in the Dec. 26 issue of the Journal of the American Medical Association.
The researchers found that brief neurological problems occurred in 548 of the subjects. Of those, 282 were classified as focal (suggesting a problem in a specific area of the brain), while 228 others seemed to be more of a widespread problem in the brain. The rest, 38 subjects, had incidents that fit into both categories.
Those who had focal incidents were more than twice as likely to have a stroke as the others; their risk of a stroke within three months after an incident was 3.5 percent. Patients with non-focal incidents had a 56 percent higher risk of stroke and 59 percent higher risk of senility than those who didn't experience such a problem.
"Our findings challenge the strong but unfounded conviction that non-focal [incidents] are harmless," the authors wrote.
In a commentary that accompanied the study, Dr. S. Claiborne Johnston, director of the Neurovascular Disease and Stroke Center at the University of California, San Francisco, wrote that there's too little information about how to handle patients who experience these problems: "There is no consistent evaluation, no guidelines for treatment, and no information on prognosis. This study argues that, whatever is causing these events, the prognosis justifies greater attention."
In any event, people should call 911 if they have any "new neurologic deficit," such as weakness, numbness, difficulty speaking, poor vision on one side, memory loss or a sudden headache associated with nausea and neck pain, Hillis said. Emergency care is needed for this condition "even if it only lasts for five to 10 minutes."
Learn more about transient ischemic attacks at the American Heart Association.