Patients who experience symptoms described as transient neurological attacks, such as temporary amnesia or confusion, may have a higher risk for stroke and dementia, according to a study in the December 26 issue of JAMA: The Journal of the American Medical Association.
Transient neurological attacks (TNAs) are episodes involving temporary (less than 24 hours) neurological symptoms. These symptoms can be nonfocal (that can include nonlocalizing cerebral symptoms), focal (known as transient ischemic attacks [TIAs], similar to ischemic stroke, except for duration [commonly 2-15 minutes, maximum 24 hours]), or a mixture of both focal and nonfocal. Although it has been well-documented that patients with TIA are at high risk of major vascular disease, few studies have examined whether nonfocal TNAs are a serious health threat, according to background information in the article.
Michiel J. Bos, M.D., M.Sc., of Erasmus Medical Center, Rotterdam, the Netherlands, and colleagues studied the incidence and prognosis of focal, nonfocal and mixed TNAs. The study included 6,062 participants who were age 55 years or older and free from stroke, heart attack, and dementia when they entered the study (1990-1993), and were followed-up until January 2005.
During the study a TNA occurred in 548 participants; 282 of these were classified as focal, 228 as nonfocal, and 38 as mixed. In both men and women, the incidence rates for nonfocal TNAs were almost as frequent as focal TNAs, and for both types of events the incidence rates strongly increased with increasing age. Mixed TNAs were less frequent.