People Who Suffer From Transient Neurological Attacks May Have A Higher Risk For Stroke

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Main Category: Stroke
Also Included In: Neurology / Neuroscience;  Cardiovascular / Cardiology
Article Date: 26 Dec 2007 - 8:00 PDT

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If you suffer from temporary amnesia or confusion - transient neurological attacks (TNAs) - you may have a higher risk of developing a stroke, according to an article published in the Journal of the American Medical Association (JAMA), December 12 issue.

TNAs are less than 24 hours long; they are episodes of temporary neurological symptoms. The symptoms might be non-focal - non-localizing cerebral symptoms, focal - transient ischemic attacks (TIAs) which are similar to ischemic stroke but which last from minutes up to no more than 24 hours, or they might be both non-focal and focal.

The authors explain that TIAs are known to raise the sufferer's risk of major vascular disease. However, not much is known about the risks non-focal TNAs pose to health.

Michiel J. Bos, M.D., M.Sc., Erasmus Medical Center, Rotterdam, the Netherlands, and colleagues looked at the occurrence and prognosis of focal, non-focal and combination TNAs. The study involved 6,062 people aged 55 years or more - they were all free from heart attack, stroke and dementia at the beginning of the study - 1990-1993. They were followed-up until January 2005.

During this period 548 people experienced a TNA, of which 282 were focal, 228 non-focal, and 38 were mixed (both). Incidence rates for TNAs were almost the same for focal and non-focal for both men and women. Incidence rates for both types increased significantly with age. The researchers also found that mixed TNAs were much less frequent.

During the follow-up period the researchers found that..

-- there were 619 cases of stroke
-- 848 cases of ischemic heart disease
-- 662 vascular deaths

Those who had had focal TNA had over the twice the risk of stroke and 2.6 times the risk of ischemic stroke, compared to people without TNA. Within 90 days of a focal TNA the risk of stroke was 3.5%. The risk for people with non-focal TNA was 56% higher for stroke and 59% higher for dementia, compared to people without TNA.

People who had mixed TNAs were at raised risk of stroke, particularly ischemic stroke; ischemic heart disease, especially heart attack; and vascular death and dementia, compared to people without TNA.

The researchers write "Our findings challenge the strong but unfounded conviction that non-focal TNAs are harmless. On the contrary, our findings suggest that non-focal TNAs are not only a risk factor for stroke, but also for dementia."

"Incidence and Prognosis of Transient Neurological Attacks"
Michiel J. Bos, MD, MSc; Marie Josee E. van Rijn, MD, PhD; Jacqueline C. M. Witteman, PhD; Albert Hofman, MD, PhD; Peter J. Koudstaal, MD, PhD; Monique M. B. Breteler, MD, PhD
JAMA. 2007;298(24):2877-2885.
Click here to see abstract online

Written by - Christian Nordqvist
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