Incidence and Prognosis of Transient Neurological Attacks

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.

Context Transient neurological attacks (TNAs) are attacks with temporary (<24 hours) neurological symptoms. These symptoms can be focal, nonfocal, or a mixture of both. The prognostic significance of TNAs with focal symptoms (better known as transient ischemic attacks [TIAs]) is well understood. Conversely, hardly anything is known about the prognostic significance of TNAs with nonfocal or mixed symptoms.

Objective To study the incidence and prognosis of focal TNAs (or TIAs), nonfocal TNAs, and mixed TNAs.

Design, Setting, and Participants The study population comprised 6062 community-dwelling Rotterdam Study participants who were aged 55 years or older and free from stroke, myocardial infarction, and dementia at baseline (1990-1993). They were followed up for events until January 1, 2005. We analyzed the associations between incident TNAs and subsequent adverse events with age- and sex-adjusted Cox regression models.

Main Outcome Measures Stroke, ischemic heart disease, or dementia.

Results During 60 535 person-years, 548 participants developed TNA (282 focal, 228 nonfocal, and 38 mixed). The incidence rate per 1000 person-years was 4.7 (95% confidence interval [CI], 4.1-5.2) for focal TNA, 3.8 (95% CI, 3.3-4.3) for nonfocal TNA, and 0.6 (95% CI, 0.4-0.9) for mixed TNA. Participants with focal TNA were at higher risk of subsequent stroke than participants without TNA (n = 46 vs 540; hazard ratio [HR], 2.14; 95% confidence interval [CI]; 1.57-2.91) but had an equal risk of ischemic heart disease and dementia. Nonfocal TNA patients were at higher risk of stroke (27 vs 540; HR, 1.56; 95% CI, 1.08-2.28) and dementia (30 vs 552; HR, 1.59; 95% CI, 1.11-2.26) than participants without TNA. Mixed TNA patients were at higher risk of stroke (6 vs 540; HR, 2.48; 95% CI, 1.11-5.56), ischemic heart disease (8 vs 779; HR, 2.26; 95% CI, 1.07-4.78), vascular death (8 vs 594; HR, 2.54; 95% CI, 1.31-4.91), and dementia (7 vs 552; HR, 3.46; 95% CI, 1.72-6.98) than participants without TNA.