Incidence and prognosis of transient neurological attacks

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. Conclusion Patients who experience nonfocal TNAs, and especially those with mixed TNAs, have a higher risk of major vascular diseases and dementia than persons without TNA.