Triggering risk factors for ischemic stroke: a case-crossover study.
BACKGROUND
While vascular risk factors for stroke are well established, little is known about factors that may precipitate the acute event. In this study the authors investigated the association between exposure to seven potential triggers during waking hours and acute onset of ischemic stroke.


METHODS
In a case-crossover study, 200 consecutive stroke patients were interviewed 1 to 4 days after the event using a validated questionnaire. Reported exposure to potential triggers including negative and positive emotions, anger, sudden posture changes as response to a startling event, heavy physical exertion, heavy eating, and sudden temperature changes during a 2-hour hazard period prior to stroke onset were compared to the same period during the preceding day and to average exposures in the last year.


RESULTS
Seventy-six patients (38%) reported exposure to at least one of the study triggers during the 2-hour hazard period. For all factors combined, the OR was 8.4 (95% CI 4.5 to 18.1). The OR for negative emotions was 14.0 (95% CI 4.4 to 89.7), for anger 14.0 (95% CI 2.8 to 253.6), and for sudden changes in body posture in response to a startling event 24.0 (95% CI 5.1 to 428.9). It is important to interpret the reported ORs as estimates of a short-term 2-hour period relative risk and not as cumulative risks.


CONCLUSIONS
Negative emotions, anger, and sudden changes in body posture in response to a startling event appear to be independent triggers for ischemic stroke.
Koton
S
S
Epidemiology and Preventive Medicine, Sackler Faculty of Medicine, Tel-Aviv University, Israel. silvia.k@icdc.health.gov.il
Tanne
D
D
Bornstein
N M
NM
Green
M S
MS
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000453:epidemiology* / Q000209:etiology; D015897:Comorbidity; D004435:Eating; D004644:Emotions; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D002546:Ischemic Attack, Transient / Q000453:epidemiology / Q000209:etiology; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D005082:Physical Exertion; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D011187:Posture; D012306:Risk; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D013312:Stress, Physiological / Q000453:epidemiology; D013315:Stress, Psychological / Q000453:epidemiology; D011795:Surveys and Questionnaires; D013696:Temperature; D013997:Time Factors
D000319:Adrenergic beta-Antagonists; D010975:Platelet Aggregation Inhibitors