Letter to the Editor Seasonal Variation, Weekly and Daily Rhythm of Transient Ischemic Attack in

To the Editor: We read the very important article by Manfredini et al1 with great interest. Numerous reports have proven that the occur-rence of a heart attack, cerebral infarction, or transient ischemic attack (TIA) shows seasonal changes, which may be influenced by prevailing weather conditions as well.2-5 Hungary, a small country in the middle of Europe, lies in the Carpathian basin, with similar climate as the mentioned region of Italy, although our results differ. We have performed our study on patients admit-ted to Neurology wards in Hungary between 2005 and 2007 with the diagnose of TIA (n12 556, mean age 65.5+ 14.9 years, 42.14%males). Based on our results, the peak period of TIA incidence was during spring, while lowest number of events occurred during autumn (F 13 603, P <.001). The occur-rence of TIA in case of females was the highest in April, while in case of males in May, and the lowest was in December in both sexes (F 26 738, P <.001). Furthermore, the time of onset of TIA also showed a weekly variation. The highest morbidity of TIA was found on Monday in case of both sexes (Z 17 982, P <.001). Based on our findings, we may conclude that TIA may be somehow influenced by the internal rhythms of the organism, as well as external factors, such as weather, and also the typical seasonal changes of nutrition and regular workout. The more risk factors one bares, the higher the chance of having TIA