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Background: Sometimes migraine aura changes from attack to attack, raising the question of whether the change is heralding an ischemic stroke or an unusual aura. Differentiating unusual migraine aura from the onset of an acute ischemic stroke in patients with migraine with aura (MwA) can be challenging., Objective: The aim of this cohort study was to assess clinical characteristics that help distinguish between MwA and minor stroke in patients with a previous history of MwA who presented with suspicion of stroke., Methods: We interviewed patients with MwA and ischemic stroke (MwA + IS) and patients with MwA and unusual aura, but without ischemic stroke (MwA - IS) from a tertiary hospital using a structured questionnaire. We assessed how symptoms of ischemic stroke or unusual aura differed from usual, that is, the typical aura in each patient. Stroke or exclusion of stroke was verified by multimodal magnetic resonance imaging., Results: Seventeen patients with MwA + IS and twelve patients with MwA - IS were included. New focal neurological symptoms (13/17 [76%] vs. 3/12 [25%]), change of the first symptom (10/17 [59%] vs. 1/12 [8%]), and absence of headache (6/15 [40%] vs. 2/10 [20%]) were more often reported during ischemic stroke. The physical examination was normal in 8/17 (47%) MwA + IS and in 6/12 (50%) MwA - IS patients. In 5/17 (29%) patients with MwA + IS, there were unequivocal physical signs suggestive of stroke such as persistent visual loss, ataxia, or paresis., Conclusion: There are clues from the history that might help identify stroke in patients with MwA with changed aura symptoms. These might be particularly useful in patients presenting without physical findings suggestive of stroke., (© 2024 The Authors. Headache: The Journal of Head and Face Pain published by Wiley Periodicals LLC on behalf of American Headache Society.)

In the context of mixed markets, Matsumura and Kanda (J Econ 84(1): 27–48, 2005) show that social welfare in free entry equilibrium is maximized when there exists a public firm in the market. En passant, these authors state that this outcome is connected to the entry-deterring influence of a public firm. In this way, they counter-act the excess entry problem of Mankiw and Whinston (Rand J Econ 17(1): 48–58, 1986). We explain this result arguing that the state-owned firm can be an indirect instrument to regulate entry. In fact, under free entry equilibrium welfare may be greater with the presence of a public firm than with a social planner. [ABSTRACT FROM AUTHOR]