In the linked systematic review (doi:10.1136/bmj.b3914), Schürks and colleagues assess the association between migraine and cardiovascular disease, including stroke, myocardial infarction, and death as a result of cardiovascular disease.1

Migraine is a highly prevalent chronic condition characterised by a hyper-responsive nervous system that predisposes to recurrent episodes of severe headache and autonomic disturbance.2 Roughly a quarter of people who have migraine experience temporary neurological symptoms, known as aura, before some or all of their headaches. Aura is distinguished from other causes of brief recurrent neurological disturbance, such as transient ischaemic attacks, by its gradual onset and disappearance, the presence of both positive and negative features, and its duration of an hour or less.

Visual disturbances are the most common sort of aura, although sensory or motor auras can also occur. Patients with aura can be identified using the visual aura rating scale (table⇓), which assigns a point value to common aura features.3 Its developers make the clinically relevant observation that to identify patients with aura it is necessary only to detect visual aura, because 99% of people with non-visual auras …