By Dr Linxin Li
Miss A is 30 years old. She has history of migraine with visual aura since her teenage years, which normally starts with blurred vision followed by a mild headache. She is otherwise fit and well.

This morning she woke up feeling fine. However, whilst cycling to work, her vision became blurred. She tried to phone her friend but had difficulty using the mobile. When she finally managed to get through, she noted she had expressive dysphasia. All symptoms improved after 2 hours and she developed a mild left-sided headache.

She was seen subsequently at the emergency department with normal neurological exam but an MRI scan showed an acute infarct in the posterior temporal/occipital region. MR angiogram showed normal intra and extracranial vessels.

Vote for a migrainous infarction?

According to the International Classification of Headache Disorders 3rd edition (ICHD-3), a migrainous infarction would need to fulfil the following criteria
A. Occurring in a patient with migraine with aura and typical of previous attacks that one or more aura symptoms persists for >60min
B. Neuroimaging demonstrates ischaemic infarction in a relevant area
C. Not better accounted for by another ICHD-3 diagnosis

Our patient had history of migraine with visual aura. This episode was of gradual onset with progression and involved her usual visual aura. The episode lasted for 2 hours and MRI confirmed an ischaemic stroke in a relevant area. All seemed to fit.
Migrainous infarction is rare, accounting for 0.2-0.5% of all ischaemic strokes and the physiopathology is uncertain, with the main hypothesis suggesting severe vasoconstriction caused by cortical spreading depression. The posterior circulation is mostly involved (70-82%) and there also appears to be a female predominance.1,2

Unfortunately the story continued.

Miss A had been fine for 8 years after this initial presentation until she was admitted again after an episode of left arm weakness following an episode of her usual migraine with aura. MRI showed an acute right frontal cortical infarct. This time, she went on to have a bubble echo which demonstrated a large persistent PFO! We have perhaps finally got the culprit!

PFO is associated with cryptogenic stroke and one hypothesis for the potential causal link is that PFO may allow vasoactive chemicals to bypass the pulmonary circulation and enter the cerebral circulation resulting in ischaemia.3 If this was true, it perhaps wouldn’t be surprising that PFO is also associated with migraine, as suggested by several studies.3 We all know that migraine is associated with an increased risk of ischaemic stroke. However, when migraine meets ischaemic stroke, we also should not forget about other potential causes, including searching for a PFO!

 

Reference

  1. Lee MJ, Lee C, Chung C-S. The migraine–stroke connection. Journal of Stroke. 2016;18:146-56.
  2. Sochurkova D, Moreau T, Lemesle M, Menassa M, Giroud M, Dumas R. Migraine history and migraine-induced stroke in the Dijon stroke registry. Neuroepidemiology 1999;18:85-91.
  3. Sathasivam S, Sathasivam S. Patent foramen ovale and migraine: what is the relation between the two? Journal of Cardiology 2013; 61: 256-9