| Affiliation |
(AGL) Chairman, Department of Ophthalmology, The Methodist Hospital, Houston, Texas; Professor of Ophthalmology, Weill Cornell Medicine, New York City, New York; (SP) Baylor College of Medicine, Houston, Texas |
| Transcript |
So today we're going to be talking about retinal migraine, but really we don't call it that anymore. We call it retinal vasospasm. However because of historical purposes you need to know its related to migraine. I'll leave that in there. As you know, most patients with retinal migraine have the International Headache Society (IHS) criteria for migraine and that's going to be diagnosed by the quality which is usually throbbing, alternating hemicranial headache, last hours at a time, disrupts activities of daily living, and you have to have 2 of the 4 autonomic dysfunction (photophobia, sonophobia, lights and sounds, nausea and vomiting). It has to be severe enough to interrupt activities of daily living. Typically, the patient will go lie down, dark room, go turn off the lights and you have to have multiple headaches. They can't just have one. Those are the typical features of migraines, so that's one of the first requirements we have to have. We have to meet the criteria for migraine, and then as you know in most, patients have migraine aura. So when you have migraine aura, it's classically a scintillating scotoma with a fortification component which means it's got a jagged line, it's got a flashing light, and it typically moves across the visual field, so it starts small and moves across the visual field. We call this march/build up. This squiggly line is the fortification scotoma because it looks like a fort from above, and the flashing component is scintillating. It's usual bilateral and simultaneous and lasts20 minutes, and then the headache follows. So, a bilateral, simultaneous, fortification and scintillating scotoma with march and build up that is bilateral, simultaneous, and followed by the typical migraine headache is our normal aura. However, some patients with migraine have unilateral rather than bilateral vision loss. When it's that unilateral visual loss, that is what is referred to in the literature as retinal migraine. Amazingly, some of these patients have had fundoscopy during these events which show the vasospasm. When the central retinal artery spasms, they lose their vision, and then it comes back. It can be described as a tunneling or altitudinal or diffuse visual lose. The key differentiating features of retinal migraine are 1: You have to have the migraine. 2: Episodes are stereotyped which means they are the same each time. 3: They generally last 15-20 minutes at a time. 4: It has to completely resolve, so we're going to be very, very nervous about the diagnosis of migraine if they have a field defect, or a RAPD or they have a residual field defect, so migraine should really be reversible. So, before you make the diagnosis of retinal migraine, you really better make sure that they have migraine, and probably if its unilateral, we're going to work this up because this is amaurosis fugax: transient monocular vision loss, and that's a TIA, a transient ischemic attack. So, that's going to be the echo, EKG, carotid doppler, MRI of the brain. However, sometimes the workup is entirely negative. It's a young patient. Amazingly, the more episodes they have the better. That seems counterintuitive, but if you've only had 2 episodes that can still be an ischemic lesion from emboli. If you've got 20 episodes, you're going to feel better about that being migraine. Once you get 200 episodes over 20 years, that's migraine for sure. So, you need to know a little about retinal vasospasm. It produces acute unilateral loss of vision, and in the setting of migraine, that is called retinal migraine. |
