We’ve talked a lot about migraine aura – especially visual aura – here in the past. Typically, visual aura hits before an attack of pain in migraine, although sometimes it hits all by itself, and can be quite debilitating in its own right.
But what if that visual aura never went away?
That’s what does happen to some people. I’ll get more specific in a moment, but first a couple of important notes…
Is this migraine?
There is some debate over whether these visual symptoms should come under the classification of migraine at all. Now of course, there are many things that can cause aura-like symptoms, shall we say. So of course those other issues need to be ruled out before you can even consider whether or not this is migraine-related.
Next, we have to ask if the visual symptoms are the same as migraine aura, or if they have unique properties. This could mean there is a different cause, though it still could be that there is a root cause involved in the migraine attacks and the visual symptoms.
Finally, even if the symptoms are the same, there is still debate over how closely they are related to migraine. Does the patient have individual migraine attacks? Could there be a common cause of both? Could it be a similar symptom from another cause? These are difficult questions to answer, though we certainly seem to be getting closer to answers as our understanding of the brain increases.
What is Persistent Migraine Aura and Visual Snow?
Last year I was corresponding with someone about persistent migraine aura, and visual snow, and they pointed me to some helpful information. I would give them credit, but for some reason I can’t find the correspondence at the moment (what? James isn’t perfectly organized? I’m so disillusioned!)! But I appreciate the nudge to post on this topic.
Persistent Migraine Aura (PMA), also known as persistent aura without infarction, is diagnosed when there are aura symptoms lasting more than a week without evidence of infarction (which refers to the death of brain cells). This is in a patient that already has migraine with aura, and then has symptoms that are typical of their migraine attacks but lasting longer.
Often these symptoms are only on one side, though not always. They can continue for weeks, even years.
Visual snow (VS) is a more specific symptom, which could be a part of PMA or not, or even a symptom that is a part of a totally different diagnosis.
As you might guess from the name, VS is when the person sees "snow", like static on an old TV, all the time. This may be a temporary condition, or pretty much permanent. VS is often accompanied by other symptoms, and other types of visual disturbances, as the video below illustrates:
What’s causing it?
That question doesn’t always have an answer. As mentioned above, often it’s related to migraine and considered a part of migraine disease.
Sometimes there are other causes – at least suspected causes. Research on VS is extremely limited, and though the visual symptoms do have some patterns and relate to other symptoms, it’s sometimes hard to know if there’s a solid related cause, or just two things that are comorbid (that tend to go together, though we may not know why), or if there’s just a coincidental relation.
In our next post on the topic, we’ll talk a little more about possible causes, and what treatments have been suggested.
For now, remember that this is a condition/symptom that is known by (some in) the medical community, and if you’re suffering from it you are by no means alone.