Why Visual Snow Syndrome is Not a Migraine Variant

Understanding Features of This Rare Health Condition

Is Visual Snow Syndrome a Migraine Aura?
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Visual snow syndrome is a unique disorder in which a person has a persistent visual disturbance, usually that of continuous, flickering tiny black and white dots or "snow" or "static" in their entire field of vision (similar to old flickering televisions).

Many people with visual snow syndrome also have migraines with or without auras. This has led to the thought that this syndrome may be a form of migraine or migraine aura. In fact, some are given the diagnosis of persistent migraine aura. But the truth is that this rare syndrome is its own health condition, it's not a migraine variant, nor a migraine aura.

Overview

Scientific research supports this syndrome as a unique, distinct medical condition. It's not a variant of migraine with aura. It's also not a psychogenic disorder or a post-hallucinogenic flashback, which people have been erroneously diagnosed with in the past. The vast number of people with this rare disorder have no history of drug abuse and have normal eye and neurological exams. Also, their visual symptoms do not get better with traditional migraine therapies.

That being said, many people with visual snow syndrome do suffer from migraines with and without auras, and this may worsen their symptoms.

Symptoms

Despite a normal eye exam and normal brain imaging tests, a person with visual snow syndrome experiences multiple visual symptoms, such as:

  • Floaters
  • Flashes of light
  • Impaired night vision
  • Color swirls
  • Persistence of a visual image despite it being removed from the field of vision
  • Sensitivity to light (called photophobia)

Another common associated symptom of this syndrome is headache, which tends to occur at the start of a visual disturbance or as the visual disturbance is worsening. Tinnitus, or ringing in the ears, may also occur along with the visual symptoms.

Cause

Scientists don't know for sure but studies have shown that people with this syndrome do have a brain abnormality in their lingual gyrus—a structure in the back of the brain in the occipital lobe.

Since visual pathways converge in the occipital lobe, experts suspect that an abnormality in vision processing is the crux behind visual snow syndrome. More specifically, the nerve cells in the brains of people with visual snow syndrome may be overly responsive to visual stimuli. These "sensitive" nerve cells then misguidedly send signals to the brain, which interprets them as real images.

Diagnosis

The diagnosis of visual snow syndrome is made if a person sees visual "snow" or "static" consistently for longer than three months in addition to two or more of the following symptoms:

  • Sensitivity to light (photophobia)
  • Impaired night vision (nyctalopia)
  • Seeing an image of an object, despite it note being there anymore (palinopsia)
  • Other visual changes, such as seeing floating objects

In order for a person to be diagnosed with visual snow syndrome, other potential causes of the symptoms such as migraine visual aura must be ruled out. Most people with visual snow syndrome have normal vision tests and normal brain images.

Treatment

Doctors don't know yet how to treat this unique condition. One 2015 report in Headache of a patient with this syndrome found that Lamictal (lamotrigine), an anti-seizure medication, was effective in eliminating symptoms. Lamictal also helped decrease the number of migraine attacks she had per month. That being said, this was a study on one patient. Studies that look at a larger number of patients would be helpful.

A Word From Verywell

If you think you might have vision snow syndrome, be sure to get it check out by your doctor. You need a proper eye exam and neurological exam to rule out other medical conditions. The good news is that now scientists know this syndrome is not a migraine variant, and is linked to a certain part of the brain. This will hopefully spur research into how to best treat this very real, but rare, health condition.

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