People who have experienced “visual snow” know what it means. Their vision tends to be distorted by white spots that resemble what you see on the television when there is no signal.

At the latest meeting of the International Headache Society, the topic of visual snow was addressed in four presentations. The first presentation by British and Swiss researchers attempted to give a definition, so that this phenomenon can be studied scientifically. They collected data on 636 subjects by using an online survey of patients. 636 is a surprisingly high number because this is thought to be a relatively uncommon symptom. I certainly do not see more than a handful of patients each year. They found this phenomenon to be present with equal frequency in men and women and 39% reported to have it all their lives. The majority (56%) saw black and white static, 44% saw colored spots, while 45% experienced flashing, and 52% described it as transparent. The most common non-visual symptom was tinnitus, or ringing in the ears, which was present in 74%. Only 226 patients gave information on headaches and 83% of them suffered at least one attack of migraine. They concluded that visual snow is an unrecognized symptom, which can be very disabling and which deserves further research.

The second presentation reported on 90 patients of the original 636 who agreed to keep a diary of their symptoms for 30 days. The results showed that the visual snow was least noticeable outdoors, in bright sun. It was most pronounced at night. The amount of distraction that was caused by visual snow was correlated to the size and density of the static.

The third study by German and Swiss doctors showed that visual snow is a phenomenon that is common in migraine sufferers, but it is distinct in its character. They came to this conclusion by testing the excitability of the visual cortex of the brain.

The fourth paper described the effectiveness of various treatments. The data was collected by reviewing questionnaires that were returned by 204 patients. The effect of 112 drugs was reported. Unfortunately, less than half (92) of the responders had any relief from medications. Antidepressants and anti-epilepsy drugs were most commonly used. Only 29% improved from benzodiazepine drugs (Valium or diazepam, Klonopin or clonazepam, and other). Recreational drug use was reported 117 times and in 32% produced worsening and in 61% there was no change.

We clearly do not know how to treat this condition, but if you have it, have your doctor check your RBC magnesium level since magnesium deficiency increases the excitability of the nervous system. I would also check vitamin B12, D, and CoQ10 levels, thyroid function, and routine blood tests, looking for an underlying medical condition (for example, anemia) which can worsen many symptoms. Regular and sufficient amounts of sleep, exercise and meditation can also reduce the excitability of nervous system.

It is an established fact that migraine, and especially migraine with aura increases the risk of strokes. The increase in the risk is small, but according to a new study published in the British Medical Journal, it is higher during and after surgery.

The researchers examined records of 124,558 surgical patients at the Massachusetts General and two other hospitals. Among these, 8.2% or 10,179 patients had a history of migraines with 1,278 or 12.6% having migraine with aura. The risk of stroke during or within 30 days after surgery was 1-2 in 1,000 among patients without migraine history, 4 in 1,000 in those who had migraines and 6 in 1,000 in patients who had migraine with aura. So, the absolute risk of a stroke is still very small, but the relative risk is statistically much higher. They also discovered that strokes were more common in patients who during surgery needed medications to increase their blood pressure. Most of the strokes occurred within the first two days after surgery.

We do not know why migraine carries an increased risk for strokes, so the only recommendation the authors offer is for migraine diagnosis to be included in the preoperative risk assessment of patients. I would add that according to another study, taking high doses of magnesium and potassium supplements could possibly reduce this risk. Magnesium alone was shown to reduce the risk of strokes in another review of studies involving 6,477 patients. Our own research and that of others have shown the beneficial effect of magnesium on the prevention of migraines as well. Here is one of a dozen posts on magnesium on this blog that provides dosing recommendations.