Pharmacologic Approaches to Treating Visual Snow?

“Pharmacologic approaches to treating Visual Snow” refers to the use of pharmaceutical drugs and medications as treatments. If you are considering such an approach, there are a few things you need to be aware of.

New Study

Recently a relatively large study on pharmacologic treatment approaches “for Visual Snow” was published. 58 patients with Visual Snow (Syndrome) were retrospectively studied (2007-2018).

29 of those patients had refused pharmocologic treatment because they weren’t convinced of the safety and/or benefit.

For those remaining, the pharmacologic treatment that was most often prescribed and had most effect was lamotrigine, and this was described as a “partial” remission in 5/26 patients.

Three of those five patients subjectively said they had only a “minor improvement in intensity”. One said they had a “substantial reduction in intensity” and the other more precisely a: “50% reduction in intensity of visual snow”.

On the other hand, 50% had presented with adverse effects (13/26 patients) and four of these were considered to have been major adverse effects.

With other drugs ( valproate, acetazolamide, flunarizine) there was no effect, and for topiramate one out of four patients had a “partial remission” but had to stop due to adverse effects.

Overall, 85% of patients discontinued their use of medication and from the original 58, that left four to continue.

The Basis For Pharmacological Treatments

The majority of the patients who responded to lamotrigine had migraine (80% or 4/5) and migraine with aura (60% or 3/5). I wouldn’t be suprised if the two for whom lamotrigine was most effective had migraine with aura.

Lamotrigine was highly effective in reducing migraine aura and migraine attacks. The strong correlation between reduction of aura symptoms and migraine attacks stresses the potential role of aura-like events and possibly cortical spreading depression as a trigger for trigeminal vascular activation, and subsequently the development of migraine headaches.

Although open-label studies have suggested that lamotrigine may have a select role in the treatment of patients with migraine with frequent or prolonged aura, results from a placebo-controlled study in migraine without aura were negative. Both lamotrigine and topiramate may have a special role in the treatment of migraine with aura.

It has previously been noted that the greater participation of those with migraine may bias certain studies on Visual Snow

Comorbid migraine aggravates the clinical phenotype of the “visual snow” syndrome by worsening some of the additional visual symptoms and tinnitus. This might bias studies on “visual snow” by migraineurs offering study participation more likely than non‐migraineurs due to a more severe clinical presentation

….and this may also be true for migraine with aura when evaluating the merits of lamotrigine and other drugs.

The only study regularly cited with a “complete” remission from any pharmocological treatment was one in 2015, where the patient again had a long history of migraine with aura.

A 25‐year‐old woman with a 10‐year history of migraine with aura (2‐3 attacks/week) admitted for 1‐year history of visual snow. She reported continuous bright and colorful lights, palinopsia, floaters, nyctalopsia, and photopsia.

That case report had a letter response which suggests how it seems likely that lamotrigine is more effective for treating the pathophysiology in migraine or migraine with aura than it is directly for Visual Snow and Visual Snow Syndrome.

Some patients with VS reported some improvement of VS after receiving LTG, but it is still unclear whether LTG ameliorates VS acting on both VS and migraine pathophysiology or if it has a specific effect on VS. In this specific case, a concomitant effect on MWA should be hypothesized and this observation is supported by the patient’s objective reduction of headache attacks and by the evidence of an increased likelihood of having additional visual symptoms and tinnitus in VS with comorbid migraine

I myself would question if “bright and colorful lights” is meant to refer to the patient’s Visual Snow? Since there is no mention of static.

In the literature of visual snow and persistent migraine aura, some patients were described as having flashing lights, zigzag lines, scintillating scotoma occurring in one visual hemifield or showing directed movement, which have developed with a typical migraine attack. These patients likely have migraine aura and have contributed to confusion over the syndrome

There was also another later case report in 2018 suggesting lamotrigine gave a full resolution but I’ve discussed the problems there before.

According to a review in 2016: out of 121 cases of Visual Snow studied with pharmocological treatment, only one had a complete resolution, the aforementioned 2015 lamotrigine case. In most cases there was either no effect noted or in some cases there were even worsenings. The new collection of case reports does not change the earlier consensus.

No medication has shown consistently to improve or worsen visual snow or its associated visual symptoms.

Overall there is very limited basis to say that any existing pharmacological treatment at present can provide a reliable treatment for those with Visual Snow and Visual Snow Syndrome. There is more basis to suggest that certain drugs may be able to treat migraine with aura and therefore indirectly improve symptoms for subgroups if they have that comorbidity.

Conclusion

I don’t see much reason to expect that these sorts of existing drugs will suddenly become more effective in future.

‘Visual snow’ should be considered a distinct disorder and systematic studies of its clinical features, biology and treatment responses need to be commenced to begin to understand what has been an almost completely ignored problem.

There are other problems I have with these sorts of case reports in general:

1. “Visual Snow Syndrome” and “Visual Snow” are often used interchangeably, but when reporting improvements it isn’t always clear if the reference is to Visual Snow Syndrome (a collection of symptoms), or the symptom of Visual Snow specifically.
2. The description of the patient’s Visual Snow is not always clearly describing Visual Snow.
3. The degree of reduction is often not measured objectively. Even using a Visual Snow simulator would be an improvement.
4. If someone has or does not have migraine with aura and experiences an improvement from a drug known to act on migraine with aura, then it has to be explicitly noted in cases. The same applies to any other relevant drugs and comorbidities.
5. The authors in the new study suggest cognitive therapy as an alternative treatment for comorbidities such as depression, anxiety, and tinnitus. But they do not comment on the lifestyle factors such as smoking, regular alcohol use, and recreational drug among the patients they looked at. These individual factors would possibly also contribute to all those listed comorbid conditions and perhaps visual symptoms too – they should therefore be better accounted for in future treatment studies.

If it’s a case of treating comorbid conditions to improve Visual Snow Syndrome then that doesn’t necessarilly have to be achieved through drugs. Not just the pathophysiology of migraine but other factors such as stress, fatigue, anxiety, depression, brain fog etc. can usually be influenced by the same sorts of practical and safely manageable things – diet, exercise, managing oxidative stess and inflammation, sleep etc.