Can repetitive transcranial magnetic stimulation of the visual cortex ameliorate the state of patients with visual snow?

Abstract

Aims: Visual snow is a neurological condition, for which an effective treatment has not been established. The aim of this study was to find whether Repetitive Transcranial Magnetic Stimulation (rTMS) can improve the state of patients suffering from visual snow. To our knowledge, no other group has tested this method in the treatment of visual snow.

Methods: We applied rTMS of 10 and 10+1 Hz on the visual cortices of 9 patients with visual snow. Sham stimulation with the vertex as the target site was also tested. As a method of assessment, we used visual evoked potentials, questionnaires and visual snow diaries. For data evaluation, we used the Paired Sample T-test separately for each stimulation type.

Results: The Paired Sample T-test revealed a decreased sum of visual snow intensities extracted from visual snow diaries in the week after 10+1 Hz stimulation as compared to the figure in the week before (p=0.02).

Conclusion: We detected a trend indicating an improvement of patients' condition based on the data from visual snow diaries. Research on a larger group of patients is required to confirm these findings; however, our study provides a framework to build upon (Tab. 4, Fig. 1, Ref. 22).

Keywords: persistent aura without infarction; rTMS occipital cortex.; visual snow.