A series of migraineurs with episodic visual snow suggests a condition that is distinct from visual snow syndrome.
Episodic visual snow was associated with migraine attacks in a case series of three adults who denied any visual snow outside of the migraines, based on data collected at an outpatient headache center.
Visual snow, a condition in which patients experience visual distortion of tiny, flickering dots resembling analog television static, is often a comorbid condition in migraineurs with and without aura. However, “to our knowledge, this is the first report of patients with an episodic form of visual snow strictly occurring with migraine attacks,” wrote Julius Hodak, MD, of the University of Bern (Switzerland), and colleagues.
In a research letter published in JAMA Neurology, the investigators described 3 adults with histories of migraine but no aura who presented to a tertiary headache center between January 2016 and December 2017, in addition to 1,934 adults with migraine but no visual snow. The three patients initially presented with headaches, and neurologic and MRI results were normal.
Two patients experienced black and white episodic visual snow, and one experienced black and yellow visual snow. In one patient, visual snow occurred for less than 2 minutes before and during a migraine attack. The other two patients experienced visual snow during the entire migraine attack.
Based on these patients, the researchers proposed distinguishing episodic visual snow from visual snow syndrome, in which patients experience continuous visual snow and other visual symptoms. In addition, the cases were notable because of the patients’ lack of aura, the researchers wrote.
“In clinical practice, a detailed history in patients reporting visual flickering is therefore necessary to differentiate aura from [episodic visual snow],” they added, because an aura diagnosis would affect patient guidance on contraception use or the timing of triptans.
