Dr. Kirsten Müller-Vahl, a doctor based in Hanover, Germany told the Jerusalem Post that she has been seeing more and more teen and young adult girls coming in with tics. Müller-Vahl, who has treated Tourette’s for 25 years, said while people who have the disorder usually have their own unique tics, the girls she was seeing recently had the same ones.

She quickly discovered that those patients were mimicking the tics of a German YouTuber who shares online how she lives with the disorder.

While there’s no national or international data compiled on the extent of the issue, The Journal reported that some medical centers are seeing as much as 10 times their usual cases of tics. Before the pandemic, centers would see one or two cases a month, but now some say they’re seeing between 10 or 20 a month.