Fainted & Had What the Doc Called a Mild Seizure in the Middle of Juvederm Lip Injections, Cant Be Normal?

Went in for juvederm on my lips (first time) doctor was at the last injection for my upper lip I began to feel super light headed and the next thing I know I have nurses and doctors standing over me holding me down on the table trying to cool me off asking me a million questions telling me I just had a mild seizure. I had no idea where I was and felt like I time warped there. Now the injections werent too painful, I wasnt super nervous, could this be due to an allergic reaction?