Correspondence: Inaccurate reference leads to tripling of reported FND prevalence

• Perez et al asserted that FND is the "2nd most common" diagnosis in outpatient neurology. • Stone et al (2010), cited by Perez et al, does not support the “2nd most common” claim. • In Stone et al, a broad “functional/psychological” category was the second most common. • FND is not synonymous with the “functional/psychological” category in Stone et al.