Cognitive decline over time in patients with chronic pain and headache: how can different outcomes be explained?

aDepartment of Neurology, Suroit Hospital, Salaberry-de-Valleyfield, QC, Canada bDepartment of Dentistry, Jewish General Hospital, Lady Davis Institute for Medical Research, Montreal, QC, Canada cFaculty of Dentistry, McGill University, Montreal, QC, Canada *E-mail address: [email protected] (K. dos S. Ferreira) Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article.