1. School of Physical and Occupational Therapy, Faculty of Medicine, McGill University, Montreal
2. School of Rehabilitation, Faculty of Medicine and
3. Migraine Clinic Val des Arbres, Laval
4. Montreal Migraine Clinic, Montreal
5. Department of Mathematics and Statistics, University of Montreal, Montreal
6. Charles LeMoyne Hospital and Montreal South Shore Headache Clinic, Greenfield Park, and
7. Faculty of Medicine, University of Sherbrooke, Sherbrooke, Quebec, Canada.