The Prevalence of Familial Hemiplegic Migraine With Cerebellar Ataxia and Spinocerebellar Ataxia Type 6 in Portugal - Barros, J.; Ruano, L.; Domingos, J.; Tuna, A.; Damásio, J.; Alonso, I.; Silveira, I.; Sequeiros, J.; Coutinho, P. (Headache, 2013)