Erratum to: J Neurol DOI 10.1007/s00415-012-6628-x

Unfortunately, some of the co-authors were not included in the original publication of the paper.

The complete author group is given below:

Mario Zappia · Alberto Albanese · Elisa Bruno · Carlo Colosimo · Graziella Filippini · Paolo Martinelli · Alessandra Nicoletti · Graziella Quattrocchi · Giovanni Abbruzzese · Alfredo Berardelli · Roberta Allegra · Maria Stella Aniello · Antonio E. Elia · Davide Martino · Daniela Murgia · Marina Picillo · Giovanna Squintani