[1] Neurol Inst Fdn C Besta, Neuroimmunol & Muscle Pathol Unit, I-20133 Milan, Italy
[2] Neurol Inst Fdn C Besta, Myopathol & Immunol Unit, I-20133 Milan, Italy
[3] Neurol Inst Fdn C Besta, Expt Neurophysiol Unit, I-20133 Milan, Italy
[4] Neurol Inst Fdn C Besta, Clin Neurophysiol Unit, I-20133 Milan, Italy
[5] John Radcliffe Hosp, Weatherall Inst Mol Med, Neurosci Grp, Oxford OX3 9DU, England