[1] Univ Cattolica Sacro Cuore, Neurol Inst, Rome, Italy
[2] Hosp Nacl Paraplej, Unidad Neurol Func, Toledo, Spain
[3] CTO, Dept Neurosurg, Rome, Italy
[4] CTO, Dept Neurophysiol, Rome, Italy
[5] Neurol Inst, Sobell Dept Neurophysiol, London, England
[6] UCL Natl Hosp Neurol & Neurosurg, London WC1N 3BG, England