[1] Univ Kansas, Dept Neurol, Kansas City, KS USA
[2] Univ Roma La Sapienza, Dept Neurol Sci, Rome, Italy
[3] Univ Calif San Diego, Sch Med, Div Neurosurg, San Diego, CA 92103 USA
[4] Albany Med Coll, Albany, NY 12208 USA
[5] Albany Med Ctr, Albany, NY USA
[6] Donau Univ Krems, Dept Clin Med & Prevent, Krems, Austria
[7] Oregon Hlth & Sci Univ, Dept Neurol Surg, Portland, OR 97201 USA
[8] Univ Liverpool, Sch Clin Sci, Div Neurol Sci, Pain Res Inst, Liverpool L69 3BX, Merseyside, England
[9] UCL, Dent Hosp, Hosp Eastman, London WC1E 6BT, England