[1] Burdenko Inst Dept Neurosurg, Moscow, Russia
[2] Belfast Hlth & Social Care Trust, Dept Neurosurg, 274 Grosvenor Rd, Belfast, Antrim, North Ireland
[3] Ege Univ, Dept Neurosurg, Izmir, Turkey
[4] Liaquat Natl Hosp & Med Coll, Neurosurg, Karachi, Pakistan
[5] Burdenko Natl Med Res Ctr Neurosurg, Moscow, Russia