[1] Univ Iowa Hosp & Clin, Dept Neurosurg, Iowa City, IA 52242 USA
[2] Univ Miami, Dept Neurosurg & Radiol, Miami, FL USA
[3] Univ Iowa Hosp & Clin, Dept Neurol, Iowa City, IA 52242 USA
[4] Univ Iowa Hosp & Clin, Dept Neurol & Neurointervent Radiol, Iowa City, IA 52242 USA
[5] Univ Iowa Coll Publ Hlth, Dept Epidemiol, Iowa City, IA USA
[6] Univ Iowa Hosp & Clin, Dept Gen Surg, Iowa City, IA 52242 USA
[7] Dept Neurosurg, Giza, Egypt
[8] Thomas Jefferson Univ, Dept Neurosurg, Philadelphia, PA 19107 USA