[1] Cleveland Clin, Dept Neurol Surg, Cleveland, OH 44195 USA
[2] Cleveland Clin, Cerebrovasc Ctr, Cleveland, OH 44195 USA
[3] Cleveland Clin, Dept Intervent Neuroradiol, Cleveland, OH 44195 USA
[4] Cleveland Clin, Ctr Spine Hlth, Cleveland, OH 44195 USA