[1] Baylor Coll Med, Dept Neurosurg, Houston, TX 77030 USA
[2] Baylor Coll Med, Dept Intervent Radiol, Houston, TX 77030 USA
[3] Univ Texas Hlth Sci Ctr Houston, Dept Neurol, Houston, TX 77030 USA
[4] Wake Forest Univ, Dept Neurosurg, Winston Salem, NC 27109 USA