1. Department of Neurology & Neurological Sciences (G.J.W., K.A.L., P.T., L.D.K., C.M.), Stanford University, Palo Alto, CA.
2. Department of Neurosurgery (A.V.P., R.L.D.), Stanford University, Palo Alto, CA.
3. Division of Interventional Neuroradiology, Department of Radiology (A.V.P., R.L.D.), Stanford University, Palo Alto, CA.
4. Division of Cardiovascular Medicine (D.H.L.), Stanford University, Palo Alto, CA.