1. From the Department of Neurological Surgery (A.K.C., S.L.M., T.K., B.C., J.K., R.V.), University of Wisconsin, Madison
2. Department of Pathology and Laboratory Medicine, Cellular and Molecular Pathology Graduate Program (A.K.C., R.V.), University of Wisconsin, Madison
3. William S. Middleton Memorial Veteran Administration Hospital, Madison (R.V.).