1. Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, USA.
2. Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA.
3. Department of Cardiology, University of Pittsburgh, Pittsburgh, PA, USA.
4. Saints Heart and Vascular Institute, St. Anthony Hospital, Oklahoma City, OK, USA.
5. Division of Cardiac Surgery, Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, PA, USA.