1. Department of Neurology, UPMC Stroke Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
2. Faculty of Medicine, Al-Azhar University, Cairo, Egypt
3. Department of Neurology, State University of New York Upstate Medical University, Syracuse, NY, USA
4. Department of Neurosurgery, UPMC Stroke Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA