1. Department of Anesthesia (Pain Management) and Neurology and Neurological Sciences, Stanford Hospital and Clinics, Stanford, California, USA
2. Department of Neurology, Medstar Georgetown University, Washington, DC, USA
3. Department of Anesthesiology, Intensive Care, and Pain Management, Ain Shams University Faculty of Medicine, Cairo, Egypt
4. Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
5. Department of Anesthesiology, University of California, San Diego, California, USA