1. Department of Neurology, Uniformed Services University of the Health Sciences, Bethesda, Maryland.
2. Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania.
3. Center for Neuroscience and Regenerative Medicine, National Institute of Neurological Disorder and Stroke, National Institutes of Health, Bethesda, Maryland.
4. Department of Radiology and Radiological Science, Johns Hopkins University Baltimore, Maryland.
5. National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland.