1. From the Department of Neurology (H.P., V.K.V., R.N.M.), Department of Imaging Sciences & Interventional Radiology (B.T.), Department of Neurosurgery (G.C.V., P.N.), and Department of Pathology (D.A.N., R.P.), Sree Chitra Tirunal Institute for Medical Sciences & Technology, Thiruvananthapuram, India.