1. From the Departments of Neurology (D.C.B., K.C.K.K.), Medicine (L.A.R.), Anesthesia (P.R.H.), Cardiology (G.W., J.W.N), and Cardiovascular Surgery (R.A.J.), Children’s Hospital; the Departments of Neurology (D.C.B, K.C.K.K.), Pediatrics (L.A.R., G.W., J.W.N.), Anesthesia (P.R.H.), and Surgery (R.A.J.), Harvard Medical School; and the Department of Biostatistics (D.W.), Harvard School of Public Health.