From the Department of Neurology (R.S.B.), Duke University and Durham VA Medical Center, Durham, NC; PatientsLikeMe (T.V., P.W., J.H.), Cambridge, MA; Massachusetts General Hospital (E.S., R.S., E.A.M., D.S., M.C., A.S.), Boston; and Harvard Medical School (E.A.M.), Boston, MA. (At 2016-03)