1. From the Departments of Neurology (M.J.H.A., D.C.B., J.D.K., J.W.J.E., P.C.A.J.V.) and Health Sciences (R.E.S.), University Medical Centre Groningen, Groningen, the Netherlands; the Department of Neurology (J.D.K.), Vrije Universiteit Brussel (VUB), Brussels, Belgium; and the Department of Internal Medicine (T.T.), University Medical Centre Nijmegen, Nijmegen, the Netherlands.