Gavin V McDonnell1, Jeffrey A Cohen2. 1. From the MS Clinic (G.V.M.), Belfast City Hospital, Northern Ireland, UK; and Neurological Institute (J.A.C.), Cleveland Clinic, OH. gavin.mcdonnell@belfasttrust.hscni.net. 2. From the MS Clinic (G.V.M.), Belfast City Hospital, Northern Ireland, UK; and Neurological Institute (J.A.C.), Cleveland Clinic, OH.