The one-and-a-half syndrome. Clinical correlation with a pontine lesion demonstrated by nuclear magnetic resonance imaging in a case of multiple sclerosis.

Nuclear magnetic resonance (NMR) imaging has been used to visualise a localised area of demyelination in the dorsal pons of a patient who presented with an unusual disorder of eye movements, namely, the one-and-a-half syndrome. Judged clinically the patient made a nearly complete recovery, but little change was apparent in the NMR image six months later.