Miller-Fisher syndrome and pontine abnormalities on MRI: a case report. The authors report a patient with Miller-Fisher syndrome in whom MRI of the brain stem showed increased signal density on T2 sequence anterior to the fourth ventricle, on the right and the left. The authors discuss the relation between these MRI abnormalities and some clinical features of the syndrome. The authors believe that the cardinal features of Miller-Fisher syndrome are due to peripheral nervous system dysfunction, but that this does not preclude a possible central nervous system involvement. 