Skew Deviation and the Triad of the Ocular Tilt Reaction (OTR)

This is a patient who presented with vertical diplopia, who was found to have a complete ocular tilt reaction including the following features: (1) Skew deviation - right hypertropia that was about 30 prism diopters in all directions of gaze including right, left, up, down, as well as in right and left head tilt. (2) Head tilt - her head was tilted to the left (3) Ocular counter roll - the top poles of both eyes were rotated toward the left ear, in the same direction as the leftward head tilt. This patient also had mild spontaneous downbeat nystagmus that increased in lateral gaze, in addition to gaze evoked nystagmus, saccadic pursuit, and was found to have significantly elevated anti-glutamic acid decarboxylase levels in both serum and cerebrospinal fluid. Her ocular motor abnormalities localized well to the posterior fossa, and her signs and symptoms were thought to be related to an anti-GAD cerebellar syndrome.