Contraversive ocular tilt reaction after the lateral medullary infarction.

INTRODUCTION

The triad of ocular tilt reaction (OTR) is conjugated ocular torsion, skewed deviation, and head tilt. A lesion involving below the inferior pons develops ipsiversive OTR, whereas a lesion above the inferior pons leads to contraversive OTR. A lateral medullary infarction usually causes ipsiversive OTR. This is the first report of contraversive OTR following the lateral medullary infarction.

CASE REPORT

A 58-year-old woman was admitted due to sudden-onset vertigo and gait disturbance. A neurological examination revealed OTR to the left side (left head tilt, leftward ocular torsion, and skew deviation). Lateropulsion to the right and dysmetria on the right arm and leg were present. Diffusion-weighted MRI revealed an acute infarction of the right lateral medulla and the posterolateral pons. The patient slowly improved and can walk without sway after 1 week. Neither head tilt nor ataxia was observed after 3 months.

CONCLUSIONS

Lateral medullary lesion typically results in ipsilateral OTR. Contraversive OTR of our patient might be derived from the disruption of the cerebellovestibular inhibitory pathway by the lesion in the juxtarestiform body in the lateral medulla.