A case of dorsolateral pontine infarct: Description of a new vascular alternating syndrome.

INTRODUCTION

Inferolateral pontine infarcts are well-described lesions of the anterior inferior cerebellar artery territory with a wide variety of clinical presentations. We report the case of isolated unilateral hearing loss and contralateral sensation of coldness due to a dorsolateral lower pontine infarct.

CASE DESCRIPTION: We describe the case of a 48-year-old female patient who developed isolated selective high-frequency hearing loss on the left side, and contralateral hemibody sensation of coldness. MRI showed a left-sided dorsolateral lower pontine ischemic lesion. A subsequent angiogram revealed the lesion to result from the spontaneous dissection of a long circumferential branch of the basilar artery.

CONCLUSION

To our knowledge, this is the first reported case of a vascular alternating syndrome consisting of isolated ipsilateral hearing loss and contralateral thermal dysesthesia from a dorsolateral lower pontine infarct. Occlusion of a long perforating branch of the basilar artery and consequent posterolateral lower pontine infarct may result in an alternating syndrome with subtle clinical symptoms. Knowledge of this type of syndrome may direct physicians towards the diagnosis of a dorsolateral lower pontine infarct, despite vague clinical complaints.