Bilateral olivary hypertrophy after unilateral cerebellar infarction.

We describe a case of bilateral olivary hypertrophy and palatal tremor after unilateral cerebellar infarction. Hypertrophic olivary degeneration (HOD) is associated with hypersignal in the inferior olivary nucleus (ION), on T2-weighted images. HOD has been more often observed ipsilaterally to a central tegmentum tract lesion or contralaterally to a dentate nucleus or a superior cerebellar peduncle lesion. Double innervation of each ION from either dentate nucleus may have underlied the imaging and clinical findings in this 63 year-old male patient.