Olivary hypertrophic Degeneration (OHD) is usually due to hemorrhagic lesions in the “Guillain Mollaret” triangle: trangular morphologic and functional relationship between the red nucleus and inferior olivary nucleus on one side and the controlateral dentate nucleus.
The hemorrhage involves the pons-midbrain tegmentum on the same side of the olive or the controlateral superior cerebellar peduncle and/or dentate nucleus.
It is regarded as transsynaptic degeneration and has typical MR features: morphologic changes and increased signal intensity on DP-T2 weighted images, with a carachteristic chronologic evolution after acute injury.
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