Hypertrophic olivary degeneration is a form of trans-synaptic degeneration caused by an insult to the neuronal connections of the dentato-rubro-olivary pathway (i.
At any given time following a primary brainstem injury, there may be focal enlargement rather than atrophy of the inferior olivary nucleus.
The Guillain-Mollaret triangle is composed of the dentate nucleus, the red nucleus, and the inferior olivary nucleus.
There are three patterns of hypertrophic olivary degeneration as they relate to the location of the primary lesion.
Hypertrophy of the olivary nucleus following a primary brainstem injury is believed to represent a combination of cell body enlargement, vacuolation of the cytoplasm, astrocytic proliferation, demyelination, and fibrillary gliosis.
The clinical manifestations of hypertrophic olivary degeneration probably reflect a loss of inhibitory control as a result of disruption of the dentato-rubroolivary pathway.
Not all patients with hypertrophic olivary degeneration develop the classic symptoms, but virtually all patients who develop palatal myoclonus after a brainstem insult will develop hypertrophic olivary degeneration.
Case 17: Hypertrophic olivary degeneration secondary to pontine hemorrhage.
Hypertrophic olivary degeneration following pontine haemorrhage: Hypertensive crisis or cavernous haemangioma bleeding?
MR demonstration of a unilateral olivary hypertrophy caused by pontine tegmental hematoma.
Olivary degeneration after cerebellar or brain stem haemorrhage: MRI.