Figure 1
Hypertrophic Olivary Degeneration
Hypertrophic Olivary Degeneration
SectionNeuroradiology
Case TypeClinical Cases
AuthorsRania Zeitoun, MD, FRCR
Connected authors
56 years, female
Clinical History
A 56-year-old female patient presented with dizziness and a history of pontine haemorrhage (1 year ago), due to an episode of hypertension.
Imaging Findings
Figure 1: axial T2 (a) and FLAIR (b) showed an increase in the size and contour bulge of the left side of the medulla (site of inferior olivary nucleus) indicating hypertrophy, associated high signal on T2 and FLAIR images is noted.
Figure 2: the more superior cuts, axial T2 (a) revealed ipsilateral pontine irregular area of reduced volume and mixed low T1 and high T2 signal representing chronic haemorrhage. Axial DWI (b) show signal drop by hemosiderin.
Figure 3: sagittal T2 images showing pontine chronic haemorrhage and medullary high signal.
Figure 4: old CT images of the same patient, 1 year earlier show acute pontine haemorrhage .
Figure 2: the more superior cuts, axial T2 (a) revealed ipsilateral pontine irregular area of reduced volume and mixed low T1 and high T2 signal representing chronic haemorrhage. Axial DWI (b) show signal drop by hemosiderin.
Figure 3: sagittal T2 images showing pontine chronic haemorrhage and medullary high signal.
Figure 4: old CT images of the same patient, 1 year earlier show acute pontine haemorrhage .
Discussion
Hypertrophic Olivary Degeneration (HOD) is trans neuronal degeneration secondary to a pathology interrupting the dento-rubral-olivary neuronal pathway. The dentate nucleus of the cerebellum on one side with the red nucleus (brain stem) and inferior olivary nucleus (medulla oblangata) on the contralateral side constitute the triangle of Guillain and Mollaret. The red nucleus and ipsilateral inferior olivary nucleus are connected through the central tegmental tract. The red nucleus is connected to the contralateral dentate nucleus through the superior cerebellar peduncle. The inferior olivary nucleus is connected to the contra lateral dentate nucleus through the inferior cerebellar peduncle. [1, 2].
The HOD occurs on the same side of a pathology affecting the central tegmental tract and on the contra lateral side of a pathology affecting the dentate nucleus or superior cerebellar peduncle. The HOD may be bilateral in a case of pathology affecting both the central tegmental tract and superior cerebellar peduncle[1, 2].
Clinically, patients present with palatal tremors [1, 2].
The diagnosis is established by MRI. The diagnostic imaging pearls are high T2 signal and size changes of the inferior olivary nucleus. The presence of a lesion along the dento-rubral-olivary confirms the diagnosis [1-3].
The pathophysiological changes of HOD and the corresponding imaging findings vary through time. Within the first 6 months: high T2 signal of inferior olivary nucleus which persists for a long time. From 6 months and up to 3-4 years: hypertrophy of the inferior olivary nucleus. After 3-4 years: inferior olivary nucleus atrophy and decrease in size [3].
HOD is a unique neurodegenerative disorder, presenting with palatal tremors. It occurs secondary to pathology interrupting the dento-rubral-olivary pathway. The diagnosis is made by MRI. The findings are: inferior olivary nucleus high T2 signal and size changes [1-3].
The HOD occurs on the same side of a pathology affecting the central tegmental tract and on the contra lateral side of a pathology affecting the dentate nucleus or superior cerebellar peduncle. The HOD may be bilateral in a case of pathology affecting both the central tegmental tract and superior cerebellar peduncle[1, 2].
Clinically, patients present with palatal tremors [1, 2].
The diagnosis is established by MRI. The diagnostic imaging pearls are high T2 signal and size changes of the inferior olivary nucleus. The presence of a lesion along the dento-rubral-olivary confirms the diagnosis [1-3].
The pathophysiological changes of HOD and the corresponding imaging findings vary through time. Within the first 6 months: high T2 signal of inferior olivary nucleus which persists for a long time. From 6 months and up to 3-4 years: hypertrophy of the inferior olivary nucleus. After 3-4 years: inferior olivary nucleus atrophy and decrease in size [3].
HOD is a unique neurodegenerative disorder, presenting with palatal tremors. It occurs secondary to pathology interrupting the dento-rubral-olivary pathway. The diagnosis is made by MRI. The findings are: inferior olivary nucleus high T2 signal and size changes [1-3].
Differential Diagnosis List
Hypertrophic Olivary degeneration secondary to ipsilateral pontine hemorrhage.
Multiple Sclerosis
Wallerian Degeneration
Medulla Infarction
Final Diagnosis
Hypertrophic Olivary degeneration secondary to ipsilateral pontine hemorrhage.
References
[1] Salamon-Murayama, Noriko, Eric J. Russell, and Barry M. Rabin (1999) Case 17: Hypertrophic Olivary Degeneration Secondary to Pontine Hemorrhage. Radiology 213.3 (PMID: 10580959)
[2] G Osborn, SI Blaser, KL Salzman, G Katzman, J Provenzale, M Castillo, G Hedlund, A Illner, HR Harnsberger, J Cooper, BV Jones, B Hamilton Amirsys (2004) Diagnostic Imaging:Brain. I-10-94
[3] Mayank Goyal, Eric Versnick, Paul Tuite, Jean Saint Cyr, Walter Kucharczyk, Waltrer Montanera, Robert Willinsky, and David Mikulis (2000) Hypertrophic Olivary Degeneration: Metaanalysis of the Temporal Evolution of MR Findings. AJNR 21:1073–1077 (PMID: 10871017)
Case information
| URL: | https://www.eurorad.org/case/14196 |
| DOI: | 10.1594/EURORAD/CASE.14196 |
| ISSN: | 1563-4086 |
License
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Figure 3
Hypertrophic Olivary Degeneration & Pontine Haemorrhage
Sagittal T2 image:
pontine old haemorrhage and ipsilateral inferior olivary hypertrophy and high T2 signal
Figure 4
Pontine Haemmorhage
Old CT image showing pontine acute haemorrhage
Figure 5
Guillain Mollaret triangle
Coronal T2 image:
Blue circle represents the red nucleus. Orange circle represents the inferior olivary nucleus. Yellow circle represents the contra lateral dentate nucleus.
Hypertrophic Olivary Degeneration & Pontine Haemorrhage
Sagittal T2 image:
pontine old haemorrhage and ipsilateral inferior olivary hypertrophy and high T2 signal
Zeitoun R., Faculty of Medicine, Cairo University
Zeitoun R., Faculty of Medicine, Cairo University
Pontine Haemmorhage
Old CT image showing pontine acute haemorrhage
Zeitoun R., Faculty of Medicine, Cairo University
Zeitoun R., Faculty of Medicine, Cairo University
Guillain Mollaret triangle
Coronal T2 image:
Blue circle represents the red nucleus. Orange circle represents the inferior olivary nucleus. Yellow circle represents the contra lateral dentate nucleus.
Zeitoun R., Faculty of Medicine, Cairo University
Zeitoun R., Faculty of Medicine, Cairo University