Hypertrophic olivary degeneration after cerebellar or brain stem injuries: MRI findings and differential diagnosis.

This poster is published under an open license. Please read the disclaimer for further details.

Congress:

ECR 2014

Poster Number:

C-0533

Type:

Educational Exhibit

Keywords:

Hyperplasia / Hypertrophy, Education and training, Education, Diagnostic procedure, MR, Neuroradiology brain, Head and neck, Anatomy

Authors:

A. Alexandre¹, A. Botto¹, G. Izzo², T. Tartaglione¹, M. Sciandra², S. Gaudino¹, C. Colosimo²; ¹Rome/IT, ²Roma/IT

DOI:

10.1594/ecr2014/C-0533

DOI-Link:

https://dx.doi.org/10.1594/ecr2014/C-0533

Fig. 1: Guillain-Mollaret triangle: red nucleus (in red), ipsilateral inferior olivary...

Fig. 3: Different morphology between normal ION and hypertrophic ION.

Fig. 15: Bilateral HOD following an hemorrhage coming from a ruptured AVM. A: CT...

Fig. 20: Brain tumor - pilocytic astrocytoma: - A: Axial T2-w and FLAIR images...

Fig. 2: Histological demonstration of ION enlargement (HOD) in two different patients....

Fig. 19: Multiple hyperintense lesions in T2-w images: involvement of antero-lateral...

Learning objectives

To provide a review of the pathophysiology of hypertrophic olivary degeneration (HOD), discussing the relationship of HOD with lesions of the dentato-rubro-olivary pathway. To explain the clinical and MRI findings of HOD in correlation with time elapsed from primary injury, even illustrating appropriate differential diagnosis.

Background

Hypertrophic olivary degeneration (HOD) is a trans-neuronal degeneration secondary to focal lesions involving the dentato-rubral-olivary pathway, also know as Guillain-Mollaret triangle. This is a functional pathway composed by neural connections between the red nucleus, the ipsilateral inferior olivary nucleus (ION), andthe contralateral dentate nucleus of the cerebellum. Histologically the affected ION demonstrates cell body enlargement, vacuolation of the cytoplasm, astrocytic hyperplasia and proliferation, demyelination, and fibrillary gliosis. Goto et al described six phases of pathological changes over a time frame ranging from immediate onset to...

Findings and procedure details

PATHOPHYSIOLOGY OF HOD Axons from the dentate nucleus travelling through the superior cerebellar peduncle cross the midline at the level of the midbrain to reach the contralateral red nucleus (dentatorubral tract); the second connection is between the red nucleus and the ipsilateral inferior olivary nucleus (central tegmental tract). The triangle is completed by ION efferents fibers crossing the midline, entering the inferior cerebellar peduncle, and terminating into the contralateral dentate nucleus. Although it is an anatomic triangle, HOD can result from lesions of the first...

Conclusion

Even if HOD is a rare MRI finding in common clinical practice, precise knowledge of this pathological condition, familiarity with characteristic MRI features and diagnostic clues for differential diagnosis,can help in avoiding misinterpretation of HOD as other independent lesions, avoiding unnecessary further investigation.

Personal information

A. Alexandre, A. Botto, G. Izzo, T. Tartaglione, M. Sciandra, S. Gaudino, C. Colosimo. Department of Radiological Sciences. Catholic University of Sacred Heart - Agostino Gemelli Hospital. Rome. Italy. mail to: [email protected]

References

•Guillain G, Mollaret P. Deux cas de myoclonies synchrones et rhythmes velopharyngo-laryngo-oculo-diaphragmatiques. Rev Neurol 1931;2:545-566. •Gerace C, Fele MR, Luna R, Piazza G. Bilateral hypertrophic olivary degeneration. J Neurol Neurosurg Psychiatry. 2006 January; 77 (1) : 73. •Arora V, Nijjar IS, Sandhu PS, Singh J, Abrol R, Roopa. Hypertrophic olivary degeneration following trauma - a case report. Indian J Radiol Imaging 2006;16:701-4. •Gatlin JL, Wineman R, Schlakman B, Buciuc R, Khan M. Hypertrophic Olivary Degeneration After Resection of a Pontine Cavernous Malformation: A Case Report....