Hypertrophic olivary degeneration resulting from posterior fossa masses and their treatments

Abstract

Purpose Characterize hypertrophic olivary degeneration (HOD) that develops from posterior fossa masses and their treatments. Methods Retrospectively reviewed MR images and clinical data of 10 patients with posterior fossa masses and HOD. Results Eight patients had cerebellar lesions, and two patients had pontine lesions. Lesions consisted of tumors, demyelination, and nonspecific necrosis. MRI showed T2 hyperintense signal in the inferior olive a median 86 days after the diagnosis of a posterior fossa lesion. HOD presented prior to surgery (n=2), after surgery (n=3), after surgery/radiation therapy (n=4), or without treatment (n=1). Conclusions HOD may develop from posterior fossa masses and surgical and/or radiation therapy.

Delayed Occurrence of Hypertrophic Olivary Degeneration after Therapy of Posterior Fossa Tumors: A Single Institution Retrospective Analysis

“…Figure 2 illustrates that all but one case of HOD followed the causal hypothesis of a HOD causing a lesion within the dentato-rubro-olivary-pathway and its unidirectional orientation. Conclusively, no HOD was found in the literature with damage to the efferent olivocerebellar fibers, which do not functionally affect the olive itself [10,15]. One case was MR-negative, which could be explained either by a small radiotherapeutic lesion below the 3 Tesla detection threshold or between MRI slices, or the presence of idiopathic, non-traumatic HOD.…”

“…However, none of the patients in this study showed any signs of HOD on MRI acquired within 3 months prior to surgery. In a recent case series, Hirano et al suggested that HOD develops either primarily as a result of the tumor mass itself, or secondarily as a result of treatment [15]. Hirano et al also included patients with posterior fossa masses of non-tumor origin.…”

“…and an experienced neurologist (M.S.-P.). HOD was diagnosed if a typical circumscribed hyperintensity of the inferior olivary nucleus in T2-weighted images with or without hypertrophy and without enhancement or diffusion restriction was present [6,7,11,15,16].…”

“…HOD may also develop in patients with brain tumors in the posterior fossa affecting the GMT, either primarily due to tumor infiltration of the DROP or secondarily as a result of therapeutic measures such as neurosurgery or radiation therapy [15].…”

Orthostatic Tremor and Orthostatic Myoclonus: Weight-bearing Hyperkinetic Disorders: A Systematic Review, New Insights, and Unresolved Questions

“…However, this could not be proven in a study of OT patients 98. Additionally, the intriguing findings of Gallea et al, notably hypertrophy of the cerebellar vermis and SMA in OT, may be akin to the hypertrophy of the inferior olive in patients with lesions within various locations of the dentatorubral tract or central tegmental tract (Guillain–Mollaret triangle)100 and reflect that there are potentially multiple OT generators within cerebellothalamocortical pathways.…”