肥大性小葉変性症．症例報告

Hypertrophic olivary degeneration: A case report.

• Meltem Özdemir
• Aynur Turan
• Rasime Pelin Kavak
• Alper Dilli

抄録

肥大性小葉変性症は、神経細胞の肥大・液胞化、白質の脱髄、下小葉核の線維性グリア症など、さまざまな病理学的過程を経て発症するまれな疾患である。ほとんどの場合、ギラン・モラレ経路に関与する破壊的病変に続発する。肥大性小葉変性症の主な原因となる破壊的病変としては、脳卒中、外傷、腫瘍、脳外科的介入、脳幹空洞腫のガンマナイフ治療などが報告されている。この病変は、口蓋振戦の症状を呈し、通常、拡大した非強化性の結節性病変として現れ、磁気共鳴画像（MRI）上で信号強度の増大を示す。肥大性小葉変性症のMRI像は，腫瘍，梗塞，脱髄性病変，感染症などのより重篤な病態と非常によく似ているため，MRIで肥大性小葉変性症を同定することは非常に重要である．口蓋振戦が発症する2年前に虚血性脳卒中の既往歴のある患者に肥大性小葉変性を認めた1例を紹介する。

Hypertrophic olivary degeneration is a rare occurrence in which different pathological processes including enlargement and vacuolation of the neurons, demyelination of the white matter, and fibrillary gliosis of the inferior olivary nucleus take place. It mostly develops secondary to a destructive lesion involving the Guillain-Mollaret pathway. The mostly reported destructive lesions causing hypertrophic olivary degeneration are stroke, trauma, tumors, neurosurgical interventions, and gamma knife treatment of brainstem cavernoma. It presents with symptomatic palatal tremor, and typically appears as an expansive nonenhancing nodular lesion that shows increased signal intensity on magnetic resonance imaging (MRI). The identification of hypertrophic olivary degeneration on MRI is of great importance as its MRI appearance is very similar to those of more severe pathologies, including tumors, infarction, demyelinating lesions, and infections. We present a case of hypertrophic olivary degeneration in a patient with a history of ischemic stroke two years before the development of palatal tremor.

Copyright: © 2019 Indian Journal of Radiology and Imaging.