舌下神経麻痺単独症状で発症した大孔部髄膜腫の1手術例

A Case of Foramen Magnum Meningioma Manifesting as Hypoglossal Nerve Palsy

Ⅰ．はじめに

　大孔部髄膜腫はすべての頭蓋内髄膜腫のうちおおむね1.5〜3%^5,8,21)，後頭蓋窩髄膜腫の6.5%と言われており，比較的稀である^5,8)．その多くは後頭部痛，後頚部痛，歩行障害，感覚障害など多様な症状で発症するが⁵⁾，舌下神経麻痺単独で発症することは稀である．

　今回われわれは，舌下神経麻痺のみで発症した大孔部髄膜腫をtranscondylar approachにて全摘出し，症状が改善した症例を経験したので，文献的考察を含めて報告する．

　We report a case of foramen magnum meningioma manifesting as hypoglossal nerve palsy. A 72-year-old woman presented with progressive hypoglossal nerve palsy and lingual atrophy on the left side. Gadolinium-enhanced T1-weighted magnetic resonance imaging revealed a heterogeneously enhanced mass lesion with dural tail sign partially extending into the hypoglossal canal. The transcondylar approach was performed to expose the hypoglossal canal and resect the tumor completely. Histological examination revealed a transitional meningioma. The postoperative course was uneventful. Hypoglossal nerve palsy improved gradually after the operation.